2007 Annual Report 1a.Objectives (from AD-416) Develop conservation tillage systems technologies for Southeastern soils (Coastal Plain, Tennessee Valley, Piedmont, and Blackbelt) that improve soil quality, increase plant available water, improve profitability, and conserve natural resources. Specific objectives include: (1) develop cover crop management technologies that enhance soil protection from rainfall events, increase soil organic matter accumulation, and suppress weeds; (2) develop and evaluate row crop production technologies that enhance sustainability, productivity, and environmental quality of degraded soils and increase plant available water; and (3) integrate new components and technologies into conservation management systems that reduce soil erosion, drought stress, and risk associated with production agriculture. 1b.Approach (from AD-416) Coordinated plot and field-scale studies will be implemented to develop strategies for managing soils to reduce economic risks of short-term drought and increase farm profitability, improve soil quality, and enhance carbon storage. Problems include: (1) increasing crop rooting depth; (2) improving soil properties associated with infiltration and water retention; (3) developing decision aides for improved soil and water management and increased profitability; (4) developing integrated weed management strategies through improved understanding of interactions between cover crop residue and weed biology/ecology; (5) developing design principles for improved implements that facilitate management of cover crops, soil compaction, and high-residue conservation cropping systems; and (6) assess and predict economic viability of conservation practices. 3.Progress Report This research is a major contributor to the multi-location Renewable Energy Assessment Project (REAP; 5440-12210-009-00L). 4.Accomplishments Reducing fuel costs for in-row subsoiling Soil compaction limits the productivity of most soils found in the Southern United States. Periodic in-row subsoiling provides adequate loosening to promote root growth and maximize crop yields. However, the cost of this operation has become even more expensive with rapidly escalating fuel prices. Much research suggests, however, that the fuel component of subsoiling can be decreased by as much as 54% by several methods: proper selection of subsoiler shanks, appropriate selection of tillage depth, operating at the proper soil moisture condition, using cover crops, and controlling vehicle traffic. Use of these methods should allow the conservation practice of in-row subsoiling to be used as a valuable part of an overall conservation agricultural system. This accomplishment partially addresses NP 216 Agricultural System Competitiveness and Sustainability Objective 1A2. Develop specific conservation management practices and document their benefits on natural resource quality for agronomic crop production systems. Using automatic steering to control traffic and increase crop yields Producers in the Coastal Plain of the southeastern U.S. manage soil compaction in conservation tillage systems by strip-tillage prior to planting. However, planting directly over the loosened zone of soil can be difficult in high-residue conservation tillage systems where cover crop production is maximized. Tractors with automatic steering capability could assist with adjacent placement of deep tillage and planting operations, but little is known about the accuracy necessary to maximize rooting development, reduce succeeding soil compaction, and optimize crop yield. An experiment was conducted in south-central Alabama to evaluate the distance deep tillage can be from the cotton row and still affect cotton growth and soil loosening. Results suggest that if the deep tillage exceeds two inches away from the cotton row, cotton yields are reduced by 24 to 52 percent and net revenues from cotton production by as much as 38 to 83 percent. In addition, larger farms may benefit from highly accurate automatic steering systems, while smaller farms may need to go with cheaper alternatives, such as foam markers. This accomplishment partially addresses NP 216 Agricultural System Competitiveness and Sustainability Objective 1A2. Develop specific conservation management practices and document their benefits on natural resource quality for agronomic crop production systems. Selection of in-row subsoiler shanks for conservation tillage systems For use in conservation tillage systems, belowground soil disruption should be maximized while aboveground disruption should be minimized. To assist in choosing the best shank for in-row subsoiling systems which accomplish both objectives, comparisons were made between several shanks commonly used for conservation tillage systems to provide in-row subsoiling prior to planting. A field experiment was conducted to compare energy requirements and soil disruption of three commonly available shanks used for in-row subsoiling. Shallower subsoiling resulted in reduced subsoiling forces and reduced surface soil disturbance. The bentleg subsoilers provided maximum soil disruption and minimal surface disturbance and allowed surface residue to remain mostly undisturbed. Bentleg shanks provide optimum soil conditions for conservation systems by disrupting compacted soil profiles while leaving crop residues on the soil surface to intercept rainfall and prevent soil erosion. This accomplishment partially addresses NP 216 Agricultural System Competitiveness and Sustainability Objective 1A2. Develop specific conservation management practices and document their benefits on natural resource quality for agronomic crop production systems. Site-specific in-row subsoiling saves fuel Many soils in the United States suffer from excessive soil compaction and have to be annually tilled to eliminate these deep compacted layers. New spatial technologies may allow some fuel used for tillage to be saved while producing optimal yields. An experiment was performed for four years to compare site-specific subsoiling to uniform deep subsoiling on cotton response and energy requirements for tillage. Prior to in-row subsoiling, the soils were mapped to determine the depth of the compacted layer and the site-specific subsoiling treatments supplied tillage to the correct depth without going too deep or too shallow. Results from these experiments showed that similar cotton yields were produced with site-specific