生物质炭与氮肥配施对旱地红壤微生物量碳、氮和碳氮比的影响

Effects of Biochar Combined with Nitrogen Fertilizers on Microbial Biomass C,N and Carbon-to-nitrogen Ratio of Upland Red Soil

以江西典型旱地红壤为研究对象,设置生物质炭和氮肥2个因素(生物质炭4个水平分别为0t/hm^2,5t/hm^2,20t/hm^2,40t/hm^2;氮肥4个水平分别为0kg/hm^2,60kg/hm^2,90kg/hm^2,120kg/hm^2),研究了生物质炭施入大田3a后对旱地红壤微生物量碳、氮及碳氮比的影响。结果表明:与对照相比,生物质炭与氮肥配施有效地提高了土壤微生物量碳,提高幅度为18.22%~122.74%,对土壤微生物量氮的提高效果更为明显,提高幅度为20.86%~312.91%。生物质炭与氮肥配施后土壤微生物碳氮比有不同程度的降低,降低幅度为18.11%~51.56%,其中以20t/hm^2生物质炭与60kg/hm^2氮肥以及40t/hm^2生物质炭与120kg/hm^2氮肥的比例施用后对微生物碳氮比的降低效果最为明显。因此,通过生物质炭与氮肥配施可以提高旱地红壤中微生物量碳、氮及土壤氮素生物活性。

This study was carried out to investigate the effects of biochar and nitrogen fertilizer on microbial biomass C,microbial biomass N and carbon-to-nitrogen ratio in typical upland red soil in Jiangxi province.The field experiment was conducted with a 4×4factorial design at biochar application rates of 0t/hm^2,5t/hm^2,20t/hm^2 and 40t/hm^2,and nitrogen fertilizer application rates of 0kg/hm^2,60kg/hm^2,90kg/hm^2 and 120kg/hm～2.The microbial biomass C,microbial biomass N and carbon-to-nitrogen ratio under different treatments were determined after 3years.The results indicated that biochar combined with nitrogen fertilizers could increase soil microbial biomass C and soil microbial biomass N by 18.22%～122.74%and 20.86%～312.91%respectively.The carbon-to-nitrogen ratio was decreased by 18.11% ～51.56% after the application of biochar with nitrogen fertilizers.The carbon-to-nitrogen ratio was reduced obviously by applying 20t/hm^2 biochar with 60kg/hm^2 nitrogen fertilizer,and by applying 40t/hm^2 biochar with 120kg/hm^2 nitrogen fertilizer.This study illustrated that the application of biochar combined with nitrogen fertilizers could improve the microbial biomass C,N and biological activity of soil nitrogen.