禾本科绿肥还田对盐碱地棉田土壤碳氮及微生物量碳氮的影响  

Effects of returning gramineous green manure to cotton field on soil carbon and nitrogen in saline alkali soil

作　　者：王敬宽 高枫舒 张楷悦 李帅 柳新伟[1] WANG Jingkuan;GAO Fengshu;ZHANG Kaiyue;LI Shuai;LIU Xinwei(College of Resources and Environment,Qingdao Agricultural University,Qingdao 266109,China)

机构地区：[1]青岛农业大学资源与环境学院,青岛266109

出　　处：《中国生态农业学报（中英文）》2023年第3期396-404,共9页Chinese Journal of Eco-Agriculture

基　　金：国家重点研发计划项目(2021YFD190090308);山东省现代农业产业技术体系棉花岗位创新团队(SDAIT-03-06)资助

摘　　要：为探讨绿肥还田对盐碱地棉田土壤碳氮和微生物量碳氮的影响,于2018—2019年选取黑麦草‘冬牧70’和大麦‘驻大麦4号’2种耐低温耐盐碱的禾本科绿肥进行原位还田试验,设置冬闲农田-棉花(T1)、黑麦草-棉花(T2)和大麦-棉花(T3)3个处理,测定不同处理和绿肥还田后不同时期(15 d、50 d、110 d和180 d)棉田土壤有机碳(SOC)、土壤全氮(TN)、土壤微生物量碳(SMBC)和微生物量氮(SMBN)的含量,并计算土壤微生物熵(SMQ)和土壤微生物量碳氮比(SMBC/SMBN)值。结果表明,T2和T3均能显著增加SOC、TN含量,并在180 d时达最大值9.50 g∙kg^(−1)、798.84 mg∙kg^(−1)和9.91g∙kg^(−1)、759.34 mg∙kg^(−1),分别显著高于T1处理。T2和T3的SMBC、SMBN含量在整个还田期的变化动态基本一致,呈前期稳定增长且显著高于T1,后期有所降低且在110 d时略低于T1的变化动态;并且均在50 d时达最大值,此时较T1分别高出81.46%、47.76%和77.33%、43.13%;同时还田后T2处理不同时期的SMBC和SMBN含量均高于T3。SMQ不同处理的变化趋势与SMBC一致,2种绿肥处理除110 d外均高于T1处理,T2在15 d时达到最大值2.82%,而T3在50 d时达到最大值2.98%。各处理SMBC/SMBN值均在4~7之间变化,由此可判断绿肥还田后土壤中微生物群落以细菌为主;同T1相比,除110 d外T2和T3均表现出较高的SMBC/SMBN值。综上所述,在盐碱地冬闲农田种植绿肥并还田可以显著提高棉田土壤碳氮和土壤微生物量碳氮含量,改善土壤微生物群落组成和提高土壤微生物固碳效应,为后茬作物生长提供养分。研究结果对盐碱地冬闲田的合理利用具有指导意义。To explore the effect of gramineous green manure on soil carbon and nitrogen contents in saline alkali cotton fields,two low-temperature-and saline alkali-tolerant gramineous green manures,ryegrass‘Dongmu 70’and barley‘Zhudamai No.4’were selected for in situ returning experiments from 2018 to 2019.Three treatments were set up:winter fallow farmland-cotton(T1),ryegrass-cotton(T2),and barley-cotton(T3).The contents of soil organic carbon(SOC),soil total nitrogen(TN),soil microbial biomass car-bon(SMBC),and soil microbial biomass nitrogen(SMBN)were measured in different treatments at different periods(15,50,110,and 180 d)after returning green manure to field.The soil microbial quotient(SMQ)and ratio of soil microbial biomass carbon to ni-trogen(SMBC/SMBN)were calculated.The results showed that both T2 and T3 significantly increased the contents of SOC and TN,and reached maximum values of 9.50 g∙kg^(−1)and 798.84 mg∙kg^(−1)(T2)and 9.91g∙kg^(−1)and 759.34 mg∙kg^(−1)(T3)at 180 d after returning green manure,respectively,and they were significantly higher than those of T1 treatment by 29.60%and 27.85%(T2)and 35.20%and 25.13%(T3),respectively.The variation dynamics of SMBC and SMBN contents in T2 and T3 were basically similar throughout the returning period,indicating a trend of stable growth in the early stage and significantly higher contents than those in T1,and a de-crease in the latter stage and slightly lower contents than those in T1 at 110 d.The maximum values of SMBC and SMBN were 217.84 mg∙kg^(−1)and 34.51 mg∙kg^(−1)for T2,and 212.88 mg∙kg^(−1)and 33.43 mg∙kg^(−1)for T3 at 50 d and were higher than T1 by 81.46%and 47.76%,and 77.33%and 43.13%,respectively.In addition,the contents of SMBC and SMBN at different periods after returning to the field demonstrated that T2 was higher than T3.The change trend in SMQ in different treatments was consistent with that of SMBC.The two green manure treatments showed higher SMQ except for 110 d.T2 reached a maximum value of 2.82%at 15 d,

关 键 词：绿肥还田 盐碱地 棉田 土壤碳氮 土壤微生物量碳氮 

分 类 号：S142[农业科学—肥料学]