冠层温度定量诊断覆膜作物水分状况试验研究

Crop Canopy Temperature as an Index for Assessing Quantitatively Water Status of Cotton and Corn Mulched with Plastic Film

作物缺水指标 CWSI( Crop Water Strese Index)和冠层 -空气温差 ( Tc-Ta)是利用冠层温度评价作物水分状况的重要方法。 1 998和 1 999年在新疆乌兰乌苏农业气象站试验田内开展了对覆膜棉花和玉米的研究。结果表明 :CWSI能够指示作物根系层的水分状况 ,而 ( Tc-Ta)受到环境因素 (太阳辐射、空气饱和差 )的较大影响。另外 ,对用标准化的冠层 -空气温差法 NDT( Normalized Difference of Temperature)定量诊断作物水分状况的可行性进行了研究。结果表明该方法在很大程度上能消除环境因素的影响 ,直接指示作物根系层的水分状况 ,并提出了覆膜棉花和玉米各生育阶段需灌溉的临界 CWSI及

CWSI and canopy air temperature difference ( T c T a ) are two important indexes, related with crop canopy temperature, for assessing crop water status. A field experiment was conducted to determine suitable CWSI and ( T c T a ) values for assessing water status of cotton and corn mulched with plastic film in 1998 and 1999. The results showed that CWSI was a good indicator of moisture in root zone, and ( T c T a ) was influenced by many environment factors, such as solar radiation, and vapor pressure deficit. Moreover, the utilization of NDT (Normalized Difference of Temperature) for assessing quantitatively water status of cotton and corn mulched with plastic film also was studied. Research results showed that influences of environment factors can be minimized significantly with adapting NDA as index, and NDA is a good index for assessing water status in root zone soil. The critical values of CWSI and NDT for assessing water status at each growth stage of cotton and corn mulched with plastic film also were determined with experiment data.