本文選題：耕作方式 + 土壤有機碳��； 參考：《中國農(nóng)業(yè)大學》2017年博士論文

【摘要】：為明確秸稈還田技術與耕作方式互作對華北平原麥-玉兩熟區(qū)農(nóng)田土壤固碳和作物生產(chǎn)的影響,本研究于2008年在中國農(nóng)業(yè)大學吳橋實驗站開始了長期定位試驗,分別設置了免耕秸稈還田(NTS)、深松秸稈還田(STS)、旋耕秸稈還田(RTS)、翻耕秸稈還田(CTS)和對照翻耕秸稈不還田(CT)5個處理。本文主要研究了2013-2015年冬小麥-夏玉米生長期內(nèi)耕作方式對各作物收獲期農(nóng)田土壤物理結構、有機碳庫和作物生產(chǎn)的影響,同時綜合評價了麥-玉兩熟農(nóng)田作物生產(chǎn)的碳足跡以及有機碳與作物產(chǎn)量的相關性。主要結果如下:(1)耕作方式對土壤物理結構的影響差異較大,NTS處理增加了0-20 cm土層的容重,而對深層的影響與其他耕作方式相同,而且NTS處理的土壤總孔隙度和毛管孔隙度均比其他4個處理低。CTS和STS處理減小了0-20 cm土層容重,增大了0-30 cm土層的土壤總孔隙度和毛管孔隙度。NTS處理增大了5-20cm土層2mm團聚體的比例,且顯著提高了0-20cm土層內(nèi)土壤團聚體平均重量直徑(P0.05)。(2)秸稈還田與耕作方式互作條件下,對土壤有機碳的影響主要集中在0-30 cm土層。0-5 cm土層的有機碳含量隨耕作強度的降低顯著增加。0-10 cm 土層,NTS增加了土壤有機碳含量和儲量,提高了土壤有機碳的層化率(P0.05),而RTS處理的有機碳含量與其相差較小。CTS和STS促進了 0-20 cm土層土壤有機碳的均勻分布,且CTS處理增加了 10-20 cm 土層的有機碳含量,減小了 0-30 cm土層的層化率。0-5 cm土層的各粒級水穩(wěn)性團聚體有機碳含量均以NTS處理最大,顯著高于其他處理(P0.05);10-20cm土層,0.25-2mm有機碳含量以CTS處理最大,CT處理最小,但其他3個處理差異不大(P0.05)。(3)耕作方式對有機碳組分的影響主要表現(xiàn)在0-30 cm土層,而對大于30 cm 土層影響較小。NTS處理增加了0-5 cm土層的顆粒有機碳、重組和輕組有機碳組分,而降低了易氧化有機碳的含量,但均高于CT處理(P0.05)。RTS處理增加了0-10 cm土層的有機碳組分,易氧化有機碳含量均高于其他處理。STS和CTS處理增加了 10-20 cm土層的土壤有機碳組分含量,促進了有機碳組分的均勻分布,CT處理有機碳組分含量在各土層中均為最小。(4)與CT相比,NTS處理延長了冬小麥生育期,對夏玉米生育期的影響與其它處理一致。STS和CTS提高了冬小麥的出苗率,NTS處理降低了冬小麥出苗率(P0.05),但各耕作方式對夏玉米出苗率影響無差異。NTS和STS相對提高了冬小麥凈光合速率,減小了光合午休現(xiàn)象。比較其產(chǎn)量得出,CTS和STS冬小麥、夏玉米產(chǎn)量較高,水分利用效率表現(xiàn)為CTS處理相對較大,CT處理的最小。(5)比較各耕作方式的碳足跡發(fā)現(xiàn),在考慮或不考慮有機碳儲量的變化時,均以NTS處理的碳足跡最小,其值為-0.03-0.63 kg C02-eq hm-2 year-1,CT處理最大,其值為0.22-0.75 kg C02-eq hm-2 year-1其他3個處理在不考慮有機碳時相差不大,考慮有機碳時的大小順序為RTSSTSCTS。且當計算有機碳時,CT處理的碳足跡有所增加,主要是由于有機碳儲量減少所致。通過對各指標的相關性分析得出,有機碳與水穩(wěn)性團聚體有機碳以及有機碳組分呈極顯著正相關關系(P0.01)。
[Abstract]:Clear straw technology and interactive effects of Tillage in North China wheat maize cropping area two farmland soil carbon sequestration and crop production, the study on 2008 at the Wuqiao experiment station of China Agricultural University began a long-term experiment were set up (NTS), no tillage subsoiling and straw (STS), rotary tillage and straw returning (RTS), conventional tillage (CTS) control and conventional tillage without straw (5 CT). This paper mainly studies the 2013-2015 year winter wheat summer maize growth period of Tillage on the crop harvest period of soil physical structure, effects of organic carbon and crop production, and comprehensive evaluation of wheat maize two crops crop production of carbon footprint and correlation between organic carbon and crop yield. The main results are as follows: (1) the difference of tillage effects on soil physical structure of the larger, NTS treatment increased 0-20 cm soil bulk density, and The deep influence of the same with other farming methods, and NTS soil total porosity and capillary porosity were lower than the other 4 treatments.CTS and STS treatment decreased 0-20 cm soil bulk density, increased 0-30 cm soil total porosity and capillary porosity of.NTS treatment increased 5-20cm 2mm soil aggregate proportion, and significantly increased in 0-20cm soil layer soil aggregate mean weight diameter (P0.05). (2) of straw and tillage interaction conditions, effects