subsoiling while reducing fuel requirements by 24 or 43%. Use of this technology may offer cotton producers the opportunity to reduce their inputs while maintaining excellent yields and protecting the environment. This accomplishment partially addresses NP 216 Agricultural System Competitiveness and Sustainability Objective 1A2. Develop specific conservation management practices and document their benefits on natural resource quality for agronomic crop production systems. Optimizing nitrogen usage of winter cover crops Maximizing winter cover crop biomass requires additional applications of nitrogen. However, summer legumes may offer an opportunity to supply a portion of the nitrogen requirements for these winter cover crops. This study assessed the nitrogen contribution of peanut residue to a rye winter cover crop in a conservation system for the 2003-2005 growing seasons. Treatments consisted of peanut residue retained or removed from the soil surface, and varying nitrogen fertilizer application rates applied in fall soon after planting the rye cover crop. Peanut residue did not affect rye biomass yields, but additional nitrogen supplied in the fall significantly increased rye biomass yield. Although growers should be encouraged to leave peanut residue in the field, specific nitrogen rates recommended for a winter annual grass cover crop should not be reduced. This accomplishment partially addresses NP 216 Agricultural System Competitiveness and Sustainability Objective 1A2. Develop specific conservation management practices and document their benefits on natural resource quality for agronomic crop production systems. 5.Significant Activities that Support Special Target Populations A Specific Cooperative Agreement with Tuskegee University was created to work with limited-resource vegetable growers selected from within the Black Belt or Prairie soil region of Alabama to:. 1)develop vegetable cropping systems that increase soil organic carbon and improve efficiency of organic nitrogen applications; reduce soil compaction; and reduce nutrient and soil losses through runoff;. 2)network with limited-resource farmers to improve their access to agronomic information; and. 3)provide technical and analytical support for sustainable soil management to limited-resource vegetable producers. A cooperative agreement was formed with a minority limited resource farmer in southern Mississippi to (1) develop conservation tillage vegetable production systems for small and limited resource farmers in the Southeast that improve soil quality, increase crop yields and maintain farm profitability; (2) examine the socio-economic factors affecting the adoption of conservation practices by this farmer group to develop effective outreach strategies; and (3) provide access to agronomic and economic information, as well as technical assistance concerning conservation technologies. Other partners on the project include USDA-Natural Resource Conservation Service in Mississippi, a local small farm cooperative and Alcorn State University. 6.Technology Transfer Number of invention disclosures submitted 2 Number of patent applications filed 2 Number of U.S. patents granted 1 Number of web sites managed 2 Number of non-peer reviewed presentations and proceedings 50 Number of newspaper articles and other presentations for non-science audiences 43 Review Publications Meso, B., Balkcom, K.S., Wood, C.W., Adams, J.F. 2007. Nitrogen contribution of peanut residue to cotton in a conservation tillage system. Journal of Plant Nutrition. 30:1153-1165. Balkcom, K.S., Shaw, J.N., Reeves, D.W., Burmester, C.H., Curtis, L.M. 2007. Irrigated Cotton Response to Tillage Systems in the Tennessee Valley. Journal of Cotton Science. 11:2-11. Balkcom, K.S., Wood, C.W., Adams, J.F., Meso, B. 2007. Suitability of Peanut Residue as a Nitrogen Source for a Rye Cover Crop. Scientia Agricola. 64(2):181-186. Causarano, H.J., Shaw, J.N., Franzluebbers, A.J., Reeves, D.W., Raper, R.L., Balkcom, K.S., Norfleet, M.L., Izaurralde, R.C. 2007. Simulating field-scale soil organic carbon dynamics using EPIC. Soil Science Society of America Journal. 71:1174-1185. Raper, R.L., Arriaga, F.J. 2007. Comparing Peak and Residual Soil Pressures Measured by Pressure Bulbs and Stress-State Tranducers. Transactions of the ASABE. 50(2):339-344. Tekeste, M.Z., Raper, R.L., Tollner, W.E., Way, T.R. 2007. Finite element analysis of cone penetration in soil for prediction of hardpan location. Transactions of the ASABE. 50(1):23-31. Kornecki, T.S., Price, A.J., Raper, R.L. 2006. Performance Of Different Roller Designs In Terminating Rye Cover Crop And Reducing. Applied Engineering in Agriculture. 22(5):633-641. Siri-Prieto, G., Reeves, D.W., Raper, R.L. 2007. Tillage requirements for integrating winter-annual grazing in cotton production: plant water status and productivity. Soil Science Society of America Journal. 71(1):197-205. Raper, R.L. 2007. In-row subsoilers that reduce soil compaction and residue disturbance. Applied Engineering in Agriculture. 23(3):253-258. Raper, R.L., Bergtold, J.S. 2007. In-Row Subsoiling: A Review and Suggestions for Reducing Cost of this Conservation Tillage Operation. Applied Engineering in Agriculture. 23(4):463-471. Price, A.J., Reeves, D.W., Patterson, M.G., Gamble, B.E., Balkcom, K.S., Arriaga, F.J., Monks, D. 2007. Weed Control in Peanut Grown in a High-Residue Conservation-Tillage System. Peanut Science. Peanut Science. 34:59-64. Price, A.J., Barker, W., Burke, I.C., Thomas, W.E., Wilcut, J.W. 2006. Interference and seed-rain dynamics of jimsonweed (datura stramonium l.) in peanut (arachis hypogaea l.). Peanut Science. 33:142-146. Fisher, L.R., Burke, I.C., Price, A.J., Smith, W.D., Wilcut, J.W. 2006. Uptake, translocation, and metabolism of sulfentrazone and sulfentrazone plus clomazone in flue-cured tobacco transplants. Weed Technology. 20:898-902. Price, A.J., Reeves, D.W., Patterson, M.G. 2006. Evaluation of weed control provided by three winter cereals in conservation-tillage soybean. Renewable Agriculture and Food System. 21(3):159-164. Price, A.J., Charron, C.S., Sams, C.E. 2005. ALLYL ISOTHIOCYANATE AND CARBON DIOXIDE PRODUCED DURING DEGRADATION OF BRASSICA JUNCEA TISSUE IN DIFFERENT SOIL CONDITIONS. HortScience. 40(6):1734-1739. Reeves, D.W., Price, A.J., Patterson, M.G. 2005. Evaluation of three winter cereals for weed control in conservation-tillage non-transgenic cotton. Weed Technology. 19:731-736.