中國農業科學 ?? 2020, Vol. 53 ?? Issue (5): 977-989.doi: 10.3864/j.issn.0578-1752.2020.05.010

? 土壤肥料·節水灌溉·農業生態環境 ? 上一篇    下一篇

秸稈還田深度對土壤溫室氣體排放及玉米產量的影響

朱曉晴,安晶,馬玲,陳松嶺,李嘉琦,鄒洪濤(),張玉龍   

  1. 沈陽農業大學土地與環境學院/農業農村部東北耕地保育重點實驗室/土肥資源高效利用國家工程實驗室,沈陽 110866
  • 收稿日期:2019-06-03 接受日期:2019-11-12 出版日期:2020-03-01 發布日期:2020-03-14
  • 通訊作者: 鄒洪濤 E-mail:[email protected]
  • 作者簡介:朱曉晴,E-mail:[email protected]
  • 基金資助:
    遼寧省重點研發計劃項目(2019020050-JH2/102);沈陽市中青年科技創新人才支持計劃項目(RC170580);遼寧省“百千萬人才工程”資助項目(2016921066)

Effects of Different Straw Returning Depths on Soil Greenhouse Gas Emission and Maize Yield

ZHU XiaoQing,AN Jing,MA Ling,CHEN SongLing,LI JiaQi,ZOU HongTao(),ZHANG YuLong   

  1. College of Land and Environment, Shenyang Agricultural University/Northeast Key Laboratory of Conservation and Improvement of Cultivated (Shenyang) Ministry of Agriculture and Rural Affairs/ National Engineering Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Shenyang 110866
  • Received:2019-06-03 Accepted:2019-11-12 Online:2020-03-01 Published:2020-03-14
  • Contact: HongTao ZOU E-mail:[email protected]

摘要:

【目的】秸稈還田是培肥地力、增加土壤有機質和改善土壤結構的重要技術手段,但以往的研究表明秸稈還田會加速土壤溫室氣體的排放。本研究通過對秸稈不同還田深度下農田土壤溫室氣體排放特征和產量的研究,明確降低溫室氣體排放量的最佳還田深度,以期為合理利用秸稈、提高作物產量,實現農業可持續發展提供科學依據。【方法】采用大田微區試驗,以玉米為供試作物,設置4個還田深度,采用靜態箱-氣相色譜法測定整個玉米生長季不同還田深度下溫室氣體(CO2、CH4、N2O)的排放特征,產量及產量構成因素。試驗共設5個處理,還田深度分別為0—10 cm(T1)、10—20 cm(T2)、20—30 cm(T3)和30—40 cm(T4),同時以不還田處理作為對照(CK)。【結果】(1)在整個玉米生長季CO2和N2O均表現為排放,CH4表現為吸收。CO2累積排放量為T3處理最高,較CK顯著增加了28.6%,T4處理增加最少,較CK顯著增加了17.1%(P<0.05),但T1與T4處理之間差異不顯著;而N2O的累積排放量T2處理為最高,與CK相比,累積排放量顯著增加111.3%,T4處理增加最少,與CK相比顯著增加了12.8%(P<0.05);CH4則表現為吸收,且秸稈還田后降低了農田土壤對CH4的吸收能力,吸收量表現為CK處理>T4處理>T3處理>T1處理>T2處理,且各還田處理與CK之間差異顯著(P<0.05)。(2)秸稈不同還田深度下,與對照相比,各處理玉米產量均顯著增加,增產在5.6%—20.8%(P<0.05),但各處理之間的穗長、穗粗和行粒數差異不顯著。當秸稈還至30—40 cm時,產量最高,較CK增加了20.8%,表明秸稈還田對提升土壤肥力及作物增產有重要作用。(3)從溫室氣體綜合增溫潛勢(GWP)和溫室氣體排放強度(GHGI)來看,在100年尺度上,GWP表現為T2處理>T3處理>T1處理>T4處理>CK處理,而GHGI表現為T2處理>T3處理>T1處理>CK處理>T4處理,表明與CK相比,各處理均增加了玉米季溫室氣體的綜合增溫潛勢,而T4處理則降低了玉米季溫室氣體排放強度,說明秸稈深還至30—40 cm可在一定程度上緩解全球增溫潛勢。【結論】秸稈還田會顯著增加CO2和N2O排放,降低對CH4的吸收能力;秸稈深還至30—40 cm可相對降低綜合增溫潛勢,降低溫室氣體排放強度,同時顯著增加玉米產量。因此,為實現較高的玉米產量和較低的溫室氣體排放強度,秸稈深還至30—40 cm是較為合理的土壤改良培肥方式。

