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United States Department of Agriculture

Agricultural Research Service


Location: National Soil Dynamics Laboratory

2009 Annual Report

1a.Objectives (from AD-416)
There is an urgent need to develop organic waste management systems in the southeastern United States that preserve and improve the soil resource and provide for environmental quality. The objectives of this project are to:.
1)Develop soil phosphorus loading capabilities, following application of animal manure, for soils of the southeastern United States with differing chemical and physical characteristics;.
2)Determine the impact of long-term application of poultry litter and other organic waste on soil quality in the southeastern United States;.
3)Develop best management practices for manure application to row crops (corn and cotton) that maximize production while minimizing offsite environmental impacts in the southeastern United States;.
4) Develop improved knowledge of waste management impacts on manure-derived nutrient interactions (phosphorus solubility and nitrogen mineralization) at the soil surface; and.
5)Develop and assess performance of equipment for applying poultry litter in a shallow subsurface bands in pastures and row crops.

1b.Approach (from AD-416)
Soils are the primary resource for agricultural production and their protection and improvement are essential for agriculture in the United States. Application of organic waste to soil can potentially improve soil conditions and provide nutrients needed for plant production. However, poor methods of application of organic waste can lead to nutrient loss from agricultural land by runoff and leaching. These potential non-point source nutrient losses can contribute to environmental degradation, eutrophication of surface waters, and possible human health risks. Because of this growing environmental concern regarding organic waste disposal, field and laboratory studies will be established to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. In order to develop effective solutions, basic understanding of these processes must be further developed. Laboratory and field studies will be conducted to determine functional relationships of soil processes and soil dynamics, especially for P and N. Studies will investigate the effects of animal waste application on soil P loading. Relationships for benchmark soils will be developed between soil test P levels in soils receiving animal manure applications and runoff losses of P and N using rainfall simulation plots and small watersheds in the southeastern United States. Studies will be initiated to develop best management practices for manure application and to determine the long-term impact of manure application on soil properties in the southeastern United States. Efforts will also be made to develop equipment and assess its performance for applying poultry litter in a shallow trench in pastures and row crops to reduce nutrient loss potential from the litter. Management practices and fundamental knowledge developed in the course of this project should result in greater production and environmental benefit, with reduced nutrient losses, now and in the future.

3.Progress Report
Because of the growing environmental concern regarding organic waste disposal, new field and laboratory studies were established to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. We have initiated a new series of field studies in the Sand Mountain region of Alabama to evaluate the impact of fertilizer and poultry litter application methods as affected by tillage systems on crop production and trace gas losses to the atmosphere. A four-trench litter applicator implement was designed, constructed, and used for applying poultry litter in field experiments. Computer modeling was utilized to evaluate poultry litter application timing in Alabama. Studies of use of gypsum as a soil amendment to reduce phosphorus losses in the rainfall runoff were conducted. Studies to evaluate Clean Chip Residual (CCR) as an alternative greenhouse substrate component for annual bedding plant production was conducted.

1. Study of Manure N Mineralization. Interest in manure management and its effects on nitrogen availability (nitrogen mineralization) has increased in recent years. Understanding N mineralization rates of manure under different environmental conditions could be important in managing N more efficiently. A study evaluated how soil textural, wetting and drying, and temperature conditions affect N mineralization. In this study, Alabama soils were compared to a soil from Illinois. Soils that received manure addition were more effective in generating available N than soils without added manure. The Illinois soil released more N compared to the Alabama soils, probably due to the texture and native climatic conditions of the soil. Temperature also influenced the N availability with more N being produced at higher temperatures. Soil wetting and drying did not impact the N release. This study indicates that in order to maximize the use of the N derived from manure addition to soil different regions and temperatures need to be considered.

