本文關(guān)鍵詞： 秸稈 溶解性有機(jī)質(zhì) 腐解 光譜學(xué)特征 川西平原　出處：《光譜學(xué)與光譜分析》2017年09期 　論文類型：期刊論文

【摘要】：為掌握川西平原保護(hù)性耕作模式下還田秸稈腐解過程的光譜學(xué)特性,追溯還田秸稈對川西地區(qū)生態(tài)系統(tǒng)結(jié)構(gòu)的影響過程,采集了該地區(qū)主要種植作物油菜、水稻的秸稈樣本,利用紫外-可見吸收光譜(UVVis)、三維熒光光譜(3D-EEM)和傅里葉變換紅外光譜(FTIR)三種光譜學(xué)表征手段,闡明秸稈各腐解階段溶解性有機(jī)質(zhì)(DOM)的光譜學(xué)特征,對比不同農(nóng)作物秸稈快速淋溶階段DOM(0~0.5d)與腐解過程(0.5~90d)的光譜學(xué)特征差異性,解析其變化機(jī)理。結(jié)果表明:還田秸稈腐解過程中DOM的光譜學(xué)特性差異明顯,伴隨著芳香性物質(zhì)的溶出、降解以及新生腐殖類物質(zhì)的形成;由秸稈快速淋溶階段釋放DOM的E_2/E_3值最大而SUVA_(254)值最小可知該階段溶出的物質(zhì)芳香性和分子量相對較小;其芳香性組分的溶出主要集中在腐解前期(≤10d),表現(xiàn)于該階段E_2/E_3值逐漸減小且SUVA_(254)值逐漸增大,DOM中多糖峰、芳香C和酰胺峰變?nèi)?難分解的纖維素、半纖維素和大分子蛋白質(zhì)主要在腐解后期被降解;DOM中酚類、羰基類和羧酸類物質(zhì)數(shù)量增加,使得DOM與有機(jī)污染物、金屬離子的相互作用增強(qiáng),進(jìn)而調(diào)節(jié)農(nóng)田土壤中污染物的遷移轉(zhuǎn)化過程。本研究為川西平原秸稈還田的環(huán)境意義提供了基礎(chǔ)數(shù)據(jù)和新證據(jù),為該地區(qū)農(nóng)業(yè)廢棄物處理與資源化提供了依據(jù)。
[Abstract]:In order to understand the spectral characteristics of straw decomposition under conservation tillage in West Sichuan Plain, the effects of returning straw on ecosystem structure of western Sichuan were traced, and the straw samples of rape and rice were collected. The spectroscopic characteristics of dissolved organic matter (DOM) in various stages of decomposition of straw were elucidated by means of UV-Vis absorption spectrum, 3D-EEM and FTIR. The spectral characteristics of DOM in the rapid leaching stage of different crop straw were compared with that in the decomposing process (0.5 ~ 90 d), and the mechanism of the change was analyzed. The results showed that the spectral characteristics of DOM were obviously different during the decomposing process of straw in the field. With the dissolution and degradation of aromatic substances and the formation of new humic substances, the E _ 2 / E _ (3) of DOM released from the rapid leaching stage of straw was the largest and the value of SUVA _ (254) was the lowest. The aromaticity and molecular weight of the substances dissolved at this stage were relatively small. The dissolution of aromatic components was mainly concentrated in the early stage of decomposition (鈮，

本文編號：1529742