本文選題：氣候變化 + 糧食安全�。� 參考：《中國農(nóng)業(yè)科學(xué)院》2015年碩士論文

【摘要】：水稻是我國最主要的糧食作物之一,60%以上的人口以稻米為主食。稻田是農(nóng)業(yè)環(huán)境中CH4排放的重要來源,約占全球人為排放量的1/4。如何在持續(xù)提升水稻產(chǎn)量的同時,減少農(nóng)田溫室氣體的排放,實(shí)現(xiàn)高產(chǎn)低碳稻作已經(jīng)成為亟待解決的重要科學(xué)問題和生產(chǎn)技術(shù)。已有研究表明,土壤耕作措施和秸稈還田均可以影響稻田溫室氣體排放,但對其交互效應(yīng)尚不明確。因此,本文以我國主要的水稻生產(chǎn)區(qū)域-雙季稻區(qū)為研究對象,開展了不同耕作方式和秸稈還田方式對雙季稻區(qū)水稻生產(chǎn)力和稻田溫室氣體排放影響的研究,同時在100年的尺度上評價不同處理下稻田的周年溫室效應(yīng)。主要研究結(jié)論如下:(1)與翻耕相比,旋耕條件下早稻和晚稻的產(chǎn)量均較高,但差異不顯著;秸稈還田顯著提高早稻和晚稻的產(chǎn)量。水稻產(chǎn)量的高低主要取決于有效穗數(shù)和穗粒數(shù)。其中,晚稻產(chǎn)量主要受穗粒數(shù)的影響,與翻耕秸稈全量還田相比,翻耕根茬還田、旋耕根茬還田和旋耕秸稈全量還田處理下的穗粒數(shù)分別高出7.9%、23.9%和10.6%;早稻產(chǎn)量則主要受有效穗數(shù)的影響,與旋耕秸稈全量還田相比,翻耕根茬還田、翻耕秸稈全量還田和旋耕根茬還田處理有效穗數(shù)分別高出約13.7%、6.2%和21.6%。(2)秸稈還田顯著增加了早稻和晚稻稻田CH4的排放,但降低了冬閑期CH4的排放。與旋耕相比,翻耕顯著降低了兩季水稻稻田CH4的排放,但對N2O的影響不顯著。早稻和晚稻稻田CH4排放均呈現(xiàn)出雙峰的趨勢,但第一個峰值出現(xiàn)時間有所不同,晚稻峰值出現(xiàn)在分蘗盛期,而早稻峰值出現(xiàn)略晚。與根茬還田相比,翻耕方式下晚稻季、冬閑和早稻季秸稈換全量還田下CH4排放量分別增加了47.3%、26.1%、5.4%,旋耕方式下則分別增加了39.7%、7.1%、6.1%。與旋耕相比,根茬還田下晚稻季、冬閑、早稻季翻耕處理的CH4排放分別降低了96.1%、45.4%、30.0%;而秸稈全量還田下則分別降低了約86.0%、82.7%和30.8%。(3)在100年尺度上,CH4的排放量決定全球增溫潛勢(GWP)。本研究中,GWP呈現(xiàn)出和CH4累積排放量一樣的趨勢,即秸稈全量還田大于根茬還田,旋耕大于翻耕,且差異均達(dá)到顯著水平。稻田溫室氣體排放強(qiáng)度(GHGI)由產(chǎn)量和GWP共同決定。GHGI在晚稻季趨勢與GWP一致,而早稻季差異不顯著。周年效應(yīng)上,由于冬閑期CH4排放量較低,故GWP與CH4排放趨勢一致,即秸稈全量還田顯著大于根茬還田,旋耕顯著大于翻耕。由于翻耕+根插還田處理中晚稻產(chǎn)量低,所以在翻耕秸稈全量還田處理中周年GHGI最低。因此,對于雙季稻區(qū)而言,在翻耕方式下進(jìn)行秸稈全量還田是一種較好的高產(chǎn)低碳稻作措施。
[Abstract]:Rice is one of the most important food crops in China. Rice fields are an important source of CH4 emissions in the agricultural environment, accounting for about a quarter of the world's anthropogenic emissions. How to continuously increase rice yield, reduce greenhouse gas emissions from farmland and realize high-yield and low-carbon rice cropping has become an important scientific problem and production technology to be solved urgently. Previous studies have shown that both soil tillage and straw return can affect greenhouse gas emissions from paddy fields, but the interaction effects are not clear. Therefore, the effects of different tillage methods and straw returning methods on rice productivity and greenhouse gas emissions from paddy fields were studied in this paper, which is the main area of rice production in China. At the same time, the annual Greenhouse Effect under different treatments was evaluated on the scale of 100 years. The main results were as follows: (1) the yield of early rice and late rice under rotary tillage was higher than that of tillage, but the difference was not significant, and straw returning to field significantly increased the yield of early rice and late rice. The yield of rice mainly depends on the number of effective panicles and the number of grains per panicle. The yield of late rice was mainly affected by the number of grains per panicle. The yield of early rice was mainly affected by the number of effective panicles, and the yield of early rice was mainly affected by the number of effective panicles, compared with the total amount of straw returned by rotary tillage, the number of grains per ear was increased by 7.9% and 10.6%, respectively, and the yield of early rice was mainly affected by the number of effective panicles. The number of effective spikelets of total tillage and root-stubble returning treatments were about 13.7% and 21.60.20% higher than that of tillage, respectively.) the CH4 emissions of early rice and late rice paddy field were significantly increased by straw returning, but the CH4 emission of winter idle period was decreased. Compared with rotary tillage, tillage significantly reduced the CH4 emission from two rice paddy fields, but had no significant effect on N2O. Both early rice and late rice paddy showed a double peak trend of CH4 emissions, but the first peak appeared in different time, the peak of late rice appeared at the peak of tillering period, and the peak value of early rice appeared a little late. Compared with the return of stubble to the field, the total CH4 emissions in late rice season, winter idle season and early rice season were increased by 47.3% 26.1% and 5.4% respectively under tillage, and 39.7% (7.1%) and 6.1% under rotary tillage, respectively. Compared with rotary tillage, the CH4 emissions of late rice season, winter fallow and early rice tillage were reduced by 96.1U 45.4V 30.0g, respectively, while the total return of straw was reduced by 86.0% and 30.8%, respectively. The CH4 emission of CH4 determined the global warming potential in 100 years. In this study, GWP showed the same trend as the cumulative emissions of CH4, that is, the total return of straw was greater than that of stubble, and the rotation tillage was larger than that of tillage, and the difference reached a significant level. Greenhouse gas emission intensity (GHGI) from paddy field was determined by yield and GWP. The trend of GHGI in late rice season was consistent with that of GWP, but there was no significant difference in early rice season. Because of the low CH4 emission during winter idle season, the trend of GWP and CH4 emissions was the same, that is, the total return of straw was significantly larger than that of stubble, and the rotation tillage was significantly larger than that of tillage. Due to the low yield of middle and late rice in the tillage and root planting treatment, the annual GHGI was the lowest in the total tillage straw returning treatment. Therefore, for the double cropping rice area, it is a better measure of high yield and low carbon rice to return straw to the field under tillage.
【學(xué)位授予單位】：中國農(nóng)業(yè)科學(xué)院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S511.42;S181

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相關(guān)期刊論文 前1條

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本文編號：1778205