Research On The Effect Of Agrotechnical Practice On Fractions Of Organic Carbon And Their Stability In Oasis Farmland

In order to reveal the characteristics of soil organic carbon and its components under differentmanagement measures in the cotton fields, exploring the changing process of cotton fields soil organiccarbon and its fractions under different irrigation methods, straws and fertilization measures. Thevariation of the different agricultural management practices on soil quality was estimated. In this study,we used arid region of Xinjiang cotton field soil as the research object. Stratified sampling, teseted soilorganic carbon (TOC) and organic carbon active component: easily oxidized organic carbon (EOOC),water-soluble organic carbon (WSOC), hot water-soluble organic carbon (HWSOC), microbial biomasscarbon (SBMC) to reflect the changes characteristics of the soil, research component of soil organiccarbon under different management measures and its stability, Studies the soil organic carbon fractionsand the stability of different management practices, Analysis of the relationship between the cotton soilorganic carbon under different agricultural management practices and soil quality. To explore theimpact of different agricultural management practices on the ecological environment of the cottonfields, Scientific theoretical basis for reasonable fertilization system, improving the soil fertility ofcotton fields and the sustainable use of resources. The main results are as follows:1. Under the two irrigation ways, the TOC content was lower before sowing, higher during theblooming period, peaked in the mature period, TOC content were between in6-13g/kg. Under thesame fertilization measures, the TOC content of traditional irrigation was higher than the dripirrigation. Under the same soil layer of conventional flooding, the TOC content was also greater thanthe drip irrigation under plastic film; Under the same irrigation methods, different fertilizertreatments on the same soil layer between the cotton fields TOC content was (NPK+OM)> OM>NPK> CK. The EOOC content of soil is low before planting cotton, the EOOC content reachedmaximum value during the cotton blooming period, however in mature EOOC content significantlydecreased, between0.4to4.0g/kg. Under the same straw and fertilization measures, the soil EOOCcontent of film drip irrigation treatment was significantly greater than conventional irrigation. Underthe same irrigation and fertilization measures, straw returned treatment soil EOOC content wasgreater than the unreturned straw. Under the same irrigation methods, different fertilizer treatmentson the same soil layer between the cotton fields soil EOOC content was (NPK+OM)> OM> NPK>CK.2. Two Irrigation, fertilization treatments NPK+OM treatment of WSOC/TOC HWSOC/TOC wasthe largest. This showed that NPK fertilizer and organic fertilizer with high activity of soil organiccarbon, poor stability. Under same fertilizer measures, the EOOC/TOC of film drip irrigationtreatment was significantly greater than conventional irrigation. Under the same fertilizationmeasures and irrigation methods, the EOOC/TOC of straw returned was significantly more than nostraw returned, showed that the way of film drip irrigation and straw returned had higher soilactivity.3. Drip irrigation under plastic film mode, compared with all the fertilizer treatments of no CK, the LIcof OM, NPK and NPK+OM treatment increased17.88%,20.60%,19.63%, respectively, and the manner of conventional flood irrigation, the LIc of OM, NPK and NPK+OM treatment wereincreased by24.62%,39.29%, and41.75%, than no fertilizer CK respectively. Drip irrigation underplastic film mode, compared with CK treatment, the RIc of OM, NPK and NPK+OM treatmentwere reduced18.27%,20.96%, and20.42%, respectively. The manner of conventional floodirrigation, compared with CK treatment, the RIc OM, NPK and NPK+OM treatment were reduced20.32%,36.91%, and40.14%, respectively. These results showed that organic and inorganicfertilizers significantly increased the soil organic carbon active components, and also increased theorganic carbon activity index, but it reduced the organic carbon recalcitrance.4. Under the same processing, comparison between different soil layers, soil total organic carbon andthe active components showed a decreasing trend with the increase of soil depth, the surfaceaccumulation effect was obvious.5. The correlation analysis of between soil total organic carbon and activated carbon component. Theresult showed that the soil organic carbon content and the activated carbon component peaked highlysignificant level and the activated carbon component had the good correlation, which shows theclose relationship between the activated carbon components, the active ingredient is able tocharacterize the changes of TOC in the soil.