Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2004
Publication Date: 3/15/2005
Citation: Nielsen, D.C., Unger, P.W., Miller, P.R. 2005. Efficient water use in dryland cropping systems in the Great Plains. Agronomy Journal. 97:364-372. Interpretive Summary: The Great Plains of North America is dominated by a semiarid climate characterized by limited precipitation that is highly variable. Successful rainfed (unirrigated) farming systems must make efficient use of this limited and variable precipitation. This paper reviews practices that increase the efficiency with which precipitation is stored in the soil and used by the cropping system, and reviews three case studies of continuous cropping (no fallow period) from the northern, central, and southern Great.
Technical Abstract: Successful dryland crop production in the semiarid Great Plains of North America must make efficient use of precipitation that is often limited and erratic in spatial and temporal distribution. Water use efficiency and precipitation use efficiency increase with residue management practices that increase precipitation storage efficiency, soil surface alterations that reduce runoff, cropping sequences that minimize fallow periods, and use of appropriate management practices for the selected crop. Precipitation use efficiency (PUE) on a mass-produced basis is highest for systems producing forage and lowest for rotations with a high frequency of oilseed crops. Throughout the Great Plains region, PUE decreases with decreasing latitude for rotations of similar make-up of cereals, pulses, oilseeds, and forages. Forage systems in the southern Great Plains appear to be highly efficient when PUE is computed on a price-received basis. In general across the Great Plains, increasing intensity of cropping increases PUE on both a mass-produced basis and on a price-received basis.