United States
Environmental Protection
Agency
Robert S. Kerr Environmental Research EPA-6OO/2-79-1 79
Laboratory August 1979
Ada OK 74820
Research and Development
&EFK
Research Needs
Assessment—
Livestock Manure
Management in the
United States
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, US. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2 Environmental Protection Technology
3 Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6 Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
RESEARCH NEEDS ASSESSMENT - LIVESTOCK MANURE
MANAGEMENT IN THE UNITED STATES
by
Research Needs Assessment Task Groups
Edited by
R. K. White
The Ohio Agricultural Research and Development Center
Wooster, Ohio 44691
and
The Ohio State University
Columbus, Ohio 43210
Grant No. R-806025
Project Officer
R. D. Kreis
Source Management Branch
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
-------
DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental
Research Laboratory, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
-------
FOREWORD
The Environmental Protection Agency was established to coordinate
administration of the major Federal programs designed to protect the
quality of our environment.
An important part of the Agency's effort involves the search for
information about environmental problems, management techniques and new
technologies through which optimum use of the nation's land and water
resources can be assured and the threat pollution poses to the welfare
of the American people can be minimized.
EPA's Office of Research and Development conducts this search
through a nationwide network of research facilities.
As one of these facilities, the Robert S. Kerr Environmental
Research Laboratory is responsible for the management of programs to:
(a) investigate the nature, transport, fate and management of pollutants
in groundwater; (b) develop and demonstrate methods for treating waste-
waters with soil and other natural systems; (c) develop and demonstrate
pollution control technologies for irrigation return flows, (d) develop
and demonstrate pollution control technologies for animal production
wastes; (e) develop and demonstrate technologies to prevent, control
or abate pollution from the petroleum refining and petrochemical in-
dustries, and (f) develop and demonstrate technologies to manage pol-
lution resulting from combinations of industrial wastewaters or indus-
trial/municipal wastewaters.
This report contributes to the knowledge essential if the EPA
is to meet the requirements of environmental laws that it establish
and enforce pollution control standards which are reasonable, cost
effective and provide adequate protection for the American people.
William C. Galegar, DirecAJr
Robert S. Kerr Environmental
Research Laboratory
iii
-------
ABSTRACT
The purpose of this report is to identify and assess research needs for
livestock manure management as related to environmental quality. Task groups
of six to nine professionals were formed to assess research needs for each of
the areas studied. The areas considered were:
1. Unconfined animal production
2. Small livestock facilities (less than 300 animal units)
3. Resource recovery from animal manures
4. Conservation of energy and nutrients in animal manure
management systems
5. Land application of animal manure and wastewater
6. Odors: cause and abatement in animal production
The research needs identified are all important but were put into three
categories of priority, first, second and third. No rating was made within
these three groups. For each research need a focus was noted, whether the
need was related to environmental quality, demonstration, livestock produc-
tion, education or energy.
This report was submitted in fulfillment of Grant No. R-806025 by the
Ohio Agricultural Research and Development Center under the sponsorship of the
U.S. Environmental Protection Agency. This report covers the period,
May 22, 1978 to April 30, 1979, and work was completed as of June 1979.
iv
-------
CONTENTS
Foreword ill
Abstract iv
Abbreviations and Symbols vi
Acknowledgment vii
1. Introduction 1
2. Summary of First Priority Research Needs 4
3. Unconfined Animal Production 7
4. Small Livestock Facilities (Less than 300
Animal Units) 14
5. Resource Recovery from Animal Manure 18
6. Conservation of Energy and Nutrients in Animal
Manure Management Systems 23
7. Land Application of Animal Manure and Wastewater 32
8. Odors: Cause and Abatement in Animal Production 42
References 48
-------
LIST OF ABBREVIATIONS AND SYMBOLS
Abbreviations
ARM - agricultural runoff management
ASCS - Agricultural Stabilization and Conservation Service (USDA)
BLM - Bureau of Land Management (USDI)
BMP - best management practice
BOD - biochemical oxygen demand
BTU - british thermal unit
CAST - Council for Agricultural Science and Technology
DOE - Department of Energy (United States)
EPA - Environmental Protection Agency (United States)
GLC - gas liquid chromatography
NCLWM - National Conference on Livestock Waste Management
NPDES - National Pollution Discharge Elimination System
PL - public law
SCS - Soil Conservation Service (USDA)
SEA - Science and Education Administration (USDA)
USDA - United States Department of Agriculture
USDI - United States Department of the Interior
USLE - universal soil loss equation
Symbols
C:N - carbon nitrogen ratio
NH/-N - ammonia nitrogen
NO.-N - nitrate nitrogen
N2 - free nitrogen
N»0 - nitrous oxide
vi
-------
ACKNOWLEDGMENTS
The author gratefully acknowledges the many individuals and agencies
which contributed to this research needs assessment publication. The research
needs assessment task groups, whose names and membership are listed in the
Introduction, are acknowledged for their major role in the development of this
publication.
In connection with the development of this publication a National Confer-
ence of Livestock Waste Management was held in Columbus, Ohio on May 23 and
24, 1978. The impact of the conferees to the research needs assessment work-
shops is acknowledged. The U.S. EPA Environmental Research Information
Center, Cincinnati, Ohio was a co-sponsor of the conference and their help is
acknowledged in this project.
The author is also indebted to Lynn Shuyler, Chief, Animal Production
Section and Douglas Kreis, Project Officer of the U.S. EPA, Robert S. Kerr
Environmental Research Laboratory, Ada, Oklahoma for their cooperation in
the National Conference on Livestock Waste Management and for providing direc-
tion concerning the scope of this project.
vii
-------
SECTION 1
INTRODUCTION
Over a decade of federal funding has been directed towards research and
demonstration projects related to the handling and disposal/utilization of
livestock manures and wastewaters. More recently, federal funding has been
used for developing educational materials on livestock waste treatment and
system management. At this point in time there is a need to assess the com-
pleted research and to identify areas that need additional research. This is
particularly important in light of changing national priorities . Duplication
of past research efforts must be avoided.
This Research Needs Assessment document was prepared by task groups of
professionals working in the area of their topic assignments. These task
groups prepared working papers which were used as a basis for workshop ses-
sions held as part of The National Conference on Livestock Waste Management
(NCLWM), May 23-26, 1978, Columbus, Ohio. The task groups then prepared their
respective sections of this publication. Each of these sections were based on
the respective working papers, conference presentations and subsequent work-
shop discussions.
The six research needs-assessment areas and the task group memberships
were as follows:
1. UNCONFINED ANIMAL PRODUCTION
F. J. Humenik*, North Carolina State University, Raleigh, North Carolina.
J. Powell**, Oklahoma State University, Stillwater, Oklahoma.
J. W. Doran, USDA-SEA, Lincoln, Nebraska.
H. Geyer, USDA-SEA, Washington, D.C.
P. R. Middaugh, South Dakota State University, Brookings, South Dakota.
J.W.D. Robbins, Louisiana Tech University, Ruston, Louisiana.
P. Westerman, North Carolina State University, Raleigh, North Carolina.
2. SMALL LIVESTOCK FACILITIES (LESS THAN 300 ANIMAL UNITS)
D. Badger*, Oklahoma State University, Stillwater, Oklahoma.
R. L. Phillips**, USDA-SCS, Hyattsville, Maryland.
G. L. Casler, Cornell University, Ithaca, New York.
*Task Group Leader
**Task Group Co-Leader
-------
S. W. Melvin, Iowa State University, Ames, Iowa
T. Huntrods, Minnesota Pollution Control Agency, Minneapolis, Minnesota
D. A. Norman, Ohio Department of Natural Resources, Columbus, Ohio
3. RESOURCE RECOVERY FROM ANIMAL MANURE
P. R. Goodrich*, University of Minnesota, St. Paul, Minnesota
L. W. Smith**, USDA-SEA, Beltsville, Maryland,
J. R. Fischer, USDA-SEA, Columbia, Missouri
J. P. Fontenot, Virginia Poyltechnic Institute, Blacksburg, Virginia
W. J. Huffman, Battelle-Columbus Laboratories, Columbus, Ohio
R. J. Smith, Iowa State University, Ames, Iowa
4. CONSERVATION OF ENERGY AND NUTRIENTS IN ANIMAL MANURE
MANAGEMENT SYSTEMS
R. C. Loehr*, Cornell University, Ithaca, New York
R. 0. Martin**, Agway, Inc., Syracuse, New York
D. L. Day, University of Illinois, Urbana, Illinois
C. B. Gilbertson, USDA-SEA, Lincoln, Nebraska
T. L. Loudon, Michigan State University, E. Lansing, Michigan
L. M. Safely, University of Tennessee, Knoxville, Tennessee
D. H. Vanderholm, University of Illinois, Urbana, Illinois
5. LAND APPLICATION OF ANIMAL MANURE AND WASTEWATER
J. W. Sweeten*, Texas A&M University, College Station, Texas
J. A. Moore**, University of Minnesota, St. Paul, Minnesota
S. E. Bishop, University of California, Riverside, California
S. Klausner, Cornell University, Ithaca, New York
A. C. Mathers, USDA-SEA, Bushland, Texas
T. M. McCalla, USDA-SEA, Lincoln, Nebraska
D. L. Reddell, Texas A&M University, College Station, Texas
K. R. Reddy, North Carolina State University, Raleigh, North Carolina
S. R. Wilkinson, USDA-SEA, Watkinsville, Georgia
6. ODORS: CAUSE AND ABATEMENT IN ANIMAL PRODUCTION
C. L. Barth*, Clemson University, Clemson, South Carolina
J. R. Miner**, Oregon State University, Corvallis, Oregon
L. F. Elliot, USDA-SEA, Washington State University, Pullman, Washington
D. T. Hill, University of Florida, Gainsville, Florida
C. E. Ostrander, Cornell University, Ithaca, New York
D. J. Warburton, University of Illinois, Urbana, Illinois
In each of the respective sections there is a description of the needs
area, a discussion on the scope of present information and a listing of
research needs. All the research needs are important but they are placed
into one of three priority categories: first, second and third. The number-
ing of research needs within each category does not indicate priority rating.
The judgment of importance may have regional differences and will need to be
evaluated by researchers and by those who support the research.
*Task Group Leader
**Task Group Co-Leader
-------
The research needs were categorized according to relationships with the
following areas: environmental concerns, demonstration, livestock production,
education (service) functions and energy issues. These foci of research may
be used by agencies and institutions to identify research needs related to
their emphases. For example, an educational focus can be related to extension
programs; environmental concerns are of primary interest to the United States
EPA and State pollution control agencies; livestock production needs are re-
lated to the USDA-SEA and to livestock associations; etc. All of these needs
are of interest to universities and research organizations.
-------
SECTION 2
SUMMARY OF FIRST PRIORITY RESEARCH NEEDS
Each research needs section is comprised of a list of topics prioritized
into three groups, which are delineated first, second or third. This summary
will present the needs in the first priority category for each research area.
The reader is referrred to the respective sections for more detailed discus-
sion and a complete list of research needs.
It is important that research activities be coordinated so that data are
comparable, have maximum usefulness and address the particulr research area
completely. In many instances it is appropriate to use multidisciplinary re-
search teams to obtain the necessary results.
UNCONFINED ANIMAL PRODUCTION
A coordinated multidisciplinary study, incorporating representative loca-
tions of (1) nongrazed (background conditions), (2) well managed and
(3) poorly managed grazing land, to evaluate water quality impacts and to pro-
vide data base information to assess the technical reliability of bacterial
indicators is the overall first priority research need. Specific subsets of
this overall research need are as follows:
1. Determine the relationships between grazing practices, site condi-
tions and water quality parameters, especially sediment.
2. Adapt and/or develop new methods of survey, analysis and statistical
interpretation for evaluating the impacts of animal management prac-
tices on aquatic and terrestrial ecosystems.
3. Determine the effectiveness of promising alternative management prac-
tices for reducing pollutant loads in receiving waters.
4. Determine the feasibility of using plant biomass as an indicator of
and criterion for assessing water quality by determining the quali-
tative relationships between livestock grazing pressure, plant bio-
mass and runoff water quality.
SMALL LIVESTOCK FACILITIES (LESS THAN 300 ANIMAL UNITS)
1. Evaluate the effectiveness of small feedlot runoff controls.
-------
2. Establish criteria for defining and communicating information on best
management practices (BMPs) for livestock production facilities and
related pollution control practices.
3. Identify institutional and social constraints related to and develop
a strategy for the implementation of environmental improvement
technologies and management practices.
