长期施肥管理变更后稻田土壤甲烷排放研究

发布时间：2018-06-16 14:28

本文选题：CH_4排放 + 水稻土　；参考：《湖南农业大学》2015年硕士论文

【摘要】：基于30年水稻土长期施肥定位试验,在保证原有定位试验正常开展的前提下,将部分化肥处理变更为有机肥处理(或反之),得到4种新处理：常量有机肥改为化肥(N-C),高量有机肥改为化肥(H-C),化肥改为常量有机肥(C-N),常量有机肥改为高量有机肥(N-H)及3种原有处理：化肥(CF),常量有机肥(NOM),高量有机肥(HOM),共7个施肥处理。自2012至2014年,通过连续观测两年水稻轮作周期内不同处理CH4排放通量季节变化,探讨不同有机碳水平水稻土上外源有机碳及土壤有机碳含量对田间CH4排放的影响。结果表明：施化肥处理全年CH4排放通量范围在-0.18 mg·m-2·h-1～3.75 mg·m-2·h-1之间变化,施有机肥处理全年CH4排放通量范围在-0.04mg·m-2·h-1～75.89mg·m-2·h-1之间变化。有机肥处理改施化肥后田间土壤CH4的排放量显著降低,化肥处理改施有机肥或有机肥处理增施有机肥后田间土壤CH4的排放量显著提高。外源有机碳的输入量是决定田间CH4年排放量的决定性因素,外源有机碳输入量(x)与水稻土CH4年累积排放量(y)之间满足直线方程：y=0.1677x+2.746(R2=0.9642,n=21)。土壤有机碳同样也是影响稻田CH4排放的因素,在不同有机碳水平的水稻土上施用等量相同化肥或有机肥,土壤有机碳含量高的水稻土都更有利于CH4的产生。单施化肥稻田土壤有机碳含量(x)和水稻土CH4年累积排放量(y)之间的指数方程：y=0.5154x-4.3454(R2=0.932,n=9)。有机肥可促进土壤有机碳分解释放CH4,土壤有机碳含量相同的条件下,高量有机肥比常量有机肥的土壤有机碳分解比率高1.52%,等量相同有机肥但土壤有机碳含量不同的条件下,土壤有机碳分解比率无显著差异；同样,土壤有机碳也可促进有机物料碳分解释放CH4,在常量有机肥或高量有机肥处理中,土壤有机碳含量高者比低者的有机物料碳分解比率分别多出3.29%和2.52%。
[Abstract]:Based on the long-term fertilization experiment of paddy soil for 30 years, under the premise of ensuring the original location test to be carried out normally, By changing part of chemical fertilizer treatment to organic fertilizer treatment (or vice versa), four new treatments were obtained: conversion of constant organic fertilizer to chemical fertilizer N-Cn, heavy organic fertilizer to chemical fertilizer H-CX, chemical fertilizer to constant organic fertilizer to C-NN, and constant organic fertilizer to high quantity organic fertilizer. N-H) and three original treatments: CFN, NOMN, HOMN, 7 fertilization treatments. From 2012 to 2014, the effects of exogenous organic carbon and soil organic carbon content on Ch _ 4 emission from paddy soils with different organic carbon levels were investigated by observing the seasonal changes of Ch _ 4 emission fluxes from different treatments during two successive cropping cycles. The results showed that the flux range of CH4 emission varied from -0.18 mg m-2 h-1h -1 to -0.04 mg m-2 h-1~75.89mg m-2 h-1 in the whole year under chemical fertilizer application and from -0.04 mg m-2 h-1~75.89mg m-2 h-1 to -0.04 mg m-2 h-1~75.89mg m-2 h-1 in organic fertilizer treatment. The emission of Ch _ 4 from field soil decreased significantly after organic fertilizer treatment and organic fertilizer treatment or organic fertilizer treatment increased the field soil Ch _ 4 emission. The input amount of exogenous organic carbon is the decisive factor to determine the annual emission of CH4 in the field. The linear equation between the input amount of exogenous organic carbon (x) and the annual cumulative discharge of CH4 in paddy soil is 1: y0. 1677x 2.746 R2 (0.9642). Soil organic carbon is also a factor affecting Ch _ 4 emission in paddy fields. Applying the same amount of chemical fertilizer or organic fertilizer to paddy soil with different organic carbon levels, the paddy soil with high organic carbon content is more conducive to Ch _ 4 production. The exponential equation between the soil organic carbon content of paddy field and the annual accumulative discharge of Ch _ 4 in paddy soil is: y0. 0. 5154x-4. 3454N ~ (2) ~ (2) ~ 0. 932n ~ (2). Organic fertilizer can promote the decomposition and release of CH4 from soil organic carbon. Under the condition of the same content of soil organic carbon, the decomposition ratio of soil organic carbon of high organic fertilizer is 1.52% higher than that of constant organic fertilizer, and the same amount of organic fertilizer but different content of soil organic carbon. There is no significant difference in soil organic carbon decomposition ratio; similarly, soil organic carbon can also promote the release of CH4 from organic materials, which can be used in the treatment of constant organic fertilizer or high organic fertilizer. The decomposition ratio of organic materials with high soil organic carbon content was 3.29% and 2.52% higher than that of low organic materials, respectively.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154.1

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