【正文】 sing mechanism, as well as the economic and social benefits in the drip irrigation under mulch, and the study of organic carbon is also mainly focuses on humus element position, functional groups structure and properties, but the study between organic carbon active fraction and physical fractionation carbon pool were lacked. In this paper, takes cotton soil as the research object, uses the organic carbon fraction technology, developing the influence of drip irrigation under mulch cultivation model on variation characteristics of organic carbon fraction in cotton soil, and studying on the correlation between the inter organic carbon pool with soil fertility and yield, to investigate the variation law of organic carbon in the drip irrigation under mulch, and conclusion that :（1）Compared with natural soil, the soil organic carbon show increase trend by drip irrigation under mulch and conventional irrigation in 68a, significantly increased by 67%～112%,and decreased after correlation analysis of soil organic carbon, different organic carbon fractions, soil physical and chemical properties and yield show that tillage at the natural soil with low organic carbon ,can increase the storage of soil organic and improve the productivity of the farmland by irrigation 68a which will be a suitable tillage and irrigation years, and the soil of oasis farmland may bee potential carbon sink. After 68a, the soil organic carbon of oasis farmland showed decreased trend, and the cultivated land fertility existing degradation risk. (2) Compared with natural soil and conventional irrigation, drip irrigation under mulch cultivation model improved the soil labile organic carbon (LOC), microbial biomass carbon and carbon management index(CMI), and respectively increases by an average of %,% and %, enhanced the activity and shorten the turnover time of soil organic carbon, and it was beneficial to the improvement of soil nutrient effectiveness and cultivated land fertility.（3）Irrigation 68a, as pared with that natural soil, soil light and sand organic carbon increased by average of % and % in the drip irrigation under mulch, and in the conventional irrigation increased by average of %and %, and then became decreased after 68a。 but the silt organic carbon increased with the irrigation years. The heavy and clay organic carbon increased with the irrigation years is different from the conventional irrigation, and annual average increased more than kg1. Silt and clay organomineral colloidal plex for the protection and control effect of organic carbon became strengthened, enhanced (4) Compared with natural soil, drip irrigation and conventional irrigation increased 250μm of waterstable aggregates, 53~250μm microaggregates and carbon content and organic carbon in the soil and the distribution of the ratio of different membrane 47a under the postirrigation, 50μm of waterstable aggregates and carbon content showed a downward trend, and 53~250μm microaggregates of the carbon content in the drip rate of increase is higher than the conventional irrigation。 drip irrigation under plastic film and conventional irrigation reduces the 53μm aggregates the content and distribution in the soil the ratio of carbon aggregates in the ratio of total organic carbon distribution in the performance of the downward trend in aggregate difference is that under the conditions of the carbon in the drip irrigation under plastic film on a declining trend, and under conventional irrigation has been an upward trend. Soil physical structure may tend to sound development.