Optimizing water use and crop yield with deficit irrigation techniques: A comprehensive overview and case study from Morocco

Abstract

Water scarcity is a global challenge that threatens agricultural productivity and food security. Irrigation agriculture consumes most of the world’s freshwater resources and often suffers from low water use efficiency. To address water shortages, deficit irrigation techniques have been developed to minimize water inputs while sustaining or enhancing crop yields and quality. Deficit irrigation consists of allocating a minimum amount of water to the crop. It can be applied either for the entire growing season (sustained deficit irrigation) or for specific crop stages (regulated deficit irrigation). Another technique is partial root zone drying, which involves alternately irrigating different parts of the root system. This causes partial water stress and increases the water uptake efficiency. These techniques aim to maximize net water use efficiency by exploiting the physiological responses of crops to water stress. This paper provides a theoretical background on deficit irrigation, a review of recent studies on its effects on different crops and environments, and a case study in Morocco where sustained deficit irrigation was applied to peach trees in a semiarid region. The findings showed that sustained deficit irrigation reduced water use by 20% without affecting fruit yield or quality and increased water productivity by 33%. This paper also discusses the challenges and opportunities for implementing deficit irrigation in different contexts and provides some recommendations for future research and development.