Seasonal variations of soil nitrogen mineralization under different land-use types in a coastal area in northern Jiangsu, China
The variations of soil mineral N under four different land use types (i.e.poplar plantation,crop-poplar integrated system,grassland,and cropland) in a coastal area of northern Jiangsu were investigated by a close-top incubation method.The net N mineralization rate under each of the four land use types was higher in spring than in autumn,winter and summer.The net N mineralization rate decreased in order of poplar plantation,crop-poplar integrated system,cropland and grassland.Ammonium N and nitrate N showed obvious seasonal variations under the four land use types.The concentrations of ammonium N and nitrate N were generally higher in spring than in other three seasons.The soil mineral N decreased with increasing soil depth.In 10-25 cm soil layer,the soil mineral N concentration was significantly different between poplar plantation and crop-poplar integrated system.In poplar plantation and grassland,the soil mineral N concentration was significantly different between 25-40 and 0-10,10-25 cm soil layers.The concentration of soil mineral N was significantly higher in poplar plantation than in cropland and grassland in 0-10 cm soil layer.
国家科技期刊平台
NSTL
万方数据
维普
