Studies of Evapotranspiration and Crop Coefficient in Relation to Soil Water Suction and Leaf Area Index

Abstract

The authors suggest a model which estimates evapotranspiration using soil water suction, Leaf Area Index, potential evapotranspiration. The model is as follows ; ET= {f1 (ψm) ×f2 (LAI) +g1 (ψm) ×2 (LAI)}×E_p, ET: Evapotranspiration, f1 (ψm), f1 (LAI), g1 (ψm), g2 (LAI): Coefficients which represent relationship between soil water suction, LAI and evapotranspiration respectively, Ep: potential evapotranspiration. We can calculate crop coefficient using this model.
In this report, we discuss the model at first. After that, we discuss on crop coefficients of soybean.
In this report, we discuss the model at first. After that, we discuss on crop coefficients of soybean.
Calculated crop coefficient using measured 0.1 m depth soil water suction is about 10% smaller than that of abound in soil moisture.
No dimensional soil surface evaporation and transpiration decrease with soil water content per volume. They are fitted by linear and exponential lines respectively.