Improving Irrigated Lowland Rice Water Use Efficiency under Saturated Soil Culture for Adoption in Tropical Climate Conditions

Abstract

: Saturated soil culture is one of the water saving techniques that can improve water productivity. However, it is either less implemented or adopted because it consumes more time and energy. Therefore, an experiment was conducted to determine the effective water depth that can keep soil moisture close to saturation for a commonly practiced irrigation interval, combined with a rainfall pattern for increasing water productivity. The design was a randomized complete block with three replications and four water treatments representing 120% (T120), 180% (T180), 240% (T240), and 300% (T300) of soil saturation or the application of 2, 3, 4 and 5 cm water depth. The results showed that the application of 3 cm was the effective depth. It decreased plant height, tiller number, chlorophyll content, and panicle number per hill by 12.37%, 20.84%, 7.59%, and 70.98%, respectively. The decrease of these parameters is followed by total recovery due to effective rainfall contribution, which led to low yield sacrifice (6% of reduction) and 40% of water saving. We argue that weekly application of a 3 cm water depth and matching crop needed-water period with the onset of rainfall may be implemented and recommended as suitable saturated soil culture practice for rice production in high water demand conditions.

Keywords

• saturated soil culture
• lowland rice yield
• water productivity
• tropical climate