on soil organic carbon mainly concentrated in the organic carbon content of 0-30 cm.0-5 cm soil layer decreased with soil tillage intensity significantly increased.0-10 cm soil, NTS increased soil organic carbon content and reserves, improve stratification ratio of soil organic carbon (P0.05), organic carbon content and RTS and.CTS STS are small and promote the uniform distribution of 0-20 cm soil organic carbon, and CTS With the increased organic carbon content of 10-20 cm soil layer, 0-30 cm soil layer decreased the rate of.0-5 of the cm soil water stable aggregate organic carbon content in NTS treatment was the highest, significantly higher than other treatments (P0.05); 10-20cm 0.25-2mm soil organic carbon content in the CTS treatment, CT treatment is the lowest. But the other 3 treatments had no difference (P0.05). (3) effects of Tillage on soil organic carbon fractions mainly in 0-30 cm soil layer, and the soil above 30 cm affected.NTS treatment increased the particulate organic carbon in the soil layer of 0-5 cm, and the recombinant light fraction organic carbon fractions, and decreased the content of easy the oxidation of organic carbon, but the treatment was higher than that of CT (P0.05).RTS treatment increased organic carbon group 0-10 cm soil layer, easily oxidized organic carbon content is higher than other treatment.STS and treatment CTS increased the soil organic carbon fractions in 10-20 cm soil layer, promote the organic carbon The uniform distribution of components, CT contents of organic carbon fractions in each soil layer was the smallest (4). Compared with CT, NTS treatment prolonged the growth period of winter wheat, the effects of the growth period of summer maize and other favorable.STS and CTS increased the germination rate of winter wheat, NTS treatment reduced winter the wheat germination rate (P0.05), but the tillage on maize seedling emergence rate of no difference between.NTS and STS relatively improve the net photosynthetic rate of winter wheat decreased, photosynthetic midday depression. Compared to the yield obtained, CTS and STS of winter wheat, maize yield, water use efficiency for CTS processing is relatively large CT, the smallest. (5) found that the tillage carbon footprint, considering or not considering the variation of organic carbon, the carbon footprint of NTS treatment was the minimum, the value of -0.03-0.63 kg C02-eq hm-2 year-1, CT, kg C02-eq hm-2 0.22-0.75 whose value is yea R-1 the other 3 treatments are not considered when the organic carbon had little difference, considering the organic carbon in the order of RTSSTSCTS. and the calculation of organic carbon, CT carbon footprint increased, mainly due to a decrease in organic carbon storage. The correlation of each index analysis, organic carbon and water stable aggregates carbon and organic carbon fractions showed significant positive correlation (P0.01).

【學位授予單位】：中國農(nóng)業(yè)大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：S512.1;S513
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本文編號：1738474