生物炭与有机肥配施对茶园土壤有机碳组分的影响OA

[Objective]Effects of varied fertilization schemes using biochar and/or manure on soil organic carbon(SOC)at tea plantation were analyzed.[Method]In a field experimentation at a tea plantation,test lots were applied continuously for 4 years with conventional chemical fertilizer(NPK),50%chemical fertilizer replaced by manure(M50),50%chemical fertilizer replaced by manure with 10 t·hm-2 added biochar(M50+B10),and 50%chemical fertilizer replaced by manure with 20 t·hm-2 added biochar(M50+B20)followed by conventional fertilization.After 2 years of the restoration of conventional fertilization management,differentiate contents and distribution of SOC fractions(Foc)in the soil under the applications of biochar and organic fertilizer separately or in combination were analyzed.[Result]In comparison to NPK,M50 raised the microbial biomass carbon(MBC)in soil by 56.30%without significant effect on SOC or Foc.M50+B10 and M50+B20 increased the SOC by 28.61%-40.36%,MBC 3.43-3.71 times,particulate organic carbon(POC)1.97-2.26 times,and mineral-bound organic carbon(MOC)by 79.18-89.43%but significantly lowered the MOC/POC ratio by 39.18-41.01%.Meanwhile,M50+B20 also significantly elevated the iron-bound organic carbon(Fe-OC)concentration by 87.76%.The sensitivity indices on the labile Foc indicated that MBC and POC were most sensitive to the different fertilization schemes.[Conclusion]In two years of conventional fertilization after a 4-year combined application of biochar and organic fertilizer on a tea plantation,a residual effect of increasing SOC as well as labile and stable Foc in the soil continued.However,the organic carbon pool became less stable.