绿肥还田对土壤有机碳组分及碳转化酶活性的影响  

Effects of Green Manure Return on Soil Organic Carbon Component and Carbon Invertase Enzyme Activities

作　　者：管彤彤 张燕 陶海宁 董秀 沈禹颖[1] GUAN TongTong;ZHANG Yan;TAO HaiNing;DONG Xiu;SHEN YuYing(College of Grassland Agricultural Science and Technology,Lanzhou University/National Key Laboratory of Grass Seed Innovation and Grassland Agro-Ecosystem,Lanzhou 730020)

机构地区：[1]兰州大学草地农业科技学院/草种创新与草地农业生态系统全国重点实验室,兰州730020

出　　处：《中国农业科学》2024年第14期2791-2802,共12页Scientia Agricultura Sinica

基　　金：国家重点研发项目(2022YFD1300803);国家自然科学基金(42307430);甘肃省青年科技基金计划(22JR5RA533)。

摘　　要：【目的】探究绿肥还田对旱作麦田土壤有机碳组分和碳转化酶活性的影响,为土壤质量提升及“碳中和”目标的实现提供数据支撑。【方法】在甘肃陇东旱塬典型黑垆土上开展毛苕子(Vicia villosa Roth)-冬小麦(Triticum aestivum L.)和饲用油菜(Brassica napus L.)-冬小麦5年轮作系统绿肥还田试验,分析毛苕子、饲用油菜覆盖和翻压还田后冬小麦不同生育时期4个土层(0—5、5—10、10—20、20—25 cm)土壤有机碳(SOC)、易氧化有机碳(EOC)、微生物量碳(MBC)含量和β-1,4-葡萄糖苷酶(βG)、纤维二糖水解酶(CBH)、β-木糖苷酶(βX)、几何平均酶(GMEA)活性的变化特征。【结果】绿肥还田方式对土壤有机碳组分含量及CBH和βX活性有显著影响。与覆盖还田相比,毛苕子和饲用油菜翻压还田能够使0—25 cm土层土壤SOC、EOC和MBC含量提高12.9%、12.1%、53.8%,βG和CBH活性提高了3.2%、10.2%,且对20—25 cm土层的影响最显著。冬小麦不同生育时期的土壤活性有机碳含量及土壤酶活性有显著差异,其中土壤EOC和MBC含量分别在冬小麦成熟期和返青期达到最高,βG、CBH、βX和GMEA活性在冬小麦孕穗期达到最高。βG在不同覆盖方式下变化最显著,活性最高,是绿肥还田后参与土壤碳转化过程的主要酶。不同土层土壤碳组分含量和碳转化酶活性存在显著差异,均随着土层深度的增加而降低。绿肥类型也显著影响土壤碳组分及酶活性,其中饲用油菜还田土壤SOC、MBC含量和βG、CBH、βX、GMEA活性是毛苕子还田的1.08、1.21、1.15、1.23、1.19、1.18倍。结构方程模型表明,绿肥还田方式通过调控其累积分解速率影响SOC的积累,通过影响土壤pH、SOC的累积及绿肥累积分解速率影响GMEA活性。土壤有机碳累积受绿肥还田量影响的效应大于还田方式,而碳转化酶活性反之。【结论】黄土高原夏闲期种植饲用油菜并翻压还田能提高0—25 cm土层【Objective】The aim of this study was to explore the effects of green manure return to the field on the content of soil organic carbon components and the activities of carbon invertase enzymes in dry-crop wheat fields,so as to provide data support for the improvement of soil quality and the achievement of the goal of“carbon neutrality”.【Method】The green manure return field experiment in a 5-year rotation system of hairy vetch(Vicia villosa Roth)-winter wheat(Triticum aestivum L.)and forage rape(Brassica napus L.)-winter wheat was conducted on a typical black clay soil in the Longdong dry loess area of Gansu Province.Soil organic carbon(SOC),easily oxidizable organic carbon(EOC),microbial biomass carbon(MBC)content andβ-1,4-glucosidase(βG),cellobiose hydrolase(CBH),β-xylosidase(βX)geometric mean enzyme activity(GMEA)activities were analyzed in four soil layers of different stages of winter wheat after the mulching and overturning of hairy vetch,forage rape.【Result】The method of green manure returning to the field had a significant effect on the content of soil organic carbon components and the activities of CBH andβX.Compared with mulching,hairy vetch and forage rape overturning were able to increase the content of soil SOC,EOC and MBC by 12.9%,12.1%and 53.8%,while the activity ofβG,CBH increased by 3.2%and 10.2%,respectively,and the most significant effect was found in the 20-25 cm soil layer.There were significant differences in soil labile organic carbon content and soil enzyme activities at different winter wheat growth period,in which soil EOC and MBC content reached the highest at the maturity and greening stage of winter wheat,respectively,and the activities ofβG,CBH,βX and GMEA reached the highest at the booting stage of winter wheat.The soilβG activity had the most significant changes and highest in different return methods and it was the main enzyme participating in the soil carbon transformation process after green manure returned to the field.Soil carbon component content and ca

关 键 词：绿肥 还田方式 还田量 有机碳组分 碳转化酶 黑垆土 

分 类 号：S153.6[农业科学—土壤学] S154.2[农业科学—农业基础科学]