WEST VIRGINIA POULTRY PRODUCTION SURVEY pdf

Agronomic management is an area that needs targeted programming to demonstrate toproducers how they can maximize poultry litter as a fertilizer.Overall, the producers are showing a commi

WEST VIRGINIA POULTRY PRODUCTION SURVEY

A Report on Implementation of Water Quality Improvement Practices in the Five Eastern Panhandle Poultry

Producing Counties.

Requested By

The West Virginia Poultry Water Quality Advisory Committee

Prepared by:

Thomas Basden, Extension Specialist

West Virginia University Extension Service

Andrew Walker, Non-Point Source Specialist

West Virginia Soil Conservation Agency

Rapid expansion of the West Virginia poultry industry hasprompted questions concerning the effect of this expansion uponwater quality This survey was conducted during October andNovember of 1994 to determine the level of Best Management Practice(BMP) implementation in order that educational and technicalprogramming could be targeted toward specific BMPs needing greaterattention Using a set of 52 questions, poultry producersdemonstrated their management of poultry litter and mortality andhow they were making agronomic decisions on their farms Improvedmethods of poultry litter storage, application, and distributionare occurring Poultry mortality management has made a dramaticshift to composting as a low-cost solution Agronomic management

is an area that needs targeted programming to demonstrate toproducers how they can maximize poultry litter as a fertilizer.Overall, the producers are showing a commitment to voluntary landstewardship that will ensure continued, environmentally soundgrowth of the poultry industry in the Potomac Valley

TABLE OF CONTENTS

Introduction

Purpose Of Study

Methods And Materials

Results And Discussion

Section I Type of Production and Geographic LocationSection II Size and Type of Farm Operations

Section III On-farm Litter Utilization

Section IV Litter Distribution to and Utilization by Non-poultry Producers

Section V Litter Storage and Land Application

Section VI Agronomic Management

Section VII Manure and Litter Analysis

Section VIII Crop and Forage Management

Section XI Mortality Management

Section X State and County Regulations

Conclusions

References

Appendix A Questionnaire Form

Appendix B Tables of Results

Appendix C Follow Up Survey, Sept 1995

Appendix D Watershed Map

Perdue Farms, Inc.; Rocco Farms, Inc.; Wampler-Longacre1

The rapid expansion of the poultry industry combined with West Virginia's established beef cattle industry has generated questions about the effects of the large number of animals on water quality

in this watershed State and Federal Agricultural Agencies including Natural Recourse Conservation Agency, Consolidated Farm Service, State Soil Conservation Agency, West Virginia University, WVU Extension Service and the West Virginia Department of Agriculture have joined together to address these concerns through educational and technical programs This collaboration has evolved into the Potomac Headwaters Project.

To determine the best utilization of agency personnel, a needs assessment is underway A component of that assessment was the completion of a survey of poultry producers to determine specific sizes of operations, management of litter, types of equipment utilized, and specific agronomic decisions The poultry integrators agreed to distribute and collect the survey from each 1

of their producers This was done during the fall of 1994 Because of the industry cooperation, 53% (199 respondents) of the surveys sent out were returned by producers A 53% return is commonly an acceptable number for this type of study Therefore, the conclusions should allow agricultural producers, the poultry industry, and State and Federal Agencies to use this study as a planning tool to ensure the continued growth of all agricultural activity while maintaining and improving water quality in the five county area.

PURPOSE OF STUDY

The purposes of this study were threefold First, to determine the degree of implementation of water quality improvement practices by the poultry producers in the Potomac River Watershed Second, utilize the responses to this questionnaire to target technical and educational programming on specific management practices Finally, to demonstrate the successes which are already occurring through voluntary adoption by producers.

METHODS AND MATERIALS

A 52 question survey was initiated during the summer of 1994

in the Potomac Inter-Agency Water Quality Office (See Appendix A for questionnaire form) The document was reviewed by district conservationists, county agents, university specialists, and poultry integrators During October and November the questionnaire was distributed to 375 poultry producers in the five county 2 poultry producing area, collected by the integrators upon completion, and returned to the Water Quality Office A database was prepared and all returned surveys were entered into it

CMR Research Associates were contracted to statistically analyze the results Included in this report are frequency distributions for each questionnaire item Included in Appendix B are 65 tables presenting the responses to the 52 questions within the survey.