4. Evaluate modifications of small livestock facilities which are neces-
sary to meet pollution control requirements.
5. Define the impact of federal, state, and local environmental regula-
tions on small livestock operations.
RESOURCE RECOVERY FROM ANIMAL MANURE
1. Improve materials handling equipment and systems to maintain the
"freshness" of waste material and minimize the loss of nutrients
and energy.
2. Assess the safety of feeding processed animal manure with respect to
human and animal health and develop methods of processing that elimi-
nate hazards.
3. Design turn-key systems for on-farm applications of thermochemical
processes and evaluate economics of their mass production.
4. Evaluate the flexibility of thermochemical processes relative to
user's need for gas, liquid or solid fuels.
5. Develop methods for direct utilization of methane produced from
manure or converting it into an easily stored and transported fuel.
6. Develop turn-key anaerobic digestor design through evaluation of on-
farm size units considering management requirements and logistics of
increasing waste volumes.
CONSERVATION OF ENERGY NUTRIENTS IN MANURE MANAGEMENT SYSTEMS
1. Determine the fundamental factors affecting energy use and nutrient
conservation.
2. Conduct a state-of-the-art analysis of energy use and nutrient con-
servation possibilities.
3. Evaluate available analytical, predictive and management models for
manure application to land and for economic analysis of animal waste
management systems.
-------
LAND APPLICATION OF ANIMAL MANURE AND WASTEWATER
1. Characterize the nitrogen and other nutrient transformations that
take place in manure and soils as they are influenced by handling
methods, soil types, crops and climate.
2. Evaluate the environmental impact of runoff from manured cropland on
receiving waters as influenced by method of application, tillage and
soil conservation practices.
3. Extend models of cost analysis to complete manure systems by regions
and by animal species and to include environmental impact.
4. Establish critical application rates of nitrogen (N), phosphorus (P),
potassium (K) and micronutrients in manure in relation to plant
uptake of these elements and quality of grain or forage.
ODORS: CAUSE AND ABATEMENT IN ANIMAL PRODUCTION
1. Locate all foreign and domestic research on odor identification,
measurement and control for all odor sources so that successful tech-
niques may be adapted or altered for use with animal manure odors.
2. Standardize the measurement and evaluation of odors with respect to
measurement techniques, background odor information and odor
transport.
-------
SECTION 3
UNCONFINED ANIMAL PRODUCTION
Unconfined animal production refers to the grazing or pasturing of live-
stock on range land and pastures. The current trend in livestock production
is towards confinement. However, a significant portion of livestock produc-
tion can be included in the unconfined animal production category. Beef
feeder calves are produced almost exclusively on pasture or range; about 30
percent of hog production is still on pasture; most dairy farms, except in the
Southwest, use pasture when seasonal conditions permit; and sheep production
is mainly a range and pasture operation. Over 50 percent of the land within
the United States is used for unconfined animal production.
Identifying research needs relating to unconfined animal production is an
inherent necessity for the technically valid, cost effective and practical
implementation of Public Law (PL) 92-500, especially Section 208 and the Rural
Clean Water Program.
SCOPE OF PRESENT INFORMATION
Most available data and on-going work, primarily sediment oriented, are
fragmented and not designed, executed, or analyzed in a manner which permits
a technically adequate assessment of the environmental impact of unconfined
animal production. Most appropriate information is referenced and summarized
by Robbins, 1978. Conference attendees agreed that the information available
to control pollution from unconfined animal production is insufficient and
that the potential for impact is significant because over 50 percent of the
land in the United States is used in unconfined animal production.
Grazing practices result in elevated counts of fecal coliforms, which
may indicate the presence of pollutants. The importance of such elevated
counts must be interpreted in light of how they affect the ecological balance
of receiving waters, how they compare with background levels, and their sig-
nificance from a health standpoint. Increased levels of nutrients in runoff
from grazing lands are often related with hydrologic erosion phenomena but
also result from unique management situations (i.e., congregation of cattle in
localized areas, cattle entering receiving water, runoff occurring shortly
after fertilization, etc.). Terrestrial and aquatic wildlife populations in
grazed and ungrazed watersheds are known to have an influence on water quality
but these influences have not been characterized or quantified. The effects
of normal populations of wildlife (established populations at the natural
carrying capacity for the area) should be used to determine baseline levels of
pollutants. Differences in type, amount, and distribution of and successional
-------
and manipulative changes in vegetation are known to affect water quality but
these effects have not been quantified.
Specific bacterial indicator groups appear to have some value for deter-
mining the relative contributions to water quality of wildlife and various
unconfined animal production units (i.e., numbers and grazing distributions).
The use of the ratio of total numbers of fecal coliforms to fecal streptococci
in water as a method to differentiate between human and animal origin of fecal
water pollution was described by Geldreich (1976). This ratio was applied by
Harms et al. (1975) and Doran and Linn (1978) to differentiate between human
and animal sources of water pollution. This technique may be utilized in
ecological studies to determine the impact of grazing animals on the relative
quality and disease potential of receiving waters.
Another bacteriological technique which may be useful in assessing the
impact of unconfined animal production on receiving waters utilizes the pres-
ence of starch hydroloyzing bacteria from the ruminant as a unique indicator
of recent bovine fecal pollution of aquatic systems. The organisms of the
Streptococcus boves group can be readily detected by indicator media and so
serve as a specific assay for unconfined animal inputs.
Information is available on the plant production capabilities on natural
grazing lands and introduced pastures under different ecological conditions
and in the absence of grazing livestock. Information is also available, but
to a lesser extent, on the effects that grazing pressure (animal-unit equiva-
lents per unit of plant biomass) has on plant maintenance and production under
certain ecological conditions and management practices. Limited information
is also available which defines the optimum or minimum forage supply at a
point in time for maintenance of long-term, sustained vegetation and grazing
livestock production. Reliable methods are available to assess plant biomass
under many ecological conditions and managment practices. Adequate methods
are available to approximate the quality of runoff water. This approach, when
combined with a determination of a minimum forage residue which will maintain
runoff water quality, presents a viable monitoring and management tool suit-
able for use over a wide geographic range.
Under PL 92-500, various Section 208 planners are utilizing mathematical
models to evaluate pollution impact from animal production and other agricul-
tural practices. The Agricultural Runoff Management (ARM) model developed for
the EPA is effective in modeling the hydrology of and to a lesser degree ero-
sion and certain chemical processes in small watersheds. At present, the
model is designed to predict stream inputs of sediment, nitrogen, phosphorus,
and certain pesticides. Testing on small watersheds in Georgia and Michigan
indicate the model is more accurate for sediment-associated chemicals than for
highly soluble chemicals. Conceptual and mathematical relationships are cur-
rently being developed for transformations, attenuation, and water transport
of nutrients, organics, and microbial parameters where animal manure has been
applied.
However, there is inadequate data for the testing, calibration, and vali-
dation of these models. In spite of the data and basic research voids,
modeling of a system forces researchers to identify these voids and direct
8
-------
research needs into critical areas. Interdisciplinary teams are needed to
integrate the hydrological, soil, climatic, management, chemical, biological
and other factors involved in a modeling approach.
RESEARCH NEEDS
The research needs in this section are presented first in an overall or
holistic approach. The additional priorities will detail specific subsets of
the holistic objective. These prioritized research needs could serve as inde-
pendent projects where funds are limited.
It will be important to coordinate the appropriate research activities
so that generated data are compatible, have maximum usefulness and adequately
fulfill the needs of the researched subject.
First Priority Group
Holistic approach. A coordinated multidisciplinary study, incorporating
respresentative locations of (1) non-grazed (natural or background condi-
tions), (2) well managed, and (3) poorly managed grazing land, to evaluate
water quality impacts and to provide data base information to assess the tech-
nical reliability of bacterial indicators. Continuing model development
should be directed towards evaluating cost-effectiveness and implementation
strategies of alternative managment practices for unconfined animal production
(Focus - Environmental, Production and Demonstration).
This research need should be integrated into on-going programs or pro-
jects such as the seven regional non-point source studies and should involve
appropriate agencies such as USDA, EPA, BLM, USDI, Forest Service, Department
of Commerce, and DOE in selecting multidisciplinary research teams. The goal
should be to expand and coordinate project planning and execution rather than
initiate new administrative units and totally new research procedures.
A demonstration-research type project would maximize use benefits, moti-
vate voluntary compliance and provide practical and effective research
stimulation and direction.
1. Determine the relationships between grazing practices, site condi-
tions, and water quality parameters, especially sediment (Focus -
Environmental, Production and Demonstrations). This research would:
a) Determine the possibility of using sediment yields
as an index to water quality impacts resulting from
unconfined animal production.
b) Establish values of unconfined animal production activ-
ities for use in the universal soil loss equation.
-------
2. Adapt existing and/or develop new methods of survey, analysis, and
statistical interpretation for evaluating the impact* of animal man-
agement practices on aquatic and terrestrial ecosystems (Focus -
Environmental). This research would:
a) estimate short-term impacts as related to elevated levels
of bacterial indicator counts, sediment, and nutrients in
runoff from grazing areas as compared to ungrazed or back-
ground areas; and
b) evaluate and compare (1) long-term impacts of animal
grazing practices as related to management levels on
aquatic and terrestrial ecosystems and (2) alternative
land use practices in areas adjacent to grazing areas
under study through surveys and statistical analysis/
interpretation of terrestrial (wildlife population,
plant communities) and aquatic ecosystems (macroin-
vertebrates, fish and plant species diversity and
community structures).
This evaluation should investigate the feasibility of using high
and low altitude remote sensing to detect larger scale ecological
changes which are related to (1) changes in terrestrial and aquatic
vegetation (density and characteristics), (2) management and livestock
patterns (mowing, fertilization, loafing areas, etc.)> and (3) water
quantity and thermal changes associated with clearing operations in
establishment of new grazing areas.
Also, it will be important to standardize the research methods
adapted or developed so they can be used by the maximum number of
disciplines and compiled for evaluation and modeling.
3. Determine the effectiveness of promising alternative management prac-
tices for reducting pollutant loads in receiving water (Focus -
Environmental, Production and Demonstration).
State-of-the-art information is being developed by an EPA funded
project entitled "Best Management Practices for Unconfined Animal
Production". Evaluation of the effectiveness of a number of manage-
ment practices that hold most promise for limiting movement of
pollutants to water and for receiving widespread adoption is urgently
needed. Examples of these practices include fencing, site surface
modification to change runoff patterns, role of buffer zones between
grazing site and streams, modification of dung degradation, livestock
traffic/congestion control, role of farm ponds in water quality im-
provement, and use of remote sensing to detect likely problem areas
such as high impact and poor site conditions.
*Impacts or changes are considered deviations from the normal seasonal or
yearly climatic variation as evaluated by comparison with a control or
established baseline.
10
-------
Determine by evaluating the qualitative and quantitative relation-
ships between livestock grazing pressure (animal-unit equivalents per
unit of plant biomass), plant biomass and runoff water quality, the
feasibility of using plant biomass as an indicator of and criterion
for assessing water quality (Focus - Environmental and Production).
The relationships between plant biomass (live, standing dead and
ground litter) and runoff water quality from different lands grazed
by livestock are virtually unkown. Effects of various kinds and
amounts of vegetation, including species composition, density, mor-
phology, root concentration, and ratio of live, standing dead and
ground litter, on runoff water quality should be determined for dif-
ferent ecological situations, management practices and seasons. The
economic and environmental benefit and cost-benefit ratio of main-
taining various plant biomass levels should be determined. Studies
designed to determine these relationships should consider and en-
deavor to eliminate, or at least document, the potential for
confounding by all factors contributing to water quality, plant bio-
mass and livestock production. The impact of improving water quality
by altering plant biomass grazing residues on animal production and
health should not be ignored. Techniques such as remote sensing,
which provide large-scale, low-cost inventories should be incorpor-
ated. Whenever possible, studies should be conducted under
representative farm and ranch conditions.
The successful achievement of this objective requires active
cooperation in the planning, implementation and evaluation stages of
the research by a multidisciplinary team of scientists in such disci-
plines as animal science, agronomy (pasture and soil), range science
(ecology and grazing management), water chemistry and biology, hydro-
logy and engineering. Interdisciplinary funding will be required.
Implementation guidelines that are developed should be standardized
for use by individuals without in-depth experience in all the disci-
plines noted.
Second Priority Group
Evaluate the ABM model or models with similar capability for predic-
ting stream inputs from grazing lands under various hydrological,
climatic, and management conditions, and further develop and refine
the models to include oxygen demand and microbial parameters (Focus
Environmental).
