土地利用类型对侵蚀黄壤腐殖质及土壤酶的影响

Effects of Land Use on Humus and Soil Enzymes of Yellow Soil Under Soil Erosion

[目的]研究土壤侵蚀条件下,土地利用类型对黄壤不同土层深度的腐殖质(胡敏酸、富里酸和胡敏素)和4种重要土壤酶的影响,为保持土壤肥力提供科学依据。[方法]采用锯齿形布点法,采集土壤表层至30cm深度的3个土层土壤样品,用3次4分法淘汰多余样品,再测定相应指标。[结果](1)保持土壤肥力最好的是灌丛和园地,耕地最容易受侵蚀;土壤肥力高低与胡敏素的含量有直接关系。(2)土壤侵蚀导致水分和氮元素流失会影响胡敏酸的含量;林地、园地和耕地土壤表层的富里酸易流失,而草地仅对于土壤表层肥力保持有作用。(3)耕作对土壤表层的脲酶、碱性磷酸酶和过氧化氢酶活性的不利影响较大;土壤侵蚀导致的土壤pH值改变对土壤酶的影响也很明显。(4)相关性分析表明腐殖质各组分含量与4种土壤酶都有着密切的联系且互相影响。[结论]黄壤受侵蚀下,土地利用类型对腐殖质及土壤酶有明显不同的影响。

[Objective]The effects of land use on humus（humic acid,fulvic acid and humin）and four kinds of important soil enzymes in different yellow soil horizon under soil erosion condition were studied in order to provide some scientific basis for maintaining soil fertility.[Methods]Soil samples were collected in different soil horizon（0—10 cm,10—20 cm and 20—30 cm）at each sample point by zigzag method.Then,soil samples of each layer were mixed evenly in situ and removing of redundant sample was performed by quartering in three times and the corresponding indicators were determined.[Results]（1）Scrub woodland and garden plot had better effect in maintaining soil fertility.However,cultivated land was extremely susceptible to erosion.Soil fertility was directly related with the content of humin of yellow soil.（2）Soil erosion may also affect humic acid content through the loss of water and nitrogen.Fulvic acid of soil in forest land,garden plot and cultivated land lost more easily.However,the grassland had only impact on maintain soil surface fertility.（3）Tillage had significantly adverse effect for activity of urease,alkaline phosphatase and catalase.Meanwhile,soil erosion also evidently affects soil enzymes through the change of soil pH value.（4）Correlation analysis showed that the content of humus component had close contact with the activities of the four kinds of soil enzymes and influenced each other.[Conclusion]The land use types of yellow soil have significantly different effects on humus and soil enzyme activity under erosion.