In the Sanjiang Plain of Northeast China, the marshland ecosystem have received increased nitrogen (N) input due to the N fertilizer application during agricultural activities. However, there is litter information on the effects of increased soil N availability on soil enzyme activities in this ecosystem. The objective of present study was to assess the effects of increased N input on marshland soil enzyme activities in the Sanjiang Plain, China. N was added as ammonium nitrate (NH4NO3) solution at four levels (0 mg N g(-1), N0; 0.1 mg N g(-1), N1; 0.2 mg N g(-1), N2; 0.5 mg N g(-1), N3). N addition suppressed soil urease activity throughout the incubation, stimulated invertase activity after 15 days of incubation, and had no effect on acid phosphatase activity except for N3 treatment at 27 days. Negative correlations were observed between the urease activity and inorganic N contents, both for NH4+ and NO3-. These findings suggested that N addition can potentially alter soil enzyme activities and might significantly change the nutrient cycles in the marsh ecosystem.
Song Yanyu,Song Changchun,Yang Guisheng,et al. Effects of N addition on soil enzyme activities in marshland ecosystem of Northeast China: an incubation experiment[C]. NEWARK:INFORMATION ENGINEERING RESEARCH INST, USA,2011.