Priority Areas: 1, 2, 3, and 5

Problem Identification:

Animal waste may be land applied at rates that are independent of localized soil fertility levels and knowledge of the nutrient content of the waste at time of its application, and therefore an increased potential to contaminate ground and surface waters with nutrients exists.

Problem Justification:

Nutrient management in Kentucky continues to affect water quality in many areas of the Commonwealth (Taraba et. al., 1993). With the recent announcements by one swine integrator to expand their operations in Kentucky and the resulting moratorium on permitting new animal production facilities, nutrient management will remain a high priority for the next several years. Unlike producers in Iowa who view animal wastes as a source of nutrients for crop production, some Southern farmers see livestock waste as a by-product from animal production to be disposed of or discarded (Hoag and Roka, 1995). The intent of this project is to demonstrate how managing animal wastes on croplands with respect to soil variability can reduce nitrate-nitrogen, nitrite-nitrogen and phosphorus levels in ground and surface waters.

Traditional farming practices treat fields as independent units and assumes homogeneous agronomic factors. The reality, especially in upland regions, is that many of these fields exhibit a wide range of variability which may be a function of multiple soil series or mapping units and past non-uniform applications of animal wastes or inorganic fertilizers. Such variability may impact water quality if these fields are managed on a field-average basis, as current practices dictate.

"Site-specific" farming or precision agriculture is now possible with the development of technologies such as the Global Positioning System (GPS) and Geographic Information Systems (GIS). GPS enables equipment operators to quickly obtain positioning information while a GIS is essentially a database for managing these geographic data. For nutrient management fields are grid-sampled for soil fertility, usually on a one to three acre basis. Grain combines equipped with yield monitors and GPS receivers log instantaneous yield and position data. Fertility and yield maps are then generated using these data and a GIS package. Utilizing both historical yields and known fertility levels, and by estimating the nutrient content of the waste to be applied, crop consultants can then generate "site-specific" waste application recommendations in the form of rate maps. Utilizing the GIS generated maps and a GPS receiver, fields can be flagged for dead-reckoning waste application. Such a method would be necessary until this technology is demonstrated, and until GPS controlled variable-rate manure applicators are commercially available. Site-specific fertilizer application services are currently available from farm suppliers in some regions of Kentucky. It seems to be a natural extension to apply these practices to optimize application of animal wastes to meet crop nutrient requirements and minimize the impact on water quality. GIS and GPS technologies have been used to manage nutrients through the application of inorganic fertilizers (Robert et al., 1991; Mulla, 1991; Carr et al., 1991; Li et al., 1992; Neuhaus and Searcy, 1993; and Birrell et al., 1993).

Objectives:

• Assess and quantify the variability in nutrient content of swine and dairy waste at the time of application.
• Develop calibration procedures and assess the uniformity of distribution of liquid-manure injection application equipment.
• Develop a prioritized set of rules for precision agriculture mapping packages to aid in selection of land areas within the farmstead that are best suited to handle the nutrient loading associated with animal waste application to minimize impacts on water quality.
• Quantify water quality impacts of traditional versus "site-specific" approaches to animal waste application.
  

Work in the first year of the project will focus on developing a GIS database and rules to govern waste application at the Worth and Dee Ellis Farm site. Equally as important is the assessment of the variability of nutrient content of the waste. The Worth and Dee Ellis site in Shelby County is comprised of approximately 3500 acres of crops and swine and dairy enterprises. Approximately 1,000,000 pounds of milk are marketed each year through the dairy operation. The farrow to finish swine operation produces approximately 3,400 market weight hogs per year. Both operations utilize manure storage pits integral to the animal production facilities. An nearby earthen storage facility, design by NRCS, is also available to store animal watses. Prior to pumping the pits, they are agitated to insure that the solids are suspended, and so that a homogeneous slurry can be land applied. All waste is injected to provide a source of nutrients to grain and silage crops and to minimize odor and volatilization of nutrients. Fields are selected for application in accordance with crop rotation and proximity to the animal enterprises.

A GIS database will be constructed utilizing soil grid sample analyses results for the cropland surrounding the animal enterprises. Agronomic data to be entered in this database will include phosphorus, potassium and soil organic matter content levels, in addition to soil water pH and other elements commonly available to the producers from soil analyses from UK Regulatory Services. GPS will be used to map and navigate to grid points. Yield monitoring capabilities have enabled the owners of Worth and Dee Ellis Farm to archive up to three years of yield data for most of the cropped areas. This historical data will be used estimate crop nutrient removal in accordance with yield. Additional items of importance to be mapped will include waterways, sinks, water dens, springs, ponds and other environmentally sensitive areas.

