沼液灌溉条件下冬小麦—夏玉米轮作农田温室气体的排放特征

发布时间：2018-07-09 14:02

  本文选题：冬小麦-夏玉米轮作 + 沼液灌溉　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：随着集约化、规模化畜禽养殖业的迅速发展,养殖废弃物利用越来越受到关注,利用养殖肥水发酵后的沼液灌溉农田是一个重要方向。但是,不合理的灌溉会带来严重的环境问题。国内外已经展开了大量关于沼液灌溉农田的研究,但大多集中在对土壤、地下水、作物影响的研究,对土壤温室气体排放的研究还较少,尤其缺乏沼液量化灌溉对农田温室气体排放规律的影响。本试验通过大田定位试验,利用静态箱-气相色谱法,设置了不同的沼液灌溉模式,即空白对照处理CK、常规施肥处理CF、灌溉两次2:1沼液处理(T1)、灌溉三次2:1沼液处理(T2)、灌溉四次2:1沼液处理(T3)、灌溉五次2:1沼液处理(T4)共6个处理,研究了在华北平原典型的冬小麦-夏玉米轮作系统下,奶牛养殖场沼液全量替代化肥灌溉后农田主要温室气体C02、N20与CH4的排放特征,同时监测了气象条件(降水量和大气温度)动态变化、土壤理化性质(土壤NH4+-N、N03--N、DOC含量)、土壤脲酶活性以及作物籽粒产量,并分析了农田土壤C02、N20与CH4的排放通量与土壤各因子间的相关性,通过综合作物产量、温室气体排放及土壤因子等经济和环境指标,提出合理的沼液灌溉模式。研究结果如下:一、沼液灌溉并没有改变土壤C02排放通量的季节性变化规律,试验田中C02的排放通量范围为 1.39-23.82 kgCO2-Chm-2·d-1;在整个轮作周期内,CK、T1、T2、T3、T4、CF 处理土壤的 C02-C 累积排放量分别为 1985.13、2424.55、2576.42、2759.88、2893.79、2797.65 kg·hm-2,其大小顺序为 T4CFT3T2T1CK,沼液灌溉与施化肥处理土壤的C02-C累积排放量差异不显著。二、沼液灌溉后T2、T3、T4处理的土壤N2O排放通量均出现峰值,且与常规施肥处理(CF)的差异性达到了显著水平;除T4与常规施肥处理(CF)外,其他处理在越冬期均出现了 N20负排放现象;与常规施肥处理(CF)相比,T3与T4处理并没有造成土壤N2O累积排放量的显著增加,而T1与T2处理明显减少了土壤N20的累积排放量。三、沼液灌溉并未改变土壤CH4排放的变化规律,但会增加土壤CH4的排放通量;沼液灌溉会导致土壤CH4出现较高的正排放峰值,但在玉米季均处于负排放水平;在整个轮作周期,各处理的CH4累积排放量均为负值,土壤是CH4的汇;各处理的CH4的累积吸收量表现出了很大的差异性,其大小顺序为CKT2T1CFT3T4。四、沼液灌溉会引起土壤NH4+-N、NO3--N含量在短时间内的增加;沼液灌溉会显著增加土壤可溶性有机碳的含量,并且这种效果具有积累性;沼液灌溉与常规施肥均提高了土壤脲酶的活性,并且随着灌溉次数的增加土壤脲酶活性越高。五、与常规施肥相比,T1处理(小麦季灌溉沼液一次+玉米季灌溉沼液一次)的小麦籽粒产量减产27.56%,而其他三个沼液灌溉处理均不会造成小麦籽粒的减产;与常规施肥相比,四个沼液灌溉处理均不会引起玉米籽粒的减产;四个沼液灌溉处理每生产 1t 作物籽粒所排放N22O-N 分别为 70.39、44.32、62.77、76.54g。六、通过相关性分析得出,土壤CO2排放通量与土壤DOC和大气温度呈显著正相关性;土壤N2O排放通量与土壤DOC和土壤NO3--N含量呈显著正相关性;土壤CH4的排放通量与土壤NH4+-N含量和土壤含水量呈显著正相关性,而与大气温度呈显著负相关性;土壤脲酶活性与土壤中NO3--N含量呈极显著的正相关性。综上所述,在本试验条件下,四个沼液灌溉模式中,T2处理(小麦季灌溉沼液两次+玉米季灌溉沼液一次)能够在保证作物籽粒产量的同时,减少CO2和N2O的排放,增加土壤对CH4-C的固定,且增加土壤DOC含量,是较为合理的灌溉模式。
[Abstract]:With the rapid development of intensive livestock and poultry farming industry, the utilization of livestock and poultry farming has attracted more and more attention. It is an important direction to irrigate farmland with mariculture of mariculture and fermented water. However, unreasonable irrigation will bring serious environmental problems. A large number of researches on irrigation of biogas slurry have been carried out at home and abroad, but most of them have been carried out. The research on the influence of soil, groundwater and crops, and less research on the emission of greenhouse gas in the soil, especially the effect of biogas slurry irrigation on the law of greenhouse gas emission of farmland. In this experiment, different biogas liquid irrigation modes are set up by static box gas chromatography, that is, blank control treatment CK, Conventional fertilization treatment CF, irrigation two times 2:1 biogas solution (T1), irrigation three 2:1 biogas slurry treatment (T2), four times 2:1 biogas slurry treatment (T3), and five 2:1 marshes (T4) treatment (T4), studied the main greenhouse gas of the dairy farm after the irrigation of the typical winter wheat summer corn rotation system in the North China Plain. The emission characteristics of body C02, N20 and CH4 were observed, and the dynamic changes of meteorological conditions (precipitation and atmospheric temperature), soil physical and chemical properties (soil NH4+-N, N03--N, DOC content), soil urease activity and crop grain yield were monitored, and the correlation between the emission flux of C02, N20 and CH4 and soil factors was analyzed. Quantity, greenhouse gas emission and soil factors and other economic and environmental indicators, put forward a reasonable mode of biogas slurry irrigation. The results are as follows: first, the irrigation of biogas slurry does not change the seasonal variation law of