[Objective] Exploring the effects of cattle manure application on soil biological characteristics and growth of poplar plantation

to provide theoretical basis for the establishment of soil fertility system and reasonable fertilization of poplar plantation.[Methods] A field experiment with four treatments

i. e. CK (neither urea nor cattle manure was applied)

CF (100% of nitrogen was provided by urea)

CM (100% of nitrogen was provided by cattle manure)

and CM+CF (50% and 50% of nitrogen was provided by cattle manure and urea

respectively) was conducted to determine effects of different treatments on physicochemical properties

microbial populations

microbial biomass carbon

microbial biomass nitrogen

active organic carbon

carbon pool management index (CPMI) and growth of poplar plantation.[Results] In comparison to CF treatment

CM+CF treatment significantly increased the populations of bacteria

fungi and total microorganism

and the contents of microbial biomass carbon and microbial biomass nitrogen increase 42.20% and 43.75%

respectively. The contents of available nitrogen

available phosphate

available potassium and exchangeable Mg were significantly increased by CM+CF treatment

while the pH value was obviously decreased. Meanwhile

the maximum value of total organic carbon content was observed in CM treatment

whereas the contents of low-labile

moderate-labile and high-labile organic carbon

and CPMI were notably increased by CM+CF treatment

indicative of 52.76

47.16 and 25.89 increases in CPMI over the values of CK

CF and CM

respectively. Additionally

the average volume growth rate in CM+CF treatment was 45.36%

which was significantly higher than those of other treatments. However

in CM treatment

fewer effects on soil and volume of poplar were observed in comparison with the one of CM+CF treatment.[Conclusion] Cattle manure co-applied with inorganic fertilizer was beneficial to improve soil biological characteristics and promote the growth of poplar plantation.