气象因子对黄土高原间套作豌豆和春小麦叶片水势的影响

在甘肃省农业科学院会宁农业试验站,对春小麦和豌豆间套作模式下,不同气象因子对春小麦和豌豆叶水势的影响进行了田间对比观测。结果表明:在半干旱地区,春小麦和豌豆的叶水势与气象因子的关系在不同生育期的表达式不同,与大气温度呈线性关系,与太阳辐射、大气相对湿度、大气水势均呈二次方程模型,与综合气象因子也呈良好的线性关系。不同气象因子对作物叶水势影响的通径分析表明,影响春小麦叶水势日变化作用最强的气象因子是大气水势,其次是大气相对湿度、大气温度和太阳辐射。大气相对湿度、大气温度和太阳辐射对春小麦叶水势日变化的直接影响小于它们通过大气水势的间接影响。对豌豆叶水势日变化直接影响最大的气象因子是大气温度,其次是大气水势、太阳辐射和大气相对湿度。大气水势、太阳辐射和大气相对湿度的直接通径系数均小于各自通过大气温度的间接通径系数,这三者对豌豆叶水势日变化的直接影响小于它们通过大气温度的间接影响。

Effects of meteorological factors on leaf water potential of spring wheat and field pea in Loess Plateau

A field experiment was conducted to investigate the effects of meteorological factors on the leaf water po -tential ( Ψ L ) of spring wheat and field pea in Loess Plateau .The results showed that the relationship between leaf water potential and four meteorological factors changed with the growth stages of spring wheat and field pea .Leaf water potential exhibited a linear relationship with air temperature (Ta ) and a quadratic relationship with solar radiation (R) ,air rela-tive humidity (RHa ) and air water potential ( Ψ a ) .A good linear relationship was observed between leaf water potential and the integrated meteorological factors .Among the four meteorological factors ,air water potential had the strongest ef-fect on the leaf water potential of spring wheat ,followed by air relative humidity ,air temperature and then solar radia-tion .The direct path coefficients of air relative humidity ,air temperature and R were smaller than their respective indi-rect path coefficients via air water potential ,indicating that the direct effects of these three factors on diurnal variations in the leaf water potential of spring wheat were less than their respective indirect effects via air water potential .A highly sig-nificant correlation between air temperature and spring wheat leaf water potential was found ,indicating a minor direct ef-fect on leaf water potential .Airtemperature was not the primary cause for diurnal variations in the leaf water potential of spring wheat but acted as the primary factor for variations in air water potential .Air temperature had the strongest direct effect on diurnal variations in the leaf water potential of field pea ,followed by air water potential ,solar radiation and then air relative humidity .Solar radiation and air relative humidity were both smaller than their respective indirect path coeffi -cients via air temperature ,indicating that the direct effects of these three factors on diurnal variations in pea leaf water potential were less than their indirect effects via air temperature .