Based on the indoor simulation experiment

the effects of amendment (biochar and calcium peroxide) on microbial biomass carbon

nitrogen and dissolved organic carbon and nitrogen in upland red soil were studied. The experiment included 4 treatments

namely CK

Ca (calcium peroxide

1.72 g/kg)

C (biochar

21.46 g/kg)

and C+Ca. The results showed that soil microbial biomass carbon

nitrogen and dissolved organic carbon had the same change tendency

which increased rapidly within 3 days

and reached the maximum on the third day

and then decreased with the time. Additionally

the effect of combined application of the two amendments was better than that of single application. The dissolved organic nitrogen increased slowly within 21 days; compared with CK

dissolved organic nitrogen under C+Ca

Ca

C treatments significantly increased by 62.1%

55.5%

and 40.9% on twenty-first days

respectively; after 35 days

the effects of C+Ca and Ca was significantly better than those of C and CK. During the 120 day incubation period

C+Ca treatment could significantly improve the average content of microbial biomass carbon

nitrogen and dissolved organic carbon and nitrogen; the ranking of average content of microbial biomass carbon from high to low was: C+Ca>C>CK>Ca

and the average content of microbial biomass nitrogen in C+Ca treatment was significantly higher than those of other treatments. the ranking of average content of soluble organic carbon was C+Ca>Ca>C>CK

and they were significantly higher in C+Ca and Ca than those of CK and C. There was a significant positive correlation between microbial biomass carbon

nitrogen and dissolved organic carbon (P<0.01)

but there was a significant negative correlation between microbial biomass carbon and dissolved organic nitrogen. Therefore

biochar and calcium peroxide can effectively improve soil microbial biomass carbon

nitrogen and dissolved carbon and nitrogen in upland red soil

and the combination of biochar and calcium peroxide is more beneficial to soil improvement.