Abstract

• Scheduling of irrigation to crops is essential for efficient utilization of available water, saving of input and enhancing yield. The study was aimed to investigate the efficient water use based on soil moisture measuring methods and to evaluate the interactions between actual and estimated water reuirement on vegetable soybean field of VFRDC. According to soil analysis, the soil type is sandy loam soil. Soil sample was collected daily for measuring actual water reuirement of vegetable soybean by Gravimetric method. The estimated evapotranspiration (ET0) of Blaney & Criddle was compared to CROPWAT method. The climate data had also recorded such as temperature, humidity, wind and sunshine hours. Crop water reuirement was measured by the method of Blaney & Criddle (1950) which is suitable method for the most of crops in Myanmar. A comparison was made between estimated crop water consumption versus actual water consumption. The result of this study showed that in young stage of crop, actual crop water consumption and estimated crop water consumption were almost eual level, but when plants became mature, the actual crop water consumption was higher than the estimated one. Based on this investigation, it must be concluded that the temperature based method for estimated crop water reuirement, Blaney and Criddle method, is the most suitable in Myanmar for irrigation schedule.