Water Production Function

New Mexico Crop Information Atriplex Water Production function or the relationship between Evapotranspiration and yield Et = evapotranspiration or water used by crop.

The water production function has grain yield expressed in kg/ha at 0 moisture content.

The reference for this work is Glenn, E., R. Tanner, S. Miyamoto, K. Fitzsimmons and J. Boyer. 1998. Journal of Arid Environments 38:45-62. The Salinity of the leacheate was 35,600 to 39,200 mg/l and the leaching fraction was 0.04. The salinity of the applied was 5732 mg/l . Some salt precipitation in the soil profile must have been occurring. Nitrogen content 1.36%

Crop Coefficient

New Mexico Crop Information Atriplex nummularia-Salt-bush 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 January 1 based on the averaging method of calculating GDD with a maximum temperature cutoff of 104 F and a minimum cutoff temperature of 50 F. The Base Temperature is 50 F.

The equation for the crop coefficient (k) is presented in the figure

Crop Coefficient =Etact/Etpot for a closed canopy that is not under moisture stress conditions and results in a yield of 38000lb/ac dry weight

The reference for this work is Glenn, E., R. Tanner, S. Miyamoto, K. Fitzsimmons and J. Boyer. 1998. Journal of Arid Environments 38:45-62. Only the second year of data was used when the crop had complete cover.