Date of this Version
Dotterer, Laura J. 2014. Optimizing Water Use through Management of Spatiotemporal Variation Using Site Specific Technologies. D.P.H. Doctoral Document, University of Nebraska, Lincoln.
The effects of landscape variability can be minimized through site-specific crop management. Variability in production agriculture affects profitability of operation mainly through yield impacts and the efficiency of input use. A field can be broken down into smaller areas called management zones. Management zones are created by an area in the field that has similar yield-limiting factors, and thus, the same rate of an input can be applied to that area to increase efficiency or yield. Variable rate irrigation (VRI) is a site specific water management tool that can be utilized to apply the optimal amount of water on all acres resulting in increased overall yields. It has the potential to enhance water resources especially in areas with limited irrigation. The sector control system changes the pivot travel speed to alter the water application rates in each sector. Whereas, a zone control system varies rates in zones by pulse width modulation of electric solenoid valves. Defining field variability to build a prescription for water application typically uses soil electrical conductivity (EC) measurements. Tools are available to make irrigation scheduling decisions, which includes methods of feel and appearance of the soil, soil water content measurement, and soil water potential. Remote sensing imagery can also be important for in season and next year’s evaluation of VRI prescriptions.
Advisor: Gary L. Hein