Mineralization and microbial biomass formation in upland soil amended withs some tropical plant residues at different temperatures

Creators Azmal Abul Kalam Mohammad

Creators Marumoto Takuya

Creators Shindo Haruo

Creators Nishiyama Masaya

A model experiment was carried out at 15, 25 and 35℃ to investigate the changes in microbial biomass and the pattern of mineralization in upland soil during 8 weeks following the addition of 8 organic materials including 6 tropical plant residues, ipil ipil (Leucaena leucocephala), azolla (Azolla pinnata), water hyacinth (Eichhornia crassipes), dhaincha (Sesbania rostrata), cowpea (Vigna unguiculata), and sunhemp (Crotalaria juncea). The amounts of CO_2-C evolved and inorganic N produced at 35℃ were about 2 times larger than those at 15℃. At any temperature, the flush decomposition of C was observed within the first week and therafter the rate of mineralization became relatively slow. A negative correlation was observed between inorganic N and C/N ratios of the added organic materials. The relationships between the amounts of cellulose or cellulose plus hemicellulose and the amount of mineralized N of the added organic materials were also negative. The changes in the microbial biomass were affected by temperatures. The amount of biomass C and N was maximum after 42 d of incubation at 15℃, and after 7 d at 25 and 35℃, and thereafter decreased. The rate of biomass decline was slower at 15℃ and faster at 35℃ than at 25℃. Regardless of the temperatures, the addition of organic materials enhanced microbial biomass formation throughout the incubation periods.

[ISSN]0038-0768

[NCID]AA00844314

[isVersionOf] [NAID]http://ci.nii.ac.jp/naid/110001718331/

[isVersionOf] [URI]http://www.blackwellpublishing.com/journal.asp?ref=0038-0768&site=1