With the incorporation of relationships developed for animal
manure, the ARM model can be an excellent evaluation and planning
tool for predicting stream inputs from pastures and rangelands, but
there are still many facets needing further research. Until more
data are gathered for testing the model on grazed lands, the ARM
model should be used mainly as a research tool and not be commonly
applied for predicting pollution impacts of unconfined animal pro-
duction. Other models predict inputs, and may be more appropriate
than the ARM model for certain uses.
11
-------
Specific aspects of research needed in modeling runoff from
unconfined animal production areas are:
a) add modeling of oxygen demand and microbial
parameters;
b) use available data to determine model predic-
tion capability;
c) identify critical inputs and relationships needed
to improve the model, and determine minmum data
requirements for desired accuracy;
d) evaluate as a planning model to determine cost-
effectiveness of changing management practices
and contiguous land use activities ;
e) continue to test the model as data become avail-
able; and
f) refine the model to include large watershed
capability.
2. Identify and evaluate models with the capability to determine impact
of stream loadings on receiving waters (Focus - Environmental).
Models to predict impact of agricultural activities on receiving
waters are not presently available. However, 208 planners are ex-
tensively using very limited models to indicate the impacts of
agricultural activities. Until these models are refined and combined
to predict importance of stream inputs in determining impact on
receiving waters, many erroneous conclusions may be reached regarding
water quality impact of agriculture, especially unconfined animal
production.
Modeling efforts have been primarily in three main areas for predicting
(1) stream inputs, (2) in-stream changes and their impact, and (3) inputs to
ponded or impounded waters and their impact. However, the combining of these
three modeling areas in order to predict the total agricultural impact on
receiving waters has not been achieved.
Third Priority Group
1. Develop and utilize the best standardized bacteriological methods to
determine the source of fecal bacteria (pathogens and indicators) and
their significance to receiving waters and contamination (Focus -
Environmental).
Much of existing bacterial information is incorrect or mislead-
ing because methodologies developed for different wastes have not
yielded consistent and reproducible results. Therefore, standardized
bacteriological methods should be developed for uniform use in
12
-------
multidisciplinary studies of bacteriological water quality of grazed
and ungrazed terrestrial and aquatic ecosystems. Specific methods
for detection and enumeration of zoonotic pathogenic bacteria, sal-
monellae, etc. should be employed to determine the kinds, numbers
and significance of these pathogens in the ecosystems.
2. Determine the levels and importance of animal fecal pathogens and
indicator microorganisms which are added to receiving aquatic envi-
ronments by (a) native fauna (background or natural conditions), and
(b) unconfined grazing livestock (Focus - Environmental).
Bacteriological studies of runoff waters and receiving rivers
and lakes by Harms et al. (1975) and Doran and Linn (1978) provide
information on unconfined grazing land runoff. Both studies indicate
the presence of significant numbers of fecal indicator bacteria in-
cluding fecal coliforms and fecal streptococci in runoff from grass
and cropland which was not grazed or fertilized within a four-year
period.
Further bacteriological research is needed to establish the
levels and significance of the indicator bacteria (and possible zoon-
otic bacterial pathogens such as the salmonellae) in waters receiving
runoff from land which has not been grazed or treated with manure.
The number of fecal coliform and fecal streptococci from ungrazed
land were frequently greater than the federal water quality standards
(Harms, 1975). The presence of large numbers of wild animals and
rodents (e.g., mice, ground squirrels, rabbits) should be evaluated
as contributing sources for ungrazed lands. The present water qual-
ity bacterial standards should be re-examined after these added data
are obtained.
The significance of grazing land runoff as to contributions of
pathogenic and indicator bacteria should be determined and reassessed
in light of infrequent storm runoff events and the die-off of intest-
inal indicator and bacterial pathogens (e.g., salmonellae). In many
grazing area bacteria may serve as short-term indicators of water
pollution and often will demonstrate that little or no significant
fecal pollution of receiving waters has occurred.
13
-------
SECTION 4
SMALL LIVESTOCK FACILITIES (LESS THAN 300 ANIMAL UNITS)
Small confined animal production units not subject to the National Pollu-
tant Discharge Elimination System (NPDES) regulations are essentially those
with less than 300 animal units that have no point source discharges of pollu-
tants into navigable waters. An animal unit is defined as one beef animal
being fed for slaughter. Equivalent animal units are assigned for other
species. The majority of livestock operations in the United States fall into
the category of this chapter. Since the large feedlot operations produce such
large quantities of manure with accompanying pollution problems, the ensuing
publicity has caused the major research efforts in animal waste management
and pollution abatement or elimination to be focused on large operations.
However, many people are not aware that the majority of livestock operations
in the United States belong to the "small" category, and that many management
systems and technologies developed for the large feedlots are not economi-
cally and/or technologically feasible for the small operations.
Past research funded by EPA, and other federal and state agencies, has
been geared to large animal production operations and to exotic technologies.
Such research has not been applicable in many respects to the water quality
and other environmental-related problems of small confined animal feeding
operations.
Therefore, it is imperative that research directed toward assisting the
small units to control and prevent pollution be emphasized more in the total
program of environmental protection.
SCOPE OF PRESENT INFORMATION
There is a wealth of information in extension and livestock industry
publications on manure management for small livestock facilities. The infor-
mation is the result of university and government research and farmer imple-
mentation. A recent summary of information on this topic is, a manual on the
evaluation and economic analysis of livestock waste management systems by
White and Forster (1978). In most topics there are gaps in the research in-
formation, and guidelines have been developed based on field experiences. An
example is anaerobic lagoons. There has been much research of an applied
nature for specific sites. Anaerobic lagoons are being used as low-cost man-
ure treatment systems in many states. Yet other states are "regulating" them
out-of-use. An area where little data exists is on the benefit-cost technolo-
gies or practices for small livestock manure systems.
14
-------
It is generally accepted that a major weakness of waste handling is the
level of management or lack of management. Most research to date has dealt
with the functional aspects of equipment, unit operations and systems. There
is a need to integrate management requirements into manure systems. This may
entail selecting an alternative technology with less equipment and management
input to insure system reliability. Also, the lack of education as to manage-
ment requirements has caused systems to fail. The development of educational
materials and programs needs to be extended to cover management guidelines.
In many cases, research information is available for alleviating environ-
mental problems associated with manure systems. This information has not been
made available to farmers, 208 planners and others involved in implementation.
Therefore, the following list of research needs includes a number of items
identified as education and demonstration.
RESEARCH NEEDS
First Priority Group
1. Evaluate the effectiveness of small feedlot runoff controls (Focus -
Environmental and Educational).
Various feedlot (barnlot) runoff control technologies have been
developed. They need to be evaluated as to their effectiveness in
improving surface water quality, e.g., vegetative areas for runoff
infiltration. Management requirements of the runoff control technol-
ogies must be included in their evaluation. It would be highly
desirable to develop a model to predict which control technologies
are best suited for various site conditions, localities and species.
This model could then be used by service agencies in designing runoff
control systems for farmers.
2. Establish criteria for defining and communicating information on BMPs
for livestock production facilities and related pollution control
practices (Focus - Environmental, Production and Educational).
Alternative management practices have been researched but little
has been done to evaluate them in relation to effectiveness in envi-
ronmental quality control or economic benefit/loss to farmers. Run-
off control, infiltration to ground water, odor potential, equipment
costs, labor requirements, benefits from nutrients, etc. must be
weighed. Regional and species differences are significant in these
alternative management practices.
Information on acceptable management practices needs to be com-
municated to decision makers in planning and regulatory roles. This
information will then be the basis for selecting BMPs.
3. Identify institutional and social constraints and develop a strategy
to implement environmental improvement technologies and management
practices on small livestock facilities (Focus - Educational and
Demonstration).
15
-------
Area and regional implementation of best management practices
will require a detailed educational and demonstration program invol-
ving many institutions.
4. Evaluate modification(s) of small livestock facilities which are
necessary to meet pollution control requirements (Focus - Production,
Environmental and Demonstration).
If BMPs are prescribed for a region, modification of existing
facilities will be required. It will be essential to implementation
that the producer be shown how the alternative practices will benefit
him. An example is how a manure storage structure will facilitate
scheduling and reduce labor inputs into spreading of manure on land.
Environmental and economic benefits from investments must be deline-
ated.
5. Define the impact of federal, state and local environmental regula-
tions on small livestock operations (Focus - Environmental and
Production).
In most cases small livestock facilities are under state regula-
\ tions. The impact of the regulations from different states and
localities should be identified. This study should assess the envi-
ronmental improvement obtained by implementation as well as the
economic impact upon individual farms and local areas. Social impli-
cations should also be studied.
Second Priority Group
1. Study the treatment efficiency of non-emptied holding ponds (Focus -
Environmental and Production).
Many runoff detention ponds are not emptied (irrigated) on a
regular basis due to management decisions. It is possible that these
detention ponds, if properly designed, might function as treatment
units and meet water quality criteria without irrigation being re-
quired. Management of overflow during rainfall would be part of the
system.
2. Develop management and operation guidelines (regional and/or state)
for lagoons and storage structures (Focus - Production, Educational
and Environmental).
Items to be considered are: rate of sludge build-up, solids
removal techniques, odor control methods, cost-effective disposal
alternatives, etc.
3. Establish the conditions for effective natural sealing of earthen
storage structures and lagoons (Focus - Environmental and Production).
Several research projects have been completed on this topic.
Yet, it is not considered effective by some State regulatory agencies
16
-------
and commercial liners are required. The scope of this research prior-
ity should be to pull together the results of completed research, fill
in the "holes" as needed and promulgate criteria for acceptable natur-
al sealing.
4. Develop acceptable management practices for handling milking facility
wastewaters (Focus - Environmental, Production and Demonstration).
With the trend to larger diary herds, the problem(s) of handling
milking facility wastewater increases. Dairy production is usually
concentrated in local areas and the impact of wastewater discharges
is significant to the area. This wastewater is usually high in Bio-
chemical Oxygen Demand (BOD) and suspended solids. It is important
to develop cost-effective methods which will maintain the quality of
the environment.
Third Priority Group
1. Develop procedure for "on-farm" tests to determine (or estimate)
fertilizer nutrients in manures or wastewaters (Focus - Production,
Educational and Environmental).
Difficult nutrient analyses are a major drawback to effective
use of manure and wastewater as a fertilizer. With a knowledge of
the nutrient content of manure, a farmer could then develop a total
fertilization program to minimize cost and avoid environment insult.
2. Identify economic and social impacts of small livestock operations
on rural economies (Focus - Educational).
Livestock production is being stopped on small farms in many
localities. Usually, monoculture of grain or other commodities is
substituted. This change is bound to have an impact on rural econo-
mies. The desirability or non-desirability of phasing out small
livestock production units needs to be determined.
3. Identify control technologies and management guidelines to prevent
silage drainage from degrading water quality (Focus - Educational and
Environmental).
Fish kills due to silage drainage entering streams occur each
year. There is a need to identify and promulgate acceptable manage-
ment practices to prevent silage drainage problems.
GENERAL CONSIDERATIONS
Physically and economically, it is impossible to implement all the short-
term requirements for achieving water quality standards in the time period
legislated. Therefore, federal and state agency planners must re-evaluate the
priorities to determine which alternative management practices should be im-
plemented by 1983. Costs of making additional improvements in water quality
17
-------
will become higher per unit of improvement. Policy makers must make a long-
term commitment to cost-sharing (grants, loans, cost-sharing aby SCS, ASCS,
etc.) if these improvements are to continue to be made at the local level.
18
-------
SECTION 5
RESOURCE RECOVERY FROM ANIMAL MANURE
Resource recovery from animal manure offers an economic incentive for
utilization of management practices which will protect environmental quality.
The economic returns can be from several products including nutrients for
animal feed and energy. Thus, benefits can accrue not only to environmental
quality but also agricultural productivity and energy production.
SCOPE OF PRESENT INFORMATION
Processed animal manure as a feedstuff is a valuable resource that con-
tains crude protein, phosphorus, and energy. These wastes are utilized
efficiently by ruminants after processing and/or biological enhancement. Pro-
cessing methods used include dehydration, ensiling alone or with other materi-
als, composting, oxidation ditch treatment, solids-liquid separation,
fermentation and chemical treatment. A major purpose in processing is to des-
troy pathogens and parasites. Increasing interest exists among producers in
utilizing animal waste for feed. The current information on refeeding is
summarized in a recent report prepared by a task force of the Council for
Agricultural Science and Technology (CAST, 1978). Data available indicate
that residues from drugs, pesticides, and toxic materials in animal wastes
have not been a hazard to receiving animal health.
