【作者】 崔振波；

【导师】 曹成有；

【作者基本信息】 东北大学 ， 生物化工， 2009， 硕士

【摘要】 为了探讨不同利用方式对草甸草地土壤质量的影响,选择科尔沁沙地西部地区天然草地、林地、开垦4年的玉米地、开垦20年的玉米地和水稻田五种利用方式为对象,通过样品采集和测试分析,研究了0～10 cm和10～30 cm土层中微生物生物量、土壤酶和土壤养分的变化特征以及三者之间的相关关系。结果表明,不同利用方式、不同土层深度对土壤养分、土壤微生物生物量、土壤酶活性具有极显著影响。土壤有机质和全氮含量均表现为0～10 cm土层高于10～30 cm土层。随着人为扰动强度和持续时间的增加,土壤养分含量逐渐降低。天然草地和林地土壤中微生物生物量C、N、P含量随土层加深而减少,且相对保持在较高水平,在两种玉米地中含量相对较低且土层间差别不大;而在水田10～30 cm土层中微生物生物量C、N含量则显著高于0～10 cm土层。土壤脲酶、蛋白酶、磷酸单酯酶、硝酸还原酶、蔗糖酶、多酚氧化酶、脱氢酶的活性在草地和林地中活性较高且0～10 cm土层＞10～30 cm土层;在4年和20年玉米地中土层间差异不显著;水田中的多酚氧化酶、脲酶、磷酸单酯酶、硝酸还原酶和蔗糖酶均表现出0～10cm土层活性显著低于10～30 cm土层。土壤微生物生物量、土壤酶活性以及土壤养分之间均存在显著的相关关系。微生物生物量C与脲酶,全氮与磷酸单酯酶和脱氢酶,有机质、全氮与微生物生物量C、N之间存在显著的回归关系。总体来看,天然草地和林地中土壤养分和生物活性维持较高水平,具有持续的生产能力,而垦荒(包括开发水田)后,土壤质量下降,而且容易引起土地沙化,因而退耕还林还草是本地区恢复土地生产力的可行途径之一。更多还原

【Abstract】 The objective of this study was to determine how different land use of meadow grassland on the biological activities of a meadow soil. The soil microbial biomass, enzyme activities and nutrients as well as the relationships among them were analyzed with five typical land use in western Horqin Sandy Land selected as test objects. Soil sample at the depth of 0-10 and 10-30 cm from natural grassland, forestry field, 4-year corn filed, 20-year corn filed and paddy field. The results showed that different land use and soil depths have significant influence on the soil nutrient contents, microbial biomass, and enzyme activities. Soil organic carbon and total N contents are both higher in 0-10 cm layer than those in 10-30 cm layer. The soil nutrient contents decreased gradually with the increase of intensity and duration of human disturbances. Soil microbial biomass C, N and P of forest land and grassland are holding at a relatively higher level, and the value decreased gradually with soil depth. The contents present lower level in two the kinds of cornfields and the difference the between two soil layers was not significant, While the contents of paddy field soil are significantly higher in 10-30 cm layer than whose in 0-10 cm layer. The activities of soil protease, urease, saccharase, phosphomonoesterase, polyphenoloxpdase, nitrate reductase and dehydrogenase of forest land and grassland were higher than other land use type, and the values in 0-10 cm was higher than those in 10-30 cm, however the difference between the two depth of 4-year and 20-year cornfields are not significant. The activities of phosphomonoesterase, saccharase, urease, polyphenol oxidase, and nitratereductase of paddy field are significantly lower in 0-10 cm layer than those in the 10-30cm layer. There existed significant correlations among soil microbial biomass, enzyme activities and nutrient contents. There are significant regression correlations between soil microbial biomass C and urease, between total N and phosphomonoesterase and dehydrogenase, between organic carbon and soil microbial biomass C and N and between total N and soil microbial biomass C and N. On the whole, soil nutrient contents and soil biological activities are at a high levels, therefore the continuable production ability was present in these two land use. Along with land reclamation, including paddy field, soil quality descended and is easily eroded to desertification. Therefore returning farmland to forests or grassland is one of the feasible ways of restoration of land productivity in this region更多还原