Water management







Introduction to water management in rice







Understand the need for good water management.



Transplanting: less seed but more labor



Why is proper water management needed?


Water is a precious and scarce resource input in rice production, so it is very important that irrigation water is used wisely and efficiently.


The current way growing irrigated rice in most Asian rice farms requires large amounts of water. For example, in India and the Philippines, an average of about 3000 liters of water is used to produce 1 kilo of rice!


The increasing shortage of water in irrigated areas because of, for example, the lack of water conservation practices and the need of water for the industrial, domestic and other non agriculture sectors, show that the present rice cultivation techniques must be improved. Better water management is needed!


Scientific studies show: "No yield loss"


Several water-savings studies conducted at experimental stations and in farmer's field with varying water supply conditions have shown that with improved water management, the water consumed in irrigated rice farms can be reduced without causing reduction in yield.





How is water being used in irrigated lowland rice fields?


The total average water use in irrigated lowland rice fields ranges from 675 mm to 4450 mm depending on the soil type, rice culture, and water management practices.


Water is consumed for land preparation, evapotranspiration, and seepage & percolation. For an average seasonal water consumption of 1900 mm, the components of water use are distributed as follows:


Roll your mouse over the pie-chart


The components of water use in lowland rice fields




1. During land preparation, most water used is lost by drainage through soil cracks.


2.Evapotranspiration represents the water productively used by the rice plant. So, to increase water productivity, the farmer must try to satisfy the evapotranspiration demand of the rice plant to enhance its full development and yield potential but with reduced total water input.


3. Another major portion of the water used in irrigated rice is lost through seepage and percolation. Seepage is the horizontal flow of water into or from a soil. Percolation is the downward movement of water through the soil.


Next lessons


Now that we understand how water is being used, and the need for water-saving management, we will discuss in the following lessons how water management can be improved.