华北潮土农田土壤酶活性对土地利用强度的响应特征探讨  

Changes of Soil Enzyme Activities in Cropland with Different Land Use Intensities in Fluvo-aquic Soil Area,North China

作　　者：盛美君 李胜君 杨昕玥 王蕊 李洁 李刚 修伟明 SHENG Meijun;LI Shengjun;YANG Xinyue;WANG Rui;LI Jie;LI Gang;XIU Weiming(Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,P.R.China)

机构地区：[1]农业农村部环境保护科研监测所,天津300191

出　　处：《生态环境学报》2023年第2期299-308,共10页Ecology and Environmental Sciences

基　　金：农业农村部环境保护科研监测所基础前沿项目(2022-jcqyrw-xwm);公益性行业(农业)科研专项(201503121-04);中国农业科学院科技创新工程项目。

摘　　要：集约化农业引发的负面效应已成为亟需解决的全球性问题。土壤酶是指示农田土壤质量变化的重要生物学指标,为探究土壤酶活性对农田土地利用强度调整的响应及其驱动因子,设置高土地利用强度(玉米-小麦轮作,MW)、中土地利用强度(临时草地-小麦,GW和玉米-临时草地,MG)和低土地利用强度(多年生草地,PG)共4个处理,在玉米拔节期、扬花期和成熟期采集土壤样品,测定土壤脱氢酶(Dehydrogenase,DHA)、纤维素酶(Cellulose,CL)、脲酶(Urease,UE)和碱性磷酸酶(Alkaine phosphatase,ALP)活性,分析其时间动态变化特征,并耦合土壤理化性质解析其驱动力。结果表明,土地利用强度降低后,土壤pH值下降,而有机质(Soil organic matter,SOM)和全氮(Total nitrogen,TN)含量上升;随着作物生长期的推进,土壤CL与UE活性整体呈现下降趋势,而ALP活性整体呈现上升趋势,土壤DHA未呈现有规律的变化;土地利用强度的降低增加了土壤DHA及ALP活性,而降低了CL与UE活性。相关分析结果表明,土壤CL和UE活性均与pH显著正相关(P<0.05),而ALP活性与pH呈极显著负相关关系(P<0.01);土壤UE活性与含水量(Soil moisture,SM)极显著负相关(P<0.01);CL活性与有效磷(Available phosphorus,AP)显著负相关(P<0.05),与铵态氮极显著负相关(P<0.01)。随机森林分析(Random forest analysis,RFA)结果表明,研究中所选定的土壤理化性质对ALP活性的解释度最高(44.66%)。冗余分析(Redundancy analysis,RDA)结果表明,pH、SM和铵态氮是土壤酶活性的关键调控因子,共同驱动土壤酶活性的变化。研究结果可为华北潮土区土地利用强度调整与保护性耕作措施的提出及优化提供基础数据支撑和理论依据。Agricultural intensification has been proved to exert profound adverse effects on soil ecological system,and has become an urgent global problem.Lowering land use intensity is considered as a feasible measure to recovery and lift up soil quality in agricultural management system.However,little is known about how land use intensity change affects activities of soil key enzymes in soil nutrient regulation.To address this knowledge gap,soil enzyme activities response characteristics were explored under agricultural land use intensity manipulation.In the current study,four treatments featuring with different land use intensities were set up,including one high land use intensity treatment(maize-wheat rotation,MW),two middle land use intensity treatments(temporary grassland rotation with wheat and maize rotation with temporary grassland,GW and MG,respectively),and one low land use intensity treatment(perennial grassland,PG).The determination of dehydrogenase,cellulose,urease and alkaline phosphatase activities was applied for soil samples collected at three stages corresponding to jointing,flowering,and maturity stages of maize,coupled with edaphic property analysis to decipher driving factors.Our results indicated that soil pH decreased with the decline of land use intensity,but it was opposite for soil organic matter and total nitrogen contents.With sampling stage extension,an overall downtrend was observed for both soil cellulase and urease activities,however,alkaline phosphatase activity exhibited an overall uptrend,while soil dehydrogenase did not present a consistent temporal dynamic.Furthermore,declined land use intensity resulted in the increase of both dehydrogenase and alkaline phosphatase activities,but the decrease of cellulase and urease activities.Correlation analysis demonstrated that dehydrogenase and urease were strongly and positively associated with pH,whereas,pH significantly and negatively impacted alkaline phosphatase.Additionally,urease showed a strong and negative linkage with soil moisture.Cell

关 键 词：华北耕作区 潮土 常规耕作 土地利用强度调整 临时草地 土壤酶活性 

分 类 号：X172[环境科学与工程—环境科学]