紫花苜蓿产量与气候因子的相关性分析

对关中地区13个5年生苜蓿品种的干草产量和≥5 ℃积温、日照时数、降水之间的关系进行了多元回归和通径分析.结果表明:紫花苜蓿干草产量与3个气候因子间存在着正相关,且都达到极显著水平;3个气象因子对产量的直接作用由大到小依次为:≥5 ℃积温＞日照时数＞降水,日照时数、降水通过≥5 ℃积温对产量产生正向间接效应;日照时数、≥5 ℃积温通过降水产生负向间接效应,≥5 ℃积温对于产量的形成具有决定作用.

Analysis of the Conrrelation between Alfalfa Yield and Climatic Factor

The correlation of yield of thirteen five-year growing alfalfa varieties and the climatic factor including accumulated temperature of above 5 ℃,sunshine hour and precipitation were studied with the method of correlation analysis and path analysis.The results showed that there was significant positive correlation between yield and climatic factor and the direct effect of three climatic factors on its yield was as follows: accumulated temperature of above 5 ℃>sunshine hour>precipitation;and sunshine hour and precipitation had large positive indirect effect on the yield through accumulated temperature of above 5℃;accumulated temperature of above 5 ℃ and sunshine hour had negative indirect effect through precipitation;and accumulated temperature of above 5 ℃ was a decisive factor in yield structure.