soil C02 emission flux, the emission flux of C02 in the test field is 1.39-23.82 kgCO2-Chm-2. D-1; in the whole rotation period, CK, T1, T2, T3, T4. The cumulative emission of C02-C in soil treated with CF was 1985.132424.552576.422759.882893.792797.65 kg. Hm-2 respectively, the order of its size was T4CFT3T2T1CK, and there was no significant difference in the cumulative emission of C02-C in soil with biogas liquid irrigation and fertilizer treatment. Two, the peak emission of T2, T3 and T4 treated soil after biogas slurry irrigation was both peak and constant. The difference of CF was significant. Except for T4 and conventional fertilization (CF), other treatments had a negative N20 emission in the overwintering period. Compared with the conventional fertilization (CF), T3 and T4 treatment did not cause a significant increase in the cumulative emission of soil N2O, but T1 and T2 treatment significantly reduced the cumulative emission of soil N20. Three, three, biogas slurry irrigation did not change the change law of soil emission, but increased the emission flux of soil CH4; the irrigation of biogas slurry would lead to a higher positive emission peak of soil CH4, but at the negative emission level in the corn season; in the whole rotation period, the CH4 cumulative emission of each treatment was negative, the soil was the sink of CH4 and the CH of each treatment. The cumulative absorption of 4 showed a great difference in the order of CKT2T1CFT3T4. four. The irrigation of biogas liquid could cause the increase of soil NH4+-N, NO3--N content in a short time, and the content of soluble organic carbon in soil could be significantly increased by the irrigation of biogas liquid, and the effect was accumulated, and the soil urea irrigation and conventional fertilization improved soil urea. The activity of the enzyme, and the higher the soil urease activity increased with the increase of irrigation times. Five, compared with the conventional fertilization, the grain yield of wheat was reduced by 27.56% by T1 treatment (one time the irrigation of the wheat season irrigation marsh liquid and the irrigation of the corn season), and the other three biogas irrigation treatments would not produce the wheat grain yield. Compared with the conventional fertilization, four biogas marshes were compared with conventional fertilization. The treatment of liquid irrigation did not cause the reduction of corn grain; the N22O-N of each 1t crop seed produced by four biogas slurry irrigation treatment was 70.39,44.32,62.77,76.54g. six respectively. The correlation analysis showed that the soil CO2 emission flux had a significant positive correlation with the soil DOC and the atmosphere temperature, and the soil N2O emission flux and soil DOC and soil NO3. The content of --N has significant positive correlation, and the emission flux of soil CH4 has a significant positive correlation with soil NH4+-N content and soil water content, but has a significant negative correlation with the atmospheric temperature, and the soil urease activity has a significant positive correlation with the content of NO3--N in soil. In this experiment, in the experimental conditions, four biogas irrigation modes, T2 treatment ( The two times of irrigation of biogas liquid in wheat season and irrigation of biogas liquid in corn season can reduce the emission of CO2 and N2O, increase the fixation of soil to CH4-C and increase the content of DOC in soil, which is a more reasonable irrigation mode.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X712
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本文编号：2109598