Because of the high moisture content of animal excreta, frequent collec-
tion and processing are desirable to minimize loss of nutrients and maintain
palatability. Materials handling problems arise in attempting to collect,
transfer, blend and store animal wastes for feeding.
Several thermochemical processes for the conversion of biomass and bio-
mass residues into useful liquid and gases for fuel or other uses are being
developed by interests within the private sector and government agencies.
These processes involve controlling pyrolysis or converting the products of
pyrolysis so that useful products are obtained. The trend in these develop-
ments if toward increased utilization of catalysts for conversion to end-use
products such as ammonia and methanol. Most of these concepts are at the
bench or pilot plant stage with some at or ready for the demonstration phase.
These processes are directed toward applications with waste production capaci-
ties ranging from 100 to 1000 tons per day.
Most investment/cost evaluations indicate that the current thermochemical
designs will not have the necessary economy-of-scale for single on-farm appli-
cation. There is a potential of combining manure with other organic wastes,
e.g., field stover, municipal sludge or refuse, etc., to make the energy con-
version efficiency and economics more attractive.
19
-------
Advantages of thermochemical processes suggest, however, that they be
evaluated to help satisfy the environmental and energy needs of farm-size
applications. One advantage is that batch or semi-continuous units can be
designed to provide an on-off capability which can be adapted to on-farm
needs/management. Another advantage is that liquid, gas, or solid fuels can
be produced and stored.
Anaerobic digestion is another method of resource recovery. When resi-
dual organic matter is exposed to microorganisms in an environment that is
devoid of oxygen (anaerobic) some of the carbon in the organic matter is
converted to methane and carbon dioxide gases. This natural process has been
used in municipal sewage treatment plants. The technology is well-developed
and, in general, operating conditions are well known.
Digesters fed livestock manures have been investigated since the late
1700's, but working units weren't developed for small farms in India and Ger-
many until the early 1900's. Most recent work has centered in the United
States because large concentrations of livestock in confinement offered
unique problems of manure management. Unlike municipal sewage sludge, it has
been found that day-to-day variations in feed composition present little
difficulty to a livestock manure digester. Other problems, however, have
been encountered. Mechanical problems assocated with transporting and hand-
ling the fibrous manure are of major importance. Some chemical compounds and
possibly drug residues may upset the digester and are of concern. The gas
must be used as produced due to the high cost of compression and storage.
Active research on several aspects of manure digestion shows that manure
from all species of livestock can be digested to produce methane, but there
will be a residue of 40-60 percent of the original organic matter. Process
conditions must be tailored to the manure of each species. A major concern
is with equipment configuration and cost. Additionally, manure in many cases
msut be diluted and therefore, the total volume to be handled and disposed of
is increased proportionately by the dilution volume.
Present energy prices do not make on-farm methane production economical,
but there are major environmental advantages that are difficult to quantify
economically. The process offers pollution abatement through stabilization
of the organic matter. This stabilization provides some odor control and
reduction of the water pollution potential. It may be possible to recover
minerals and nutrients from the liquid and solid residues that can be useful
in animal feeds.
RESEARCH NEEDS
In this section on resource recovery, research needs in four categories
are considered: (1) general needs, (2) feeding processed animal waste,
(3) thermochemical processes for energy and product recovery, and (4) anaero-
bic digestion. The research needs are prioritized for each of the categories.
20
-------
General Needs
Materials handling is a primary concern. Altering the handling character-
istics of manure by changing the animals' ration needs specific study in the
total production system.
First Priority—
Improve materials handling equipment and systems to maintain the "fresh-
ness" of the waste material and minimize the loss of nutrients and energy
(Focus - Production, Educational and Energy).
Equipment used for other manufacturing processes can often be adapted to
solve materials handling problems. The developmental cost of equipment and
system adaption are too great to be borne by individual livestock producers.
Individual areas of materials handling to be considered are: (1) collecting
manure in the shortest time after deposition, (2) conveying fresh manure, e.g.,
in pipelines, (3) blending manure with other feed materials, (4) transporting
blended feed mixture to storage or to the utilization point, and (5) storing
the manure and blended mixtures.
Second Priority—
Improve the quality or characteristics of manure through "tailoring"
animal rations to increase the efficiency of the manure processing system(s)
(Focus - Production).
Feeding Processed Animal Manure
The main informational voids are in the area of the effects on animal and
human health. Aspects of preserving and enhancing the nutritive value and
implementing the practice also require additional research.
First Priority—
1. Assess the safety of the practice by evaluating pathogens, heavy
metals, pesticides, drugs, and metabolities in the wastes from com-
mercial operations (Focus - Environmental and Educational).
2. Develop methods for processing animal waste feeds that eliminate
hazards from pathogens, microbial toxins, and internal parasites
(Focus - Environmental and Production).
3. Establish the concentration of mineral elements in processed animal
wastes and determine the accumulation and depletion of these elements
in the tissue or products of the recipient animal (Focus - Environ-
mental and Production).
4. Determine the concentration of pesticides and drugs in animal wastes
before and after processing, their accumulation and depletion in
tissue, and products of the recipient animal (Focus - Environmental).
Second Priority—
Improve continuous ensiling processes for blends of livestock wastes and
plant materials (Focus - Production). A major need is suitable equipment for
blending and conveying products.
21
-------
Third Priority--
Develop microbial enhancement processes, such as single cell protein pro-
duction from animal manures and process effluents, for use as feedstuffs
(Focus - Production). Process optimization, animal response, and safety must
be analyzed as outlined in the preceding research needs. Processes may in-
clude aerobic, anaerobic, or photosynthetic processes.
Thermochemical Processes
Because current investment/cost benefit studies indicate that these pro-
cesses will not be economical for single, on-farm installations, two research
needs arise (Focus - Energy and Demonstration).
First Priority Group—
1. Design turn-key processes for on-farm applications and evaluate eco-
nomics using mass-production costing which is employed by agricul-
tural equipment manufacturers (Focus - Energy and Demonstration).
2. Evaluate the flexibility of thermochemical processes relative to
user's need for gas, liquid, and solid fuels (Focus - Energy and Edu-
cational) . This evaluation should include catalysis for the conver-
sion of residues to liquid fuels.
3. Design large scale equipment which interchangeably uses all available
feedstocks (manure, municipal wastes and refuse, field and gin trash,
etc.)« These facilities should provide a depository where the farmer
can sell or have his manure pick up some amenable considerations for
value vs. disposal (Focus - Energy).
Anaerobic Digestion
There is much research remaining to be performed before digestion techno-
logy can be economically integrated into agriculture. A major drawback of
anerobic digestion is that the product fuel, methane, cannot be liquified at
room temperatures like the longer chain alkanes, propane and butane. It is
necessary to ensure that designs of on-farm digesters do not put an unneces-
sary management burden on the livestock producer.
First Priority Group—
1. Develop methods for utilizing methane directly or converting it into
an easily stored and transported fuel (Focus - Energy). *
2. Develop turn-key designs through evaluation of on-farm size units,
considering management requirements and logistics of increasing waste
volumes to make units feasible (Focus - Demonstration and Education-
al).
Second Priority Group—
1. Improve the efficiency of the digestion process through substrate
utilization, diagnostic methods and auxiliary equipment.
2. Develop alternative uses of the liquid and solid residues.
22
-------
Summary of Resource Recovery Research Needs
The research priority relating to materials handling relates to all the
areas of resource recovery. Research on equipment development should be co-
ordinated over all the areas. The development of turn-key systems for on-farm
use should be an ultimate objective and kept in view when other research is
conducted.
Some general concerns for all areas of resource recovery research are:
(1) safety and health of operators, (2) optimization of energy and product
recovery, (3) enhancement and protection of the environment, and (4) the eco-
nomics of alternative systems particularly in relation to total farm income.
23
-------
SECTION 6
CONSERVATION OF ENERGY AND NUTRIENTS IN
ANIMAL MANURE MANAGEMENT SYSTEMS
This topic addresses the possibility of conserving energy and nutrients
in animal manure management systems. Topic covered include: (a) the conser-
vation of labor and input energy used to handle, transport, and manage animal
manure so as to minimize the energy input to these systems, (b) the conserva-
tion of nutrients, such as nitrogen, phosphorus, and potassium, that are part
of animal manure and can be used as crop fertilizers, and (c) the conservation
of manurial energy and minerals. Also addressed briefly are other constitu-
ents, such as recovered solids, that may have economic and environmental value
if conserved.
The topic does not address the production or conversion of energy from
manures. This topic is considered in the previous section.
During the first half of this century, manure was regarded as a valuable
fertilizer, and considerable research was aimed at conserving and maximizing
the fertilizer value. However, large supplies of chemical fertilizers were
available at about the same time, during 1950's and 1960's, that changes in
the animal production industry were occurring to produce, meat, milk, and eggs
more efficiently through confinement livestock production. The low cost of
such fertilizers lessened the value of animal manures to the point where they
were no longer considered as a resource but rather a waste not worth hauling
for use as a fertilizer and to be disposed of as inexpensively as possible.
During this same period, energy costs were much lower than current costs.
Mechanical and electrical energy were utilized to increase animal and crop
production and for environmentally sound manure management systems.
The three primary uses for animal manure are as fertilizer, feed, and
energy. Other potential applications include structural products, building
material, horticultural use, and various industrial products.
In considering possibilities for conservation of energy and nutrients,
the technical and economic feasibility of individual components and of total
systems must be examined. It is possible that the cost of conserving energy
or nutrients in a particular component may be high but the application of that
component may make the overall costs of energy or nutrient conservation lower.
In addition, it is also necessary that there be a use for the conserved nutri-
ents, since if they are conserved in a form or at a time that they are unable
to be used, the conservation effort will be of little value.
24
-------
SCOPE OF PRESENT INFORMATION
The land has been, and will likely continue to be, the most appropriate
utilization method for animal manures and for the conservation of nutrients in
the manures. Spurred by increased energy and fertilizer costs, the utilization
of the nutrient content of manures for crop production is again being empha-
sized. In addition, there is the widespread recognition that the energy and
fertilizer resources of the United States are finite, and that the people as a
nation should utilize approaches that conserve rather than lose these re-
sources.
The amount of energy associated with fertilizer production and the amount
of nutrients in manure is significant. The total annual energy requirement
for fertilizer production in the United States is about 6x10 Btu, with nitro-
gen fertilizer production consuming 85 percent of that energy. This far ex-
ceeds any other agricultural activity in energy intensity. In addition, in
the 1970s, the cost of fertilizers rose more rapidly than the cost of fuel or
labor. The conservation of nutrients currently being lost from animal manures,
and the concommitant substitution for inorganic fertilizer, can reduce the
energy and energy intensive process feedstocks required for the production of
chemical fertilizer.
About 4.1 million tons of total nitrogen were in manure voided by live-
stock and poultry in 1974. Of this amount, about 2.6 million tons remained
after storage and handling losses. Of this, only about 1.4 million tons were
estimated to have been economically recoverable for use elsewhere. The phos-
phorus initially voided, that remaining after losses from manure handling
systems, and that available for recovery and use elsewhere were about 1.0,
1.0, and 0.5 million tons, respectively, for all livestock and poultry in the
United States in 1974 (Van Dyne and Gilbertson, 1978). The potassium in man-
ure voided by livestock and poultry was an estimated 2.4 million tons. About
52 percent of this amount was estimated to have been economically recoverable.
Based upon 1972 statistics, the collectable nitrogen in livestock manure
was about equal to the total nitrogen in the harvested soybean crop of that
year. It is interesting to note that there is considerably more emphasis
placed on saving a few percent of soybean nitrogen losses when compared to
the support given to minimization of the large nitrogen losses in manure.
When considering the possibilities to conserve nutrients and energy in
animal manure management systems, it is important to recognize that an animal
manure management system is part of an overall animal production system. Se-
lection of a manure management system is based upon many factors, such as air
and water pollution control constraints, cost, labor requirements, site con-
siderations, land area availability for application, crops grown, system
flexibility and dependability, and operator preference. There is no single
best system for a specific type of animal production or for a specific climate
or geography. Each system has advantages and disadvantages that must be
considered for a specific production operation.
25
-------
The following areas of information which are commonly considered to be
known include:
1) manure management systems by commodity and region;
2) quantity and constituents of manure and associated animal
wastes (urine, bedding, milking center wastes, etc.);
3) general costs and energy requirements of system components; and
4) general nutrient losses that occur in the management systems.
