基于通径分析原理的冬小麦缺水诊断指标敏感性分析

Sensitivity analysis on water deficit indicator of winter wheat based on path analysis theory

根据冬小麦田间试验结果,用通径分析的方法,把不同灌溉决策指标对干物质和叶片水分利用效率(WUE)的影响进行了分析。通过土壤水分含量、叶面蒸腾、光合有效辐射、光合作用速率、气孔导度和叶温对作物干物质产量的通径分析发现,影响干物质产量最大的是叶面蒸腾,其次是光合有效辐射和叶温。通过充分灌溉和干旱水分处理相应时刻太阳辐射、光合有效辐射、空气水汽压差、气孔导度和叶温对作物叶片WUE的通径分析发现,对于适宜水分处理来说,主要影响WUE因子不是上述5个指标,而是土壤水分状况起到决定因素;对于干旱处理来说,主要影响因子是光合有效辐射和叶面温度。通过对干物质通径分析自变量指标的增减对结果的影响分析,发现,在考虑干物质生产和作物水分利用效率最优的目标时,灌溉决策指标要注意叶面蒸腾、光合有效辐射、叶面温度和土壤水分的变化。

Based on the field experiment data of winter wheat,under 6 kinds of irrigation treatments,the sensitivity and impact of water deficit indicator used in decision-making were studied by path analysis on crop biomass and water use efficiency（WUE） of crop leaf.The path analysis method was applied to analyze the impact of soil water content,leaf transpiration（Tr）,photosynthesis available radiation（PAR）,net rate of photosynthesis（Pn）, stomata conductance（Gs） and leaf temperature（T1） on crop biomass.It is found that the most sensitive indicator affecting the yield of crop biomass is Tr,the next two indicators are Pn and T1.Furthermore,the path analysis on impact of solar radiation（Rs）,PAR,vapor pressure deficit（VPD）,Gs and T1 on WUE under sufficient irrigation and rainfeed agriculture treatment at the corresponding moment indicates that the most important factor is soil water supply for full irrigation treatment.As for the dry treatment,the main affecting factors are PAR and T1.Finally,the path analysis on the influence of the amount of independent variables on biomass shows that the attention must be paid to the variation of Tr,PAR,T1 and soil water in decision-making if setting biomass and water use efficiency as the objectives for optimization.