Soil CO₂Emission Characteristics Of Wheat Maize Intercropping Under Reduced Tillage And Stubble Covering

Global warming get unprecedented attention of the people on greenhouse gas emissions,agricultural soils, as the Earth’s carbon sinks component, was one of the important sources ofemissions of greenhouse gases, study about the soil CO₂emissions characteristics undercropping systems and conservation tillage was still very limited. In this study, a reduced tillagefield experiment was carried out to investigate the characteristics of CO₂emissions under wheatintercropping maize groups and its critical factors to analyze its mechanism in order to provide ascientific base for greenhouse gas emission reduce of the oasis irrigation area. The resultsshowed that:1. Compared to monocropping, intercropping increased soil CO₂emission. The NTSS wheattreatment decreased the later corn soil CO₂emission, the NTS treatment decreased the laterintercropping soil CO₂emission. NTSS_I and TIS_I treatments significantly increased soil CO₂emission flux than monoculture. The mean of soil CO₂emission flux in whole life of crop inNTSS_I, NTS_I, TIS_I, CT_Itreatment heighter than the corresponding monocropping by34.2%,5.8%,16.2%and11.4%.2. TISM and NTSM treatments significantly reduced the CO₂emission flux in the monoculturesoil, the former is better; NTSS_I treatment significantly improved intercropping soil CO₂emission flux; the soil CO₂emission flux of corn belt is higher than wheat belt in NTS_I, TIS_IandCT_Itreatments3. Soil CO₂emission flux in the day during whole growth period of CT_Ichanged remarkably andwas higher than other treatments. After wheat harvesting,it was lower than NTSS_I and NTS.Thisresult showed that no tillage and straw covering weakened rates of soil CO₂emission flux changein the day, no tillage increased soil CO₂emission flux after wheat harvesting.4. Compared with monocropping, straw mulching of intercropping lowered5cm groundtemperature, increased10cm soil moisture content and LAI in the whole growth period. In thewhole growth period, the average values of5cm ground temperature: NTSS_I<NTS_I<TIS_I<CT_I,the average values of10cm soil moisture content of NTSS_Iand CT_Iwere respectively11.3%and3.6%over TIS_I, average values of LAI: NTS_I>NTSS_I>TIS_I>CT_I. In intercropping condition, LAIin each growth period of CT_Iwas low, dry matter accumulation of NTSS_I, NTS_Iand TIS_Iwererespectively7.90%,19.13%and10.80%over CT_I.5. No-tillage combined with intercropping increased sensibility of soil CO₂emission flux whiletillage combined with intercropping reduced it. Q10of5cm soil showed that NTSS_I>NTSSM,NTS_I>NTSM, CT_M>CT_I, TISM>TIS_I. In intercropping condition, Q10values showed that NTS_I>TIS_I>NTSS_I>CT_I. Contribution rates of soil CO₂emission flux showed that,5cm soiltemperature contribution rate was maximum, contribution rate of10cm soil moisture content was35%, the average value of LAI contribution rate was11%, contribution rate of dry matteraccumulation was10%.