不同比例猪粪混合玉米秸秆还田对黑土腐殖质组成及胡敏酸结构特征的影响

Effects of Different Proportions of Pig Manure Mixed with Corn Straw Returning to the Filed on Humus Composition and Humic Acid Structural Characteristics in Black Soil

利用不同比例风干猪粪混合玉米秸秆进行还田,在试验田微区共设置6种处理,分别为CS[m(秸秆)∶m(风干猪粪)=10∶0]、M0[m(秸秆)∶m(风干猪粪)=0∶10]、M1[m(秸秆)∶m(风干猪粪)=9∶1]、M2[m(秸秆)∶m(风干猪粪)=8∶2]、M3[m(秸秆)∶m(风干猪粪)=7∶3]、M4[m(秸秆)∶m(风干猪粪)=6∶4]。通过测定土壤有机质、腐殖质各组分的碳含量和分析胡敏酸(HA)的元素组成、红外光谱特征、热稳定性质及荧光光谱特征,探究不同比例猪粪混合玉米秸秆还田对黑土腐殖质组成和HA结构特征的影响。结果表明:与对照相比,不同比例猪粪混合玉米秸秆还田显著提高了土壤有机质、腐殖质各组分含量,且M2处理的提高量最大。在HA的结构特征方面,CS、M1处理增强了HA的脂族性、促进其结构年轻化;M2、M4处理增强HA的芳香性,使其结构更稳定、复杂。综上,在不同比例混合玉米秸秆还田的条件下,M2处理增加土壤有机质和土壤腐殖质各成分含量最大,M2处理使胡敏酸分子结构最稳定、复杂。

Different proportions of air-dried pig manure mixed with corn straw were used for returning to the field.A total of 6 treatments were set up in the micro-plot of the experimental field,namely∶CS(straw∶air-dried pig manure=10∶0),M0(straw∶air-dried pig manure=0∶10),M1(straw∶air-dried pig manure=9∶1),M2(straw∶air-dried pig manure=8∶2),M3(straw∶air-dried pig manure=7∶3),M4(straw∶air-dried pig manure=6∶4).By measuring the carbon content of soil organic matter and humus components and analyzing the elemental composition,infrared spectral characteristics,thermal stability properties and fluorescence spectral characteristics of humic acid(HA),the effects of different proportions of pig manure mixed with corn straw on the composition of black soil humus and the characteristics of HA structure were explored.The results showed that compared with the control,different proportions of pig manure mixed with corn stalk returning to the field significantly increased the content of soil organic matter and humus components,and the M2 treatment had the largest increase.In terms of the structural characteristics of HA,CS and M1 treatments enhanced the aliphatic properties of HA and promoted its structural rejuvenation;M2 and M4 treatments enhanced the aromatic properties of HA,making its structure more stable and complex.In conclusion,under the conditions of different proportions of pig manure mixed with corn straw returning to the field,M2 treatment increased the content of soil organic matter and soil humus the most,and M2 treatment made the molecular structure of humic acid the most stable and complex.