土壤湿度对小麦出苗及幼苗生长的影响

Influence of Soil Moisture on the Germination and Seedling Growth of Wheat

土壤水分不适能显著影响小麦出苗及幼苗生长 ,表现为显著降低出苗率 ,减少单位面积的苗数 ;同时显著影响幼苗单株生长 ,表现为干重、叶面积下降。土壤水分不适对小麦群体的影响表现为单位面积的干重和叶面积指数 (LAI)下降。采用通径分析衡量了出苗率和单株幼苗生长两因子对群体影响的大小。结果表明 :单位面积干重下降主因是单株干重下降 ,叶面积指数下降主因是出苗率下降。土壤湿度大于1 7%且小于 44%时 ,对小麦出苗及幼苗生长各项指标的影响幅度一般在 2 0 %以内 ,而低于 1 7%或高于 44%的土壤湿度对小麦的影响幅度急剧增加。小麦对土壤水分不适具有一定的适应性反应。

The germination and seedling growth of wheat are influenced significantly by soil moisture,which is shown by the reductions in the percentage of germination,the growth rate,the leaf area index(LAI) and the accumulation of the dry weight per ha.The results suggest that the decrease in the dry weight per unit area is mainly caused by the decrease in the dry weight per ear,while the decrease in the LAI is mainly caused by the decrease in the percentage of germination.