Assessment of Cover Crops in Dryland Cropping Systems in the Colorado Plateau.

Dryland crop production in SW Colorado and SE Utah is practiced at relatively high elevation (≥ 6000 ft.) on soils that are prone to erosion due in part to sloping terrain and low soil organic matter content. There is also a low level of inputs, which combined with low and erratic precipitation results in generally low crop yields. Moreover, conventional tillage, and low cropping intensity (mostly wheat-fallow) are common and add to the challenges of dryland farming in this region of the Colorado Plateau. Hence, a Western SARE sponsored project was initiated in 2015 to determine if and how cover crops can enhance the sustainability of dryland cropping systems in this challenging environment. Our hypothesis is that cover crops grown during the fallow period between two cash crops such as winter wheat will achieve one or more of the following benefits: (1) reduce soil erosion, (2) improve soil fertility and biological activity or (3) suppress weeds, without negatively impacting the profitability of the cropping system. In order to test this hypothesis, several field trials were established in 2015 and 2016. In these trials, several cover crop mixtures were planted during the fallow period and a sizeable amount of data has been collected. The results of the first full year of this project will be presented.