Study of Black Soil Enzyme Activity in Soybean Field Under Long-Term Different Fertilizations

Based on scientific observation station of arable land conservation and agriculture environment of Heilongjiang,Ministry of Agriculture( built in 1979),selected four typical fertilization treatments( no fertilizer,organic fertilizer,chemical fertilizer and organic fertilizer combined with chemical fertilizer),collected soil sample after soybean harvest in 2011 to study effect of long-term different fertilizations on main kinds of enzymes activities( β-glucosidase,urease and phosphatase) of black soil. The results showed that the no fertilizer treatment had lower enzyme activities,fertilization treatment could increase black soil enzyme activities,urease and phosphatase had bigger response degree than β-glucosidase; there was no significant difference between effects of organic fertilizer and chemical fertilizer on soil enzyme activities; however,treatment of organic fertilizer combined with chemical fertilizer could increase soil β-glucosidase,urease and phosphatase activities significantly. Meanwhile,there were significant and positive correlationships among soil enzyme activities and contents of soil organic,soil total nitrogen,soil total phosphate and soil available phosphate,significant and negative correlationships among soil enzyme activities and soil p H. Long-term treatment of organic fertilizer combined with chemical fertilizer could increase soil enzyme activity in soybean field,which had close relationships with soil nutrients.