Circular Buffer Strips of Perennial Grasses: Preliminary Assessment.

Water levels continue to decline in the Ogallala aquifer, which has converted the Great Plains from dust bowl to a major food producing and exporting region of the US. Reducing well outputs and recent pumping quota restrictions from irrigation districts are leading to partial pivots, where high value crops are grown with full irrigation and the remaining area is used for dryland crops. The existing system cannot conserve high intensity rainfall and the evaporation loss from frequently irrigated pivots is high. Strong winds in the region compound the problem. If not addressed, the current system will continue to degrade natural resources, decrease productivity and reduce resiliency of agriculture. Therefore, a field study was initiated to compare novel concept of circular buffer strips (CBS) with conventional system. Circular buffer strips, which rearranges underutilized portion of a center pivots into circles of perennial grasses, is expected to improve many ecosystem benefits, while adding a few management benefits. We used 30ft wide CBS alternating with 60ft crop strips (one fourth of the pivot facing predominant wind direction is used). Buffer strips were planted to six tall grass species mixture (including two cool season species) in August 2016 and grain corn was planted in May 2017. Now, grass buffers are well established. We have initiated a few preliminary observations to assess effects of single or multiple buffer strips on microclimate, soil water content, and productivity. Details of the CBS concept and preliminary results will be presented.