华北地区滴灌控制基质势对生菜产量和水分利用的影响

Effects of soil potential on lettuce growth and water use efficiency under drip irrigation in semi-humid regions of north China

利用三年试验资料研究了华北地区滴灌条件下,不同基质势处理(-10 kPa,-20 kPa,-30 kPa,-40 kPa,-50 kPa)对结球生菜产量、水分利用效率(WUE)及灌溉水利用效率(IWUE)等的影响。结果表明:随着滴头正下方0.2 m深度处土壤基质势控制的降低,整个生育期结球生菜的灌溉水量、累计耗水量明显减少,而水分利用效率和灌溉水利用效率随着土壤基质势控制的降低明显升高,但不同处理生菜总产量无显著差异。三年监测数据表明,受生长期降雨影响,大部分时间土壤基质势实际都维持在-30 kPa以上。因此,露地滴灌种植生菜,缓苗后,可通过控制滴头正下方0.2 m深度处土壤基质势下限高于-30 kPa来指导灌溉。

Three years experiments were carried out to investigate the effects of different soil matric potential（from-10 to-50 kPa） on the lettuce growth and water use efficiency under drip irrigation condition in North China.The results showed that with the soil matric potential decresesed at 0.2 m depth immediately under drip emitters the irrigation amount and the accumulative consumed water in whole growing were obviously reduced,but the irrigation water use efficiency obviously increased and didn＇t affect the total yield significantly.The observation results during three years showed that the majority of soil matric potential was distributed above-30kPa.So in north China plan,for field-grown lettuce,it can be used to schedule irrigation by controlling the soil matric potential at 0.2 m depth immediately under drip emitters above-30 kPa.