關鍵詞: 溫室氣體, 秸稈還田深度, 排放通量, 玉米產量, 綜合增溫潛勢

Abstract:

【Objective】 Straw returning is an important technical means to improve soil fertility, increase soil organic matter and improve soil structure. However, previous studies have shown that straw returning can accelerate the emission of greenhouse gases in soil and increase greenhouse effect. Through the study of greenhouse gas emission characteristics and maize yield of farmland soil under different straw returning depths, the optimum returning depths were determined in this study, in order to provide scientific basis for rational utilization of straw, increase crop yield and realize sustainable agricultural development. 【Method】 In the field micro-plot experiment, maize was used as the test crop, and four returning depths were set up, which were 0-10 cm (T1), 10-20 cm (T2), 20-30 cm (T3) and 30-40 cm (T4), respectively. At the same time, the non-returning treatment was used as the control (CK), with a total of five treatments. Static box-gas chromatography was used to determine the greenhouse gases (CO2, CH4, N2O) emission characteristics under different returning depths in whole maize growing season, and yield and yield components at maturity were measured. 【Result】 (1) During the whole maize growing season, both CO2 and N2O showed emission, but CH4 showed absorption. The cumulative emission of CO2 was the highest under T3 treatment, which increased by 28.6% significantly compared with CK. The increase rate of cumulative emission of CO2 under T4 treatment was the least, which was significantly increased by 17.1% compared with CK (P<0.05), but the difference between T1 and T4 treatment was not significant; the cumulative emission of N2O was the highest under T2 treatment. Compared with CK, the cumulative amount of N2O increased significantly by 111.3%, the increase rate under T4 treatment was the least, and the CK increased significantly by 12.8% (P<0.05). However, CH4 showed absorption, and the absorption capacity of CH4 in farmland soil was reduced after straw returning; the absorption capacity was CK treatment>T4 treatment>T1 treatment>T3 treatment>T2 treatment, and there were significant differences between treatments and CK (P<0.05). (2) Compared with the control, the yield of maize in each treatment increased significantly, and the yield increased by 5.6%-20.8% (P<0.05). However, there were no significant difference in ear length, ear diameter and grain number between treatments. When the straw returned to 30-40 cm, the yield was the highest, which increased by 20.76% than that under CK, and it indicated that straw returning had an important effect on improving soil fertility and increasing crop yield. (3) According to the comprehensive greenhouse gas effect (GWP) and greenhouse gas emission intensity (GHGI), on the scale of 100 years, GWP showed T2 treatment>T3 treatment>T1 treatment>T4 treatment>CK treatment, while GHGI showed T2 treatment>T3 treatment>T1 treatment>CK treatment>T4 treatment. Compared with CK, all treatments increased the comprehensive greenhouse gas effect, while T4 treatment reduced greenhouse gas emission intensity in maize season, indicating that straw returning to 30-40 cm could alleviate the global warming trend to a certain extent. 【Conclusion】 Straw returning could increase CO2 and N2O emissions significantly, but increase the absorption capacity of CH4. The straw returning to 30-40 cm could reduce the global warming potential and the intensity of greenhouse gas emissions, and increase the maize yield significantly. Therefore, in order to simultaneously achieve higher maize yield and lower greenhouse gas emission intensity, straw returning to 30-40 cm was a more reasonable way of soil improvement and fertilization.

Key words: greenhouse gases, straw returning depths, emission flux, maize yield, global warming potential

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