硅肥和生物质炭添加对毛竹林土壤活性硅组分的影响

Effects of silicon fertilizer and biochar on active silicon components in Phyllostachys edulis forest soil

【目的】探究施用硅肥和生物质炭对毛竹Phyllostachys edulis人工林土壤水溶性硅、生物可利用硅、有机结合态硅、铁锰氧化物结合态硅、无定形硅(生物成因和成土成因)、总硅质量分数的影响;分析土壤水溶性硅与土壤活性硅组分和土壤特性之间的关系。【方法】遵循析因试验设计,共4个处理,分别为对照(S0B0)、施用硅肥450 kg·hm^(−2)(S_(1)B_(0))、施用生物质炭10 t·hm^(−2)(S_(0)B_(1))、硅肥和生物质炭配施(S_(1)B_(1))。【结果】硅肥提高毛竹林土壤中生物可利用硅和铁锰氧化物结合态硅。生物质炭增加无定形硅库(主效应)。硅肥和生物质炭配施提高了土壤水溶性硅。硅肥、生物质炭添加和土层深度均改变土壤活性硅组成,促进它们之间的相互转化。土壤有机碳质量分数与土壤活性硅组分存在极显著正相关(P=0.002)。此外,硅肥添加可直接和间接提高土壤水溶性硅,介导土壤硅组分之间转化,并提高土壤活性硅库容。生物质炭添加提高土壤水溶性硅积累,一方面增加植物源硅,另一方面提高土壤pH,提高成土成因无定形硅质量分数,调控土壤硅在各组分分布。【结论】施用硅肥和生物质炭促进了毛竹人工林土壤活性硅的积累,并改变了其相互转化,但其转化路径存在不同。

[Objective]This study aims to investigate the impact of applying silicon fertilizer and biochar on water-soluble silicon,bioavailable silicon,organically bound silicon,iron-manganese oxide bound silicon,amorphous silicon(biogenic and pedogenic),and total silicon mass fraction in Phyllostachys edulis forest soil,and analyze the relationship between soil water-soluble silicon,soil active silicon components and soil characteristics.[Method]Based on the factorial design,4 treatments were used,including control(S_(0)B_(0)),application of silicon fertilizer at 450 kg·hm^(−2)(S_(1)B_(0)),application of biochar at 10 t·hm^(−2)(S_(0)B_(1)),and combination of silicon fertilizer and biochar(S1B1).[Result]Silicon fertilizer increased bioavailable silicon and iron-manganese oxide bound silicon.The addition of biochar increased the amorphous silicon reservoir(main effect).The combined application of silicon fertilizer and biochar increased the water-soluble silicon in soil.The addition of silicon fertilizer,biochar,and soil depth all changed the composition of soil active silicon and promoted their mutual transformation.There was a highly significant positive correlation between soil organic carbon mass fraction and soil active silicon component (P=0.002). In addition, the addition of silicon fertilizer could directly and indirectly improve soil water-soluble silicon, mediate the conversion of soil silicon components, and improve the solubility of soil active silicon pools. The addition of biochar improved the accumulation of water-soluble silicon in soil. On the one hand, it increased botanical silicon. On the other hand, it increased soil pH and the mass fraction of amorphous silicon in soil formation, and regulated the distribution of soil silicon in each component. [Conclusion] The application of silicon fertilizer and biochar promotes the accumulation of active silicon in soil and changes their mutual conversion in P. edulis forest, but the transformation pathways are different. [Ch, 4 fig. 5 tab. 41 ref.]