不同地区油菜秸秆制备的生物质炭对酸性红壤的改良效果

从江西鹰潭、安徽宣城、江苏南京和淮阴等4个地区收集油菜秸秆,在500℃下厌氧热解制备生物质炭,比较生物质炭的pH、盐基离子和碳酸盐含量的差异,并在20 g/kg加入量下考察其对安徽宣城pH 4.1的酸性红壤改良效果。结果表明,江西鹰潭油菜秸秆炭pH、盐基离子和碳酸盐含量最低,安徽宣城油菜秸秆炭次之,江苏淮阴和南京油菜秸秆炭的相应参数值最高。当用这4种油菜秸秆炭改良土壤酸度时,改良效果表现为江苏淮阴>江苏南京>安徽宣城>江西鹰潭,与生物质炭pH、盐基离子和碳酸盐含量一致。因此,利用秸秆生物质炭改良土壤酸度时,不仅需要考虑炭化条件和秸秆类型,作物的产地差异也需要进行考量。

Amelioration of Ultisol Acidity by Biochars Derived from Canola Straws from Different Areas

The species and amounts of cations, and its uptake by plants varied with cultivating soils. Hence, the base cations and alkaline substances in the crop straw biochars, and the ameliorating effects of these biochars on acidic soils should vary with the sites of crop straw collected. However, the regional difference of biochars derived from crop straws have been rarely studied. In the present study, the biochars were prepared from canola straws collected from Yingtan in Jiangxi province, Xuancheng in Anhui province, Nanjing and Huaiying in JiangSu, respectively at 500 oC under anaerobic condition. The pH values, contents of base cations and carbonates in these biochars were measured. The amelioration effects of canola straw biochars on an acidic Ultisol collected from Xuancheng, Anhui Province were examined with incubation experiments at 20 g/kg addition level of the biochars. Results showed the biochar of canola straw from Yingtan had the lowest pH value, contents of base cations and carbonate, followed by the biochar of canola straw from Xuancheng, and the biochars of canola straw from Huaiying and Nanjing had the highest pH and the contents of base cations and carbonate. The amelioration effects of these biochars on soil acidity of the Ultisol followed the order: Huaiying > Nanjing > Xuancheng > Yingtan, consistent with pH, the contents of base cations and carbonate in these biochars. Therefore, the amelioration effects of crop straw biochars on acid soils depended not only on the pyrolysis condition and crop residue types, but also on the sites of crop straw collected.