| The national payed serious attention to energy agriculture,the various types of biogas projects in rural have been developed,and rural energy issues had been effectively resolved,but a lot of biogas generated had not been fully utilized,leading to the serious waste of resources in recent years.There were a lot of studies involved in the affection taken to the soil C and N from the organic fertilizer which contened the straw,green manure,and livestock and poultry manure.Wheras there was no report about the research that the affection to the change of soil C and N content from the application on biogas residue in different cropping patterns.As a result,in the same content of nitrogen, phosphorus and potassium under the conditions to application of fertilizer as a control, useing field experiments to study the effects of soil carbon and nitrogen content in the form of impact that use biogas residue in "corn/soybean-wheat" intercropping,"Cotton-wheat" rotation,"Rice-Rape" rotation and four kinds of different orchards planted patterns; through the experiment to study that continuous use of biogas for the "cotton - wheat" rotation fields,soil C,N distribution patterns of the profiles.The main results were as follows:(1) All application of biogas in different cropping pattems were conducive to accumulate TOC,easily oxidized organic carbon,hardly carbon and humic acid oxidation (FA+HA),and increased 0.75～2.06g/kg,0.44～1.40g/kg,0.14～1.16g/kg respectively compared to control.Besides,the changing of orchards was significant of all.In orchards,TOC,easily oxidized organic carbon and humic acid oxidation(FA + HA) were obviously higher than other cropping patterns,especially to the latter two.And each the increase amplitude was 28.50%,50.83%and 61.80%.Absolute terms from the content, easily oxidized organic carbon,hardly carbon,humic acid oxidation(FA + HA) and organic carbon were synchronous changed with total organic carbon.In "Rice-rape" rotation,increment and increase amplitude of difficult oxidized organic carbon were both reached to the maximum compared to the control.(2) "Corn/Soybean-Wheat" intercropping,"Cotton-wheat" rotation,"Rice-rape" rotation and orchards,four kinds of planting mode were dealed with the application of biogas residue,the content of soil microbial carbon and nitrogen were more than that in control micro-organisms,increments between 6.71～149.54mg/kg.From the microbial carbon Point of view,compared to the control,the largest increase was in the orchard,and its figure was 149.54%,followed by the "rice-raPes" rotation,wheras the "corn/soybean-wheat" intercropping was the smallest increment,only 6.71%.From the microbial nitrogen point of view,compared to the control,the largest increase was in the "Cotton- wheat",and the increasing number was 91.35%,followed by the orchards. Compared to the control,the increments of the "corn/soybean - wheat" intercropping and "rice-rape" were both between 30%～37%.(3) "Corn/Soybean-Wheat" intercropping,"Cotton-wheat" rotation,"Rice-rape" rotation and orchards,four kinds of planting mode were dealed with the application of biogas residue.Then the content of the acid solution nitrogen in the soil organic nitrogen fraction was higher than the nitrogen content of non-acid solution.Compared with those in the control of the nitrogen content,the nitrogen content in the acid solution increased by 10.03%～30.89%,while the nitrogen content in the non-acid solution reduced about 2.53%～40.32%.The nitrogen in the acid solution,the various patterns of amino acid nitrogen content of the soil were high ranging between 201.3～231.5mg/kg,and various patterns of amino sugar N content in soil was lowest ranging from 62.1 to 93.6mg/kg. Compared with the control,the nitrogen content of the unknown acid solution alone of "Rice-rape" rotation increased,while the content of the other kinds of planting mode reduced.After the application of biogas,soil nitrogen content of amino acids of orchard increased the most by 84.00%.Comparing to the control,and the content of "Cotton-wheat" rotation increased the least by only 15.67%;The ammonia nitrogen content of soil of "cotton-wheat" rotation increased the largest over the control by 65.60%, while the smallest increase was orchard only 18.70%;The soil amino sugar N content in the orchard increased the largest to the control about 64.07%,while "Rice-rape" rotation was the smallest increase to control by only 16.02%.(4) Application of biogas residue promoted the accumulation of soil organic carbon, readily and hardly to be oxidized organic carbon with the extension of biogas residue use time.However,the increasing range of each layer was inconsistent.The content of total organic carbon,readily oxidized carbon and hardly oxiddized carbon were increased extremely signifcantly in the 0～30cm soil layer after 3 years of biogas residue's continous application.(5) The soil MBC and MBN increased with time limit that the biogas residue was applied,and in the 0～50cm profile,the content of soil MBC and MBN decreased with the depth increased under every treatment.When the biogas residue was applied from 1 to 3 year, in the 0～30 cm Profile,soil MBC and MBN changed markedly,in the 30～40cm Profile, the soil MBC and MBN became stable and when the biogas residue was applied five years, the impaction was,more obvious,but there was no effect in the 40～50cm profile.In the 0～30cm profile,the amplification of the soil microbial biomass C descent with the increased time limit:When the biogas residue applied one year,soil MBC increased 31.73%than the accustomed farming,in three years,it increased 21.63%compared to one year,and in five years,it increased 13.54%compared to three years,in the 0～10 cm profile, the change tendency of MBN was coincident with MBC,in the 10～30cm layer,the amplification of MBN decreased with the tine went on.And the trend of MBC/SOC and MBN/TN were the same with MBC.When biogas residue was applied just one year, MBC/MBN increased than accustomed farming in the topsoil,but they reduced when biogas residue was applied three years.So we can see for the rotation pattern "cotton-wheat", if the biogas residue was applying three years continued,it would improve soil fertility effectually in the 0～30cm profile.(6) After the application of biogas,accumulation of soil nitrogen to amino nitrogen and unknown acidolysis N;biogas compared between different application period,in addition to the individual level,the soil nitrogen in the amino acid-N,amino sugar-N and ammoniacal-N in the proportion of total N order as follows:5-year application of biogas＞3-year application of biogas＞1-year application of biogas＞customary farming;total soil nitrogen and organic acid solution of total nitrogen,amino nitrogen,ammonia nitrogen and amino sugar-N content increased with soil depth reduced,and the acid solution of unknown concentration of the nitrogen first and then decreased;for the same soil layer, acid soil nitrogen content of each component and the relative content of the absolute size of the order were:unknown acidolysis N＞amino acid N＞ammoniacal N＞amino sugar N.
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