[Effect of straw pretreatment on soil microbial biomass and respiration activity].
Winter wheat straw particles (0.5 ~ 2.0mm) were soaked with 8.0 g.L-1 H202(pH11.0), 12.5 g.L-1 Na0H or H2S04 solution for  8 h and dried at 80 degreeC.  Soils amended with the pretreated straw and inorganic N were incubated aerobically at 25 degreeC for 60 days.  The C02 emission rate and soil microbial biomass C and N were measured at different time.  The results showed that during the earlier stage of incubation, the pretreatments of straw increased soil microbial biomass C by 1.0 ~ 1.4 folds, but decreased soil microbial respiration activity.  During the  later stage of incubation, the Na0H and H2S04 pretreated straw decreased soil microbial biomass carbon by 28% and 42%, respectively, while increased the soil microbial respiration activity.  The straw pretreated by H202 increased soil microbial biomass nitrogen by 90% after the 15th day of incubation.  The pretreatments of straw increased  the fungi/bacteria ratio at different special time.  It could be concluded that soil microbial biomass and respiration activity could be changed after the pretreated straw was added into the soil.
Li
Guitong
G
College of Resource and Environment, China Agricultural University, Beijing 100094, China. lgtong@mail.cau.edu.cn
Zhang
Baogui
B
Li
Baoguo
B
D018533:Biomass; D002244:Carbon / Q000032:analysis; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis; D010101:Oxygen Consumption; D012988:Soil Microbiology
D005308:Fertilizers; D002244:Carbon; D009584:Nitrogen