Water Resources Research Act Program

Details for Project ID 2007TX271B

Comparative evaluation of actual crop water use of forage sorghum and corn for silage.

Institute: Texas
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-29
Total Federal Funds: $5,000 Total Non-Federal Funds: $23,175

Principal Investigators: Nithya Rajan, Stephan Maas

Project Summary: Identification of suitable cropping systems is essential to conserving water. In the Texas High Plains, farmers grow forage sorghum and corn for silage. Although the primary purpose of growing both crops is the same, there is a significant difference in water use between the two. Corn demands more water to produce the same biomass compared to forage sorghum. The proposed study is designed to provide accurate estimates of crop water use (CWU) for corn and forage sorghum using a spectral crop coefficient Ksc that is specific to the field under study. Ksc is similar to a standard crop coefficient, except that it is evaluated from remote sensing (satellite or aircraft) imagery. Thus, daily CWU can be estimated as the product of potential evapotranspiration and Ksc. Estimated values of daily CWU will be tested against actual field measurements of evapotranspiration obtained using eddy covariance systems.