Effect of Different Land Use Types on Soil Dissolved Organic Carbon and Nitrogen in Yellow River Delta

Taking the slightly saline soil of Kenli County in the Yellow River Delta as the study object, the soil dissolved organic carbon (DOC) and nitrogen (DON) in different land use types was studied based on field sampling and statistical analysis. The results showed that there are certain differences of DOC and DON in different land use types of soil. The average concentrations of DOC and DON are highest in crop land soil and vegetable soil by the values of 128.2 mg/kg and 86.6 mg/kg respectively, the lowest concentration of DOC and DON in unused land soil and the concentration is 52.2 mg/kg and 20.1 mg/kg separately. The percentages of DOC/TOC and DON/TN are all biggest in vegetable soil by the values of 1.45% and 9.62% respectively, and these values much higher than that in the other three land use types soil, while the percentages of DON/TDN has no significant difference in these four land use types soil. The correlations between DOC, DON and the other forms of carbon and nitrogen are reached the significant or very significant levels in study area soil, while the significant levels are different in these four land use types soil.