Effect of Residue Management On Soybean Production and Key Soil Quality Characteristics.

Double crop wheat-soybean can be a very beneficial and economical production system for soybeans grown in the Mid-South.  However, production practices must be utilized that ensure optimum stand establishment and minimize stresses to the soybean crop throughout the season.  One management practice thought to be critical is residue management.  While research interest in this has increased in recent years, much is still unknown and continual evaluation is necessary.  Therefore, field trials were established in 2011 and 2012 at two Louisiana locations, evaluating the effects of residue management practices on soybean production and quality as well as critical soil quality characteristics.  Experiments evaluated four residue management techniques (Full residue, Burned, Mowed, and Tilled) arranged in a randomized complete block design.  Soybean production characteristics were evaluated, during reproductive growth as well as yield and soybean seed quality measurements were taken at harvest.   Initial soil samples were collected prior to wheat establishment and then collected following soybean harvest each year.  Soil samples were analyzed for total C and N percent, bulk density, extractable plant nutrients, CEC, infiltration, pH, and EC.  Residue management techniques were found to statistically influence soybean production, with burned treatments achieving 57% higher soybean seed yield compared to the lowest yielding treatment, which was full residue.  Conversely, the burned treatments possessed lower %C and %N levels than that of the full residue treatments.  This indicates that while the burned treatments may have provided the soybean production system with optimum growing conditions, it may not be the best long-term sustainable option due to the decrease in soil quality.