黄土高原丘陵区不同土地利用方式对土壤理化性质的影响

对晋西北黄土高原丘陵区持续利用30年的小叶锦鸡儿人工林、农田、杨树林、小叶锦鸡儿和杨树的混交林地以及撂荒地的土壤理化性状进行了研究。结果表明,不同土地利用方式对土壤理化性质影响很大。小叶锦鸡儿和杨树的混交林以及小叶锦鸡儿人工林可以降低土壤容重,提高土壤酶活性、有机质和全N含量,从而改善土壤肥力。混交林和小叶锦鸡儿人工林的土壤培肥作用高于杨树纯林。粗放的农业耕作措施提高土壤容重,降低土壤养分含量,使土壤退化。撂荒地一定程度上可以起到培肥土壤的作用。在黄土高原丘陵区,种植小叶锦鸡儿人工林以及小叶锦鸡儿和杨树的混交林是较好的生态重建和植被恢复方式。

Effects of different land-uses on soil physical and chemical properties in the Loess Plateau of Shanxi Province

Soil properties under five landuses,Caragana microphylla land,farmland,poplar forest,fallow land,and mixed plantation of Caragana microphylla and poplar in a typical Loess Plateau region,northwest of Shanxi Province were studied.Results show a significant influence of land-use on soil properties.Caragana microphylla and mixed poplar and Caragana microphylla plantation improve enzyme activity,total nitrogen and organic matter contents leading to higher soil fertility compared with artificial poplar forests.Cultivation practices increase soil bulk density,decrease enzyme activities,total nitrogen and organic matter contents of cropland soils resulting in soil degradation.Land fallow improves soil fertility to some extent.It is further shown that growing Caragana microphylla and mixed Caragana microphylla and poplar plants are the most sustainable ways for vegetation rehabilitation in the Loess Plateau.