用小定额(36—48毫米),低强度(5.7毫米/小时)喷灌,就可使土层湿润到40—60厘米。既省水,大致上又满足了冬小麦对供水层的要求,灌溉湿润土层深度,受灌水定额、灌水前表层土壤基模势的影响。土壤基模势与小麦叶水势呈显著正相关。冬小麦各生育期,除成熟期外,耗水层内土壤基模势为-0.1—-0.7巴(土壤含水量为田间持水量的85—65%),低于-0.7巴,将严重影响产量。这下限值-0.7巴比传统的土壤有效水下限值(-15巴)高得多。 Sprinkling with a small fixed amount (36-48 mm) of low intensity (5.7 mm / h) will wet the soil to 40-60 cm. It not only saves water, but also largely meets the requirement of winter wheat for water supply, the depth of irrigation of wet soil, the fixed quota of irrigation and the modulus of soil base before irrigation. Soil base potential and wheat leaf water potential was significantly positively correlated. At all growth stages of winter wheat, except for the mature stage, the soil base-mode potential in the water-bearing layer ranges from -0.1 to 0.7 bar (soil water content is 85-65% of field capacity) and below -0.7 bar, which will seriously affect the yield . This lower limit of -0.7 bar is much higher than the traditional effective soil water limit (-15 bar).