[Soil nitrogen net mineralization and nitrification in typical Calamagrostis angustifolia wetlands in Sanjiang Plain].
From June 2004 to July 2005, the dynamics of soil inorganic N pool and N net mineralization/nitrification rates in typical meadow Calamagrostis angustifolia wetland (TMCW) and marsh meadow C. angustifolia wetland (MMCW) in Sanjiang Plain were studied by top-closed PVC tube in situ incubation method, with the affecting factors and annual N net mineralization/nitrification investigated. The results showed that the soil inorganic N in the two wetlands had evident dynamic characteristics. The NH4(+) -N and NO3(-) -N contents were much higher in TMCW soil than in MMCW soil, and the soil N net mineralization/nitrification rates in the two wetlands presented significant fluctuations. Biological immobilization, denitrification, and abundant precipitation in rainy season were the main reasons inducing the N net mineralization/nitrification rates to be negative, and temperature, precipitation, soil organic matter content, soil C/N ratio and soil pH were the main factors resulting in the significant differences of soil inorganic N pool and N net mineralization/ nitrification rates between the two wetlands. The annual N net mineralization and nitrification and the percentage of nitrified N in mineralized N were much higher in TMCW soil than in MMCW soil, suggesting that TMCW soil was superior to MMCW soil in N availability and available N-maintaining capacity.
Sun
Zhi-Gao
ZG
Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China. zhigaosun@yahoo.com.cn
Liu
Jing-Shuang
JS
D000641:Ammonia / Q000032:analysis / Q000378:metabolism; D001673:Biodegradation, Environmental; D002681:China; D009566:Nitrates / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D009609:Nitrous Oxide / Q000032:analysis / Q000378:metabolism; D006109:Poaceae / Q000254:growth & development* / Q000378:metabolism; D012987:Soil / Q000032:analysis*; D053833:Wetlands
D009566:Nitrates; D012987:Soil; D000641:Ammonia; D009609:Nitrous Oxide; D009584:Nitrogen