添加蔗渣生物质炭对农田土壤有机碳矿化的影响

【目的】研究蔗渣生物质炭施用后农田土壤有机碳（SOC）矿化动态，为合理利用有机废弃物资源提供科学参考。【方法】在25℃、100%空气湿度条件下培养100 d，研究生物质炭不同添加量（0.1%、0.5%、1.0%和2.0%，以干土计）下水田和旱地土壤有机碳的矿化特征。【结果】各处理土壤有机碳矿化速率随时间的变化符合对数关系（P＜0.01）；土壤特性、生物质炭添加量及两者的交互作用对土壤总有机碳矿化有极显著影响（P＜0.01）；与对照相比，添加低量（0.1%）的生物质炭水田土壤有机碳累积矿化量降低了2.18%，旱地土壤有机碳累积矿化量降低了4.62%；添加低量生物质炭（0.1%和0.5%）对旱地SOC矿化的影响效果更明显，而添加高量生物质炭（1.0%和2.0%）则对水田土壤的影响效果更明显；培养前期生物质炭对水田土壤原有有机碳矿化正激发效应高于旱地土壤，后期对旱地土壤的负激发效应更稳定且维持时间更长。【结论】添加生物质炭不改变SOC矿化趋势。添加低量（0.1%）的生物质炭可抑制SOC矿化、促进SOC的积累。

Effects of Biochar on Soil Organic Carbon Mineralization of Farmland

【Objective】To provide scientific reference for the rational use of the resources of organic waste, the SOC mineralization dynamics after biochar added were studied. 【Method】The paddy and upland soils with addition of different amounts of biochar (0.1%, 0.5%,1.0%, 2.0%, calculated on the dry soil) were incubated for 100 days under 25℃ and 100% air humidity. 【Result】 The change of soil organic carbon mineralization rate with time conformed the logarithmic relationship (P＜0.01). The SOC mineralization was affected significantly (P＜0.01) by soil use pattern, the added amount of biochar and their interaction. Compared with controls , the SOC mineralization in paddy soil was reduced by 2.18% and 4.62% in upland soil when 0.1% biochar was added. The response of the mineralization of SOC to the addition of biochar in upland soil was more significantly than those in paddy soil when lower amount of biochar (0.1% and 0.5%) was added. However, the opposite tendency was observed when higher amount of biochar (1.0% and 2.0%) was added. The positive priming effect of biochar on native SOC mineralization in paddy soil was higher than upland for the early stage of incubation experiment, but for later stage of incubation experiment the negative priming effect of biochar on native SOC mineralization in upland soils was more stable. 【Conclusion】The tendency of SOC mineralization remained the same after addition of biochar (0.1%-2.0%) under the condition of incubation experiment. Low added amount of biochar (0.1%) promoted the accumulation of soil organic carbon.