摘要
微生物功能多样性是土壤健康的重要指标,在多种生物地球化学过程中发挥关键作用。本研究基于多年田间小区定位试验,设置间作和单作2种种植模式和4个施氮水平(N_(0),0kg·hm^(-2);N_(125),125 kg·hm^(-2);N_(250),250 kg·hm^(-2);N_(375),375 kg·hm^(-2)),采用Biolog-Eco微平板法,分析了间作与施氮量对土壤微生物代谢活性、多样性和6类碳源利用率的影响。结果表明:施氮处理显著提高了间作和单作土壤的平均颜色变化率(AWCD)值、Simpson指数和Shannon指数,并在N;处理时达到最大值。施氮提高了微生物对氨基酸、胺类和酚类碳源的利用率,但降低了对聚合物的利用。与同一氮水平的单作相比,间作提高了微生物的AWCD值、Simpson指数和Shannon指数,并在N;处理下间作优势最大。间作和施氮均显著影响了6类碳源的代谢活性,且间作提高了微生物对氨基酸和碳水化合物类不稳定碳源的利用率。冗余分析和线性回归分析显示,土壤温度、含水率和土壤有机碳含量的升高是导致AWCD值增加的主要环境因素。因此,间作后土壤理化性状的改变是导致施氮调控下微生物代谢活性增强的主要原因。
Soil microorganism is an important indicator of soil health and plays a critical role in biogeochemical processes.We collected soil samples from a multi-year in-situ field experiment with two cropping modes(maize monocropping and maize-potato intercropping)subjected to four nitrogen(N)levels(N_(0),0 kg·hm^(-2);N_(125),125 kg·hm^(-2);N_(250),250 kg·hm^(-2);N_(375),375 kg·hm^(-2)).By using the Biolog-ECO microplate method,soil microbial metabolic activity,diversity and utilization of six carbon groups were analyzed.The results showed that N application significantly increased the average well color development(AWCD)values,Simpson and Shannon indices,with the highest value at N250 in mono-and inter-cropped soils.Moreover,N application promoted the utilization of amino acids,amines and phenolic compounds,but decreased the utilization of polymers.Compared with monocropping at the same N level,intercropping improved the AWCD values,Simpson and Shannon indices,with a maximal improvement at N250.Intercropping and nitrogen application significantly affected the metabolic activities of the six carbon-source groups.In addition,intercropping improved the utilization of labile carbon sources,such as amino acids and carbohydrates.Results of the redundancy analysis and linear regression showed that intercropping and N application elevated AWCD values by increasing soil temperature,water content,and soil organic carbon content.Therefore,the changes in soil physicochemical properties after intercropping were the main reason for the enhancement of microbial metabolic activity under N application.
作者
王顶
伊文博
李欢
陈林康
赵平
龙光强
WANG Ding;YI Wen-bo;LI Huan;CHEN Lin-kang;ZHAO Ping;LONG Guang-qiang(Yunnan Scientific Observation Station for Cultivated Land Conservation of Ministry of Agriculture and Rural Affairs,Yunnan Agricultural University,Kunming 650201,China;College of Resources and Environmental Science,Yunnan Agricultural University,Kunming 650201,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2022年第3期793-800,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41967004)
云南省中青年后备人才项目(2017HB027)资助。
