Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2009
Publication Date: 11/13/2009
Citation: Vigil, M.F., Nielsen, D.C., Benjamin, J.G., Calderon, F.J., Mikha, M.M. 2009. Alternative Dryland Cropping Systems to Wheat Fallow. Agronomy Abstracts. Presented at the ASA-CSSA-SSSA Annual meeting. Nov. 1-5, 2009. Pittsburg, PA.
Technical Abstract: Winter wheat-summer fallow (W-F) in the Central Great Plains of the U.S.A. is not a long-term sustainable dryland system due to a high potential for erosion and associated soil degradation. Utilizing no-till and more intensive cropping we have developed several alternative rotations to wheat fallow. In this paper, we examine rotation benefits that though inconsistent from year to year are greater in the longer four year rotations than in three year rotations. Twenty-three different 2 yr, 3 yr, and four yr rotations were developed using the dryland crops, wheat, corn, proso-millet, sunflower, forage-triticale, pea and forage millet. Summer fallow was also included in several of the rotations. Market yield, biomass, water use and nutrient use were measured over a 16-yr period (4 complete cycles of the four year rotations). We found that in 5 of the first 12-yrs that wheat yields after fallow were greater in the four-yr rotations than in WF-no-till. With three-yr rotations a similar trend was observed. However the yield increases was less. When averaged over the whole 16-yr period yield differences due to rotation and fallow were highly significant for winter wheat but insignificant for corn and other summer crops. With this experiment we have documented improvements in soil quality with increases in rotation intensity. However those rotations that are best for the soil sometimes have lower returns to land and capital inputs.