有机物料添加对菜地土壤氮素转化和温室气体排放的影响  

The effect of organic material addition on vegetable soil nitrogen transformation and greenhouse gases emissions

作　　者：郭树芳 翟丽梅[2] 王洪媛[2] 刘宏斌[2] 赵宝义[1] 雷宝坤[1] GUO Shu-fang;ZHAI Li-mei;WANG Hong-yuan;LIU Hong-bin;ZHAO Bao-yi;LEI Bao-kun(Institute of Agricultural Environment and Resources,Yunnan Academy of Agricultural Sciences,Kunming Yunnan 650205;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Key Laboratory of Nonpoint Source Pollution Control,Ministry of Agriculture and Rural Affairs,Beijing 100081)

机构地区：[1]云南省农业科学院农业环境资源研究所,云南昆明650205 [2]中国农业科学院农业资源与农业区划研究所/农业农村部面源污染控制重点实验室,北京100081

出　　处：《中国土壤与肥料》2024年第10期26-34,共9页Soil and Fertilizer Sciences in China

基　　金：云南省基础研究计划项目(202101AU070102);云南省财政厅专项(530000221100000648476);云南省农业联合专项(202301BD070001-019);中央级公益性科研院所基本科研业务费专项(1610132019050);兴滇英才支持计划项目。

摘　　要：为了探讨菜地土壤氮转化速率及其对不同有机物料添加后的响应特征,为菜地土壤合理施肥提供科学依据,以洱海流域典型菜地土壤为研究对象开展室内培养试验(25℃,田间持水量的60%,5 d),采用^(15)N同位素成对标记技术和氮转化速率计算模型研究了土壤无机氮含量变化和氮转化速率及其对秸秆、生物炭和牛粪3种有机物料添加的响应。结果表明:(1)菜地土壤铵态氮和硝态氮含量随培养时间均呈降低趋势,有机物料添加后降低了土壤无机氮含量。(2)5 d培养期间土壤的平均初级氮矿化速率、初级硝化速率、NO_(3)^(-)消耗速率和NH_(4)^(+)固定速率分别为-28.5、-3.93、1.52和11.9 mg·kg^(-1)·d^(-1)。菜地土壤矿化速率和硝化速率均为负值,土壤以氮的微生物固定为主。(3)有机物料添加后土壤氮矿化速率增加,虽然速率仍为负值,但秸秆添加效果显著。秸秆添加还显著降低了土壤初级硝化速率,但有机物料添加后NH_(4)^(+)固持速率增加,特别在秸秆和生物炭添加后显著增加。(4)秸秆添加显著增加了土壤N_(2)O和CO_(2)排放量,生物炭添加有降低土壤N_(2)O和CO_(2)排放量的趋势但无显著影响,牛粪添加也无显著的影响。对于洱海流域菜地土壤,高碳氮比(C/N)的有机物料添加能增加氮微生物固定作用,但随着时间增加,有机物料有增加矿化作用的趋势,其中生物炭一定程度上降低了土壤CO_(2)和N_(2)O排放量,且增加菜地土壤无机氮含量进而提升其土壤氮供应能力。由此可见,在洱海流域菜地土壤优化施用高C/N的有机物料,科学施肥,能维持土壤的供氮能力,确保菜地土壤的可持续利用,还可能降低温室气体排放。In order to explore the soil nitrogen transformation rates and their responses to different organic materials for the vegetable soil to provide a scientific basis for the rational fertilization of the vegetable soil,the vegetable soil in the Erhai Lake basin was used as the research object to carry out incubation experiment at 25℃and 60%of water holding capacity for15 days.A paired^(15)N tracing incubation trial combined with a nitrogen conversion rate calculation model was conducted to investigate the vegetable soil nitrogen transformation rates and their responses to addition of organic materials(straw,biochar and cow manure).The results showed that:(1)The contents of vegetable soil ammonium nitrogen and nitrate nitrogen contents showed a decreasing trend with the increasing of time,and they decreased after the addition of three organic materials.(2)The average soil gross mineralization rate,soil gross nitrification rate,NO_(3)^(-)consumption rate and NH_(4)^(+)fixation rate during the 5-day incubation period were-28.5,-3.93,1.52 and 11.9 mg·kg^(-1)·d^(-1),respectively.The soil nitrogen mineralization rate and nitrification rate were negative,and thus the vegetable soil was dominated by microbial fixation of nitrogen.(3)The nitrogen mineralization rates increased after the addition of organic materials.Although the rates were also negative,only the effect of straw addition was significant.Straw addition also significantly reduced soil gross nitrification rate.However,the soil NH_(4)^(+)fixation rate increased after the addition of organic materials,especially after the addition of straw and biochar.(4)Straw addition significantly increased soil N_(2)O and CO_(2)emissions,while biochar had a decreasing trend but had no significant effect,and cow manure also had no significant effect.For the vegetable soil in the Erhai Lake basin,the addition of organic matter with high carbon nitrogen ratio(C/N)could increase the nitrogen microbial fixation,but with the increase of time after organic matter input,the organic

关 键 词：有机物料 氮转化速率 温室气体 秸秆 生物炭 牛粪 

分 类 号：X144[环境科学与工程—环境科学] S153[农业科学—土壤学]