ประสิทธิภาพการใช้น้ำของข้าวนาปรังที่ปลูกในนาดินเหนียวภาคกลาง

Abstract

Evapotranspiration (ETP) and Water Use Efficiency (WUE) were conducted at Suphanburi Rice Research Center and Pathumthani Rice Research Center during 2001-2003 and 2006-2007. There were 2 irrigation methods carried out in 2001-2003: Intermittent irrigation and saturated soil by surface irrigation compared to shallow continuous flooding (control). It was found that intermittent irrigation, saturated soil by surface irrigation and shallow continuous flooding resulted the EPT of 983, 601 and 1,155 m3/rai, respectively. It can be concluded that (EPT and WUE) could reduce water using about 14.9 and 47.9 percent respectively. In addition, quantity of water used by these two methods less than those compared to shallow continuous flooding about 172 and 554 cubic m/rai, respectively. Water use efficiency of intermittent irrigation, saturated soil by surface flooding were 0.57-0.68 and 0.96-1.07 respectively whereas WUE of shallow continuous flooding was 0.55-0.52 kg of paddy rice/cubic m 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 the treatment with planting rice on the top of the ridge gave the highest efficiency (0.84 kg of paddy rice/1 cubic m of water use). The response of 7 rice varieties grown in dry season during 2001-2003 with 3 methods of water application revealed that, at Suphanburi Rice Research Center, rice yield of every treatments reduced 7.6-12.2 percent compared to those of shallow continuous flooding method, whereas rice yield grown under all treatments at PRC was higher than shallow continuous flooding method 7.3-10.3 percent.