| 摘要: |
| 采用地膜覆盖和施加γ-HCH（0 ng·g−1、50 ng·g−1、500 ng·g−1）双因素处理进行紫苜蓿（Medicago sativa L.）盆栽培养试验，通过静态箱-气相色谱法研究了地膜覆盖与施加γ-HCH对土壤温室气体（N2O、CH4和CO2）排放的影响。结果表明：（1）供试土壤是N2O的排放源和CH4的弱吸收汇。（2）土壤N2O和CO2排放通量与土壤含水率和土壤温度呈显著正相关（P＜0.05）。（3）地膜覆盖显著抑制了无植物处理第28—35 d土壤N2O的排放（P＜0.05），以及无植物处理土壤施加γ-HCH时土壤对CH4的吸收峰值（P＜0.05）；且地膜覆盖极显著促进了CO2的排放（P＜0.01）。（4）高浓度γ-HCH（500 ng·g−1）处理下N2O排放通量显著高于低浓度γ-HCH组（P＜0.05），施加高浓度γ-HCH（500 ng·g−1）极显著促进无植物处理和种植苜蓿时无覆盖土壤对CH4的吸收峰值（P＜0.01）；施加γ-HCH会抑制CO2的排放（P＞0.05）。 |
| 关键词: 地膜覆盖 γ-HCH 温室气体 全球增温潜势（GWP） 农田土壤 |
| DOI：10.7515/JEE202023 |
| CSTR：32259.14.JEE202023 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31570440）；陕西省青年科技新星计划项目（2016KJXX-83）；陕西省自然科学基础研究计划青年人才项目（2015JQ4101）；陕西省教育厅科学研究项目（14JK1731） |
| 英文基金项目:National Natural Science Foundation of China (31570440); Shaanxi Province Youth Science and Technology New Star Plan (2016KJXX-83); Natural Science Basic Research Plan in Shaanxi Province (Young Talent Project) ?(2015JQ4101); Scientific Research Project of Shaanxi Provincial Department of Education (14JK1731) |
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| Responses of soil greenhouse gas emissions to plastic film mulching and γ-HCH addition |
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ZOU Qian, WANG Sen, DING Liuyi, LI Jiao, XIAO Dan
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1. Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Xi’an, 710127, China
2. College of Urban and Environmental Sciences, Northwest University, Xi’an 710127, China
3. Shaanxi Xi’an Urban Forest Ecosystem Research Station, Xi’an 710127, China
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| Abstract: |
| Background, aim, and scope Increased concentrations of greenhouse gases exacerbate the greenhouse effect, with the resulting climate change posing threat to human society and ecosystems. Soil acts as an important source and sink of the main greenhouse gases (N2O, CH4 and CO2). As a global agricultural method, plastic film mulching had a certain impact on greenhouse gas emissions. P-HCH caused global concern due to their high toxicity, persistence, and significant adverse effects on ecosystems. In this study, the influence of P-HCH on soil greenhouse gas emissions under mulching was investigated by measuring the emission flux of soil greenhouse gas (N2O, CH4 and CO2) and soil physical and chemical properties. Materials and methods The experiment was conducted by the static chamber technique. Twelve treatments (CK 0, CK 50, CK 500, CK 0′, CK 50′, CK 500′, NM 0, NM 50, NM 500, PM 0, PM 50, PM 500) were designed with plastic mulching and without plastic mulching under different concentrations of γ-HCH (0 ng·g−1, 50 ng·g−1, 500 ng·g−1), and control treatment without plant). Each treatment was repeated for 3 times. Soil temperature and moisture, greenhouse gases were measured and collected once a week. N2O, CH4 and CO2 emission fluxes were determined by GC. Results (1) Soil was the emission source of N2O and the weak absorption sink of CH4. (2) The N2O and CO2 emission flux were positively correlated with soil moisture content and temperature (P＜0.05). (3) Plastic film mulching significantly inhibited N2O emissions in soils without plant treatment from 28 to 35 d (P＜0.05), and the absorption peak of CH4 in soils without plant treatment under the application of γ-HCH (P＜0.05), whereas CO2 emissions (P＜0.01) were significantly increased. (4) N2O emission flux under high concentration of γ-HCH (500 ng·g−1) was significantly γ-HCH (P＜0.05); high concentration of γ-HCH (500 ng·g−1) significantly promoted the peak absorption of CH4 in alfalfa planting (P＜0.01), with CO2 emissions inhibited by applying γ-HCH (P＞0.05). Discussion Under plastic film mulching, γ-HCH affected the emissions of CH4, N2O and CO2 through nitrification, denitrification and soil microorganisms. Plastic film mulching significantly increased soil moisture and CO2 emissions. The application of γ-HCH enhanced the carbon metabolism of the rhizosphere soil under mulching, as well as the absorption of CH4. Meanwhile, γ-HCH had a certain inhibitory effect on soil respiration with bacteria involved in carbon degradation in rhizosphere soil to reduce CO2. The high concentration of γ-HCH (500 ng·g−1) inhibited nitrification, and enhanced the denitrification process, promoting N2O emission. Conclusions (1) N2O and CO2 emission flux was positively correlated with soil moisture content and soil temperature (P＜0.05). (2) The soil was the emission source of N2O and the weak absorption sink of CH4. (3) Plastic film mulching exhibited an inhibition effect on N2O emissions in soils without plant treatment, and the absorption peak of CH4 in soil without plant treatment under the application of γ-HCH, while promoting CO2 emission. (4) High concentration of γ-HCH (500 ng·g−1) significantly promoted N2O emission flux (P＜0.05), and the peak absorption of CH4 in the soil without plant treatment and in the alfalfa soil without plastic film mulching treatment (P＜0.01). Recommendations and perspectives The results are conducive to understanding of the impact of different agricultural practices on soil greenhouse gas emissions. |
| Key words: plastic film mulching γ-HCH greenhouse gas global warming potential (GWP) farm soil |