(5) Soil organic carbon pool and subbase and with soil pH, CEC, EC, total nitrogen, active nitrogen physical and chemical index and significant correlation between the yield. Natural soil tillage cultivation, the different interactions between the organic carbon fractions of crop production have a direct or indirect effects, and the oxidation activity of soil organic carbon, light organic carbon, microbial biomass carbon and organic carbon in sand on the oasis farmland and soil productivity Quality of significant changes can be used as evaluation indicators of the sensitivity. Keyword: Film Drip Irrigation。 Oasis farmland。 Cotton field。 Organic Carbon fractions目 錄第一章 前言 1 研究的意義 1 膜下滴灌技術(shù)的國(guó)內(nèi)外研究進(jìn)展 1 土壤有機(jī)碳分組技術(shù)的國(guó)內(nèi)外研究現(xiàn)狀 5 11 本文研究目的和必要性 14第二章 研究?jī)?nèi)容與目標(biāo) 16 研究目標(biāo) 16 研究?jī)?nèi)容 16 研究技術(shù)路線 16第三章 材料與方法 18 樣品采集與處理 18 測(cè)定方法 19 數(shù)據(jù)處理與統(tǒng)計(jì)分析 22第四章 結(jié)果與分析 24 膜下滴灌條件下土壤總有機(jī)碳的變化 24 膜下滴灌條件下土壤易氧化活性有機(jī)碳含量及CMI 26 膜下滴灌條件下土壤微生物量碳的變化 29 膜下滴灌條件下土壤物理組分碳庫(kù)的變化 30 討論 50 小結(jié) 53第五章 土壤有機(jī)碳庫(kù)以及與土壤理化性質(zhì)和產(chǎn)量間的關(guān)系 56 不同有機(jī)碳庫(kù)與總有機(jī)碳之間的關(guān)系 56 不同分組有機(jī)碳庫(kù)間相關(guān)性分析 57 不同有機(jī)碳庫(kù)與土壤理化性質(zhì)及產(chǎn)量相關(guān)性分析 58 小結(jié) 60第六章 結(jié)論與展望 62 主要結(jié)論 62 本研究的特色與創(chuàng)新點(diǎn) 63 研究展望 64參考文獻(xiàn) 65致謝 72作者簡(jiǎn)介 7377新疆農(nóng)業(yè)大學(xué)碩士學(xué)位論文第一章 前言 研究的意義農(nóng)田土壤是一種重要的土地利用類型，其面積達(dá)133 800萬(wàn)hm2，碳儲(chǔ)量約為140～170Pg (1Pg= 1015g)，達(dá)到全球陸地碳貯量的10 %（楊景成等，2003）。農(nóng)田土壤有機(jī)碳含量和組成不僅反映了土壤有機(jī)質(zhì)水平，說(shuō)明了營(yíng)養(yǎng)元素N、P等的可利用狀態(tài)，并影響著土壤的物理性狀，而且還與農(nóng)田質(zhì)量的可持續(xù)能力密切相關(guān)(張國(guó)盛等,2005)，是農(nóng)田系統(tǒng)穩(wěn)定性與持續(xù)的重要指標(biāo)。農(nóng)田生態(tài)系統(tǒng)土壤碳庫(kù)研究一直是農(nóng)業(yè)、生態(tài)和環(huán)境領(lǐng)域的一個(gè)主要方向，土地利用、耕作、作物類型、種植密度、灌溉、施肥等管理措施以及其他人為活動(dòng)都能快速影響農(nóng)田有機(jī)碳庫(kù)，其碳庫(kù)可以在5～10a的尺度上快速調(diào)節(jié)。因此，研究干旱區(qū)灌溉條件下農(nóng)田土壤有機(jī)碳及其變化趨勢(shì)，對(duì)于正確評(píng)價(jià)該區(qū)農(nóng)田土壤肥力及土壤質(zhì)量演變規(guī)律，制訂合理可行的保持農(nóng)業(yè)持續(xù)發(fā)展的管理措施都具有重要的理論與實(shí)踐意義。膜下滴灌是當(dāng)今先進(jìn)的節(jié)水灌溉技術(shù)和覆膜栽培技術(shù)相結(jié)合的產(chǎn)物，同傳統(tǒng)的灌水方式和栽培技術(shù)相比具有節(jié)水、高產(chǎn)、優(yōu)質(zhì)和高效的優(yōu)點(diǎn)。在覆膜和滴灌的綜合效應(yīng)下，土壤水肥環(huán)境以及作物的生長(zhǎng)與常規(guī)條件不同，土壤物理化學(xué)環(huán)境、土壤微生物環(huán)境都發(fā)生了變化。而新疆作為我國(guó)重要的優(yōu)質(zhì)棉花生產(chǎn)基地和對(duì)外出口地，棉花產(chǎn)業(yè)已經(jīng)成為新疆經(jīng)濟(jì)發(fā)展中重要的支柱產(chǎn)業(yè)。棉花種植面積、種植年限以及種植模式在不斷地變化，棉花連作和膜下滴灌成為新疆棉花種植的主要栽培模式。在這樣的種植模式下，開展膜下滴灌土壤有機(jī)碳的變化研究，能夠幫助我們進(jìn)一步認(rèn)識(shí)農(nóng)業(yè)管理措施下棉田土壤有機(jī)碳的變化特征，為探索有效的農(nóng)業(yè)管理措施提供依據(jù)。另一方面，西北干旱區(qū)農(nóng)業(yè)屬于綠洲灌溉農(nóng)業(yè)，對(duì)土壤有機(jī)碳的研究主要集中在總有機(jī)碳水平上，缺乏對(duì)土壤有機(jī)碳組分變化特征的研究，因此開展干旱區(qū)綠洲棉田土壤有機(jī)碳組分的研究可以為新疆棉花產(chǎn)業(yè)的持續(xù)發(fā)展以及土壤的持續(xù)利用提供基礎(chǔ)資料和科學(xué)依據(jù)。 膜下滴灌技術(shù)的國(guó)內(nèi)外研究進(jìn)展棉花膜下滴灌（Cotton underfilm Drip Irrigation）技術(shù)是新疆在節(jié)水灌溉實(shí)踐中，將滴灌管帶鋪設(shè)于地膜下，使滴灌技術(shù)和地膜栽培技術(shù)相結(jié)合而形成的一種新型的田間灌溉方法，為內(nèi)陸干旱區(qū)發(fā)展高效節(jié)水灌溉開辟了一個(gè)新途徑，是我國(guó)農(nóng)業(yè)灌溉節(jié)水技術(shù)的重大發(fā)展。 地膜覆蓋技術(shù)的研究概況地膜覆蓋技術(shù)是20世紀(jì)中葉，隨著塑料工業(yè)的興起而發(fā)展起來(lái)的。1951年日本開始試驗(yàn)應(yīng)用塑料薄膜代替油紙和玻璃, 此后在農(nóng)業(yè)上的應(yīng)用便得到迅速發(fā)展(張德奇等, 2005)。20世紀(jì)50年代初期美國(guó)在夏威夷首先應(yīng)用地膜覆蓋，1963年開始在亞利桑那州用覆膜機(jī)進(jìn)行棉花黑膜地面覆蓋栽培，覆膜機(jī)能連續(xù)進(jìn)行鋪膜和播種兩項(xiàng)作業(yè)，提前兩周播種，棉花增產(chǎn)顯著(張國(guó)村,1984)。法國(guó)、意大利、英國(guó)、聯(lián)邦德國(guó)、西班牙、韓國(guó)等國(guó)家在地膜覆蓋栽培