Enhancing Sustainable Cropping Systems Through the Use of Cover Crops

Abstract

An on-going experiment was established in Lahoma, OK to evaluate intensified cropping system and determine the possibility of including selected cover crops in rotation as well as evaluation of the use of GreenSeekerTM technology in determining in-season N applications. The experimental design was split plot with rotation being the main plot and N treatment as the subplot. The experiment was broken into two parts: a winter wheat based rotation and a grain sorghum based rotation. Within rotations, additional crops were included as well as legume cover crops. N treatments were comprised of a non-limiting N-Rich strip, N based on the farmer's practice, a control, and N based on GreenSeekerTM technology. Grain yield, N treatments, and interactions were statistically analyzed. Incorporation of an intensified cropping system is feasible in areas of Oklahoma receiving >762 mm of annual precipitation. Rotations including additional crops appear to be possible with little effect on wheat and grain sorghum grain yields. Rotations are most effective when soil moisture is allowed to recharge but without extended fallow periods (>60 d). The most effective rotations seemed to incorporate a broadleaf crop into the rotation which disrupted the weed cycle and allowed different herbicides to be used for control. The inclusion of cover crops was beneficial by providing ground cover at different periods of the year and additional N to the following crops. The GreenSeekerTM treatment reduced total N applied in all treatments. This technology offers a potential reduction in N applications and costs in many current cropping systems.