不同植被恢复模式对土壤肥力的影响

将野外调查和室内分析相结合,测定了刺槐、荆条、侧柏和苜蓿等几种不同植被恢复模式下农田土壤有机质和速效养分含量,并采用新复极差法检验了有机质含量的差异性,结果表明:黄土高原渭北旱塬丘陵沟壑区不同植被恢复模式各层土壤有机质含量均随深度而递减,土壤有机质有一定的表聚性,其中荆条、侧柏土壤有机质表聚性表现最为明显;几种不同植被恢复模式能够显著提高土壤有机质含量水平,改善土壤肥力;植被恢复后能明显提高土壤速效氮、速效钾水平,而对速效磷的提高却非常有限;土壤速效钾在苜蓿植被下有少量减少,中幼龄侧柏导致土壤速效氮、速效磷明显下降。最后,对植被恢复提高土壤肥力的机理和不同植被对土壤肥力的恢复效应进行了探讨。

Effects of Various Vegetative Restoration Patterns on Soil Fertility

The soil organic matters and available nutrients of several vegetative restoration patterns including Robinia pseudoacacia,Vitex negundo var.heterophylla,Platycladus orientalis,Medicago sativa and farmland were measured and their difference were checked by DUNCAN method.The results showed as the follows:soil organic matter contents under the several vegetative restoration patterns was decreased with soil deep increased,which was more obvious foe Vitex negundo var.heterophylla and Platycladus orientalis;several vegetative restoration patterns all increased soil organic matter content remarkably;soil available nitrogen and available potassium increased mach more than available phosphorus did after vegetative restoration,but soil available potassium under Medicago sativa vegetation decreased slightly and young Platycladus orientalis caused remarkable reduction of soil available nitrogen and available phosphorus.The mechanism of vegetative restoration improvement soil fertility and the under various vegetation were discussed.