Caution should be used, however, in indicating that adequate details are
known about the above items. Unfortunately, the information is known primar-
ily in general terms from limited studies.
While some of the quantity and quality values are known for fresh manure
and extraneous material, little real knowledge is available concerning the
actual characteristics resulting form existing management systems. The opera-
tion of each management system varies and so will the resultant characteris-
tics of the wastes. The quantity and quality is related to the feed and water
intake of the animals as well as to the type of management alternatives.
Comprehensive research to identify the effect of feed, water, housing,
climate, and management on waste characteristics, energy use and nutrient con-
servation is not recommended due to the cost and difficulty of such research.
However, to the extent possible either in each research project, actual situa-
tion, or published report, information on the detailed waste characteristics,
energy use and nutrient conservation should be determined, discussed and in-
terpreted in terms of these variables. Too often data on these items are
reported sparsely and are rarely related to management conditions.
RESEARCH NEEDS
The research needs are formulated to acquire the unknown but required in-
formation that can identify the quantity of energy and nutrients that can be
conserved as part of manure management systems and the cost of that conserva-
tion. Such information can be used to develop processes and systems that are
compatible with animal production systems. In addition to conserving energy
and nutrients, these processes and systems must be environmentally sound in
other aspects, must result in an economically viable production system, and
should enhance the overall energy efficiency of the total production system.
The research needs that were identified are briefly described below.
In addition to the technical research activities that are described,
labor and other management considerations should also receive careful evalua-
tion as follows:
1. the skill and time needed to manage the "better" conservation
approaches;
26
-------
2. the ability to integrate such approaches into existing animal
production systems and practices;
3. determination of management techniques necessary to achieve
maximum energy and nutrient conservation for different systems;
4. documentation of effects of poor nutrient and energy conserva-
tion on production economics; and
5. interaction of manure management systems, environmental re-
quirements, energy use and economics on utilization of manures.
In each of these research areas, there must be appropriate multidisciplinary
inputs and activities to develop the necessary results.
First Priority Group
1. Determine the fundamental factors affecting energy use and nutrient
conservation (Focus - Environmental and Production).
This information is needed to identify the type of nutrient
losses and energy use that occurs in a manure management system, the
processes to which conservation approaches should be best applied for
maximum benefit, the type of conservation that may be considered, and
the alternative approaches that can be used. Conservation of the
maximum amount of nutrients for subsequent use reduces the threat of
air and water pollution from uncontrolled entry of these nutrients
into the environment.
Specific needs that can be included under this area of need
include:
a) losses of nutrients such as nitrogen in different
handling, storage, and land application units or
systems;
b) effect of bedding on nutrient retention, energy
for handling and transport, and ultimate impact
on animal health and product quality;
c) relative amounts of labor and input energy required
per animal unit per unit time for all waste handling
and management operations for different production
conditions;
d) comparison of the costs of different energy forms—
petroleum, electrical, etc.—needed for specific tasks
and for alternative equipment that can accomplish those
tasks;
e) biological, chemical, physical mechanisms affecting
the conservation of nutrients; and
27
-------
f) effect of time, climate, feed, types of bedding,
water use, and management alternatives on energy
use, manure nutrient content, and nutrient con-
servation.
2. Conduct a state-of-the-art analysis of energy use and nutrient conser-
vation possibilities (Focus - Environmental and Educational).
There is a diverse amount of information on the energy use and
nutrient conservation that accompanies currently used and other pos-
sible waste management components and systems. This information
should be assembled and critically analyzed to ascertain the amounts
of energy and nutrients that can be conserved and identify the more
feasible possibilities. This analysis should be done for different
commodities and management possiblities.
These analyses should include:
a) a summary of the cost associated with specific manure
management possibilities that enhance conservation;
b) an estimate of the amount of nutrients and energy
that can be conserved with utilization of "better"
conservation approaches throughout all components
of a system; and
c) the possibilities of utilizing the conserved nutrients.
The analysis should be assessed on the basis of possible management
systems and on the basis of specific topics such as:
a) nutrient conservation—handling, processing,
economics, energy, nutrients, size of operation,
type of animals, general management options,
technical components, environmental impact, and
acceptance by users and the public;
b) energy conservation (handling, processing, etc.); and
c) manure as a feed source (handling, processing, etc.).
3. Evaluate available models for manure application to land and for
economic analysis of livestock waste management systems (Focus -
Environmental and Production).
The available analytical, predictive, and management models
greatly enhance the opportunity to make maximum use of nutrients and
energy in livestock waste management systems, thus minimizing uncon-
trolled discharge to the environment. For widespread use of the
models, the assumptions and coefficients need to be verified and cal-
brated under different climatic and management conditions. Perhaps
28
-------
as many as eight separate studies, with different commodities, in
different parts of the United States should be conducted. The
studies should include energy inputs, specific costs, types of soils
and crop yields, environmental impacts, and feed and waste character-
istics. The studies should be conducted on a large enough scale to
obtain realistic data.
4. Demonstrate the better components/systems for energy and nutrient
conservation as related to animal waste management (Focus - Environ-
mental, Production, Educational and Energy).
There are several components and/or systems for waste management
that can be used now to demonstrate the better approaches for nutri-
ent conservation and energy use. These should be demonstrated at
either actual or experimental farms generally on a "side-by-side"
situation to obtain reasonable comparisons and meaningful cost and
conservation values.
Such possibilities include:
a) methods of loading and unloading storage units to
maximize nutrient savings;
b) incorporation of manure handling with irrigation
water;
c) nitrogen losses in land application - surface spread
vs. immediate incorporation - with differences evalu-
ated by crop yield comparisons;
d) variations in collection and storage systems - more
frequent manure removal and handling; covered and un-
covered storage; flushed vs. scraped manure systems; and
e) effect of bedding and types of bedding.
Second Priority Group
1. Evaluate the utilization of conserved nutrients when applied to land
(Focus - Environmental and Production).
Incorporation of animal manures and conserved nutrients in land
for crop production continued to be the most appropriate approach to
use the constituents in the manure. Consideration must be given to
the ultimate use of the conserved nutrients, since if they are con-
served in a form or at a time that they are unable to be used, the
conservation will be of little value. In addition, the cost of en-
ergy required to conserve and use the nutrients should not exceed the
value of the conserved nutrients. Desirably, the cost of the energy
to conserve the nutrients should be considerably less than the value
of the conserved nutrients.
29
-------
Possible topics included in this need are:
a) an analysis of the energy required to conserve the
nutrients, when the energy is needed, the form of
the energy, and the competition of the energy supply
with other energy demands, such as planting or har-
vesting;
b) storage and timing interrelationships (timing of
application) to obtain "best" crop response;
c) comparison of the various techniques to handle,
transport, and apply the manure (comparison of
energy used to nutrients conserved);
d) amounts of chemical and biological forms of nutrients
that can be recovered from all manure handling systems
(animal to crop) and their component parts (i.e.,
animal to collection, collection to storage, etc.);
e) energy use and nutrient concentration at various
points in manure handling and storage systems;
f) methods available for enhancing nutrient retention—
anaerobic storage, plow-down, injection, etc. Evalu-
ation of energy required to conserve nutrients.
g) availability of manurial nutrients (especially nitrogen)
to plants once material is on or in the ground.
Nutrient retention during application should be deter-
mined; and
h) energy required for system components—for conserva-
tion, utilization, and pollution control.
2. Develop/improve equipment for handling of "as-produced" manure
(Focus - Production, Educational, Environmental).
There is a need to develop better energy efficient equipment to
handle as-produced manure for large and small production units. Such
equipment is needed to collect, mix, transport and apply manure.
This equipment should minimize soil compaction, promote more
uniform distribution when the manure is applied to the land, and en-
hance nutrient retention.
Included in this development is the need for better information
on the physical properties - size of particles, viscosity, etc. of
the manure to be handled. Also included is the feasibility of feed
additives and ration balancing to enhance the dry matter content of
manure and the ability of handling the manure as a solid.
30
-------
3. Development management and system specification recommendations so
that producers can obtain minimum energy use and maximum nutrient
conservation in manure management systems (Focus - Educational).
Included in this need are techniques to measure actual energy
use with available equipment, scheduling of equipment, desirable in-
tegration of system components, duration of use, integration into
cropping programs, etc. The information should be presented in bul-
letins and short courses.
Third Priority Group
1. Identify institutional constraints to the adoption of "better" energy
and nutrients conservation approaches (Focus - Environmental and Edu-
cation) .
Even though better conservation approaches may be developed and
are shown to be cost effective, they will have little effect until
they are adopted. An analysis needs to be made to determine what, if
any, institutional constituents may restrain or delay such adoption.
When such constraints become known, efforts can be made to reduce or
eliminate them. Such constraints may be (1) inadequate transmission
of the available information, (2) traditional use of alternative
energy or nutrients, (3) inability to use the technology with cur-
curently sized animal production units, or (4) lack of capital to
purchase, install, or modify existing equipment or facilities.
2. Evaluate the environmental impact of volatile compounds and gases
lost from animal production systems (Focus - Environmental).
Large amounts of volatile compounds and gases - such as ammonia,
amines, nitrogen oxides - are lost from animal production systems.
To date there has been no detailed assessment of the impact these
compounds have on the land, crops, water, and animals when they are
ultimately deposited, nor on the atmospheric reactions related to
smog or ozone depletion. Positive and negative impacts can be specu-
lated. However, the magnitude of the different impacts is not known
but needs to be understood to estimate the priority and resources
needed to reduce the losses from the environmental standpoint. This
research need is apart from the odor implications discussed in Sec-
tion 8.
3. Develop and evaluate processes for capturing volatilized ammonia
(Focus - Environmental and Production).
Ammonia will volatilize and may result in environmental problems
within confined animal production buildings and adjacent to such
buildings. The ammonia could be recovered from the off-gases or any
liquid wastes and stored for use at an appropriate time in crop pro-
duction.
31
-------
4. Assess the energy use and nutrient conservation with "non-traditional"
commodities (Focus - Environmental and Educational).
Considerations of energy and nutrient conservation center on
beef, dairy, poultry and swine facilities since these are the major
animal production commodities. However, there are other animal pro-
duction operations that also lose nutrients and may be inefficient
energy users. An analysis of the nutrient and energy conservation
possibilities in these commodities is warranted to place the magni-
tude of such losses and inefficiencies in national perspective.
These "non-traditional" commodities include: horses, sheep, ducks,
rabbits, fur-bearing animals.
5. Assess the recovery of fibrous residues for bedding and horticultural
use (Focus - Environmental and Production).
In addition to nutrients, there are other resources that can be
recovered from animal manures. These include:
a) use of separated or composted solids for bedding, and
b) recovery of separated residues for horticultural use on
parks, for plant mulch, or for growing seedlings.
This need would include an assessment of potential markets, possibil-
ities of product uniformity and quality, impact on plant and animal
health and environmental quality.
32
-------
SECTION 7
LAND APPLICATION OF ANIMAL MANURE AND WASTEWATER
The return of animal manures to the land represents the completion of
a natural recycling process. The biological, chemical, and physical prop-
erties of soil provide an excellent treatment facility for biodegradable
wastes.
Methods of application of manure depend on the crop and the type of
manure. Solid, slurry, or liquid manure may be spread on the surface and
incorporated. Liquid manure may also be applied by irrigation, usually
through a big gun-type sprinkler. The method chosen will depend on the
nature of the site, the state of the material, and the crop that is being
fertilized. For conservation of nitrogen, surface application is not recom-
mended because ammonia is volatilized. Immediate incorporation conserves most
of the nitrogen and is recommended where practical.
The quantity and quality of manure available for land application de-
pends on the type and number of animals, ration fed, manure management system
and climate. The USDA, Economics, Statistical, and Cooperative Service
reports the number of animals, and many publications give estimates of the
manure produced by each animal. A recent summary of animal waste utilization
on crop and pastureland was prepared by the EPA and USDA (in press).
Generally, animal manure contains the elements essential for plant
growth. The rates of manure applied usually are based on its nitrogen and
salt content. Therefore, chemical analysis should be obtained because the
nutrient and salt content varies with management.
In humid areas where salinity is not a problem, adequate manure may be
used to supply the nitrogen required by the crop. However, in areas of low
rainfall or irrigated areas, salt concentrations must be considered so that
salinity will not become the limiting factor in crop production. In irri-
gated areas sufficient irrigation water must be applied to move the salt
below the root zone.
