Crop Residue Management and Tillage Interactions for Soybean/Corn Rotations.

A multi-year field study to evaluate corn/soybean rotation and the impact of tillage and residue management is being conducted at the Delta Research and Extension Center (DREC) near Stoneville, MS and at the North Mississippi Research and Extension Center (NMREC) at Verona, MS.  Since soil quality changes occur at a slow rate, a long-term was initiated in 2011 to evaluate the effects of corn and soybean residue management and tillage system on soil quality (soil physical, chemical and biological properties), grain yield, crop residue yield and nutrient content, along with the economic implications of the crop production systems.  The DREC study is irrigated with singe-row corn and twin-row soybean planted on 40-in beds (102-cm).  The NMREC study is conducted under rainfed conditions with both corn and soybean planted in single rows on 38-in (96-cm) beds.  The studies incorporate a burn vs no-burn residue management whole plot system with four (4) tillage system as the subplots.  Only corn residue is burned at each location.  The tillage systems include 1) no-tillage, 2) conventional tillage [2 disking+subsoiling+bedding+rolling (TerraTill® one-pass)], 3) reduced tillage [TerraTill®, in-row subsoil-bed-roll (one pass operation)], and 4) reduced tillage – No subsoil (bed+roll only).  Data collected at both locations include bed heights, residue cover, in-season growth characteristics, grain yields, crop residue biomass, soil root resistance and other soil quality measurements.  Soil cores are analyzed for microbial. Physical, and chemical characterization following harvest.  The residue collected at harvest is analyzed for nutrient content.  Emergence and plant development are being monitored for both corn and soybean at each location.  Supplemental irrigation has been used at the DREC location with the delivery through rollout pipe manage with the PHAUCET (Pipe Hole and Universal Crown Evaluation Tool, NRCS) management tool.    As expected ground cover has been greater under no-tillage conditions with little effect of tillage on yields.