The results are presented in bar graph format to clarify and condense the number of tables presented by CMR Research Associates.

A 90% confidence interval was used for all questions The number

of responses to individual questions vary because of non-response error On the bottom left side of each bar graph is a percentage response from total number of poultry producers in the Potomac Watershed and the actual number of responses

A short follow up survey is contained in Appendix C This was conducted in September 1995 with 90% of producers responding to the questionnaire

RESULTS AND DISCUSSION

Section I Type of Production and Geographic Location

Q1 What type birds do you raise?

All producers that returned surveys responded to this question The breakdown of bird types shows that in the sample

Section I Figures 1-4, Type of Production

and Geographic Location

6

Q3 How many houses do you operate?

Figure 3 shows a distribution of the number of houses per operation The average number of houses per producer is 3 [90% CI{± 0.21}]

Q4 In what watershed is your operation located?

Figure 4 shows that the largest concentration of producers (34%) is located in the largest watershed, the South Branch (see Appendix D) The second largest concentration (13%) is in a much smaller watershed, the Lost River area

The significance of the distribution by bird type is the large number of broiler producers that have 6 to 7 flocks per year and a corresponding accumulation of litter to store or apply at each cleanout The other bird types have one or two cleanouts per year with reduced accumulation of litter

The 53% of producers that accumulate 101-400 tons/year of litter have a manageable amount that can be stored in a shed or under a tarp without difficulty The 27% of producers accumulating 401-800 tons/year have a greater challenge storing, applying and/or selling this quantity of litter

Seventy-seven percent of producers have from 1 to 3 houses Operations of this size should allow a producer flexibility in litter utilization through storage, application and/or selling of the product Producers with 6 or more houses account for 9% of total producers These operations should have large treatable acreage available, large storage facilities and/or written plans to facilitate distribution of the litter to other agricultural producers

Lost River watershed has limited treatable acreage for the large animal numbers located in the valley, making redistribution

of litter to other areas a high priority (Appendix D) The Water Quality Incentive Program (WQIP) funded by USDA in 1994 has been implemented and is designed to encourage improved management of livestock manure and poultry litter within the Lost River watershed In Grant County, the Mill Creek watershed also has a large number of producers in relation to the treatable acreage

Section II Size and Type of Farm Operations

Q5 How many acres do you normally operate?

Figure 5 shows the distribution of farm sizes The largest group consists of farms which operate less than 50 acres at 28%, followed by 51-100 acres at 13%, 101-250 acres at 22%, 251-500 acres at 21% and over 500 acres at 16%

Q6 Is your farm mainly grassland/hay, row crops, timber or other?

Figure 6 shows that 84% of the farm land is grassland/hay.

Section II Figures 5-7, Size and Type of Farm Operation

This constitutes the largest potentially treatable land area for litter application on farms in the sample group

Q7 What percent of your farm is grassland/hay?

A mean of 61% [90% CI{± 3.0}] was reported Most producers have a large portion of their operation in pasture and/or hay

Q8 What percent of your farm is row crops?

The mean percentage reported was 9 [90% CI{± 2.0}] The distribution in Figure 7 shows a large number of respondents (57%) having no row crop production at all

Q9 What percent of your farm is timber?

The mean percentage reported was 31 [90% CI{± 3.4}]

Based on Q7-Q9, the average poultry farm in this survey consists of 60% grassland/hay, 10% row crops and 30% timber

The 28% of producers with less than 50 acres have the greatest challenge in not over applying litter on their limited acreage and

to find markets for the litter that is surplus to their operation.

These producers (n=46) sold a mean percentage of 81% [90% CI{± 7.4}] of their litter Producers with greater than 50 acres (n=125) sold a mean percentage of 33% [90% CI{± 4.7}] of their litter From this analysis, the producers with less than 50 acres are clearly marketing their litter that they cannot utilize on the farm The producers with greater than 50 acres are also redistributing a third of their litter off the farm This redistribution is an important best management practice that producers are implementing

The 57% of producers without row crops reinforce the need to have educational and technical programs that ensure proper application rates on pasture and hay land With only 10% of farm land in row crops, the nutrient loading of crop land needs to be monitored closely to reduce excess nutrient application (Wagger and Mengel, 1988; Wood, 1992)

Section III Figures 8-11, On-farm Litter Utilization

Q12 What percent of the litter you use is for fertilizer?

