| 摘要: |
| 【目的】研究氮肥和秸秆还田对夏玉米土壤氧化亚氮（N2O）排放及活性氮组分的影响，以期为关中地区合理高效种植制度优化提供一定的理论支持。【方法】于2020-2022年，在陕西省关中地区进行大田定位试验，试验设置施氮量和秸秆还田方式2个因素，其中施氮量包括传统施氮（N1）和减量施氮（N0.7）2个水平，秸秆还田方式包括秸秆不还田（S0）和秸秆还田（S）2个水平，采用随机区组设计，共计4个处理，分别为传统施氮+秸秆还田（N1S）、减量施氮+秸秆还田（N0.7S）、传统施氮+秸秆不还田（N1S0）和减量施氮+秸秆不还田（N0.7S0），测定不同处理的土壤N2O排放通量、土壤活性氮组分（硝态氮（NO-3-N）、铵态氮（NH+4-N）、无机氮（IN）、有机氮（DON）、微生物生物量氮（MBN））含量以及夏玉米产量和单位产量N2O累积排放量，并分析了土壤N2O排放通量与土壤活性氮组分的相关性。【结果】在同一施氮量处理下，与秸秆不还田（S0）处理相比，秸秆还田处理（S）增加了土壤N2O累积排放量、NO-3-N、NH+4-N、IN、DON、MBN含量以及夏玉米产量和单位产量N2O累积排放量；在同一秸秆还田方式下，与传统施氮（N1）处理相比，减量施氮（N0.7）处理降低了土壤N2O累积排放量、NO-3-N、NH+4-N、IN、DON、MBN含量以及夏玉米产量和单位产量N2O累积排放量。与N1S0处理相比，N1S和N0.7S处理显著增加了夏玉米产量和N2O累积排放量，N0.7S0处理显著降低了夏玉米产量和N2O累积排放量。相关性分析结果显示，土壤N2O排放通量与土壤NO-3-N、NH+4-N、IN、DON和MBN含量存在极显著正相关关系。【结论】 传统施氮+秸秆不还田处理比较，传统施氮+秸秆还田处理和减量施氮+秸秆还田具有明显的增产效应，减量施氮+秸秆不还田处理可显著降低N2O排放。 |
| 关键词: 夏玉米 减量施氮 秸秆还田 N2O排放 |
| DOI：10.13207/j.cnki.jnwafu.2025.01.004 |
| 分类号: |
| 基金项目:国家自然科学基金项目(31971859)；陕西省循环农业工程技术研究中心项目(2019HBGC-13) |
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| Effects of nitrogen fertilizer and straw return on nitrous oxide emission and soil reactive nitrogen fractions in summer maize field |
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ZHANG Zhihao, HUANG Yuming, BAI Yuxin, PENG Hao, HUANG Chaolong, HAO Xiaoyi, REN Guangxin
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College of Agronomy,Northwest A&F University,Yangling,Shaanxi 712100,China
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| Abstract: |
| 【Objective】This study investigated the effects of nitrogen fertilizer and straw return on nitrous oxide (N2O) emission and reactive nitrogen fractions in summer maize farmland soils to provide support for establishing a rational and efficient cropping system in Guanzhong,Shaanxi.【Method】The field locating experiment was conducted in Guanzhong,Shaanxi from 2020 to 2022.The trial was set up with two factors of nitrogen application and straw return method.Nitrogen applications included two levels of traditional nitrogen application (N1) and reduced nitrogen application (N0.7),and straw return methods included two levels of straw not returned to field (S0) and straw returned to field (S) in a randomized block group design.A total of four treatments including traditional nitrogen application+straw returned to field (N1S),reduced nitrogen application+straw returned to field (N0.7S),traditional nitrogen application+straw not returned to field (N1S0) and reduced nitrogen application+straw not returned to field (N0.7S0) were used to determine soil N2O emission fluxes,soil reactive nitrogen fractions of nitrate nitrogen (NO-3-N),ammonium nitrogen (NH+4-N),inorganic nitrogen (IN),dissolved organic nitrogen (DON) and microbial biomass nitrogen (MBN),summer maize yield and cumulative N2O emission per unit of yield.Correlations between soil N2O emission flux and soil reactive nitrogen fractions were also analyzed.【Result】With same nitrogen levels,straw-returned treatments (S) increased soil N2O cumulative emissions,contents of NO-3-N,NH+4-N,IN,DON and MBN,summer maize yield and N2O cumulative emissions per unit of yield,in comparison to strawnotreturned treatments (S0).With same strawreturned methods,reduced N application treatment (N0.7) reduced soil N2O cumulative emissions,contents of NO-3-N,NH+4-N,IN,DON and MBN,summer maize yield and cumulative N2O emissions per unit of yield,in comparison to conventional N application treatments (N1).Compared with the N1S0 treatment,the N1S and N0.7S treatments significantly increased summer maize yield and N2O cumulative emissions,and the N0.7S0 treatment significantly decreased summer maize yield and N2O cumulative emissions.There were highly significant positive correlations between soil N2O emission fluxes and contents of soil NO-3-N,NH+4-N,IN,DON and MBN.【Conclusion】Compared with the traditional nitrogen application+straw not returned to the field treatment,the traditional nitrogen application+straw returned to the field treatment and the reduced nitrogen application+straw returned to the field treatment had apparent yield increase effects,and the reduced nitrogen application+straw not returned to the field treatment significantly reduced N2O emission. |
| Key words: summer maize nitrogen reduction straw return N2O emission |
