干旱区防护林营造方式对沙漠化土地恢复能力的影响研究

通过对防护林体系营造方式对沙漠化土地的恢复和重建能力的研究,发现固氮灌木树种对沙漠化土地肥力恢复的作用十分显著。采用工程措施与生物措施相结合的组合造林技术是恢复沙漠化土地肥力最有效的方法。在沙漠化土地上营造乔、灌混交防沙阻沙林带,可以明显地提高土壤的有机质和氮素水平。建立农田防护林网可以有效地改善土壤水环境和物理性质,并能增加土壤微生物,使土壤微生物的种群数量较荒漠化土地有较大幅度提高。土壤微生物的数量分布与种植植物的种类和人为经营强度有关。草田轮作是干旱区改土培肥的好形式,新开发荒漠地以第一年农作物+第二年牧草+第三年农作物的轮作制度较好。

Impact of Shelterforest Patterns on Rehabilitation of Desertified Land in Arid Area

This paper focuses on the impact evaluation of shelterforest patterns on the rehabilitation of desertified land.The results show that the nitrogen-fixing shrub species have notable effect on desertified land's rehabilitation processes.The most effective method for soil fertility rehabilitation of desertified land is to integrate engineering with biological afforestation techniques.Tree and shrub mingled shelterbelt can increase soil organic matter and nitrogen obviously;the soil moisture,physical properties and microbe population within protected area are also increased significantly.The soil microorganism's amount within protected area relates to plant types and human management.The rotation of crops and grasses is a good form to improve soil fertility in arid area.The optimized pattern is crop rotating with grass year by year in a new reclaimed wasteland.