无压灌溉日光温室番茄作物-皿系数研究

以-25 kPa作为土壤水势临界值,将作物—皿系数(Kcp)设为0.2,0.4,0.6,0.8,1.0,1.2六个处理,研究了不同灌溉水量时的番茄产量、品质和灌溉水利用效率。通过经济效益评价,研究了杨凌地区无压灌溉温室番茄获得最高经济效益时的作物—皿系数。通过张力计读数变化规律,研究了利用张力计测量无压灌溉湿润体内土壤水势的特点。研究结果表明,Kcp为0.2~0.8时,灌溉水量的增加对番茄产量影响不大;Kcp为1.0~1.2时,灌溉水量的增加能显著提高番茄产量和果实大小;Kcp为0.2时的灌溉水量能极显著提高番茄的灌溉水利用效率。在综合考虑了杨凌地区水价、番茄使用目的和市场价格波动规律后,Kcp取值1.2能获得最高的经济效益。作物—皿系数法计算灌溉水量时的滞后性特点和张力计埋设位置,是判断利用张力计监测土壤水势临界值方法有效性的两个重要因素。

Crop-pan coefficientis the ratio between crop water consumption and pan evaporation.Using-25 kPa as the soil water potential threshold,and designing six treatments for crop-pan coefficient Kcp=0.2,0.4,0.6,0.8,1.0,1.2,study was made on tomato yield,quality and irrigation water use efficiency under different irrigation water amount.The crop-pan coefficient which acquired highest economic effectiveness was studied through the economic effectiveness analysis,while the measurement character of soil water potenti...