2. Study of Long-Term Effect on Soil Quality Parameters After 10 Years of Altered Treatment. Soils in the Southeastern USA, are relatively infertile, highly eroded, and low in organic matter resulting from over 200 years of intensive row crop agriculture that has utilized conventional tillage practices. Also, this region is leading the nation in poultry production (Arkansas, Georgia, and Alabama) generating large amount of poultry litter, which could potentially benefit infertile soils by supplying them with organic matter. A few studies have investigated manure application to crop land in the southeast, typically in 2-year studies, which have resulted in conflicting amounts of soil organic matter retained in the soil. A laboratory study evaluated long-term effects of less intensive tillage practices (>25 years) in conjunction with poultry litter application (>10 years) to soil in order to evaluate soil fertility improvements and soil organic matter retention. Our results show that farmers in the Southeastern region could build up soil organic matter thereby improving soil quality of highly eroded soils with the implementation of conservation practices that utilize organic amendments such as poultry litter.

3. Determined Benefits of Shallow Subsurface Band Application of Poultry Litter. Poultry litter is typically land-applied by broadcast surface application, but this method has a high potential for undesirable transport of litter nutrients off the field into streams, rivers, lakes, and other bodies of water. An experimental four-trench litter applicator field implement that applies litter in shallow subsurface bands in soil was used in five field experiments. When the poultry litter is applied in subsurface bands, compared to traditional broadcast surface application, results show that phosphorus and nitrogen nutrients in water running off field plots are reduced by 80 to 95%. Use of the implement by producers and others who apply litter to fields is expected to reduce pollution of streams, rivers, lakes, and other bodies of water.

4. Developed Alternative Greenhouse Substrate Component for Annual Bedding Plant Production. Traditional substrate (pine bark) for greenhouse production in the horticulture industry is becoming increasingly scarce, increasing the expense of its utilization. Studies were conducted with Auburn University in Auburn, AL. to evaluate Clean Chip Residual (CCR) as an alternative greenhouse substrate component for horticulture plant production. CCR is a by-product of in-field forest operations, which generate “clean chips” used in paper manufacturing. CCR is composed of the remaining material (wood, needles and bark) and is either sold for fuel or spread back across the harvested area. Processed CCR was compared to traditional greenhouse substrate to grow perineal and woody nursery crops. Similarities among treatments in these studies indicate that CCR is a potentially viable substrate option for use as a component/replacement for pine bark or peat moss in greenhouse production.

5. Evaluation of the Impact of Poultry Litter Application Timing on Nutrient Losses Using Computer Modeling. Changes in the utilization practices of animal manures for fertilization have been encouraged to reduce the potential of nonpoint pollution of lakes and streams from agricultural land. However, the potential impact of changing some of these practices has not been fully studied. Studies to examine the potential impact of limiting poultry litter application times on nutrient movement important to water quality were conducted. The WinEPIC model was used to simulate poultry litter applications during the winter months and chemical fertilizer application, with both cool season and warm season grass pastures on the major soil regions of Alabama. Results indicated that factors other than plant Phosphorus (P) uptake during the growing season were the dominant regulators of the amount of soluble P lost in runoff. Also, the results would indicate that best management practices such as are administered with the P index are more important than plant growth factors in determining N and P losses to the environment.

6. Impact of Gypsum Applied to Grass Buffer Strips on Reducing Soluble P in Surface Water Runoff. Due to environmental concerns, Improved methods to reduce phosphorus loading to surface waters associated with animal production are needed. Studies to evaluate the use of gypsum as a soil amendment to reduce losses of phosphorus from poultry litter in forage based production systems were conducted. The project used rainfall simulation studies to quantify the potential for gypsum to reduce phosphorus in surface water runoff. Gypsum applied to grass buffer strips was effective in reducing soluble P concentrations (32–40%) in surface runoff, while the untreated buffer strip was somewhat effective in reducing soluble P (18%). Results indicated that gypsum could be utilized in filter strip areas where animal manures are utilized to reduce environmental degradation due to excess phosphorus.

5.Significant Activities that Support Special Target Populations
A National Soil Dynamics Laboratory (NSDL) soil scientist was invited as the Keynote speaker for the Annual Small, Limited Resource, Minority Farm Conference held at Kentucky State University, November 18-20, 2008. The speech consisted of talking to an audience of approximately 200 about Coping with Changes in Agriculture. The Audience consisted of primarily small farmers and a few Extension and Researcher.

