砾石覆盖年限对连作农田土壤微生物和酶活性的影响  

Temporal Effects of Gravel-Sand Mulching on Soil Microbial Population and Soil Enzyme Activity in Croplands with Continuous Cultivation

作　　者：邱阳[1] 王亚军[1] 谢忠奎[1] 张亚娟[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《水土保持通报》2011年第5期65-68,181,共5页Bulletin of Soil and Water Conservation

基　　金：中国科学院农业项目"黄土高原中西部地区资源高效型生态农业研究与示范"(CASN-115-06-08)

摘　　要：以中国科学院皋兰试验站的连续砾石覆盖2,7,11,15和20a的连作西瓜农田为对象,对不同覆盖年限连作西瓜农田土壤中微生物数量、过氧化氢酶、淀粉酶、蔗糖酶、多酚氧化酶、脱氢酶酶活性进行了研究。结果表明,随着砾石覆盖年限的增加,土壤微生物数量逐渐降低,在覆盖7～11a时最为稳定,此后微生物多样性指数和均匀度指数持续降低。在0～20a范围内,砾石覆盖下多数土壤酶活性随着覆盖年限的延长呈抛物线变化趋势,在砾石覆盖10～11a之前呈上升趋势,随后呈下降趋势。总体而言,在砾石覆盖11a左右的农田中,土壤酶活性最高,砾石覆盖超过15a的农田土壤酶活性较低,作物减产,需要停耕堆肥,重新换沙来维持产量。这一结果可为砾石覆盖农田土壤的持续利用与科学管理提供基础依据。Soil samples collected from continuous croplands with 2,7,11,15 and 20 year gravel-sand mulching in Gaolan Research Station,Gansu Province were analyzed for soil microbial population and soil enzyme activities.The results show that with increase of mulching time,soil microbial population decreased from the beginning to a low stable state in about 7 to 11 years,and then the Shannon diversity index and Mclntosh diversity index continued to decrease.The enzyme activities of soils showed a parabola curve over time.Most of them increased and reached their peaks in 10 to 11 years,and then declined.The soil enzyme activity of the cropland covered for more than 15 years was so low that the yield of the crops decreased.At this stage,farming practices should be stopped,and compost should be added with renewal of soil sand to recover the productivity of the land.The results of the study can provide a theoretical basis for the sustainable utilization and management of the gravel-sand mulched croplands.

关 键 词：砾石覆盖 连作 酶活性 西瓜 

分 类 号：S791.2[农业科学—林木遗传育种]