Water Use Efficiency for Dry Season Rice Production in the Central Plain

Abstract

Evapotranspiration (ETP) and water use efficiency (WUE) trials were conducted at Suphan Buri Rice Research Center and Pathum Thani Rice Research Center during 2001-2003, and 2006-2007, respectively. There were 2 irrigation methods, intermittent irrigation and saturated soil compared to shallow continuous flooding (control). It was found that intermittent irrigation, saturated soil by surface irrigation and shallow continuous flooding resulted in the ETP of 983, 601 and 1,148 m³/rai, respectively. These two irrigation methods could reduce water use by 14.4 and 47.6%, and the quantities of water use were less than those of shallow continuous flooding by 165.4 and 547.0 m³/rai, respectively. WUE of intermittent irrigation, saturated soil by surface flooding were 0.57-0.68 and 0.96-1.07 kg of paddy rice/m³ of water use whereas WUE of shallow continuous flooding was 0.52-0.55 kg of paddy rice/m³ of water use. Furrow irrigation method by growing rice on the top and side of the ridge had been conducted. It was found that WUE of which planting rice on the top of the ridge gave the highest efficiency (0.84 kg of paddy rice/m³ of water use). The response of 7 rice varieties grown in dry season with 3 methods of water management revealed that, at Suphan Buri Rice Research Center rice yields of intermittent irrigation and saturated soil reduced by 7.3 and 2.7%, whereas at Pathum Thani Rice Research Center the yields of the two methods were higher than that of shallow continuous flooding at 9.6 and 7.3%, respectively.