NEW MEXICO CLIMATE CENTER

New Mexico Crop Information

Warm Season Grass coefficient(k) to calculate evapotranspiration(ET) where Et=k*Eto

Eto = reference evapotranspiration or potential evapotranspiration referenced to grass.

Crop Coefficient uses growing degree days (GDD) accumulated from planting based on the averaging method of calculating GDD with  a maximum cutoff temperature of 86 F and and lower cutoff temperature of 50 F and a base temperature is 50 F. The reference evapotranspiration was  calculated using Samani's procedure and the temperature data from Newell South Dakota 1971. The rangeland grass plots were irrigated to represent non stress conditions. 

Reference

Crop coefficients for rangeland.

Journal of range management. 43, no. 6 (Nov 1990): p. 482-485.

Link to Range Land Water Use Efficiency