生物质炭配比施肥对栗钙土团聚体有机碳含量及其氧化稳定性的影响

Effects of biochar fertilization ratios on the organic carbon content and oxidation stability of chestnut aggregates

为了解生物质炭和尿素、磷酸二胺、缓释复混肥配比施肥对栗钙土团聚体有机碳含量及其氧化稳定性的影响,设置每公顷300 kg尿素+300 kg磷酸二铵(NP)、300 kg尿素+300 kg磷酸二铵+7500 kg生物质炭(NP+C)、750 kg缓释复混肥(RZ50)、750 kg缓释复混肥+7500 kg生物质炭(RZ50+C)及空白对照(CK)5种处理。结果表明:RZ50+C可以保持土壤有机碳的氧化稳定性不变,NP+C加速了土壤有机碳的矿化;生物质炭的施入在一定程度上降低了1~0.5 mm和0.25~0.154 mm粒级团聚体中有机碳的含量,NP+C相较于单施NP在>2 mm,1~0.5 mm两个粒级团聚体中有机碳氧化稳定性显著降低,RZ50+C相较于单施RZ50在>2 mm粒级团聚体中有机碳氧化稳定性显著提高。不同处理对土壤有机碳含量及其氧化稳定性发挥的影响范围及影响程度具有较大差异。

300 kg urea+300 kg diammonium phosphate(NP),300 kg urea+300 kg diammonium phosphate+7500 kg biochar(NP+C),750 kg slow-release compound fertilizer(RZ50)and 750 kg slow-release compound fertilizer+7500 kg biochar(RZ50+C)per hectare and blank control(CK)are set in this study in order to understand the effects of biochar,urea,diamine phosphate and slow-release compound fertilizer on the organic carbon content and oxidation stability of chestnut aggregates.The results show that RZ50+C can maintain the oxidation stability of soil organic carbon,and NP+C can accelerate the mineralization of soil organic carbon;the application of biochar reduces the content of organic carbon in the particles of 1-0.5 mm and 0.25-0.154 mm to a certain extent.Compared with single application of NP,the oxidation stability of soil organic carbon in the particles of>2 mm and 1~0.5 mm is significantly decreased by the application of NP+C.Compared with the single application of RZ50,the oxidation stability of organic carbon in the particles of>2 mm is greatly improved by RZ50+C.There exist significant differences in the range and degree of influences of different treatments on the content of soil organic carbon and its oxidation stability.