Manure samples will be collected for analysis when the swine and dairy pits are pumped in the spring and fall. Analytes will include nitrite-N, nitrate-N, total-N, phosphate-P, total-P, and potassium. A representative sample will be collected from each slurry tank load at pumping. A hydrometer will be used to determine the specific gravity of the slurry. Temperature will be recorded at the same time. Rapid assessment at pumping might be feasible if the nutrient levels and solids content are found to correlate well with the fluid density that includes the suspended solids. Other types of rapid nutrient content methods will be evaluated for the same application.

A set of rules for applying animal wastes will be developed based on environmental policies in the Commonwealth of Kentucky (Bowden, 1978; and Hoag and Roka, 1995) and the nutrient content of the waste (Collins et al., 1995; Sutton et al., 1979; Krider, 1995; and Wells, 1996). The rules will be established based on historical cropping and manure application, and the need to reduce impacts on water quality. Application rules will be provided in variable and fixed rate formats. As application technology evolves, variable-rate waste application will become commonplace. However, for many Kentucky producers the rules will be used to select application areas within a field that lend themselves to dead reckoning for navigation. That is to either flag the field using GPS, or provide a map with landmarks that will guide the applicator.

Just as important as the rules based process and nutrient content determination is calibration of the application equipment. Worth and Dee Ellis Farm utilizes application equipment that consists of a tank wagon with positive air pressure metering, and multiple shanks for injecting the waste slurry. This equipment will be calibrated for slurries of varying solids content in addition to insuring uniform application from shank to shank.

Much of the cropland at Worth and Dee Ellis Farm has been instrumented with weirs and automated water quality sampling equipment under the Phase II of S.B. 271. We will continue to utilize this equipment to assess and monitor "site-specific" animal waste management versus practices currently in place. The geology of the Outer Bluegrass soils lends themselves readily to monitoring as much of the near-surface ground water becomes surface water as it flows from wet weather springs in the area. A combination of the near-surface and surface water that flows over the weirs that are in place. Storm events will be sampled for N and P levels, with monitoring continuing at periodic intervals as long as flow is present. Background nutrient levels will be established during the first year of the investigation. As an indication of long-term nutrient movement suction lysimeters will be installed at 35 and 70 cm depths to permit monitoring of near surface water quality from fields where animal wastes have been applied. Areas of high and low fertility will be selected to contrast the mineralization or volatilization of N and P nutrients. A total of 18 sites in each field will be selected for monitoring.

The second phase of this project will involve identifying three additional cooperators with livestock and cropping operations in Kentucky. Two cooperators will be selected such that yield monitor data is available for land to be used for waste application. Preference will be given to cooperators who have established cropping and yield histories for the land in question. The UK Woodford County Research farm will be included as the third cooperator. A similar approach to the one utilized at Worth and Dee Ellis Farm will be undertaken to develop a GIS database for managing animal wastes. The objectives for this year of the project will involve grid sampling and data collection necessary to develop the database. The GIS-based rules for waste application will be utilized to make recommendations for the producers to follow in subsequent years.

Implementation of "site-specific" waste management practices will begin at the Worth and Dee Ellis Farm site during the second year. Water quality monitoring will be continued consistent with the guidelines proposed under the Work Plan for Year 1 at this location.

Background nutrient levels will be established during the second year of the investigation at the sites of the two of the three second year cooperators (excluding the Woodford County Farm as baseline data is currently being collected in cooperation with S.B. 271 and E.P.A. Section 319h projects). As an indication of long-term nutrient movement suction lysimeters will be installed at 35 and 70 cm depths to permit monitoring of near surface water quality from fields where animal wastes have been applied, or will be applied. Areas of high and low fertility will be selected to contrast the mineralization or volatilization of N and P nutrients. A total of 8 lysimeter sites at the farmsteads of the two additional cooperators will be selected for monitoring.

Work Plan (Year 3):

Implementation of "site-specific" waste management practices will begin at the two cooperator’s farms identified during the second year of the investigation (excluding the UK Woodford County Research Farm), with continued implementation at the Worth and Dee Ellis Farm site. Water quality monitoring will be continued and consistent with the guidelines proposed under the Work Plan for Year 1 at the Worth and Dee Ellis Farm site.

• Guidelines for GIS/GPS management of animal wastes on croplands will be developed to illustrate the potential to reduce nitrate-nitrogen, nitrite-nitrogen and phosphorus in near-surface waters at the Worth and Dee Ellis Farm Site.
• An annual report will be submitted to the College of Agriculture and the cooperators at the end of the first year funding cycle. This report will summarize of all monitoring activities.

