Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2008
Publication Date: 5/13/2008
Citation: Vigil, M.F., Mikha, M.M., Nielsen, D.C., Benjamin, J.G., Calderon, F.J. 2008. Alternative Crop Rotations in the Semi-arid Central Great Plains Region: How Much Fallow? Evaluating the Economics. Meeting Proceedings. Presented at the XXI Congreso Argentino de la Ciencia Del Suelo. 13 al 16 de Mayo de 2008. Potrero de los Funes (San Luis) Argentina. Page 524. Interpretive Summary:
Technical Abstract: The traditional crop production system in the semi-arid Central Great Plains Region (CGPR) of the U.S.A. is winter wheat (Triticum aestivum L.)-summer fallow (WF) or one crop every two years. This system is not a long-term sustainable dryland system. It is conducive to soil degradation and provides minimal returns on investment in the CGPR. Recently, utilizing no-till and more intensive cropping, we have shown several alternative rotations as superior to WF. Our objectives here are to evaluate several of these alternative rotations for economic yield, changes in soil quality, and economic returns. The economics returns to land labor and capital of 7 alternative rotation sequences (established in 1991) is compared and we report some of the effects of rotation intensity on changes in soil organic matter, soil aggregate stability. Specifically we evaluate how far we can push the system to eliminate fallow. Grain yields were measured in each rotation over an 11-year period starting 4 years after rotation establishment (1994-2004). The grain yield data was used to develop rules of thumb regarding long term average yields as affected by rotation sequence and then an economic analysis of net returns to land labor and capital was generataed for the 7 rotations. That analysis indicated the most favorable sequences were wheat-millet (Panicum miliacium L.)-fallow (WMF) wheat-corn (Zea mays L.)-millet-fallow (WCMF) and wheat-millet (WM). The poorest performance was measured with WF and WCM. With respect to soil quality enhancement the best rotations were the continuously cropped WCM followed by WCMF and WCF and the poorest were with WF.