Abstract
The fungal or bacterial biomass in some forest or arable sites of a volcanic soil in Tokyo was measured by the direct count method employing sonication to disperse soil particles and phenolic aniline blue as a stain. Almost 100% of the biomass of fungal or bacterial species added into autoclaved forest or arable soil was recovered by using this method. The microbial biomass measured by this method showed a good correspondence with that measured by the chloroform fumigation-extraction method. The fungal biomass in soils of the forest sites (55-107 g C m^<-2>, n=6) was larger than that in the soils of the arable sites (5.2-31 g C m^<-2>, n=5). The fungal biomass in the plots with various treatments in upland fields was as follows: 31 g C m^<-2> in the soil treated with manure and subjected to shallow tillage, 17 g C m^<-2> in the soil treated with manure and subjected to deep tillage, 12 g C m^<-2> in the soil treated with chemical fertilizers and subjected to shallow tillage, 8.7 g C m^<-2> in the soil treated with chemical fertilizers and subjected to deep tillage. Herbicide application did not affect the fungal biomass. On the other hand, the bacterial biomass in soils hardly differed among the forest (7.5-11 g C m^<-2>, n=6) and arable sites (5.0-9.2 g C m^<-2>, n=5), and that in the plots with various treatments in upland fields was almost identical (5.4-8.1 g C m^<-2>). The biomass ratios of fungi/bacteria of the forest sites (5.5-12) were higher than those of the arable sites (1.0-5.7). We also showed that the biomass ratios decreased with the decrease in the total microbial biomass.