• Development of guidelines for GIS/GPS management of animal wastes on croplands will be continued to illustrate the potential to reduce nitrate-nitrogen, nitrite-nitrogen and phosphorus in near-surface waters on a statewide basis.
• Guidelines for GIS/GPS management of animal wastes on croplands will be implemented at the Worth and Dee Ellis Farm in Shelby County.
• "Site-specific" management information will be disseminated to farmers, farm service providers, livestock producers and fertilizer dealers via a field day to be held at Worth and Dee Ellis Farm during the second year of the project. The field day will be conducted during the month of June or July.
• One workshop will be conducted on "site-specific" management of animal wastes during the second cropping seasons of the project. Details to be provided to farmers and farm service providers will include: equipment selection and cost considerations, potential for reducing nutrient inputs, overall economics and recommendations for implementing "site-specific" management practices. This workshop will be held during the month of January or February.
• An extension publication will be developed regarding "site-specific" animal waste management. This publication will cover hardware and software considerations for collection, management and analyses of field data.
• An annual report will be submitted to the College of Agriculture and cooperators at the end of the funding cycle. This report will summarize of all development, workshop and monitoring activities.

• Guidelines for GIS/GPS management of animal wastes on croplands will be implemented at two additional locations in the Commonwealth.
• "Site-specific" waste management information will be disseminated to farmers, farm services, livestock producers and fertilizer dealers via a field day to be held at Worth and Dee Ellis Farms during the third year of the project. The field day will be conducted during the month of June or July.
• Two workshops will be conducted on "site-specific" management of nutrients during the third cropping season of the project. Details to be provided to farmers and farm service providers will include: equipment selection and cost considerations, potential for reducing nutrient inputs, overall economics and recommendations for implementing "site-specific" management practices. These workshops will be held during the months of January and February.
• A second extension publication will be developed regarding "site-specific" animal waste management. This publication will focus on cropping practices that are appropriate for "site-specific" farming and the overall economic and environmental benefits. Both extension publications will be made available to clientele in both printed and electronic formats.
• Quantification of these results and the economic impact of the practices may provide sufficient information to support the development of a new BMP for nutrient management for animal wastes. A recommendation for the development of such a BMP will be written and provided as part of the final project report.
• A comprehensive report will be submitted to the College of Agriculture and cooperators at the end of the final funding cycle. This report will summarize all development, extension and monitoring activities.

Bowden, J.P. 1978. Livestock Waste Management – Questions and Answers Concerning Laws and Regulations. Extension Publication AEN-44. College of Agriculture, University of Kentucky, Lexington.

Birrell, S.J., K.A. Sudduth and S.C. Borgelt. 1993. Crop yield and soil nutrient management. ASAE Paper No. 931556. St. Joseph, Michigan: ASAE.

Carr, P.M., G.R. Carlson, J.S. Jacobsen, G.A. Nielson and E.O. Skogley. 1991. Farming soils, not fields: a strategy for increasing fertilizer profitability. Journal of Production Agriculture. 4:57-61.

Collins, E.R., Jr., J.D. Jordan and T.A. Dillaha. 1995. Nutrient values of dairy manure and poultry litter as affected by storage and handling. Animal Waste and the Land-Water Interface. pp. 343-353.

Hoag, D.L. and F.M. Roka. 1995. Environmental policy and swine manure management: waste not or want not? American Journal of Alternative Agriculture. 10:163-166.

Krider, J.N. 1995. Innovative utilization of animal waste. Proceedings of the National Livestock, Poultry and Aquacultural Waste Management Conference. pp. 82-87. St. Joseph, Michigan: ASAE.

Li, Y., R.L. Kushwaha and G.C. Zoerb. 1992. Design and control of a digital control system for variable rate nitrogen fertilization. ASAE Paper No. 923035. St. Joseph, Michigan: ASAE.

Mulla, D.J. 1991. Using geostatistics and GIS to manage spatial patterns min soil fertility. Automated Agriculture for the 21st Century. St. Joseph, Michigan: ASAE. 336-345.

Neuhaus, P.E. and S.W. Searcy. 1993. Variable planting density and fertilizer rate application system. ASAE Paper No. 931554. St. Joseph, Michigan: ASAE.

Robert, P.C., W.H. Thompson and D. Fairchild. 1991. Soil specific anhydrous ammonia management system. Automated Agriculture for the 21st Century. St. Joseph, Michigan: ASAE. 418-426.

Sutton, A.L., D.H. Vanderholm, and S.W. Melvin. 1979. Fertilizer value of swine manure. Pork Industry Handbook. Extension Publication No. ASC-80. College of Agriculture, University of Kentucky, Lexington.

Taraba, J.L. et al. 1993. Agricultural Chemical Use Impacts on Kentucky Groundwater Resources--1992 Status Report. College of Agriculture, Kentucky Geological Survey and Institute for Mining and Minerals Research; University of Kentucky

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