Overview of recent study on improvement approaches and methods for crop water productivity

This paper presents an overview of the advancement in study and topics of the improvement approaces and methods for crop water productivity on the basis of elaborating the main factors that affect crop water productivity. The maximum yield obtained from unit water, i.e. maximizing the crop water productivity, is one of the most important topics of study on agricultural water saving. The coordination of higher crop water productivity with moderate crop yield has important significance in the effective use of water in arid and water shortage areas. Combining the biological water-saving measures, such as improvement of variety inheritance and adjustment of crop physiological characteristics, with engineering solutions including the water saving irrigation method, deficit irrigation, and agronomic manipulation (increase of soil fertility and organic matter, protective tilling measure, etc.) may solve the problem of water shortage in agriculture to a certain extent. New scientific method and information are needed in the study on the approaches and methods to improve crop water productivity, starting mainly with gene improvement of crop variety, economic efficiency analysis considering the maximization of net social benefit of irrigation economy and risk management of crop income, etc.