Experimental Study on Soil Field Water Capacity Determination by Enclosing Frame Flooding Instrument Method

Field water capacity is one of the important soil moisture constants，and it is the basic information indispensable for carrying out moisture evaluation and drought analysis to guide scientific irrigation.Traditional indoor and outdoor methods for measuring field water capacity are complex to operate，which brings certain difficulties to soil moisture evaluation.By combining advanced wireless soil measurement sensor technology with traditional framed flood irrigation method，a new method based on wireless sensors was proposed，which used“moving average moisture content method”and“moving average method”to calculate and determine soil field capacity.Validation experiments were carried out on farms with different soil types in Shaanxi，Beijing，Jilin and Hebei.Results showed that compared with traditional ring cutting method，average relative error of measurement results of framed submerged irrigation instrument method was 4.89%.The results were relatively stable，field capacity measured by the two methods was consistent with variation of soil depth.The framed submerged irrigation instrument method was reliable，convenient and practical for measuring soil field capacity.It is an effective method for soil moisture monitoring and evaluation and suitable for popularization and application.