Higher net N mineralization and lower immobilization were found under submerged than aerobic conditions. In addition, N mineralization was more rapid in submerged first peak within 2-4 weeks than aerobic conditions Figure 1,2, 3, 4 a, b. Mineralization of organic N is generally higher Gale and Gilmour 1988; Ono 1989, Vityakon et al. 2000 and more rapid
Broadbent 1979 in submerged than in aerobic soils. This is partly because the microflora in flooded soils have lower N requirement stemming from their lower synthetic efficiency compared with the aerobic population Broadbent 1979. According to Ono 1989 the population of fungi and many actinomycetes, that had higher synthetic capacity, i.e., incorporated more C into their tissue, than bacteria, decreased as compared to bacteria after soil flooding. Leaching and/or dilution of polyphenols may also lower efficiency of the compounds in binding proteins and consequently inhibit N release under submerged conditions.