Agriculture and Environment: Rice

Better Management Practices: Reduce Effluents

Allowing water to stay longer in the rice fields may be a simple way to reduce farm agrochemicals in runoff.

Scientists at the Texas Agricultural Experiment Station have determined how many days water should stand in rice fields to allow breakdown of chemicals to safe levels.

For example, some 22.7 kilograms per hectare (20 pounds per acre) of chemicals is the normal chemical content of water runoff from rice fields managed traditionally. If the water is left on the field for 5-7 days longer, the level is reduced to 6.8 kilograms per hectare (6 pounds per acre), which is considered safe. In addition, the chemical fertilizers will be available to the roots of the next crop.

Synthetic fertilizers affect water quality, altering the microbial balance that is the key to the conversion of organic matter and dissolved minerals into usable form. Water in rice paddies or in settlement ponds can be treated with microbial organic matter that is inoculated with beneficial microorganisms to re-establish its balance either for improved efficiency in the pond or prior to release from the pond.