Wheat Post-Harvest Residue Management Impacts (in a wheat-soybean double crop system) On Soil Quality Indicators.

The choice of post-harvest residue management techniques implemented could have a significant effect on environmental quality, crop yield, and the subsequent utilization of our land resources. Producers often tend to make decision on the type of residue management techniques to adopt sorely from the economic (labor and yield) viewpoint with very little or no attention given to the environmental implications or the long-term effects of such measures. Wheat-soybean double crop system is an important practice that aims to economically utilize climate, land and other production resources in optimizing the production of wheat and soybean. The practice entails the planting of soybean on the same piece of land immediately after wheat harvest in early/mid June. Notable post-harvest wheat residues management techniques commonly employed in this system include: (i) residue burning-no till, (ii) residue burning-conventional tillage, (iii) full residue retention-no till, (iv)full residue retention-conventional tillage, and (v) residue shredding-no till-no burn. The benefits of these techniques vary with regard to their impacts on weed management, moisture conservation, labor, cost, and yield. Burning of post-harvest wheat residues which is the most commonly employed techniques is reportedly associated with air and soil quality impairment and often highly discouraged. However, the increasing demand placed on wheat and soybean for food and alternative energy needs could only exacerbate this problem if alternative options are not evaluated and the right awareness created. Thus, the main objective of this study is to evaluate the impacts of five selected post-harvest residue management techniques on key soil quality indicators, namely: total phosphorus, plant available phosphorus, total nitrogen, total carbon, organic matter, dissolved organic carbon, particulate organic carbon, cation exchange capacity, pH, electrical conductivity, extractable nutrients (nitrogen, phosphorus, and potassium), bulk density, infiltration, and top soil depth. Findings from this study will be presented.