Establishment and Survival of Perennial Grasses On Previously Irrigated Cropland.

Establishment and Survival of Perennial Grasses on Previously Irrigated Cropland

D.A. Wilson, T.A. Bauder, E.M. Wardle, N.C. Hansen, J.E. Brummer

            Along the Front Range of Colorado irrigation water is crucial resource for crop production.  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 research to determine cover crop rotational strategies to help a farmer reclaim or convert formerly irrigated land to a non-irrigated rangeland ecosystem utilizing perennial grasses. Cover crops enable this transition because they help reduce nutrients like nitrogen. By lowering N and increasing cover with cover crops, weeds can be outcompeted. For our research project, we evaluated various cover cropping rotational strategies to prepare the land for the establishment of perennial grasses. 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. The future of this research is to establish warm 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 dry land cropping system. This will help control weeds, reduce erosion, and remove excess nutrients as well as develop techniques to establish perennial grasses to prevent soil erosion and nutrient loss to consequently protect Colorado water resources.