Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 2/22/2008
Publication Date: 7/20/2008
Citation: Delgado, J.A., Essah, S., Dillon, M., Ingham, R., Manter, D.K., Stuebe, A., Sparks, R. 2008. Sustainable Cover Crop Rotations with Potential to Improve Yields, Crop Quality, and Nutrient and Water Use Efficiencies-. Soil and Water Conservation Society Proceedings. Interpretive Summary:
Technical Abstract: Intensive crop rotations that leave small amounts of crop residue over the surface can increase the field’s susceptibility to erosion. This is the case in potato rotations grown in south central Colorado on sandy coarse soils with low organic matter content that are susceptible to wind erosion. We have been conducting cover crop and crop rotation studies in this region for over a decade. Our results show that winter cover crops, summer cover crops with limited irrigation, and rotations with deeply-rooted small grains are good management alternatives to reduce wind erosion, increase nutrient cycling of macro and micro nutrients, increase nutrient use efficiencies, and reduce nitrate leaching to groundwater in this region. Summer cover crops with limited irrigation can also increase water use efficiencies. Additionally, preliminary results show that the total marketable tuber yield, was increased by 12 to 30% when potatoes followed a sorghum-sudan green manure instead of wet fallow plots. The tuber quality for the potatoes following sorghum-sudan was superior, with 40% higher production of tubers greater than 8 ounces. We will present our results from these studies, including the use of isotopic 15N label fertilizer to trace the nitrogen cycling from a sorghum-sudan summer crop into the potato crop. These studies are helping NRCS personnel, extension agents, and CSU personnel to improve best management practices and nutrient recommendations for this region.