Utilizing Cover Crops to Stabilize and Reclaim Previously Irrigated Cropland.

Utilizing Cover Crops to Stabilize and Reclaim Previously Irrigated Cropland

D.A. Wilson, R.J. Pearson, T.A. Bauder, N.C. Hansen, J.E. Brummer

Along the Front Range of Colorado irrigation water is very important for farmers to produce a productive crop. However, farmers have to compete with urban sprawl and adapt to changing water laws, as well as declining water tables. These factors, along with drought, are making it very difficult for farmers to produce any viable crops or use the land that they previously farmed because they have lost their water. Colorado State University Extension has been conducting demonstrative research to determine cover crop rotational strategies to help a farmer reclaim or convert formerly irrigated land to a non-irrigated rangeland ecosystem by using cover crops. Cover crops enable this transition because they help reduce nutrients like nitrogen. Weeds love high nitrogen levels in the soil. By lowering N and increasing cover with cover crops, weeds can be outcompeted. For our research project, we evaluated various different cover cropping rotational strategies. The location of our demonstrative research site is near Greeley, Colorado, in a field that lost irrigation water due to well shutdowns mandated by the State of Colorado in the spring of 2006. The initial results from this plot show that cover crops help to suppress weeds and remove nutrients from the soil. The ability to control weeds, reduce water and wind erosion will help lower nitrates in the soil, thereby reducing N leaching. Colorado grass species do not do well in a high nitrogen environment. It is very exciting to see the possibilities of a cover cropping system as many local farmers and cooperatives are very interested to see how this study progresses. The future of this research is to establish warm season grasses and cool season grasses. The goal of this research is to be able to provide recommendations to farmers to help them convert formerly irrigated land to a non-irrigated rangeland or dryland cropping system. This will help control weeds, reduce erosion, and remove excess nutrients as well as develop techniques to establish native grasses to prevent soil erosion and nutrient loss to consequently protect Colorado water resources.