2007 Annual Report 1a.Objectives (from AD-416) (1) Develop vegetable cropping systems that increase soil organic C and improve efficiency of organic N 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 supports to small-scale vegetable producers in the area of sustainable soil management. 1b.Approach (from AD-416) Two limited-resource vegetable growers will be selected from within the Black Belt or Prairie soil region of Alabama. Paired treatments will be imposed in replicated experiments conducted side by side in farmers' fields. The two sites will be selected to represent a diversity of soils and cultural practices. The study will run through twelve (12) multiple-cropping seasons (2002-2006), beginning in fall 2002 with planting of cover crops. The paired treatments, replicated four (4) times at each of two sites are: (1) Tuskegee University Rotation and Nutrient Management System vs. (2) Farmers'Rotation and Nutrient Management System (Control). This control will be standardized between the two sites. The Tuskegee University rotation (no-till) will use broiler litter, and the application rate will be based on P (200 kg P/ha) with supplemental mineral N (two weeks after planting as side dressing) and/or K based on soil tests. Farmers' rotations will use mineral fertilizers according to their cultural practices with conventional tillage. The minimum design will be a randomized complete block design of 2 management systems with each phase of the rotation in 4 replications, for a total of 16 plots per site. An optional expansion of the study would be strip split plot design with vertical plots being tillage (no-till and conventional), horizontal plots being management system (farmers and Tuskegee system), and subplots or intersection plots being nutrient source (broiler litter vs. mineral fertilizer). Both phases of the rotation would be present each year. 3.Progress Report This report serves to document research conducted under a Specific Cooperative Research Agreement between ARS and Tuskegee University. Additional details of research can be found in the report for the in-house project 6420-12610-003-00D, "Conservation Systems Research for Improving Environmental Quality and Producer Profitability." A thesis is being prepared and will available for discussion on the significance of the project and its impacts on Alabama farmers. The following conclusions are tentatively drawn: a) Soil pH was not affected by the various treatments and remained acidic through the experimental period. b) Sweet potato storage root yields were very high in 2003 at both sites but tended to decrease in 2004 and 2005. Results for 2006 growing season are not available at the present time. c) Organic C increased substantially in the no-till broiler litter-amended soils between 2003 and 2005. This indicates that the cropping systems adopted (introduction of cover crops and no-till cropping systems) are improving soil quality. Increased organic matter content of soil will improve soil water holding capacity that could lead to improved crop yield during adverse climatic conditions. d) Just like soil organic C, organic N also increased considerably over time. e) Particulate organic matter (POM) fractions were isolated but analysis of organic C and N contents of the fractions are not available at this time. The ADODR has monitored activities via email correspondence and teleconferences.