施用生物质炭对黑土黑碳含量和结构特征的影响

生物质炭(Biochar,Bc)是黑碳(Black Carbon,BC)的一种,当前关于生物质炭在农业上的研究大都集中在其对土壤理化性质和作物生长的影响,而关于施用生物质炭对土壤黑碳结构和数量影响的研究很少.为了解施用生物质炭对土壤黑碳的影响,本试验采用盆栽试验的方法,设置4个处理,施加生物质炭量分别为0(CK)、6、12和24 t·hm-2,采用Wolbach-Anders法对土壤中的黑碳进行提取,运用元素分析、红外光谱和热重分析等方法研究了不同施入量的生物质炭对土壤黑碳产生的影响.实验结果表明:施用玉米秸秆生物质炭能明显增加土壤中黑碳的含量,随着生物质炭施用量的增加,不同处理相对于对照(CK)中土壤黑碳含量分别提升7.04%、22.96%和46.90%.施用玉米秸秆生物质炭降低了黑碳的脂族性、氧化性,提升了黑碳的缩合度、芳化度,提高了黑碳结构的稳定性,提高了土壤黑碳的热稳定性.施用玉米秸秆生物质炭能够提高p H,提高土壤的速效养分含量.

Effect of biochar application on the content and structural characteristics of black carbon in black soil

As a kind of black carbon (BC), biochar (Bc) is widely investigated in agriculture on its effects on physicochemical properties of soil and crop growth. There are however few studies about the effects of Bc application on the content and structural characteristics of BC in black soil. Four treatments were designed in pot trials, with the applied amount of CK, 6 t·hm^-2, 12 t·hm^-2 and 24 t·hm^-2, respectively. The method Wolbach-Anders were adopted to extract the black carbon, and the structural changes of BC were indicated by the elemental composition, FTIR (Fourier Transform infrared spectroscopy) and thermogravimetric analysis. The experiment results showed that maize straw Bc application can improve soil BC content significantly. With the increase of Bc application, different treatments raised BC content by 7.04%, 22.96% and 46.90%, respectively, in comparison with the CK. Maize straw Bc application lowered the soil BC aliphatic and oxidation degree, improved soil BC degree of condensation, aromaticity, and improved the stability of soil BC structure and thermal stability. Maize straw Bc application can improve soil pH and increase soil available nutrient content.