作物水分胁迫指数与土壤含水量关系探讨

Primary investigation on the relationship between the crop water stress index and the soil moisture.

基于冠层温度的作物水分胁迫指标CWSI(Crop Water Stress Index)广泛用于指导作物灌水时间,利用自动气象站的观测资料分别计算了不同供水处理条件下冬小麦中午12:00的作物水分胁迫指数,并将作物水分胁迫指数和对应的土壤含水量进行相关分析,以探讨用作物水分胁迫指数确定灌水量的可行性。结果表明,二者是一定相关性,但相关关系不密切,复相关系数为0.54,作物水分胁迫指数随土壤含水量的降低呈明显的增大趋势;作物水分胁迫指数随气象因子的波动表现出明显的波动性,且在作物遭受较严重水分胁迫下波动性更强,这预示着利用作物水分胁迫指数直接定量标识作物土壤水分状况的可靠性不强。

Crop water stress index(CWSI) is widely used in determinating irrigation time but seldom in determi-nating irrigation water amount. The objective of this paper is to investigate the relationship between the CWSI and the soil moisture and the possibility of using it to determinate the irrigation water amount. Analysis of the CWSI of the different irrigation treatment plots indicated that CWSI increased with the decrease of soil water content and showed variations caused by fluctuation of the weather factors. The correlation coefficient of CWSI to soil mois-ture content was only 0.54. This indicates that CWSI may not be used reliably for determinnating the irrigation amount.