The mean percentage was 91 [90% CI{± 2.2}]

Q13 What percent of the litter you use is for feed?

The mean percentage reported was 8 [90% CI{± 1.8}] To estimate the amount of litter generated per producer per year that

is utilized as a livestock feed, we used the following formula: (average number of houses per producer X average litter produced per house {151 tons} X 7.9%) Using this formula we estimate 32 tons of litter per producer per year is utilized as livestock feed.

Q14 What percent of the litter for fertilizer is used on grassland?

The mean percentage was 82 [90% CI{± 3.3}] The distribution

of responses is shown in Figure 10

Q15 What percent of your litter is used for row crops?

A mean percentage of 16 [90% CI{± 3.1}] was reported Figure

11 shows the distribution of the litter use on row crops with 61.3%

of producers utilizing 0% or not having any row crops These results concur with question 7 and 8 that asked about land use

By far the largest percentage of litter is utilized as fertilizer Pasture and hay land have nutrient loading capacities capable of receiving the greatest part of the litter produced because they constitute the largest acreage.

Broiler litter as a cattle feed supplement needs to be promoted Broiler producers that sell their litter to cattlemen for feed supplement could benefit from having their litter analyzed for feed value, and using the results as a marketing tool A program of litter sampling could be established by using integrators to provide sample kits to producers who are nearing the clean out period within their houses Integrators could then pick

up the kits and take them to a central location

Section IV Litter Distribution to and Utilization by Non-poultry Producers

Q16 Do you sell or give away all, some, or none of your litter you produce?

The results are similar to those of question 10, in that 27% [90% CI{± 5.2}] of producers sell none or keep all, 57% [90% CI{± 5.8}] of producers use some or sell some, and 16% [90% CI[± 4.3}]

of producers sell all or use none of their litter

Q17 What percent of your litter do you sell or give away?

The mean percentage was 46 {90% CI{± 4.8}] Asking a question about the amount of litter utilized by the producer (question 10,11) and then asking the producer what percentage of the litter

is sold or given away (question 16,17) are two ways to ask the same question The results are the same for both series of questions and adds more validity to the results See Appendix B for question

17 distribution of responses.

Q18 What percent of the litter you sell is used for fertilizer?

The mean percent was 73 {90% CI{± 5.2}] Figure 12 shows the distribution of producers with 60% selling 76-100% of their litter

as fertilizer, 19% selling 26-50% as fertilizer and 9% selling 0%

as fertilizer

Q19 What percent of the litter you sell is used for feed?

A mean percent of 21 [90% CI{± 8.1}] was reported Figure 13 demonstrates the distribution of responses with 60% of producers not selling any (0%) of their litter as feed, 21% selling 26-50% for feed and 10% selling 76-100 as feed This breakdown corresponds with the mean and distribution of responses in question

Q21 What percent of the litter you sell stays in your watershed?

Figure 14 shows the distribution for this question with 19% moving all their litter out of the watershed, 17% moving up to half

of it, and 55% retaining the litter in their watershed

Section IV Figures 12-15, Litter Distribution to and Utilization by Non-poultry Producers

Producers are currently marketing 46% of the litter that is produced on their operation Seventy three percent of the litter

is utilized by the buyers as fertilizer and 21% of the litter is used as a feed supplement

The distribution of litter outside of the producers' watershed accounts for 34% of the marketed litter This distribution pattern may be attributed to readily available treatable land within the watershed and/or low market price for litter that prohibits long distance hauling (Bosch and Napit, 1992).

Twenty five percent of producers sell litter that goes

outside of the Potomac Valley This distribution pattern may be affected by the same reasons mentioned above and also producers outside of the Potomac Valley may not understand the effectiveness

of litter as a fertilizer and feed supplement.

Section V Litter Storage and Land Application

Q24 What type of storage do you use for your litter accumulation?

The listed storage methods in the survey are: shed, under a tarp, in an open pile, or in some other way Figure 16 shows that 37% of producers store litter in a shed, 12% utilize a tarp to cover litter, 30% store in an open pile, and 24% some other way Other ways may include immediate land application or the selling of litter

Q25 If you have a shed, is it your own design or another design?

