Current rice farming, water resources and micro-irrigation.

Abstract

Rice is the staple food for half of the world’s population, and rice farming is a livelihood for millions of farmers in Asia. In India, it provides an individual with 32% of the total calorie and 24% of the total protein daily. This crop is mostly grown in puddled soil by transplanting, and flood irrigation is practised by farmers. Water or irrigation input to transplanted rice typically ranges from 1000 to 2000 mm depending upon the growing season, climatic condition, soil type and hydrological conditions. Facing water scarcity and climate change, reducing water requirement of this crop is a challenge. Out of 42.75 million hectare (m ha) rice area, only 25.12 m ha is under irrigation. Regarding water resources, depletion of groundwater is alarming in the north Indian states. On the other hand, it is under-utilized in eastern India. Microirrigation, i.e. sprinkler and drip methods have been used with the aim of minimizing water use and enhancing water use efficiency of rice. In addition, evidence-based scientific understandings on microirrigation for rice have been elucidated in this article. The potential of drip or sprinkler irrigation to rice on water saving as well as scientific insight and critical appraisal have been expounded on reasons of yield reduction. This comprehensive treatise would facilitate the formulation of strategies or policies on efficient management of water or irrigation for rice cultivation.