Daily Crop Evapotranspiration, Crop Coefficient and Energy Balance Components of a Surface-Irrigated Maize Field

摘要: Irrigation water shortage is affecting many areas of the world. This case in Nebraska and other USA High Plains. In Nebraska, field maize (Zea mays L.) primary irrigated row crop one most important drivers state’s economy. The typical cropping rotations are continuous following soybeans. With development ethanol bio-fuel industries, farming practices increasing. Over-pumping groundwater for irrigation, coupled with recent drought conditions, increasing production causing serious concerns about future availability sustainability resources. Increasing fuel prices, which increases pumping costs should provide an economic incentive farmers to match irrigation applications requirements. Accurate determination actual evapotranspiration (ETc) can improve utilization resources through welldesigned management programs. Reliable estimates ETc also vital developing criteria in-season management, allocations, long-term supply, demand use, design infrastructures, effect changes land use on balances (Irmak Irmak, 2008). Water creating a need growers produce crops using less water. An option more efficient systems, has already occurred large extend over last four decades Midwestern states by converting from surface overhead sprinkler systems. For example, labour shortages have driven switch systems (mainly center pivots). Currently, 3.5 million ha land, 75% pivots 25% still uses mainly furrow irrigation. Adoption drip like subsurface irrigate maize, however, been limited due their high initial cost maintenance