Long-Term Fertilization Effects on β-glucosaminidase Activity in a Chinese Mollisol

摘要

Soil polysaccharide chitin is hydrolyzed by β-glucosaminidase (EC 3.2.1.30) and yields glucosamine,making β-glucosaminidase an important enzyme in C and N cycling in soils.This study was carried out to investigate the effects of long-term organic manure and chemical fertilizer on the activity of β-glucosaminidase in Chinese Mollisols.The activity values were significantly affected by long-term organic manure and chemical fertilizer.For the effects of organic manure,β-glucosaminidase activity was the greatest in M1 (30 t manure ha-1 per year) and the least in M0 (no manure) treatment,while β-glucosaminidase activity on M2 treatment (60 t manure ha-1 per year) showed an inhibition effect compared with the M1 treatment.For chemical fertilizer addition,the activity of β-glucosaminidase was the highest in N treatment,followed by NPK,NP and no chemical fertilizer treatment (CK).These results indicated that β-glucosaminidase activity was sensitive to fertilization,especially the manure and N fertilizer.Correlation analysis showed that the activity of β-glucosaminidase was significantly correlated with organic C,total N,microbial biomass C,alkalified N,Olsen P,available K,and glucosamine,suggesting that β-glucosaminidase activity could be as an index to evaluate the fertility of soil and its significance for the study of soil biochemistry.Therefore,we assumed that the activity of β-glucosaminidase may provide reliable indicator for the long-term fertilization effect on N transformation in soil.