The total N, microbial biomass N and K2SO4-extractable N were in the ranges of 0.67-2.06 g·kg-1, 11.40-71.03 mg·kg-1and 1.28-4.60 mg·kg-1, respectively.
The results showed that the microbial biomass P in different treatments was 8.75~47.68 mg·kg -1(M 4),3.02~37.16 mg·kg -1(M 2),1.59~10.62 mg·kg -1(NPK),and 0.76~6.74 mg·kg -1(CK).
The results showed that the soil microbial biomass N was 25.52~239.12 mg·kg -1 in M 4,10.40~94.31 mg·kg -1 in M 2,6.27~87.04 mg·kg -1 in NPK,and 9.15~69.81 mg·kg -1 in CK. In same treatment,the highest value was 7~14 times higher than the lowest value.
The results showed that red soil microbial biomass P was closely related with soil total P, soil organic P and soil rapidly available P. Relative coefficients were 0.840, 0.897 and 0.944, respectively.
The results showed that the soil microbial biomass N was 25.52~239.12 mg·kg -1 in M 4,10.40~94.31 mg·kg -1 in M 2,6.27~87.04 mg·kg -1 in NPK,and 9.15~69.81 mg·kg -1 in CK. In same treatment,the highest value was 7~14 times higher than the lowest value.
The results showed that red soil microbial biomass P was closely related with soil total P, soil organic P and soil rapidly available P. Relative coefficients were 0.840, 0.897 and 0.944, respectively.
kg-1(KH2PO4) labeled with KH232PO4(3.7 KBq.g-1) together with glucose(5 000 mgC.kg-1) and urea(200 mgN.kg-1),the soils were incubated at 25℃ for 30 d. Soil microbial biomass C and P were determined at 2,6,12,18,30 d.
Long term fertilization and rotation increased the content of soil microbial biomass carbon and microbial biomass nitrogen. Increased Bc is as 62.3%~270% and increased BN is as 41.2%~353.1% as that of fallow land.
Decomposition processes of soil native C and straw C showed similar trends to dynamics of soil biomass 12C and soil biomass 14C, which indicated that decomposition rates of organic C were the apparent indication of activity of soil organisms.
The soil microbial biomass and nutrient status under the native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem (in Hunan Province, midland of China) were examined in this study.
Less litter and slower decay rate in pure Chinese fir plantation were the crucial factors leading to the decrease of soil microbial biomass and nutrient pool in this area.
The soil microbial biomass and nutrient status under the native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem (in Hunan Province, midland of China) were examined in this study.
Less litter and slower decay rate in pure Chinese fir plantation were the crucial factors leading to the decrease of soil microbial biomass and nutrient pool in this area.
The lowest (19.4 μg C/g of soil) biomass of heterotrophic microorganisms was found in the soil under the birch trees, and the highest one (41.7 and 32.0 μg C/g), under the pine and spruce ones.
The PCP degradation rates obtained with the activated soil biomass, produced either as a biomass attached to soil particles or as a flocculent biomass, were similar.