Seventeen percent of producers responded to this question Of those that responded, 48% [90% CI{± 10.6}] used their own design and 52% [90% CI{± 10.6}] used another design

Covering litter with a tarp during winter or for short periods

in the crop field must become an integral part of a litter utilization plan for all poultry producers and users Uncovered litter, even for short periods of time, has the potential of

becoming a source of nonpoint pollutants (Ritter, et al., 1994)

The people that designed their own sheds presumably did not have Government Cost Share monies available while the group that used another design had Cost Share monies available that required

a specific design The response shows that a percentage of producers are willing to build storage structures without the benefit of cost share money

Section VI Agronomic Management

Q26 When do you usually spread your litter?

Section V Figure 16, Litter Storage and Land Application

Section VI Figures 17-19, Agronomic Management

Some of the returned surveys had more than one response to this question The multiple responses show that 79% of producers apply during the spring, 27% during the summer, 71% in the fall and 26% in the winter (Figure 17)

Q27 Do you incorporate all, some or none of your litter?

Thirty percent of producers responded to this question Eleven percent [90% CI{± 4.9}] of producers incorporate all of their litter, 38% [90% CI{± 7.4}] incorporate some litter and 51% [90% CI{± 7.7}] incorporate none This was a poorly worded question and should have been broken into several yes/no questions Because of the way questions 27 and 28 were asked, few conclusions can be reached.

Q29 What type of litter spreader do you use?

Forty three percent of producers responded to this question Figure 18 shows that 65% [90% CI{± 6.1}] producers use a box-type spreader, 39% [90% CI{± 6.3}] use a fan-type spreader and 2% [90% CI{± 2}] use some other type of spreader to apply poultry litter.

Q30 Is your litter spreader calibrated?

Figure 18 shows that nearly 60% of respondents have calibrated their spreader equipment to determine the amount of litter applied per acre

Q31 Do you soil test all, some or none of your fields at least every three years?

Figure 19 shows that 32% [90% CI{± 6}] test all, 33% [90% CI{± 6}] test some and 34% [90% CI{± 6.1}] test none of their fields during a three year period

Q32 If you soil test some of your fields, what percent of your fields do you test at least every three years?

Figure 19 shows the percent distribution for question 32 with

a mean of 49.6% [90% CI{± 6.3}] of fields being tested

incorporated into the plow layer as the litter is spread This

helps to reduce nutrient loss (Breeuwsma, et al., 1995).

The box-type spreaders are designed to apply semi-solid livestock manures and tend to over-apply poultry litter The fan- type spreaders apply litter more evenly than the box spreaders and allow for reduced loading rates on pasture land The 65% of producers who use box spreaders could improve litter utilization with reduction kits that reduce application rates The 40% of producers who have not calibrated their spreaders need to do so because calibration is one component of a nutrient management plan.

In addition, nutrient management plans require a soil sample from every field at least once every three years

Section VII Manure and Litter Analysis

Q33 Do you have your litter tested for fertilizer values?

Figure 20 shows that 33% [90% CI{± 5.7}] of producers test litter for its fertilizer value and 67 [90% CI{± 5.7}] do not Q34 Do you have your litter tested for feed values?

Figure 20 shows that 16% [90% CI{± 4.5}] of producers test litter for its feed value and 84% [90% CI{± 4.5}] do not

Q35 Do you produce other livestock manures?

Figure 21 shows that 45% [90% CI{± 5.9}] of producers are diversified operations with poultry and livestock enterprises while 54% [90% CI{± 5.9}] solely produce poultry.

Q36 Do you have your other manures tested?

A response of 2% [90% CI± 1.6}] of producers test their manure for its fertilizer value

Q37 If a manure testing service was available would you use it?

Forty six percent of producers responded to this question Seventy nine percent [90% CI{± 5.1}] would use a testing service and 21% [90% CI{± 5.1}] would not

To improve utilization of litter and as a component of a nutrient management plan all producers should test litter 3 times over the period of a year or two and then once every other year or

when a production input such as feed or bedding changes (Sims, et al., 1989) Even producers that sell all their litter would

benefit from litter analysis because they could quantify the nutrient value of the litter that they were selling

With 45% of producers having both livestock and poultry components to their farming operation, testing of all types of manures is needed to quantify the total nutrients produced on each farm Accurate nutrient management plans can then be constructed.

