Rice growers need to manage ground water to ensure there is no impact on rice yield. This article explains the issues, gives tips on water management, lists thresholds and key conversions and answers commonly asked questions.

Delayed permanent water (DPW) has proven to be a successful alternative water management practice for rice growing that provides considerable water savings and significant financial benefit. 

Rice water depth management at microspore is critical in protecting the developing panicle from cold-induced floret sterility which can lead to large reductions in rice grain yield at harvest.

How much water you will use depends on how much water is in the paddock now, the date you plan to drain the crop, and how much water is drained off the crop.

Use the tables in our fact sheet to calculate an estimate of how much more water you will need.

Shallow water depth management during establishment of ponded rice crops is key to achieving high yields and water use efficiency. In shallow water, the seedling grows to the surface faster to commence photosynthesis to support more growth, better root development, develop biomass and less wind damage occurs, compared to seedlings in deep water. 

Mid-season drainage has been used by some rice growers particularly in the central and western Murray Valley for a number of years as a management tool to help avoid straighthead. 

Considerable water savings can be made by changing from aerial to drill sowing and then further water savings can be achieved by delaying the timing of the application of permanent water.

Deciding when to drain the water from your rice crop for harvest is one of the most important and difficult decisions in rice growing. In draining you must meet two objectives:

Research conducted on both red-brown earth and self-mulching clay soils has shown that rice copes well with the moisture stress and that delayed permanent water leads to considerable water savings with only a small decline in grain yield. 

Monthly water budgets to compare crop water requirements and available allocations are very important. If crop needs are likely to exceed supply then decisions about buying extra water or reducing the area of rice by draining must be made.