Review on Partial Root-zone Drying irrigation: Impact on crop yield, soil and water pollution

Water availability is the most limiting factor for the crop production sector and one of the main regulators of the spatial distribution of plants. Agriculture consumes more than two-thirds of the planet's total fresh water; this high consumption causes significant conflicts in terms of freshwater allocation between agriculture and other economic sectors. In addition, conventional irrigation cannot be sustained in many parts of the world due to rapid depletion of water resources, thus, it is considered a luxury use of water. It is noted that in recent years the methods of irrigation water application have been improved. Currently research has been directed towards irrigation strategies that reduce water applications Deficit Irrigation strategies (DI) and allowing the efficiency of its use to be increased without affecting plant growth or yield. Partial Root-zone Drying (PRD) is an effective irrigation method that saves water although it can affect the root activity of plants through the heterogeneous distribution of moisture in the soil. Indeed the basic underlying theory of this technique is the use of the hor-monal response of the roots to water stress, which can induce physiological reactions in the aerial parts of the plant, by a reduction in stomatal conductance and transpiration. Hence, the plant can limit its water losses due to transpiration, with a non-significant reduction in yield; moreover, this irrigation technique is of paramount importance in terms of minimizing groundwater pollution by reducing the return flow of irrigation water and consequently significantly reducing the leaching of agrochemical inputs to groundwater. This work aims to clarify the origin of PRD irrigation and to analyze some physiological aspects of plants grown under this tech-nique, as well as its environmentally friendly aspect. Then, to synthesize some research work on improving water productivity and its efficiency in citrus crops.

Automated summary

Water availability is a major constraint for crop production, causing conflicts in freshwater allocation. Conventional irrigation is unsustainable due to water depletion, leading to the need for improved water-saving irrigation methods. Partial Root-zone Drying is an effective irrigation technique that saves water but can affect plant root activity.