玉米秸秆腐化及炭化材料对土壤有机质转化率和胡敏酸结构的影响OA北大核心CSTPCD

To screen for organic materials that are more conducive to enhancing the conservation rate of soil organic matter(ESOM)and improving the structural characteristics of humic acid(HA)from corn straw and its decomposed and carbonized materials under the condition of equal carbon input,we calculated the carbon input(12 000 kg/hm2)according to the full amount return method.Four treatments were designed,including no addition of any material(ck),addition of corn straw(CS),ad-dition of decomposed corn straw(HCS),and addition of corn straw-derived biochar(Bc).The struc-tural characteristics of ESOM and HA(element composition,infrared spectrum,thermal stability and fluorescence spectrum)were analyzed.The results show that:after 2 years of organic material appli-cation,the ESOM of HCS was the highest,at 70.6%,which was 50.1%and 10.1%higher than that of CS and Bc treatments,respectively.In the HA structure,the H/C and I2920/1620 of HCS were the lowest,and the ratio of high temperature to medium temperature mass loss was the highest,at 1.01,0.11 and 3.45,respectively,indicating that HCS can improve molecular complexity,condensation degree,and thermal stability of HA.To sum up,compared with CS and Bc treatments,HCS treatment is more helpful to the improvement of ESOM and the stability of HA structure.