<OL> <LI> Develop and compare the biophysical and economic aspects of sustainable field cropping systems in the mid-atlantic. <LI> Assess short/long term impacts of low input, certified organic, and conventional agricultural/tillage management systems on nutrient cycling, availability, organic matter decomposition, soil fertility, quality, biology and formation of stable micro-aggregates. <LI> Develop appropriate uses of organic and inorganic by-products separately and in various combinations.
Evaluate the relationship between sustainability and the type and amounts of external inputs. Measure yield, nutrient (C,N,P,K,Ca/Mg) cycling, pH, dynamics of nutrient release from decomposing organic resources (manure, composts, legume/cover crops) and nutrient fate to crops, soil fertility/quality, water use efficiency and environmental impact. Long term plots have seven distinct systems. Natural biological interactions between plant pathogens and beneficials in soils/rhizospheres will be examined to better understand crop/soil management factors affecting natural antagonism and disease suppression. Changes in soil microbial diversity and community structure and function that enhance biocontrol and sustain plant/soil productivity will be evaluated. Lab, growth chamber and field studies will be conducted to evaluate effects of organic residuals (manures) and compost/fertilizer mixtures. Field experiments will test hypotheses of major factors resulting from the lab and growth chamber studies. Previously was 1265-12000-019-00D. (07/01)