Ph.D. Level Student
Southern Illinois University Carbondale
sowmya.koduru@siu.edu
Advised by Dr. Amir Sadeghpour

Does a Long-Term No-Till in Corn-Soybean Rotation Decrease Nitrous Oxide Emissions in Southern Illinois?

Switching from conventional tillage operations to no-till often improves soil properties long-term, but effects on nitrous oxide (N2O) emissions are less known. The objective of this study was to determine the influence of tillage practices on soil properties, N2O emissions, and corn (Zea mays L.) and soybean (Glycine Max L.) yields following 49 and 50 years of treatment implementation in a long-term corn-soybean rotation experiment in Southern Illinois, USA. The experimental design was replicated four-times Randomized Complete Block Design with four treatments. Treatments were two tillage systems including chisel tillage (RT) and no-tillage (NT). Each tillage system received either no-fertilizer or was fertilized with 196 kg N ha-1, 24 kg P ha-1 and 140 kg K ha-1 during the corn years. No fertilization was applied during soybean years. Nitrous oxide was measured prior to field operations (baseline sampling), after planting, and during corn and soybean growing seasons. Our results indicated that during the corn year, soil N2O-N emissions were similar between tillage treatments but higher for fertilized than unfertilized treatment. Similar trend was observed during the soybean year however, yield-scaled emissions were lower for NT than RT suggesting NT can reduce N2O-N losses. Over a two-year period, also we observed that NT resulted in a reduction in N2O-N emissions. Since crop yields were similar between the two tillage treatments, we suggest NT can be implemented to provide environmental and soil benefits in corn-soybean rotations.