河西半荒漠驴驴蒿草原土壤水盐动态及其对牧草生长的影响

The Dynamic of Soil Water and Salt and the Effect on Herbage Growth of Artermisia Dalailamae in Hexi Semidesert

对驴驴蒿草原三个草地型(驴驴蒿型,驴驴蒿—红砂型,驴驴蒿+珍珠型)的土壤水盐动态及其与牧草产量的关系进行了研究。结果表明:土壤水分变化受雨量的影响具有阶段性。随着土壤深度的增加,土壤含水量随时间的变化而变小。土壤各层内,春季含水量相近,并呈下降趋势,夏季变化大,秋冬则随土壤深度增加而增加,趋向稳定。盐分随水分而移动,其含量基本上随土壤深度的增加而增加。牧草产量的变化与土壤水分的变化具有“一致性”。在驴驴蒿型和驴驴蒿—红砂型中,驴驴蒿的绝对生长量与0～40cm内各土层的含水量呈显著的正相关,并建立了产量预测模型。

The dynamics of soil moisture and salts and the relation between forage output of the grassland types of Artermisia dalailamae(A. dalailamae, A. dalailamae--Reaumuria soongorica, and A. dalailamae--Salsola passerina) were studied. The results showed that the variation of soil moisture is characterized with seasons and effected by precipitation. And the variation of soil moisture with time decreased as the soil depth increases. Soil water of each layer in the 0--70cm profile in the three grassland types is similar in spring and changes widely in summer, and increases with soil depth deepening during autumn and winter. The salt reaved with water and its contents increased as the depth goes down. The change of herbage yield was similar to the change of soil moisture. The growth rate of A. dalailamae and A. dalailamae-Reaumuria soongorica was closely related with soil waters in layers of 0--40cm. A model of yield forecast was established.