Soil Nitrogen Movement under Sustainable Vegetable Production Systems
An experiment was established to determine the effect of different tillage practices, vegetable crop rotations, and pest management strategies on crop yield, plant diseases, pest and beneficial arthropods, weed species changes over time, and soil environmental consequences. This poster describes nitrogen movement from the various treatments over a 3-year rotation. The treatments are: 1) conventional tillage with chemically based IPM; 2) conventional tillage with biologically based IPM; 3) conservation tillage with chemically based IPM; 4) conservation tillage with biologically based IPM; and 5) conventional tillage with no fertilizer or pest management. Mid-season soil analyses with depth showed chemical-fertilized plowed and conservation-tilled treatments with more soil available nitrogen at most depths compared to the biological-based IPM systems (soybean meal was used as a nitrogen source). However, the biological-based systems did supply enough soil nitrogen to produce similar yield results as the chemical-based systems. Less soil nitrate was measured in the 30- to 90-cm depths at harvest from the biological-based systems than chemical-based systems. Conservation-tilled systems had greater nitrate with depth compared to conventional-tilled systems.