Active Organic Carbon and Nitrogen in Soils from Typical Cold-waterlogged Paddy Fields in Fujian

Paired between the cold-waterlogged and the nearby non-cold-waterlogged paddy fields in Fujian,the active organic carbon and nitrogen contents of 14soil samples were statistically compared using the t test.The results showed that the organic carbon content and C/N value for the cold-waterlogged soil were 22.1%and 0.56,respectively,significantly more than its counterpart.But the contents of the microbial biomass carbon(MBC)and dissolved organic carbon(DOC),as well as their proportion to the total organic carbon,were significant lower than those of the soils from the non-cold-waterlogged paddy fields.Similarly,the MBN and its proportion to the total organic nitrogen in the cold-waterlogged paddy soils were lower than those of the non-cold-waterlogged samples.The organic matters in the cold-waterlogged paddy soils were high,but quality poor insofar as the composition is concerned.It appeared that MBC and/or DOC could be used as an indicator in evaluating soil from the coldwaterlogged paddy fields.