生物炭施用对夏填闲甜高粱氮素吸收及土壤氮层间运移的影响

Effects of Biochar Application on Nitrogen Absorption of Summer Catch Sweet Sorghum and Nitrogen Transport Between Soil Layers

集约化设施土壤氮素积累日益严重,导致土壤氮素环境风险增大。试验不同用量水平生物炭,即0%,0.5%,2%,4%,8%等5个处理,研究生物炭施用对夏填闲甜高粱氮素吸收及土壤氮素变化的影响。结果表明,随着生物炭用量增加,饲用甜高粱总生物量和总吸氮量呈现先增加后减少的趋势,2%生物炭处理吸收设施土壤氮素效果最好,吸氮量为194.95 kg·hm^(-2),0.5%生物炭处理次之,吸氮量为158.54 kg·hm^(-2)。甜高粱种植前后,土壤全氮含量和土壤硝态氮含量均显著降低,减少幅度也是先增大后减小,其中2%和0.5%生物炭处理对土壤氮层间运移有良好阻控效果。5个生物炭处理中,全氮含量在2%生物炭处理降幅最大为35.49%,土壤表层硝态氮含量亦以2%生物炭处理降幅最大为69.7%,0.5%生物炭处理次之,为65.4%。综上,在本试验条件下,0.5%~2%生物炭施用水平对降低设施土壤氮素环境风险有显著效果。

Soil nitrogen accumulation in intensive facilities is becoming more and more serious,which leads to the increase of soil nitrogen environmental risk.The experiment was conducted with biochar and sweet sorghum,five different biochar levels including 0%,0.5%,2%,4%,and 8%were set,and the effects of biochar application on nitrogen absorption of sweet sorghum and soil nitrogen change were studied.The results showed that with the increase of biochar dosage,the total biomass and nitrogen uptake of forage sweet sorghum showed a trend of first increase and then decrease,2%biochar treatment had the best effect of absorbing soil nitrogen,and the nitrogen uptake was 194.95 kg·hm^(-2),followed by 0.5%biochar treatment,which was 158.54 kg·hm^(-2).Before and after planting sweet sorghum,soil total nitrogen content and soil nitrate nitrogen content decreased significantly,and the reduction range also showed a trend of increased first and then decreased,in which 2%and 0.5%biochar treatment had a good control effect on soil nitrogen interlayer transport.Among the five biochar treatments,the total nitrogen content of 2%biochar treatment decreased by 35.49%,the surface nitrate nitrogen content in 2%and 0.5%biochar treatment decreased by 69.7%,65.4%,respectively.In comprehensively,0.5%-2%biochar application level werethe optimal level,which had a significant effect on reducing the environmental risk of nitrogen in greenhouse soil.