Soil Water Balance and Water Use Efficiency of Rain-fed Maize under a Cool Temperate Climate as Modeled by the AquaCrop

Abstract

The AquaCrop model has been widely studied and examined for its feasibility and applic ability in simulating the crop growth – water relationship under tropical and warm temperate. How ever, the model is rarely tested under cool temperate climates. As the second largest agricultural ar ea of China, the Sanjiang Plain is characterized with relatively lower accumulative temperature and higher annual precipitation, showing typical features of a sub-humid and cool temperate climate. Th is study employed the AquaCrop model to compute soil water balance and water use efficiency of rain-fed maize in the Sanjiang Plain using a 5-year monitoring dataset (2011 – 2015). The results demonstrated an acceptable performance of AquaCrop in depicting soil water content, biomass accu mulation and grain yield. Soil water balance including soil water content, evapotranspiration and pr ecipitation was described throughout the growing period. The hysteresis of the daily soil water cont ent as responses to daily precipitation was revealed. Water use efficiency for the observed rain-fed maize increased with rising accumulative temperature and decreased with rising atmospheric CO2 c oncentration. This study provided a perspective for the extensive application of the AquaCrop mode l and the precise simulation in water dynamics under sub-humid and cool temperate climates.