Model development for prediction of soil water dynamics in plant production

Abstract

Optimizing water use in agriculture and medicinal plants is crucially important worldwide. Soil sensorcontrolled irrigation systems are increasingly becoming available. However it is questionable whether irrigation scheduling based on soil measurements in the topsoil could make best use of water for deep-rooted crops. In this study a mechanistic model was employed to investigate water extraction by a deep-rooted cabbage crop from the soil profile throughout crop growth. The model accounts all key processes governing water dynamics in the soil-plant-atmosphere system. Results show that the subsoil provides a significant proportion of the seasonal transpiration, about a third of water transpired over the whole growing season. This suggests that soil water in the entire root zone should be taken into consideration in irrigation scheduling, and for sensor-controlled irrigation systems sensors in the subsoil are essential for detecting soil water status for deep-rooted crops.