Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/1/2008
Publication Date: 2/18/2008
Publication URL: http://www.oznet.ksu.edu/irrigate/OOW/P08/Nielsen08b.pdf
Citation: Nielsen, D.C. 2008. Crop Residues and Soil Water. Presented at the Proceedings 20th Annual Central Plains Irrigation Conference and Exposition. Feb. 19-20, 2008. Greeley, Colo. Pages 80-83. Interpretive Summary:
Technical Abstract: Crop yield is greatly influenced by the amount of water that moves from the soil, through the plant, and out into the atmosphere. Winter wheat yield responds linearly to available soil water content at planting (bu/a = 5.56 + 5.34*inches). Therefore, storing precipitation in the soil during non-crop periods through good crop residue management is essential to profitable crop production in the central Great Plains. Precipitation is stored most efficiently during the cool months of fall, winter, and spring, averaging 65% storage efficiency in winter wheat stubble. Precipitation storage efficiency has increased from about 22% under plow systems to about 40% under no-till systems over the entire fallow period for wheat-fallow systems. Precipitation storage efficiency increases with mass of residue on the soil surface and with upright orientation of the residue Upright residues are effective at reducing wind speed and trapping snow. Sunflower residue with a silhouette area index of 0.04 can increase stored soil water overwinter by 4 inches. Good residue management through no-till or reduced-till systems will result in increased soil water availability at planting. This additional available water will increase yield in both dryland and limited irrigation systems by reducing level of water stress a plant experiences as it enters the critical reproductive growth stage.