我国南方稻田秸秆还田方式的固碳减排效应及推广政策建议

发布时间：2018-03-16 16:16

本文选题：秸秆还田　切入点：土壤固碳　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：农作物秸秆是一种多用途和可再生的生物资源。20世纪80年代以来,我国农业生产快速发展,作物秸秆的产量越来越大,作物秸秆出现区域性、结构性和季节性的过剩。而且秸秆直接作为生活燃料和饲料的比例大幅度减少,广大农民为赶农时,抢播种,总有大量的小麦、玉米、水稻等秸秆在田间被直接焚烧,屡禁不止。秸秆田间焚烧不仅浪费宝贵的资源,而且污染大气环境,威胁交通运输安全,影响城乡居民生活。我国农业可持续发展中面临的紧迫问题是如何合理有效地处理农作物秸秆。本研究以我国南方地区为研究对象,采用Meta分析法,从宏观区域角度定量分析不同秸秆还田方式对我国南方稻田土壤固碳增量和温室气体排放量的影响,以明确该区域不同秸秆还田方式的净减排潜力;通过问卷调查和农户访谈,从微观角度研究农户秸秆还田行为,以明确农户秸秆还田行为及影响农户秸秆还田行为决策的主要影响因素。通过宏观区域研究和微观农户行为的研究相结合,明确净减排条件下我国南方稻田适宜的秸秆还田方式,并据此提出相应的政策建议。本研究通过区域整合分析和实证研究,得出如下结论:1.翻耕秸秆还田(CTS)、免耕秸秆还田(NTS)和旋耕秸秆还田(RTS)均能在很大程度上提高我国南方稻田表土有机碳含量,这三种秸秆还田方式的表土有机碳相对年变化量(RM)分别达到0.42、0.37和0.64 g.kg-1·a-1;两熟制、三熟制在不同的秸秆还田方式下的RM均值为0.40和0.61 g·kg-1·a-1,且三熟制稻田在同一秸秆还田方式下RM均比两熟制大;表土固碳持续时间在CTS、NTS和RTS下分别为27年、44年和30年,且在整个固碳周期内所能增加的有机碳量分别为15.8%、23.3%和27.3%。旋耕秸秆还田相较于其他两种秸秆还田方式能最大限度地提高土壤有机碳含量,故在我国南方稻田地区为了提高土壤的固碳能力应推广旋耕秸秆还田方式。2.翻耕秸秆还田(CTS)、免耕秸秆还田(NTS)和旋耕秸秆还田(RTS)均能提高南方稻田温室气体排放,其CH4季节累计排放量分别为326.84、265.69和313.78 kg·hm-2,N2O季节累计排放量分别为1.55、1.40和1.73kg·hm-2;同一秸秆还田方式下,三熟制稻田的温室气体季节累计排放量都高于两熟制;还田秸秆种类影响稻田温室气体的排放,且稻季麦秸秆还田在不同还田方式下的CH4季节累计排放量均高于麦季稻秸秆还田,而N20季节累计排放量的情形恰好相反;旋耕秸秆还田对土壤固碳减缓全球变暖效益的抵消作用最大,而免耕秸秆还田最小。3.农户秸秆田间焚烧的意愿受到农户对秸秆还田概念的认知、农户对秸秆还田好处的了解、农户的受教育程度、农户对秸秆田间焚烧危害的了解以及禁烧政策的执行力度等五个因素的显著影响。此外,农户免耕秸秆还田技术的采纳受到农户对免耕秸秆还田的认知以及农户拥有最大一块土地的面积这两个因素的显著影响。因此,本研究认为,我国南方地区应推广适宜的免耕秸秆还田方式。政府应增加对免耕秸秆还田技术的宣传,加大对农户秸秆还田的补贴力度,提高农户秸秆还田的经济收益,并积极组织农业技术人员研究秸秆还田技术,突破秸秆还田影响出苗率、导致病虫害等问题。
[Abstract]:Crop straw is a versatile and renewable biological resources.20 century since 80s, the rapid development of agricultural production in our country, more and more high yield crop straw, crop straw and the emergence of regional, structural and seasonal excess. And straw as the fuel of life and the proportion of feed is greatly reduced, the majority of farmers to catch the farming season rob, sowing, there are a lot of wheat, corn, rice straw was burned in the field, repeated. Straw burning is not only a waste of valuable resources, but also pollutes the atmospheric environment, threatening the safety of transportation, affect the life of urban and rural residents. Pressing problems facing the agricultural sustainable development in China is how to reasonably and effectively treatment of crop straw. In this study, the southern region of China as the research object, using the Meta analysis method, from the macro perspective of regional quantitative analysis of different type of straw also in southern China Tian Fang The effects of paddy soil carbon sequestration and increment of greenhouse gas emissions, with a net reduction potential in order to clarify the different ways of straw returning; through the questionnaire survey and interviews of farmers, farmers straw returning from microcosmic angle, the main influence factors to the peasant 'behavior and the influence of straw straw farmers. Through the study of behavioral decision making regional macro research and micro behavior of farmers combined with clear net reduction of China under the condition of suitable southern paddy rice straw returning mode, and put forward corresponding policy recommendations. Through the study of regional integration analysis and empirical study, conclusions are as follows: 1. of conventional tillage (CTS), no tillage (NTS) (RTS) and rotary tillage can improve soil organic carbon content in paddy field in South China to a great extent, soil organic carbon of the three ways of straw returning relative years variation (RM) At 0.42,0.37 and 0.64 g.kg-1 A-1 respectively; two cooked, cooked three RM mean in different ways of straw returning under 0.40 and 0.61 G - kg-1 - A-1, and the three cropping paddy soil in the same way under the RM straw than the two cropping system; soil carbon sequestration duration in CTS. NTS and RTS were 27 years, 44 years and 30 years, which can increase the amount of organic carbon and carbon sequestration in the whole period were 15.8%, 23.3% and 27.3%. rotary tillage compared to the other two kinds of straw can maximize the soil organic carbon content, so in the southern paddy field area in China in order to enhance the carbon sequestration capacity of soil should promote rotary tillage.2. conventional tillage (CTS), no tillage (NTS) and rotary tillage (RTS) can improve the southern paddy field of greenhouse gas emissions, the CH4 seasonal cumulative emissions were 326.84265.69 and 313.78 kg - hm-2, N2O season Day cumulative emissions were 1.55,1.40 and 1.73kg hm-2; the same straw under greenhouse gas season three cropping paddy soil cumulative emissions are higher than two cooked rice straw; effect of the type of greenhouse gas emissions, and rice wheat straw in different ways of returning the seasonal cumulative emissions were CH4 wheat and rice straw is higher than that of N20, and the seasonal cumulative emissions of the situation is just the opposite; rotary tillage to counteract the effects of global warming on soil carbon sequestration efficiency, no tillage and minimum.3. farmers straw burning desire by the farmers cognition of the concept of straw, straw for farmers understand the benefits of the subject the education level of farmers, significantly affected farmers' understanding and damage of burning straw Jinshao policy on the execution of the five factors. In addition, farmers no tillage technology The adoption is significantly affected by the two factors of farmers on no tillage farmers cognition and has the largest land area. Therefore, this study suggests that the southern region of China should promote the suitability of no tillage. The government should increase the no tillage technology promotion, increase the farmers straw subsidies, improve farmers straw returning economic benefits, and actively organize agricultural technical personnel of straw technology breakthrough, straw returning rate of emergence, diseases and pests and other issues.

【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4

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