- Rice 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:
- Construct field channels to control the flow of water to and from your field
- The construction of separate channels to move water to and from each field greatly improves the control of water by individual farmers.
- Field channels allow water to be delivered to the individual seed beds separately and the main field does not need to be irrigated until it's time to plant in the main field.
- In addition, the ability to control water to your field is important when you need to retain water (especially after applying fertilizer so nutrients are not lost) or when you need to drain the field for harvest.
- Construction of individual field channels is the recommended practice in any type of irrigation system.
- Prepare the land to minimize water loss and create a hard pan
- Till the soil to fill cracks
- Perform shallow tillage operations before land soaking. This fills in the cracks and can greatly reduce the amount of water used in land preparation.