不同土地利用方式对农田土壤有机碳组分及土壤微生物量碳的影响

Effects of different land-use methods on the organic carbon composition and soil microbial biomass carbon of farmland soil

研究不同土地利用方式下农田土壤有机碳组分及微生物量碳的含量特征对指导伊犁河谷土壤资源的合理利用与管理具有重要意义。通过野外实地调查、样品采集、室内分析与地统计相结合的方法,研究伊犁河谷旱地、水浇地、水田、果园、撂荒地5种土地利用方式土壤有机碳(SOC)、颗粒有机碳(POC)、可溶性有机碳(DOC)、轻组有机碳(LFOC)、易氧化有机碳(EOC)和微生物量碳(MBC)的含量特征,比较分析土地利用变化对伊犁河谷农田土壤有机碳组分及微生物量碳的影响。结果表明:土壤TN、AN、AP和AK含量均表现为:水田>水浇地>旱地>果园>撂荒地;水田土壤养分含量显著高于其他4种土地利用方式;土壤SOC含量具有明显的差异特征,主要体现为:水田(25.62 g·kg^(-1))>旱地(13.80 g·kg^(-1))>水浇地(12.19 g·kg^(-1))>果园(11.58 g·kg^(-1))>撂荒地(8.81 g·kg^(-1)),且均达到显著性差异水平(P<0.05)。土壤SOC、DOC、POC、LFOC、MBC含量均呈现出:水田>旱地>水浇地>果园>撂荒地的特征,其差异达到极显著水平,而EOC含量则表现为:水田>水浇地>旱地>果园>撂荒地的特征,其差异达到极显著水平。水田土壤SOC、DOC、POC、LFOC、MBC、EOC含量均显著高于其他4种利用方式。5种土地利用方式土壤SOC与POC、LFOC、DOC之间存在极显著的正相关,其相关系数分别为0.622,0.36,0.489(P<0.01),说明土壤SOC含量是影响土壤POC、LFOC和DOC含量的重要因素。

Investigating the content characteristics of organic carbon components and microbial biomass carbon in farmland soil under different land-use methods is of considerable significance for guiding the rational utilization and management of soil resources in the Ili River Valley.By combining field investigations,sample collection,indoor analysis,and geostatistics,this study explored the content characteristics of soil SOC,POC,DOC,LFOC,EOC,and MBC in five land-use types,including dryland,irrigated land,paddy field,orchard,and abandoned land in the Ili River Valley.This study compared and analyzed the effects of land-use changes on soil organic carbon components and microbial biomass carbon in farmland in the Ili River Valley.Results showed that the contents of TN,AN,AP,and AK in soil were in the order of paddy field>irrigated land>dryland>orchard>fallow land.The nutrient content of paddy soil was significantly higher than that of the other four land-use types.The soil SOC content showed significant differences,primarily reflected in paddy fields(25.62 g·kg^(-1))>dryland(13.80 g·kg^(-1))>irrigated land(12.19 g·kg^(-1))>orchards(11.58 g·kg^(-1))>abandoned land(8.81 g·kg^(-1)),and all reached a significant difference level(P<0.05).The contents of soil SOC,DOC,POC,LFOC,and MBC showed the characteristics of paddy field>dryland>irrigated land>orchard>abandoned land,with significant differences.The EOC content showed the characteristics of paddy field>irrigated land>dryland>orchard>abandoned land,with significant differences.The contents of SOC,DOC,POC,LFOC,MBC,and EOC in paddy soil were significantly higher than those in the other four land-use types.A highly significant positive correlation was detected between soil SOC and POC,LFOC,and DOC in the five land-use types,with the correlation coefficients being 0.622,0.36,and 0.489,respectively(P<0.01),indicating that soil SOC content is an important factor affecting soil particulate organic carbon,light organic carbon,and soluble organic carbon contents.