How to manage water

watermgt-rice-fieldRice is typically grown in bunded fields that are continuously flooded up to 7−10 days before harvest.

Continuous flooding helps ensure sufficient water and control weeds.

Lowland rice requires a lot of water.

On average, it takes 1,432 liters of water to produce 1 kg of rice in an irrigated lowland production system. Total seasonal water input to rice fields varies from as little as 400 mm in heavy clay soils with shallow groundwater tables to more than 2000 mm in coarse-textured (sandy or loamy) soils with deep groundwater tables.

Around 1300−1500 mm is a typical amount of water needed for irrigated rice in Asia. Irrigated rice receives an estimated 34−43% of the total world’s irrigation water, or about 24−30% of the entire world’s developed fresh water resources.

Worldwide, water for agriculture is becoming increasingly scarce. Due to its semi-aquatic ancestry, rice is extremely sensitive to water shortages.

To effectively and efficiently use water and maximize rice yields, the following good water management practices can be done:

Different crop establishment methods require different water management practices:

Lowland rice is extremely sensitive to water shortage (below saturation) at the flowering stage. Drought at flowering results in yield loss from increased spikelet sterility, thus fewer grains. 

Keep the water level in the fields at 5 cm at all times from heading to the end of flowering.

In case of water scarcity, apply water-saving technologies such as Alternate Wetting and Drying (AWD) and consider changing planting method from puddled transplanting to non-puddled transplanting or dry-direct seeding.