Engineering Commons^™

Using A Subsurface Drip Irrigation System To Measure Crop Coefficients And Water Use Of Cowpea (Vigna Unguiculata), William R. Detar, Howard A. Funk

William R DeTar

This is a progress report for the first year of growing cowpea on a 1.8-acre experimental plot where a subsurface drip irrigation system is installed with dripperlines buried 10-11" below grade in each plant row. Row spacing is 30" and it is irrigated on a daily basis. The field is level in both directions and extra-large diameter tubing (7/8") was used so that pressures throughout the field are very uniform, with a distribution uniformity (DU) of 96%. The main goal was to find out how much water the cowpea uses. The water use is calculated by multiplying a crop coefficient …