Evapotranspiration Model of Maize Field with Ridge Culture Under Alternate Furrow Irrigation

Abstract

AbstractTo precisely predict evapotranspiration of a maize field with ridge culture under alternate furrow irrigation, a modified Shuttleworth–Wallace (S‐W) model was developed by estimating soil surface resistances in irrigated and non‐irrigated zones with a proportional coefficient of the wet area, and calculating canopy resistance with the temperature difference between the upper and lower layer canopy. A field experiment with ridge‐tillage maize with alternate furrow irrigation was carried out in the 2009 and 2010 seasons. Leaf transpiration was measured using a LI‐6400 photosynthesis system, and soil evaporation measured by micro‐lysimeter. Soil moisture, stomatal conductance and meteorological factors were collected to estimate soil surface resistance and canopy resistance. Results show that the relative errors between the simulated and observed values of daily soil evaporation were 0.0–10.3%, while the values were 1.4–7.1% for daily crop transpiration. Moreover, the mean absolute error and the root mean square error for simulating daily soil evaporation was 0.2 and 0.3 mm d‐1, respectively, while the values for daily transpiration estimation were 1.5 and 1.8 mm d‐1, respectively. The index of agreement was greater than 0.785, and the determination coefficient higher than 0.90. Therefore, the modified S‐W model can well predict evapotranspiration of ridge‐culture maize with alternate furrow irrigation. Copyright © 2015 John Wiley & Sons, Ltd.