|Ideas for Action : Save, Recycle and Do Not Pollute (IIRR, 1992, 146 p.)|
Water conservation in lowland farms
Use water efficiently, minimize conveyance and distribution losses, percolation and seepage and wasteful use on the farm.
· Check canal and canal structures regularly for any leaks or structures which are not functioning properly. Repair damaged parts or structures immediately.
· Install water monitoring devices (e.g., weir, cut-throat flume, etc.) to ensure efficient water use.
· Control the amount of water applied, based on determined water demand and normal irrigation schedule.
· Cut grasses on irrigation canals. Remove debris which obstructs the flow of water.
· Remove silt which deposits along canal bottoms. Silt lessens the water capacity and flow of irrigation canals.
· If a canal passes through highly porous soils, provide a canal lining using impermeable materials (e.g., concrete).
· Level paddy fields properly for an even distribution of water which is applied to the paddy.
· Maintain a paddy dike height of not less than 20 cm. This will prevent water from flowing over the top of the paddy and spillage during paddy to paddy irrigation. This also allows more room for storage of rainfall water as it is accumulated, especially during the rainy season.
· Compact and plaster paddy dikes thoroughly to eliminate excessive water loss due to seepage.
· During lowland irrigation, be sure to close all spillways used in upland irrigation to reduce water loss.
· Practice crop diversification after wet season rice crop. This helps to minimize the excessive use of water in rice monocropping system and to maximize the utilization of residual soil moisture throughout the dry season.
· Use mulch (cut rice straw and grasses) to minimize evaporation from the soil surface and to conserve water stored in the root zone.
· Apply terminal irrigation (last application) when the standing crop is about to be harvested. This helps to maintain soil moisture at optimum levels for tillage and land preparation for the next crop.
· Synchronize fertilizer application to be applied immediately before normal irrigation schedule in order to optimize the nutrients available in the fertilizer which are soluble (released) in water.
· If furrow irrigation is adapted, avoid overly long furrows to prevent excessive water losses which will occur from deep percolation or water entering the soil.
· The use of portable plastic tubing or pressurized irrigation system (e.g., drip irrigation, microsprinkler, etc.) has shown to be cost-effective and water-efficient for areas which are not currently served by existing irrigation services. However, these systems require a relatively high initial capital investment.