[Effects of long-term fertilization on enzyme activities in black soil of Northeast China].
In this paper, black soil samples at the depths of 0-20 cm and 20-40 cm were collected from the Hailun Agricultural Ecology Station of Chinese Academy of Sciences to study the effects of long-term fertilization on their urease, invertase, phosphatase and catalase activities and total C and N contents. The results showed that long-term application of chemical fertilizers and organic manure increased the activities of urease, invertase and phosphatase in 0-20 cm and 20-40 cm soil layers in different degree, and the combined application of them increased the activities of the three enzymes significantly, with an increment of 43.6%-113.2%, 25.9%-79.5% and 14.7%-134.4% in 0-20 cm soil layer and 56.1%-127.2%, 14.5%-113.8% and 16.2%-207.2% in 20-40 cm soil layer, respectively. However, long-term application of chemical fertilizers without organic manure had little effects on catalase activity. The activities of urease, invertase and phosphatase decreased with increasing soil depth. Long-term application of N fertilizer increased urease activity, and P fertilization had obvious positive effect on phosphatase activity. Long-term fertilization also had obvious effects on the soil total C and N contents and C/N ratio.
Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Harbin 150081, China. wsq200131@sohu.com
Shu-Qi
SQ
Wang
Xiao-Zeng
XZ
Han
Yun-Fa
YF
Qiao
Shou-Yu
SY
Wang
D002681:China; D018556:Crops, Agricultural / Q000201:enzymology / Q000254:growth & development; D005308:Fertilizers; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D012987:Soil / Q000032:analysis*; D013997:Time Factors; D014510:Urease / Q000378:metabolism*; D043324:beta-Fructofuranosidase / Q000378:metabolism*
D005308:Fertilizers; D012987:Soil; D010744:Phosphoric Monoester Hydrolases; D043324:beta-Fructofuranosidase; D014510:Urease