Section VII Figures 20-21, Manure and Litter Analysis

Section VIII Figures 22-23, Crop and Forage Management

A fact sheet describing why, when, and how to take a good litter/manure sample and where to send it is needed for all people involved in animal agriculture within the state

The 20% that would not use a manure/litter analysis service may not understand the benefit of analysis or they have already been involved with a testing program.

Section VIII Crop and Forage Management

Q38 Do you use additional commercial fertilizer, and

Q39 If so, what percent of your needs is commercial?

Figure 22 shows that 65% [90% CI{± 5.8}] of producers use no additional fertilizer In the percent distribution breakdown, 26% [90% CI{± 6.1}] of producers that use additional fertilizer only need it for 1-25% of their total needs

Q40 Do you have a nutrient management plan?

Forty four percent of producers responded to this question with 34% [90% CI{± 6}] reporting that they did have a plan and 66% [90% CI{± 6}] responded that they did not have a nutrient management plan

Q41 Do you use cover crops on all, some, or none of your crop fields?

Figure 23 shows that 44% of that group not having a cover crop program on their crop fields, 21% having covers on all the fields and 34% having covers on some of their fields

Q42 If so what percent?

The percent distribution in figure 23 shows that 57% of producers establish some degree of cover crop on their fields Q43 What type of cover crop do you use?

being applied to the nitrogen needs of crops and forages, resulting

in a phosphorus build up on fields that receive repeated

litter/manure applications (Mitchell, et al., 1992)

Sixty-six percent of producers responded that they do not have

a nutrient management document These producers need a plan in order to demonstrate on-farm utilization of poultry litter and livestock manures.

Looking back at the response concerning litter applications,

a large group of producers stated that fall applications were a common practice A portion of these fall applications occur on corn ground after harvest, making it crucial that cover crops are established to trap the available nitrogen fraction contained in the litter so it is not lost during the winter (Hooke and Gascho, 1988)

The 55% of producers that are using cover crops use small grains These are best suited to scavenge soil nitrogen residues or fall applied nitrogen found in litter or manures (Hooke and Gascho, 1988; Wagger and Mengel, 1988).

Sixteen percent of producers that raise corn use the nitrogen quick test Demonstrations showing the accuracy of this tool and its ability to save nitrogen inputs need to be continued Producers who use repeated applications of litter or manure on corn fields need to account for the organic nitrogen fraction that becomes available during the second and third year after

application (Magdoff, et al., 1984)

Section IX Mortality Management

Q45 What type of dead bird disposal do you use?

Disposal methods include; composting, rendering, incineration, burial pits, and other Figure 24 shows that 38% of producers use the composting method, 33% of producers render, 22% utilize burial pits, and 4% incinerate.

Q46 If you compost is it your own design or is it another design?

Figure 25 shows that 20% of producers responded to this question with 53% using their own non-cost-shared design and 47% using another design

Q47 Are you satisfied with your composter?

Figure 25 shows that 95% responded that they were satisfied with their composter

Q48 If not satisfied, do you know where to receive help?

Figure 25 shows that of those producers that responded, 80% knew where to receive help

Section IX Figures 24-25, Mortality Management

Section X Figure 26, State and County Regulations

28

Composting as a utilization method for mortality is a innovative best management practice that has been implemented by area producers during the past five years This new method reduces bio-security hazards associated with rendering and allows the producer to recycle the nutrients in the animal carcasses as a fertilizer (Murphy, 1992).

The survey shows that there is a high approval rating for composting with 95% of poultry producers that currently compost satisfied with the system.

As incinerators wear out through use, producers need to be encouraged to convert to composting because of its ease of use, cost effectiveness, and low environmental impact

Section X State and County Regulations

Q49 Are you aware of the need to register your incinerator?

Twelve percent of producers responded to this question with 61% [90% CI{± 11.8}] stating that they were aware that they need to register an incinerator while 39% [90% CI{± 11.8}] were unaware Q50 Are you aware of the need for sediment and erosion control plans for new construction?

Figure 26 shows that 87% of producers were aware about this regulation

Q51 Are you aware of your county siting guidelines?

Figure 26 shows that 77% of producers were aware of county siting guidelines

Q52 Has the area around your poultry house been reseeded?