Phosphorus and potassium are usually in excess when adequate nitrogen is
applied. This excess phosphorus and potassium usually does not cause pro-
blems because phosphorus is immobilized in the soil and plants do not accumu-
late toxic quantities of potassium. However, forages grown where nitrogen
and potassium are both high may cause nutritional problems (grass tetany) in
pregnant or lactating cows. It may be advisable to apply manure according
to the phosphorous or potassium needs of the crop and add commercial nitrogen.
33
-------
The season of manure application is often partially determined by stor-
age facilities and other critical farm operations. Pollution concerns are
also involved in timing manure applications with regard to probable periods
of frozen ground, intense rainfall, runoff and soil loss. Surface appli-
cation of manure in the fall or winter usually decreases the amount of runoff
and sediment loss. However, the total amount of nutrients lost usually
increases.
SCOPE OF PRESENT INFORMATION
Historically, livestock manures were not considered a problem. With
increased use of confinement livestock operations, large amounts of manure
are concentrated, resulting in environmental problems with water pollution,
flies, dust, and odors. Results of research on land application of manure
are discussed under the broad topic outlines of soil system, plant system,
animal system, and hydrological system.
Soil System
When manures are applied to the soil system, several biological, chemical
and physical properties of the soil are affected. Application of wastes is
affected by four design criteria: (1) organic loading, (2) nutrient loading,
(3) salinity, and (4) soil physical properties.
Organic Loading—
The capacity of the soil (and its microbial population) to decompose
large quantities of non-toxic materials, primarily of a polysaccharide
nature, is well documented. The carbon/nitrogen ratio (C:N) of the waste
material often dictates the rate and extent of decomposition. The rate of
waste decomposition is apparently not affected by the amount of organic
loading (Mathers and Stewart, 1970). Calculations of probable organic matter
losses suggest that soil type and climate affect decomposition rates of
organic matter.
If large applications of organic matter are made, depletion of soil
oxygen and resulting anaerobic soil conditions are potential considerations.
Potential effects of anaerobic soil conditions on the animal waste consti-
tuents and the soil are described by Parr (1974).
Nutrient Loading—
Nitrogen—Nitrogen in animal wastes exists in several forms which can
be conveniently classified as organic or inorganic nitrogen. The organic
forms require mineralization (ammonification and nitrification) before becom-
ing available for crop intake, or for movement from the root zone of crops.
The inorganic forms, NH.-N and NO--N, occur in varying quantities in animal
wastes and wastewaters.
Mineralization of nitrogen is crucial in ascertaining the effect of
animal wastes applied to the soil. When only a part of the manure decays the
first year, there is a considerable residual effect. When manure is incor-
porated into soil at the nitrogen rate needed by the crop, nitrate accumulates
34
-------
in the soil profile and leaching is minimal.
Pratt et al. (1976) in California measured mineralization rates of
manure nitrogen at 45 percent in the first year, 10 percent of the residual
nitrogen in the second year and 5 percent in the third and fourth years.
There are different mineralization rates reported in other research. These
differences may be due to the forms of nitrogen in the manure, climate, and/or
soils.
Denitrification is another process whereby manure nitrogen is lost from
the soil. It occurs when microorganisms utilize nitrate nitrogen as an
electron acceptor during their respiration in the absence of molecular oxygen,
thus releasing gaseous forms of nitrogen, such as N« and N.O. Favorable
conditions for denitrification can be created, when animal wastes are applied
on soils with heavy texture and poor drainage. Oxygen depletion and denitri-
fication can occur at micro sites within the soil. Nitrification will not
occur in the same sites where denitrification occurs, because the first pro-
cess functions under aerobic conditions, whereas the latter process functions
under anaerobic conditions. In soils treated with animal wastes aerobic and
anaerobic conditions can exist, enabling nitrification and denitrification
to occur at the same time (Reddy and Patrick, 1975 and 1976). Little work
has been done to measure denitrification losses under field conditions in
soils treated with animal wastes, possibly because of the difficulty in
measuring the gaseous end products under field conditions.
Ammonia volatilization is known to be a significant mechanism for losses
of manure nitrogen. It is particularly important in surface applied manures
(Lauer et al., 1976). Very little work has been done to estimate the
nitrogen losses as a function of climate.
Phosphorus and potassium—Research has been conducted to establish
levels of phosphorus and potassium accumulation on manured soils at various
depths. Levels of phosphorus and potassium higher than needed for optimum
yields have occured but with little downward movement. Lateral movement of
phosphorus and potassium occurs with sediment in runoff waters.
Salinity—
In areas of heavy rainfall and natural leaching, salinity is not a
problem. However, high rates of manure on soil in areas of low rainfall may
cause salt problems that reduce germination and seedling growth. When lagoon
water is used for irrigation, dilution with low salt water or limited appli-
cations may be necessary. Analysis of lagoon water for salt concentrations
is essential to determine the irrigation management necessary to prevent crop
damage. Long-term effects of animal manure application rates on soil salinity
have not been defined or evaluated.
Soil Physical Properties—
Application of solid wastes usually improves the tilth of soils. How-
ever when excess salt is applied with lagoon water, soil structure may be
weakened, water intake rates decreased, and crusting problems become severe.
35
-------
Plant System
Crop yield and quality depends on an adequate but not excessive supply
of the essential plant nutrients. A deficiency or excess of one element in
a plant will cause a chemical imbalance which generally reduces crop yield.
Manure application rates have been evaluated at several locations in
the United States. Research data are conflicting as to what rate gives
optimal crop yields and what rate suppresses plant growth and yields.
Factors causing these differences are in part due to the location but also
to manure management methods. A need exists to coordinate, standardize and
integrate ongoing research on this topic.
High application rates of manure nitrogen result in excess nitrate in
the soil. Excess nitrate will reduce sugar yields from beets. High ammonia
levels in soils with high manure application rates, have been found to inhibit
germination and plant growth. Normally, when manure applications were dis-
continued, seed germination and crop growth returned to normal the second
year.
Animal System
The short-term and accumulative effects of animal consuming crops grown
on land that has received animal manure are addressed in this section.
Nitrate Toxicity—
Nitrate accumulation in forages in response to high applications of
manure is well documented. Experimental results reporting direct nitrate
toxicity in animals grazing heavily manured forages is lacking. There are
reports of nitrate toxicity on commercial farms, some of which have been
confirmed to be nitrate toxicity by veterinarians. It is clear, however,
that high rates of manure can help set the stage for environmental stress to
precipitate a toxicity problem. An excellent summary of the nitrate problem
is presented by the National Research Council (1972).
"Forage plants may accumulate significant quantities of nitrate
when grown under drought conditions in soils rich in nitrogen, and
these plants may cause death of livestock. The extent of these
losses depends on the level of nitrogen in the soil, the species
of plants, the stage of maturity of its plants, the severity of
the drought, the prior condition of the exposed animals, and the
management practices of the livestock producer."
If the silages are made from crops containing high nitrates, there is
also the potential problem of nitrate accumulation and evolution of nitrogen
oxides during fermentation. These gases may be released from silage and may
cause death to farm workers or to animals confined near the silos (National
Research Council, 1972).
Grass Tetany—
Grass tetany is a metabolic disorder of cattle and sheep whose daily
36
-------
consumption of available magnesium is too low. Many factors have been
associated or thought to be involved in the occurrence of grass tetany. These
include temperature, rainfall, cloudiness, type and availability of forage,
soil conditions, nitrogen and potassium fertilization, age, and reproductive
status of the cow, and the cow's production level. Reports of cattle losses
attributed to grass tetany on cool-season pastures heavily fertilized with
poultry litter were confirmed by a grazing study to determine the effect of
heavy broiler litter fertilization on the incidence of grass tetany
(Stuedemann et al., 1975).
Grass tetany is not known to be a problem with warm season grasses, ex-
cept in low magnesium corn silages. Silages can be supplemented with magne-
sium to overcome the problem. Forage analyses for total nitrogen, calcium,
potassium, and magnesium can indicate the approximate potential for grass
tetany.
Tall Fescue Toxicity—
Tall fescue is grown on about 17 million acres in the mid-south region
from Missouri to the Atlantic Ocean. Tall fescue toxicity is known to occur
in animals grazing it. Some of the symptoms include lameness in hind
quarters, poor appetite and subsequent loss of weight and foot problems. Fat
necrosis (hardfat) was recognized as a herd problem of mature cattle grazing
tall fescue heavily fertilized with poultry litter in the north Georgia area.
Are there other grasses used or recommended for waste disposal where
these or other kinds of problems may be expected in utilization of forage?
The combination of excessive and/or unbalanced mineral nutrition and its
effects on chemical composition of forages and the grazing of monocultures,
may create undesirable accumulative effects on animal performance and
health. Short-term studies on digestibility and intake may not reveal these
problems but commercial producers may experience them. Nutrient recycling
from grazing cattle may also contribute to the problem by permitting dif-
ferential buildup of plant nutrients such as phosphorus and potassium over
that expected from a hay or silage harvest system.
Parasitism and Pathogens—
Research to date indicates some parasitism of animals grazing manure
fertilized pastures. This subject requires further investigation.
Several reports indicate a minimal disease potential from animal manure
application to land. It is generally accepted that cattle can safely graze
disposal areas 2 to 3 weeks after manure application. Much conflicting data
exist concerning the survival rates and mobility of pathogens in soils.
Toxic Metals—
Some producers supplement their livestock feeds with trace elements,
e.g., copper, arsenic, zinc. It is not expected that problems would arise
in using grain grown in soils fertilized with manure from animals fed trace
elements at recommended levels. Research to date has not shown manured for-
ages to cause metal toxicity to animals.
37
-------
Hydrological System
The changes in stream water quality and possible pollution of water
supplies have been investigated at several locations in the United States.
Runoff—
Application of wastes to land can affect the quality of subsequent
runoff from those lands. This is referred to as non-point pollution. The
climate of the area, the soil type, the form of the waste (liquid or solid),
and the method of application will affect the quality of the runoff. In-
creases in BOD, nutrients and coliform count have been substantiated in
runoff from manure covered land. Generally, higher application rates gave
greater pollution potential.
The season of manure application is partially determined by storage
facilities and timing of other critical farm operations. Pollution con-
cerns are involved in the timing of the manure applications with regard to
periods of frozen ground, intense rainfall, runoff and soil loss. Fall and
winter manure applications are subject to snowmelt runoff in cold climates,
which may constitute as much as 60 to 80 percent of the annual runoff.
Winter manure applications have been researched with differing conclusions
as to quantity of snowmelt and runoff occuring. There is general agreement
that winter manure applications give greater losses of nitrogen and phos-
phorus .
Spring manure applications can have a major impact upon runoff quality
and soil losses. Nutrient losses in the spring are usually associated with
soil sediment losses.
Because nutrient losses from land disposal areas are so strongly re-
lated to sediment transport from watersheds, a method for predicting erosion
from watersheds is needed. Perhaps the best known empirical sediment trans-
port model is the Universal Soil Loss Equation (USLE) developed by Wisch-
meier and Smith. However, it is one-dimensional in nature and does not
consider changes in flow direction, land slope, and flow velocity on the
watershed. Kuh and Reddell (1977) have recently described a two-dimensional
erosion model which predicts the total amount of erosion from a watershed and
the areal distribution of erosion and sediment deposition.
Ground Water—
When manure or wastewaters are applied to land the dissolved chemical
constituents may be leached into groundwater aquifers. With manure applied
to a soil having moderate to rapid internal drainage, nitrates, chlorides
and fecal coliform counts have been shown to increase markedly. Under
saturated soil conditions, the nitrate level decreased. Continued high
applications of manure slurry to the soil can contaminate the shallow
groundwater.
38
-------
RESEARCH NEEDS
First Priority Group
1. Characterize the nitrogen and other nutrient transformations
(including mineralization and losses) that take place in manure
and soils as they are influenced by handling methods, soil types,
crops and climate (Focus - Environmental, Production, and Energy).
There is a need for a better understanding of what happens
to nutrients in manures to be able to estimate the environmental
impact from applying manure to the land. Also, the conservation
of the nutrients could be enhanced. If the amount of nutrients
available to crops from manure could be reliably predicted, a
farmer could then use less commercial fertilizer than he would
presently use. Part of this research priority should be to
develop a predictive model for use by farmers when applying
manure to cropland.
2. Evaluate the environmental impact of runoff from manured cropland
on receiving waters as influenced by method of application, tillage
and soil conservation practices (Focus - Environmental).
