Issues and Challenges of Real Water Saving through Improving Water Productivity and Use of Modern Irrigation Systems (Technical Note)

Considering the severe water shortage crisis for producing agricultural products, the concept of real water saving in agriculture has been introduced recently. The reason behind this is that many researchers have realized that many approaches which are used for water saving in agriculture (e.g., improving irrigation efficiency, and even improving agricultural water productivity-WP) rely on the development of modern water-saving irrigation methods such as pressurized irrigation. These systems, when required conditions or relevant context are not fulfilled, may not lead to real water savings and may even cause an increase in water consumption. Examples of these arguments, discussion, and pieces of evidence are provided in the latest book published by FAO. In this analytical paper following explanation of the concepts, terms, the visions on real water saving, and effectiveness of modern irrigation technologies in this regard, all the activities relevant to improving WP, with the objective of water saving in agriculture, are elaborated and discussed. The paper concludes that for the purpose of recognition and selection of technical and economical approaches effective on water demand and use, water accounting framework should be set in a specific basin. Also in parallel to the attention to the development of pressurized irrigation systems in Iran, other approaches and measures, such as agronomic practices for reducing ET in agriculture (e.g. use of mulches, conservation agriculture, and proper crop rotation, etc.) should be selected. Finally, for achieving real water saving, the WP index should be evaluated based on ET and not based on applied water to the field. This should be the necessary criteria in selecting irrigation systems and other measures in regards to their effectiveness on real water savings in agriculture.