Figure 26 shows that 85% of producers have reseeded the area around their poultry house

The level of producer awareness is high for all State and

This survey was targeted to the poultry producers in the Potomac river drainage area Fifty three percent of producers returned the questionaire Producers typically answered questions that only affected their operation, contributing to non-response error To reach conclusions from the data we will assume that the sample population, those that filled out the survey, were a random average group within the total population of producers

The data shows that producers are implementing some best management practices The producers understand the value of poultry litter and are not indiscriminately land applying it as a disposal method, as some people have suggested Continued improvement of farm management practices needs to occur to ensure that water resources are maintained and/or improved.

The conclusions that can be drawn from this data and which need to be acted upon by educational and technical agencies and by poultry litter users are as follows:

1 Pasture and grass hay are our largest land use being treated with poultry litter Programs need to be developed to improve the promotion and utilization of litter as a good fertilizer source for this abundant land area

2 Some litter is leaving the Potomac Valley Programs need

to be continued in the western part of the State to promote litter

as fertilizer and feed

3 Piles of litter even for short duration storage need to

be covered Producers selling litter need to promote litter storage methods with the buyers

4 Winter applications of litter or livestock manures should

7 Producers need to determine what fields are developing nutrient imbalances from repeated litter applications and then sell their litter and purchase commercial nitrogen to bring the soil nutrients back into balance

8 A winter cover crop program needs to be initiated to reduce the loss of nitrogen during the winter months

9 Agencies and integrators need to cooperatively eliminate burial pits as a dead bird disposal method Composters need to be promoted as the best disposal method if producers cannot or do not want to render the carcasses

10 Nitrogen quick testing needs to be promoted through the use of demonstrations to develop producer trust with the results and consequently reduce the amount of litter applied to corn ground

11 Agencies need to determine what level of soil phosphorus

is excessive so standardized nutrient management planning can be established for the state of West Virginia

The improved management steps that need to continue with producers that raise poultry or utilize litter as a feed or fertilizer are not insurmountable If producers continue to adopt the aforementioned Best Management Practices and programs, their commitment to voluntary land stewardship will be evident and quantified to those that want to regulate What is needed is an interest from the producers and the ability of the different government agencies to coordinate educational and technical programs

Within the Potomac drainage, the poultry industry is not the only potential producer of non-point source pollution that needs to

be addressed Rural septic systems, State and Federal fish hatcheries, sewage treatment plants, and winter livestock feed lots located next to small streams also need to be considered

1 Bosch, D.J., and K.B Napit, 1992 Economics of transporting

poultry litter to achieve more effective use as fertilizer Journal of Soil and Water Conservation 47:342-346.

2 Breeuwsma, A.J., G.A Reijerink, and O.F Schoumans, 1995.

Impact of manure on accumulation and leaching of phosphate in areas of intensive livestock farming pp 239-249 In: Proceedings of the conference of animal waste and the land- water interface, Fayetteville Arkansas.

3 Hooke, J.E and G.J Gascho, 1988 Multiple cropping for

efficient use of water and nitrogen Pp 7-20 In: Cropping strategies for efficient use of water and nitrogen Spec Pub 51 Am Soc Agron., W.L Hargrove [ed.], Madison, Wisc.

4 Magdoff, F.R., D Ross, and J Amadon, 1984 A soil test

for nitrogen availability to corn Soil Sci Soc of Am J., 48: 1301

5 Mitchell, C.C., S.T Windham, D.B Nelson, and M.N

Baltikauski, 1992 Effects of long-term broiler litter application on coastal plain soils pp 385-390 In:

Proceedings of the National Poultry Waste Management

Symposium, Birmingham, AL Auburn University, AL

6 Murphy, D.W., 1992 New developments in mortality composters.

pp 33-40 In: Proceedings of the National Poultry Waste Management Symposium, Birmingham, AL Auburn University, AL.

7 Rayburn, E.B., R.E Blaser, and D.D Wolf, 1979 Winter

tall fescue yield and quality with different accumulation periods and N rates Agron Journal, 71:959-963

8 Ritter, W.F., A.E.M Chirside, and R.W Scarborough, 1994.

Nitrogen movement in poultry houses and under stockpiled manure From: The american society of agricultural engineers

1994 international summer meetings Kansas city Mo Paper no 94-4057

9 Sims, J.T., 1995 Characteristics of animal wastes and

waste-amended soils: An overview of the agricultural and environmental issues pp 1-13 In: Proceedings of the conference of animal waste and the land-water interface, Fayetteville Arkansas.