坝上高原防护林网内不同土地利用对土壤养分的影响——以沽源县黄盖淖镇为例

选择河北省沽源县黄盖淖镇农田、草场防护林网,在林网格内选取不同典型的土地利用/覆被类型地块,其中包括自然草地、林地、退耕还草地、旱耕地等地块.分别采集土壤样品化验,分析土壤有机质、氮、磷、钾等养分含量,揭示不同土地利用对土壤养分的影响.结果表明,莜麦耕地土壤养分含量比小麦、胡麻耕地高,撂荒杂类草地土壤养分含量比耕地高；退耕还林地土壤养分含量低于还草地,覆沙地段严禁造林；轻中度退化牧草地土壤养分含量相对较高；乔木防护林地有效减少土壤风蚀的距离不超过树高的20倍；退耕还草地土壤养分含量较高.同时,提出防护林网内土地科学、合理利用及防护林建设的若干建议.

Research on Soil Nutrient among Different Land Use in Farmland Shelterbelts Network in Bashang Plateau

Taking farmland shelterbelts network in Huanggainao Town of Hebei Province as example, selecting different typical land-use sam- ples of soil in this area, including natural grassland, forest, scrubland, farmland, the soil of nitrogen, phosphorus, potassium and organic matter Were analyzed. The results showed that： soil nutrient content in Avena nuda farmland is higher than other farmland, but lower than a- bandoned grassland ; soil nutrient content in woodland returned by farmland is lower than grassland returned by farmland, woodland can＇ t be built in the sand land ; soil nutrient content in grassland which natural or returned by farmland is higher than others＇ ; farthest effective protec- tion from the shelter can not be more than 20 times of tree height. The soil nutrients content of returning farmland to grassland is higher. The advices of how to built the shelters in noithern agricuhure-pasturage eco-zone and rational land use were proposed.