牛粪配施生物质炭的土壤碳净变化率和腐殖物质组成研究

Effects of Amendment of Biochar on Net Carbon Transformation Rate of Cow Manure and Composition of Humic Substances in Soil

牛粪是农业生产中常用的有机肥,牛粪配施生物质炭是否会提高有机物料在土壤中的碳净变化率是高效利用有机物料重要问题。通过1年田间试验施用常量(M1)和倍量(M2)牛粪、常量(CBM1)和倍量(CBM2)牛粪配施生物质炭对比了短期腐殖物质碳净变化率差异和结构特征。结果表明,与单施牛粪(M1和M2)相比,牛粪配施生物质炭(CBM2)土壤胡敏酸、富里酸和胡敏素的含量增至1.36g·kg^(–1)、2.50g·kg^(–1)和5.03g·kg^(–1);土壤胡敏酸和富里酸碳净变化率分别提高1.18%和3.67%。与施用牛粪相比,牛粪配施生物质炭胡敏酸、富里酸和胡敏素脂族碳和多糖相对含量增加;CBM2处理胡敏酸和胡敏素芳香碳相对含量增加,CBM1处理富里酸芳香碳相对含量增加。表明牛粪配施生物质炭在土壤固碳效果上优于单施牛粪,可形成更多的腐殖物质,提高胡敏酸和富里酸的碳净变化率;同时也有利于腐殖物质脂族碳和多糖相对含量的增加,而生物质炭用量不变的情况下,配施更多的牛粪可增加胡敏酸和胡敏素芳香碳相对含量。施用牛粪或牛粪配施低量生物质炭可使Hu和FA的缩合度增加,氧化度降低,而HA则相反。

【Objective】Cow dung is commonly used as organic manure in agricultural production.It comes up to be an important issue whether application of cow manure coupled with biochar or biochar-amended cow manure could increase net carbon transformation rate of the organic materials in soil as to high-efficient use of organic materials.【Method】In this study,a one-year field experiment was conducted to explore effect of application of biochar amended cow manure on net carbon transformation rate and structure of humic substances(HS)in soil by comparison.The experiment was designed to have four treatments,that is,M1(cow manure at a normal rate),M2(cow manure twice the normal rate),CBM1(M1 amended with biochar)and CBM2(M2 amended with biochar).【Result】Results show that compared with Treatment M1 and M2,Treatment CBM2 increased the content of humic acid(HA),fulvic acid(FA)and humin(Hu)up to 1.36 g·kg^(–1),2.50 g·kg^(–1)and 5.03 g·kg^(–1),respectively,and the net carbon transformation rate of HA and FA by 1.18%and 3.67%.Compared with the application of cow manure alone,the application of cow manure amended with biochar was much higher in relative content of aliphatic functional groups and polysaccharide in HA,FA and Hu.The amendment of biochar increased the relative content of aromatic functional groups of HA and Hu in Treatment CBM2,but decreased that of FA in Treatment CBM1.【Conclusion】All the findings show that CBM treatments are better than M treatments,forming more HS.Moreover,it also favors formation of aliphatic and polysaccharide functional groups.Biochar amendment increases the aromatic function groups of HA and Hu.In the treatments amended with biochar Hu and FA increases in condensation degree,while decreases in oxidation degree,but HA responds reversely.