Water Management

Following is a sampling of critical water management situations, the stage of the rice and recommended practices or precautions to help alleviate the particular situation. This information is part of the Arkansas Rice Production Handbook, published by the University of Arkansas Division of Agriculture.

1. After dry-seeding, no moisture for germination. The rice has not germinated. Flush as quickly as possible, being sure surface water does not stand for more than two days. Use multiple water inlets, if possible, to reduce flush time.

2. Soil surface is crusted. The rice has germinated but not emerged. Flush to soften crust before spikes braid or lose their penetrating power.

3. Residual herbicides have been applied, soil surface has become dry, weeds are germinating. The rice has germinated and may be emerged. Flush to activate herbicides.

4. Barnyardgrass has become drought-stressed and is less than four-leaf. The rice may or may not be emerged. Flush and apply herbicide before the grass gets too tall.

5. Seedling rice has tipburn and is dying before flooding (salinity injury). The rice has emerged but may be less than eight inches tall. Have the water tested for quality. Dilute the salts by flushing and don’t let the soil surface dry.

6. Rice has turned chlorotic (yellow) within two to four days after flooding (high pH, Zn deficiency). The rice is six to 10 inches tall. Drain immediately and, after recovery, apply zinc, add N; reflood to shallow depth.

7. History of straighthead. First, plant a tolerant variety. The rice is about two to three weeks prior to internode movement (Consider DD50 drying time frame). Drain before DD50 first drying date to allow the soil to dry thoroughly until rice plants are droughtstressed; then reflood, preferably before one-half inch internode elongation.

8. Not enough water; severe drought stress. Rice can be in various stages. Flush over quickly, then close gates and raise flood to desired depth as water becomes available.

9. Nitrogen applied on dry soil. The rice is three weeks old. Flood immediately after application to move N down into the soil.

10. Nitrogen applied into flood. Rice is at internode elongation. Prefer stable flood with little water movement. Delay pumping for 24 hours after N application.

11. Drought, pumping flow rate is low. Rice is near heading. Use multiple inlets. Clean out algae in flow pattern to ensure sufficient water as heads emerge.

12. Preparation for harvest. Rice is about 10 to 14 days after heading. Heads are beginning to drop, and some heads are beginning to ripen. Consider ceasing pumping on field in preparation for harvest 10 to 14 days after heading if there is an adequate flood on the field that would prevent drought stress during grain fill. However, if temperatures are hot, then maintain the flood to 10 more days.

Please refer to the Arkansas Rice Production Handbook to view the entire listing along with Keys to Water Management Success.