The humus composition and distribution of Lake Wuliangsuhai sediment

The paper studied the organic matter contents,humus composition and the degree of humification of the surface sediment of Lake Wuliangsuhai by chemical method.Correlation between sediment humus and physical-chemical factors were also discussed.The results showed that the organic matter of the surface sediment varied from 1.06% to 5.38%.Their distribution characteristics were related to hydraulic condition,aquatic plant distribution and human activities.In the humus composition,the content of humic acid and fulvic acid varied from 0.65 to 2.78 g/kg and from 2.19 to 8.72 g/kg,respectively.The humin is the main component in the sediment,ranging from 3.28 to 20.92 g/kg.Based on the correlation analysis of humus and environmental factors,each component is significantly correlated with the organic matter content.The pH value is significantly negative correlated with humin.Dissolved oxygen is significantly positive correlated with fulvic acids and significantly positive correlated with humin.The organic matter content increased while the content of extracted humic substances is decreased in the humification analysis.The PQ values range from 9.50% to 27.06%,with the average of 21.47%,which varied dramatically and with low degree of humification.