Much of the research to date on this topic has been done on
plots and in a few cases on single fields. The same data are needed
for watersheds. Also, the data to date have been taken at the edge
of the plot or field. This needs to be extended to the receiving
water and include an evaluation of the transport mechanisms and
the effect of tillage or soil conservation practices, e.g., buffer
strips, no-till, etc. Most soil conservation practices are
oriented to erosion prevention and need to be evaluated with respect
to nutrient transport.
Part of this research area should be to adapt existing hydro-
chemical models to predict effects of runoff from manured land on
receiving water quality.
3. Extend models of cost analysis to complete manure systems by
regions and by animal species and to include impact on the environ-
ment. (Focus - Production, Educational and Environmental).
The purpose of these models would be to help producers make
decisions on manure handling methods in relation to economic returns
and quality of the environment. The complete systems referred to
would include manure handling methods, time and labor constraints
and crop production. The economic benefits of manure on soil should
include aspects other than crop yield, e.g., erosion reduction,
improved soil tilth, etc.
The model should consider the relationship between apparent
manure nutrient values and actual production yields from commercial
fertilizer. The cost/benefit ratio for alternative application
39
-------
systems versus environmental effects should be incorporated into the
model. Also, the impact of energy in evaluating the supply/demand
relationship of commercial fertilizer and manure should be included.
4. Establish critical application rates of nitrogen, phosphorus,
potassium, and micro nutrients in manure in relation to plant
uptake of these elements and quality of forage or grain (Focus -
Production and Environmental).
Imbalance of nutrients in manures as related to plant need
lead to excess application of certain elements, e.g., applying
fertilizer based on nitrogen needs of crop will frequently give
excess phosphorus or potassium. The potential effects and manage-
ment requirements of excessive application of certain elements need
to be determined. The organic matter in manure is an excellent
chelating agent for some micro nutrients and may restrict their
plant uptake, e.g., zinc.
Second Priority Group
1. Determine the impact of increased infiltration due to manure appli-
cations on soils and upon the amount and quality of leachate leaving
the plant root zone (Focus - Environmental).
Research had documented that manure covered soils have a greater
infiltration rate. Nutrient and salt content of leachate from
manured soils are known to increase under certain conditions. There
is a need to develop a model(s) to predict the volume, rates and
quality of leachate as well as the probability of occurrence.
In dry and arid regions, salt management by leaching is essen-
tial to maintain soil productivity. The nutrient load on these
soils is important to irrigation and soil management. An under-
standing of the interactions between manure nutrients, commercial
fertilizers, infiltration of rain or irrigation water will help to
minimize the loss of nutrient from the root zone and control ground
water pollution.
2. Optimize manure application methods and systems (Focus - Production,
Educational and Environmental).
There is a need to match equipment to manure handling properties
and operating conditions to insure uniform application on fields.
Manure properties vary due to animal species, housing, bedding re-
gime, and waste handling system (liquid, slurry or solid). Perfor-
mance evaluation of equipment is needed to establish criteria for
development.
Included in this topic should be evaluation of management
options to control odor, e.g., injection or plow-down.
40
-------
Crop yields should be maximized and nutrient losses minimized
through matching how much manure is applied in relation to holding
capacity of the soil, the needs of the crop and environmental impact.
Cost of alternative unit operations should be considered.
3. Determine the influence of manure on soil properties, in particular
physical characteristic and erodability (Focus - Environmental and
Production).
Many soils in the United States with decreasing organic matter
content are experiencing reduced water intakes from rain or irri-
gation. Also, increased compaction problems from use of machinery
are occuring. The physical characteristic to be monitored should
include at least the following: tilth, structure, water holding
capacity, infiltration rate and compaction. There is need to
determine how nutrients and manure particles are transported within
the soil and attached to soil particles. The effect of organic
solids on soil properties needs to be studied as related to erod-
ability.
Third Priority Group
1. Improve sampling and analytical procedures to accurately characterize
manure, lagoon wastewaters/sludges and runoff waters used for
application to cropland (Focus - Environmental and Production).
Parameters to be considered are nutrients, metals, and organics.
2. Characterize the fate of pathogens and parasites, toxic substances
and complex organic compounds when applied to soil and plant systems
(Focus - Environmental).
Pathogens and parasites have generally not caused problems, but
researchers, veterinarians and sanitarians should be able to predict
and avoid problem situations. Concerns with the potential for animal
disease transmissions from forages or manured soils lessen the de-
mand for manure and/or restrict its application in isolated situa-
tions. Some regulatory personnel remain skeptical about the
alleged safety of manure from a pathological standpoint.
3. Investigate potential utilization by land application by by-
products from other manure uses (Focus - Production).
An example would be slurries from biogas (methane) digesters.
4. Measure the effect of non-uniform manure applications (distribu-
tion) on cropland (Focus - Environmental).
Local overloading of soils may occur due to poor spread pattern
of equipment, improper management decisions on where to spread or
transport by runoff. There is a need to evaluate local overloading
of soils and the effect upon the soil and crops. This should address
41
-------
solid and liquid application methods.
GENERAL NEEDS FOR IMPLEMENTATION
Implementation programs must include best management practices that are
designed to be regional specific. Guidelines should encourage applications
of manure to the land in such a manner as to promote maximum nutrient re-
cycling and insure environmental protection.
Education is the primary link between research and user acceptance.
Extension teaching programs must center around methods of encouraging the
use of periodic soil testing to define supplemental plant nutrient needs and
to stress how the nutrients in manure can best be used to meet plant require-
ments. The importance of an educational program was recently noted in the
report, Opportunities for More Effective Use of Animal Manure (Staats, 1976).
Demonstration programs are among the best methods available to promote
well founded ideas. Simple and straightforward demonstration projects should
be established in key locations that clearly define the value of manure as a
source of fertilizer. These demonstration experiments should be kept current
with the latest results of research. Tours of the demonstration areas should
be conducted periodically to constantly remind users of the benefits of pro-
per manure management practices from an economical and environmental stand-
point.
Programs should be designed to encourage an increased working relation-
ship between agricultural extension services, the SCS, soil and water con-
servation districts, regional planners and industry representatives.
Collectively, these groups should make a concerted effort to work closely
with individual farmers on proposed methods to encourage efficient use of
animal manures. The programs should stress the adoption of best management
practices instead of regulatory policy to improve environmental quality.
A current barrier to both the developmental and implementation pro-
cesses is a need for data banks of known information and a retrieval system
that will make this information readily available to those who have need
for it. It would require a simple, uniform system of entering information
as it becomes available, classifying and cross-referencing it according to
specific subject areas, and a simple, uniform retrieval system. This would
be extremely valuable for researchers, extension agents, planners and deci-
sion makers at all levels of government. It would be useful to public and
private organizations in providing direct technical assistance and advice
to farmers and feedlot operators.
In order for a practice to be fully accepted by agricultural producers,
sound reasons for its necessity must be shown. This approach should include
clear, concise, and well documented reasoning as to why a problem exists and
how the farmer plays a key role in helping to correct a given problem area.
42
-------
The development of farm management practices that are known to be in-
strumental in improving environmental conditions for society, should, if
possible, be designed to provide for an economic advantage to the farmer.
In order for a practice to be readily accepted, it must clearly show a sav-
ings in one or more of the following areas: (1) labor costs, (2) maintenance
costs, and (3) purchased commodities (i.e., fertilizer, fuel, feed, etc.).
Additionally, the formulated practices must be designed to fully inte-
grate into existing farm management systems. That is, competition for land,
labor, and machinery should be kept to a minimum and the practice should fit
the current cropping system as closely as possible.
43
-------
SECTION 8
ODORS: CAUSE AND ABATEMENT IN ANIMAL PRODUCTION
Large quantities of manure are deposited within confinement livestock and
poultry operations. Under typical moisture and temperature conditions this
manure is subject to anaerobic decomposition processes. Volatiles released
cause odor problems. Under dry conditions dusts may be generated which con-
tribute to nuisance conditions.
Odor nuisance is the primary complaint received by the confinement live-
stock and poultry producer. While the total number of people offended by
livestock odors is relatively small, the potential repercussions are great.
A few odor nuisances or air quality violations can easily be transformed into
odor regulations which place physical and financial restrictions on all pro-
ducers in a region or state.
Court decisions based on nuisance statutes or specific air quality con-
trol regulations threaten livestock or poultry producers. These decisions
require costly changes in the operation which can force the operation out of
business.
Four specific types of facilities or areas associated with livestock pro-
duction have been identified as sources of odor: (1) open feedlots,
(2) buildings in which animals are confined, (3) lagoons, storage pits, basins
and ponds, and (4) land used for application of accumulated manure. Individ-
ual livestock facilities may require specific odor control recommendations
based on the species of animal, the period of odor release, the intensity of
the odors at any one time or other site factors such as topography and weather
patterns.
In addition to the nuisance aspect of odors associated with livestock and
poultry production, there is logical concern with the health and safety impli-
cations of the gases, dusts and aerosols emitted. Many of the identified
volatile components are known to be acutely toxic at higher concentrations
than normally encountered. Under certain management conditions, e.g., agita-
ting a manure pit, livestock deaths have occurred. However, little is
currently known of the effects of long-term exposure to lower concentrations.
Dusts are of concern as respiratory irritants and carriers of more harmful
constituents. Aerosols from manure treatment and handling processes are
known carriers of potentially pathogenic organisms, yet little direct evidence
of health impact has been documented. Reports of increased respiratory sensi-
tivity and allergenic reactions to livestock environments are of concern.
44
-------
Significant quantities of ammonia and amines volatilize from confined
animal and poultry areas and waste management areas. These compounds are
absorbed by surface waters increasing the nitrogen content of the waters.
There is evidence that, in addition to eutrophication, amines can influence
the flora and fauna of surface waters. Information about the quantities and
kinds of nitrogen compounds that may be absorbed by surface waters from animal
feeding activities is lacking.
Economic and energy conservation considerations are important aspects of
research needs associated with odor management. These considerations must be
applied to the entire animal enterprise since more fragmented appraisals would
be misleading.
SCOPE OF PRESENT INFORMATION
Measuring and Evaluating the Nature of the Problem
Measurement Techniques—
Odor evaluation and odorant measurement have been used to study air pol-
lution from livestock and poultry production units. Odor evaluation has been
based on olfactory measurements by odor panels with investigation of odor
strength and odor acceptability. Analytical measurements of the concentra-
tions of the odorous gases, e.g., ammonia and hydrogen sulphide, have been
made.
Olfactory evaluations have inherent variability due to sampling problems
and difference in individuals' assessment. Techniques such as rating, rank-
ing, forced choice and dilution have been used. Since these techniques were
adopted from the food industry their application to the evaluation of odors
from livestock production units has had limited success. Variations of tech-
niques introduced by experimenters to meet specific needs have led to no
standard method being used. This, in turn, has led to the inability to com-
pare experimental results between researchers. Statistical analysis of data
is part of the basic requirement for olfactory evaluations. Differences in
the extent of its use has further confounded the problem.
Gas liquid chromotography (GLC) has been the primary method for identifi-
cation of odorants. The technique has led to the isolation of approximately
sixty odorous compounds in the gases emitted from livestock production units.
The procedure has limited sensitivity. Minimum detectable levels of five ppm
hydrogen sulphide are 10,000 times greater than that sensed by the human nose.
Consequently, gas collection and concentration methods are required prior to
analysis. The inadequacies of selective concentration and the inability to
specify and agree on indicator odorants have restricted the use of this
technique.
The value of standardized odorant measurement would be realized if it
were correlated with standard olfactory odor evaluations. These correlations
would eliminate the need for expensive, tedious and time consuming odor panels
in evaluating odor control alternatives. Little work has been reported in
45
-------
this area and its usefulness will be limited until the correlations can be
based on repeatable, standardized procedures.
Background Information—
Needed background information from livestock production units are odorant
evolution rates and acceptable odor levels measured by standardized techniques.
Ammonia evolution rates from cattle feedlots have been measured. Evolution
data for other major odorants from waste management regimes and livestock
species are not available. This information is required if studies on the
health and safety of operators and evaluation of odorant removal systems are
to have widespread significance.
Acceptable odor levels at specified distances from livestock operations
have not been established. If regulations are to be established for the pro-
tection of the producer and the public and comparisons made between the
effectiveness of various waste management systems, this background information
is needed.
Transport and Duration—
Transport and duration of odors have been recorded in isolated and uncon-
trolled conditions when complaints have been lodged against producers. The
influence of climatological factors, the impact of vegetative screens and the
influence of particulate matter (dust) on odor transmission are not well docu-
mented.
