Pakistan has favorable climate and fertile soils for the cultivation of rice. However, water is limiting factors. Moreover, the existing irrigation practice for growing rice are wasteful. A huge quantity of water is lost during land precipitation and crop establishment which leads to excessive evaporation and deep percolation. It is observed that farmers generally apply more water to rice field for control of weed germination than what is needed for meeting the crop water requirement.
Rice is one of the major staple food crops in Pakistan. About 13% of the cropped area of the country is used for rice production. An average yield of rice in the country is the 2.95 ton/ hector, which is much lower as compared to 7.40t/ha for the USA and 6.19 t/ha for China. On average, the world rice fields uses about 1.4 m3 of water for producing 1 kg rice with a water use efficiency (WUE) OF 0.71 KG/M3 whereas in Pakistan it is less than 0.45 kg/m3.
A major reason for this WUE is the conventional flood irrigation practice i.e. growing rice under submerged conditions. In the backdrop of increasing water scarcity, the farmers, researchers, and scientists are looking for new methods and techniques to improve rice yield and its water use efficiency. Planting of rice on beds is one the practices which can potentially improve rice yield and it’s WUE.
Pakistan council of research in water resources (PRWR) conducted series of experiments for growing rice on beds and conventional planting during 2011-2013 at its R&D center near Sargodha Punjab. Each treatment was replicated thrice. Under conventional method, on an average 144 cm of water was applied whereas water applied to bed fields was 112 cm. The amount of water applied under the bed and furrows was therefore, 23 % less than that for flooded basins. Average yield of rice grown on beds was 4156 kg/ ha whereas it was 3921 kg/ ha in flooded basins. The average WUE of rice grown on beds was 0.37 kg/m3. Whereas it was 0.27 kg/m3 under conventional practices. The average net income from the rice planted on beds was Rs. 129328/ha, whereas it was Rs. 115260/ha for the flooded basins. Therefore planting rice on beds has high potential for saving water without compromising the yield.
So like any other crops, rice has its specific water requirement and does not essentially need submerged conditions. Rice can be successfully grown on beds without compromising the yield with a water saving of over 23 %. Therefore there is need to demonstrate this technology to the farmers for its large scale adoption.