6.Technology Transfer

Number of Other Technology Transfer10

Review Publications
Torbert III, H.A., Gerik, T.J., Harman, W.L., Williams, J.R., Magre, M. Epic evaluation of the impact of poultry litter application timing on nutrient losses. Communications in Soil Science and Plant Analysis. 39:3004-3033.

Celik, A., Ozturk, I., Way, T.R. 2008. A theoretical approach for determining irregularities of the bottom of the tillage layer caused by horizontal axis rotary tillers. Agricultural Engineering International: the CIGR Ejournal. Manuscript PM 08 003. 10:1-9.

Torbert III, H.A., Krueger, E., Kurtener, D., Potter, K.N. 2009. Evaluation of Tillage Systems for Grain Sorghum and Wheat Yields and Total N Uptake in The Texas Blackland Prairie. Journal of Sustainable Agriculture. 33:96-106.

Adesemoye, A.O., Torbert III, H.A., Kloepper, J.W. 2008. Enhanced Plant Nutrient use Efficiency with PGPR and AMF in an Integrated Nutrient Management System. Canadian Journal of Microbiology. 54:876-886.

Torbert III, H.A., Krueger, E., Kurtener, D. 2008. Soil quality assessment using fuzzy modeling. International Agrophysics. 22:365-370.

Boyer, C.R., Fain, G.B., Gilliam, C.H., Gallagher, T.V., Torbert III, H.A., Sibley, J.L. 2008. Clean Chip Residual as a Substrate for Perennial Nursery Crop Production. Journal of Environmental Horticulture. 26(4):239-246.

Boyer, C.R., Gilliam, C.H., Fain, G.B., Gallagher, T.V., Torbert III, H.A. 2009. Production of Woody Nursery Crops in Clean Chip Residual Substrate. Journal of Environmental Horticulture. 27:56-62.

Hubbard, R.K., Bosch, D.D., Marshall, L.K., Strickland, T.C., Rowland, D., Griffin, T.S., Honeycutt, C.W., Albrecht, S.L., Sistani, K.R., Torbert Iii, H.A., Woodbury, B.L., Powell, J.M., Wienhold, B.J. 2008. Nitrogen Mineralization of Broiler Litter Applied to Southeastern Coastal Plain Soils. Journal of Soil and Water Conservation. 63(4):182-192.

Reiter, M.S., Reeves, D.W., Burmester, .H., Torbert III, H.A. 2008. Cotton nitrogen management in a high-residue conservation system: Cover crop fertilization. Soil Science Society of America Journal. 72:1321-1329.

Sistani, K.R., Torbert III, H.A., Way, T.R., Bolster, C.H., Pote, D.H., Warren, J.G. 2009. Broiler Litter Application Method and Runoff Timing Effects on Nutrient and Escherichia coli Losses from Tall Fescue Pasture. Journal of Environmental Quality. 38(3):1216-1223

Way, T.R., Kishimoto, T., Torbert III, H.A., Burt, E.C., Bailey, A.C. 2009. Tractor tire aspect ratio effects on soil bulk density and cone index. Terramechanics Journal. 46(1):27-34.

Watts, D.B., Torbert III, H.A. 2009. Impact of gypsum applied to buffer strips on reducing soluble P in surface water runoff. Journal of Environmental Quality. 38:1511-1517.

Tewolde, H., Armstrong, S., Way, T.R., Rowe, D., Sistani, K.R. 2009. Cotton response to poultry litter applied by subsurface banding relative to surface broadcasting. Soil Science Society of America Journal. 73:384-389.

Warren, J.G., Sistani, K.R., Way, T.R., Mays, D.A., Pote, D.H. 2008. A new method of poultry litter application to perennial pasture: subsurface banding. Soil Science Society of America Journal. 72: 1831-1837.

Last Modified: 4/19/2014
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