DETERMINATION OF EVAPOTRANSPIRATION USING THE NEUTRON SCATTERING METHOD

Abstract

The accuracy of evapotranspiration (E.T.) determinations by the neutron scattering method was found by studying each of the possible errors. For the gravelly soils studied the probable error in E.T. was less than 0.15 in. of water for a weekly period and less than 0.62 in. for a 3-month period when one sampling site was used. Increasing the number of sampling sites decreased the error but not in direct proportion. The method was used to provide values for evapotranspiration from irrigated and unirrigated corn, wheat, and clover.