Theoretical estimates of climatological effects such as temperature,
humidity, wind speed and direction may be made from the technology currently
available in other industries. Similar estimates may be made on the role of
particulate matter in the transmission of odors. However, the specific rela-
tionships of these factors to livestock odor problems and the interaction of
vegetative screens is required.
Developments in Odor Control Technology
Completed research dealing with odor control technology includes a broad
range of chemical treatment, biological processes, physical conditions and
management techniques. Primarily, open feedlot and confinement housing odor
control techniques deal with the chemical and physical properties of the waste.
A number of "deodorants" have been tested on feedlots and, almost without
exception, no satisfactory, reproducible results have been obtained. The pri-
mary reason is that weather conditions and waste characteristics vary greatly.
Confinement housing usually involves liquid waste handling although some
scrape-haul solid handling systems exist. For liquid systems, pH control,
aeration and temperature control all have been demonstrated technically effec-
tive. Economic considerations have not been well documented. Again, the
solid systems, because of the usually low moisture content, have shown consid-
erable advantage in relation to odor control.
Control of odors from lagoons and storage pits, basins, ponds or tanks
has been difficult in the past. Proper design and management techniques offer
only effective odor control at present, especially for anaerobic lagoons and
46
-------
storage units. Disinfectants have proved of little value. Enzyme treatment
and modification of feed additives have shown mixed results with type of waste
•being the most important variable. Management techniques, including emptying
pits and loading lagoons at optimum times, are affected by climatological con-
ditions.
The management of land application practices offers an effective means of
odor control. Land application usually comes after treatment in lagoons or
storage in ponds, pits, basins, or tanks. Odor potential is great. Monitor-
ing climatological conditions and making waste management decisions minimize
odor problems. Applying manure or wastewater when wind conditions promote
dilution or carry odors away from neighbors, will reduce odor problems. Im-
mediate soil incorporation through a tillage operation or injection has
avoided odor problems.
Health Impact of Odors and Odorants
Data exist which indicate the lethal and inhibitory concentrations of
various gases for man and livestock species. Similarly, there are dust levels
which have proven hazardous to human health. Data do not exist which define
the human health or livestock performance inhibition due to combinations of
dust and mixtures of gases at concentrations below those known to be toxic.
The frequent experience of persons working in confinement livestock and to
poultry buildings is one of increased respiratory sensitivity and allergenic
type reactions. Research is needed to define these health impacts and suggest
the appropriate safety measures whether they be dust filters or more elaborate
forms of human protection. Alarms and other warning devices would also be
indicated if the necessary relationships were established.
Although there are little definitive data currently available, the physi-
cal and mental health of persons living immediately adjacent and downwind of
animal facilities is of concern. Such persons may be exposed to low levels of
toxic gases, airborne dusts, aerosols and odors on a nearly continuous basis.
Aerosols and dusts have been documented to concentrate odorants and microor-
ganisms indicative of fecal contamination. Complaints of agrieved persons
have included headaches, nausea, and respiratory irritation. If these symp-
toms are validated, the use of air scrubbers, particle filters or other
devices may be indicated.
Effects of Odorants on Water Quality
Recent studies have initiated concern for water quality in the vicinity
of large animal feedlots. Volatilization of nitrogen and its transport in the
atmosphere to water bodies has been verified. Eutrophication is a threat, and
continued study of this facet of feedlot operation is important. Technology
for the control of nitrogen emissions from feedlots, is, at lease in part,
available.
47
-------
RESEARCH NEEDS
First Priority Group
1. Locate all foreign and domestic research on odor identification,
measurement and control for all odor sources so that successful tech-
niques may be adapted or altered for use with animal manure odors
(Focus - Environmental, Educational and Production).
2. Standardize the measurement and evaluation of odor (Focus - Environ-
mental) .
This research priority needs to address three aspects:
a) Measurement techniques: standardized organoleptic odor
evaluation, standardized objective measurement methods for
indicator odorants and correlation of odor evaluation and
odorant measurement results;
b) Background odor information: measure odor and odorant
evolution rates and establish acceptable livestock pro-
duction unit odor emission levels; and
c) Odor transport and duration: measure the effect of
climate, screens and barriers, particulate matter (dusts),
and odor/odorant transport, frequency and durations.
Second Priority Group
1. Develop and evaluate effective odor control technologies (Focus -
Environmental and Production).
The development of odor control technology for new and existing
livestock production facilities should consider the four principal
odor production areas of livestock facilities: (1) open feedlots,
(2) confinement housing, (3) treatment lagoons and storage pits,
ponds, basins or tanks, and (4) land application sites. Possible
physical, chemical and biological control strategies to consider in
developing control technologies should include control of moisture
and temperature in manures, absorption and adsorption of odorants,
dilution with water, containment of wastes, gas scrubbing, aeration
of wastewaters, pit ventilation control, oxidants, deodorants, disin-
fectants, bacterial cultures and enzymes, feed additives, feed
modification, and filters.
2. Establish the physiological and psychological impact(s) of odors and
odorants in or from production units (Focus - Environmental and Pro-
duction) .
There is a need to define the interactions between the toxic
gases, odorants, dust and aerosols with livestock and poultry produc-
tion and the short-term and chronic effects on animal performance and
48
-------
employee health and safety. The impacts of fugitive gases, dusts and
aerosols on the exposed general population in the vicinity of inten-
sive livestock production and manure treatment-disposal sites should
be evaluated.
Third Priority Group
1. Assess the impact of airborne volatiles on water quality (Focus -
Environmental).
This would involve measuring the aerial nitrogen contributions
of different types from confined animal and poultry units to nearby
surface waters. Also, the effects of volatiles, e.g., amines, on
flora and fauna should be assessed.
General Considerations
Economic and energy considerations are very important in all odor manage-
ment research and must be given a high priority. These considerations must
not, however, be allowed to dictate the disposition of a facet of odor control
methodology since all alternatives may be applicable in certain constrained
situations.
Odor control technology for the livestock and poultry industries must be
developed to allow appropriate growth and continued operation of the indus-
tries in response to consumer demand. Effective odor control will permit the
greatest flexibility in the utility of land resources as bases for agricul-
tural, industrial and municipal development.
Uncontrolled odors raise the fear of psychological and physiological
limitations for the animals concerned, the operator and workers and nearby
residents. It might be that one or two highly publicized odor problems in one
locality can be interpreted to be a general problem of livestock production.
The anticipated result is an odor control regulation which places needless
constraints on the entire industry of an area, state or region.
ESTABLISHMENT OF AGRICULTURAL ODOR RESEARCH CENTERS
Odor control has been a difficult and unyielding research problem. There
are large knowledge gaps in our understanding and management of odors and
odorants. A research approach that would give a high probability of success
would be the establishment of two or more odor research centers in the United
States. The permanent staff should consist of at least two odor scientists
with support personnel adequate for several scientists. Scientists interes-
ted in and qualified for animal waste odor work would be attracted to these
centers and could work there on a sabbatical leave and temporary assignments
basis. These team efforts should include agricultural and environmental en-
gineers, animal scientists, chemists, and microbiologists. Sites should be
located so that the combined programs would cover major areas of beef, dairy,
poultry and swine production in the United States.
49
-------
REFERENCES
CAST. 1978. Feeding Animal Waste. Report No. 75, Council for Agricultural
Science and Technology, Iowa State University, Ames, Iowa. 48 pp.
Conroy, L. E. and R. A. Peterson. 1977. Biomass Conversion-Subcommittee Six
Minnesota Energy Agency, St. Paul, Minnesota.
Doran, J. and D. M. Linn. 1979. Bacteriological Quality of Runoff Water
from Pasture Land. Appl. Environ. Microbial. 37:985-991.
EPA and USDA. in press. Animal Waste Utilization on Crop and Pastureland.
Environmental Protection Agency and U.S. Department of Agriculture,
Washington, D.C.
Geldreich, E. E. 1976. Fecal Coliform and Fecal Streptococcus Density Re-
lationship in Water Discharges and Receiving Waters, C.R.C. Critical.
6(4):349-369.
Harms, L., P. Middaugh, J. Dornbush, and J. Anderson. 1975. Bacteriological
Quality of Surface Runoff from Agricultural Land. Parts I and II.
Water and Sewage Works. 122(11): 71-73.
Kuh, H. and D. L. Reddell. 1977. Two-Dimensional Model of Watershed Erosion.
Tech. Rpt. 80. Texas Water Resources Institute, Texas A&M University,
College Station, Texas. 8 pp.
Lauer, D. A., D. R. Bouldin, and S. D. Klausner. 1976. Ammonia Volatiliza-
tion from Dairy Manure Spread on the Soil Surface. J. Environ. Qual.
5:134-141.
National Research Council. 1972. Accumulation of Nitrate. Report of Commit-
tee on Nitrate Accumulation. National Academy of Sciences. 106 pp.
Parr, J. L. 1974. Chemical and Biological Considerations for Land Applica-
tion of Agricultural and Municipal Wastes. FAO/SIDA Expert Consultation
on Organic Materials as Fertilizers. Food and Agricultural Organization,
United Nations, Rome, Italy. 70 pp.
Pratt, P. F., S. Davis, and R. G. Sharpless. 1976. A Four-Year Field Trial
with Animal Manures. Part I. Nitrogen Balances and Yields and Part II.
Mineralization of Nitrogen. Hilgardia. 44:99-125.
50
-------
Reddy, K. R. and W. H. Patrick, Jr. 1975. Effects of Alternate Aerobic and
Anaerobic Conditions on Redox Potential, Organic Matter Decomposition
and Nitrogen loss in a Flooded Soil. Soil Biochem. 7:87-94.
Reddy, K. R. and W. H. Patrick, Jr. 1976. Effects of Frequent Changes in
Aerobic and Anaerobic Conditions on Redox Potential and Nitrogen Loss in
a Flooded Soil. Soil Biochem. 8:491-495.
Robbins, J.W.D. 1978. Environmental Impact Resulting form Unconfined Animal
Production. EPA-600/2-78-046. U.S. Environmental Protection Agency,
Ada, Oklahoma. 34 pp.
Staats, E. B. 1976. Opportunities for More Effective Use of Animal Wastes.
Report 76-101. General Accounting Office. 40 pp.
Stuedemann, J. A., S. R. Wilkinson, D. J. Williams, H. Ciordia, J. V. Ernst,
W. A. Jackson, and J. B. Jones, Jr. 1975. Long-Term Broiler Litter
Fertilization of Tall Fescue Pastures and Health Performance of Beef
Cows. In: Proceedings Managing Livestock Wastes, ASAE, St. Joseph,
Michigan, pp. 264-268.
Van Dyne, D. L. and C. B. Gilbertson. 1978. Estimating U.S. Livestock and
Poultry Manure and Nutrient Production. Report No. ESCS-12. Economics,
Statistics and Cooperatives Service, USDA. Washington, D.C. 15 pp.
White, R. K. and D. L. Forster. 1978. A Manual on Evaluation and Economic
Analysis of Livestock Waste Management Systems. EPA-600/2-78-102, U.S.
Environmental Protection Agency. Ada, Oklahoma. 303 pp.
51
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-179
2.
4. TITLE AND SUBTITLE
RESEARCH NEEDS ASSESSMENT - LIVESTOCK MANURE MANAGEMENT
IN THE UNITED STATES
5. REPORT DATE
August 1979 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. K. White, Editor
8. PERFORMING ORGANIZATION REPORT NO.
!. RECIPIENT'S ACCESSION'NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
The Ohio Agricultural Research and Development Center
Wooster, Ohio 44691 and The Ohio State University,
Columbus, Ohio 43210
10. PROGRAM ELEMENT NO.
IBB770
11. CONTRACT/GRANT NO.
R-806025
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Lab - Ada, OK
Office of Research and Development
U.S. Environmental Protection Agency
Ada. Oklahoma 74820
13. TYPE OF REPORT AND PERIOD COVERED
Final (5/22/78 - 4/30/79)
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The purpose of this report is to identify and assess research needs for livestock
manure management as related to environmental quality. Needs identified are
prioritized and assigned to one or more function areas, such as, environmental
quality, demonstration, livestock production, education, and energy.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Agricultural wastes
Animal husbandry
Waste disposal
Animal wastes management
Research needs
Environment
Energy
Production
43F
68D
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
60
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
52
aUSGOVERHMfKTPSWTINCOfFICE: 1979-657-060/5395
------- |