Soil Humic Acid Character in Bureazom Long-term Fertilization Treatments

Based on the soil selected from long-term fixed position,the characteristics and composition of humus in different fertilized treatments were studied.The results showed: fertilization could increase the content of humus,decrease E4/E6,and improve the degree of complexity of humic acid molecule.The content of humic acid and humin increased with different inorganic,organic and inorganic-organic fertilized.The ratio of humic acid to fulvic acid also increased.The content of carbon in humin varied with form,the un-dissolved humin is the most,the ratio of it in total carbon was 47.6%-57%,the humin combined with iron was 3.1%-5.7%,and combined with clay was 2.0%-3.7%.