石灰施用对酸性土壤矿物结合有机碳形成的影响

Effects of Liming on Formation of Mineral-associated Organic Carbon in Acidic Soil

为了解石灰施用对酸性土壤矿物结合有机碳的影响并促进酸性土壤的碳固定,本研究整合已发表的相关研究并在室内设置培养试验探究石灰添加调控酸性红壤矿物结合有机碳形成的可能机制。结果表明:大部分已发表的研究发现石灰添加可以显著促进酸性土壤中矿物结合有机碳的形成。室内控制试验发现石灰添加显著促进了秸秆分解转化为微生物生物量碳,这很可能是石灰促进矿物结合碳形成的主要机制之一。室内控制试验还发现石灰添加增加了钙键结合碳的含量,但是降低了铁铝结合碳的含量。综上可知,石灰添加有利于作物秸秆在酸性土壤中被微生物分解转化为矿物结合有机碳,但可能会导致不同化学键结合碳的相对含量发生变化。

To understand how liming affects mineral-associated organic carbon(C)and promote organic C sequestration in acidic soils,the authors synthesized the published data in the literature and conducted a laboratory incubation to explore the potential mechanism of mineral-associated C formation in response to liming in acidic soils.The results showed that liming promoted the formation of mineral-associated organic C in most published studies.Our laboratory incubation experiment found that liming significantly promoted straw decomposition and increased microbial biomass C,which could be one of the main mechanisms that contribute to the formation of mineral-associated C.In addition,our laboratory incubation also found that liming reduced the formation of iron/aluminum-bound C,while it promoted the formation of calcium-bound C.Together,these results suggested that the application of lime in acidic soils could promote the formation of mineral-associated organic C,but might change the relative contents of organic C associated with different chemical bonds.