engleski

Horizontal and vertical nitrate-nitrogen distribution under different nitrogen fertilization levels

The importance of nitrate (NO3-) in the internal nitrogen cycle of arable soils has been widely recognized, especially because of accumulation of nitrate-nitrogen in the soil profile and its implications for the environment. In order to determine vertical and horizontal nitrate-nitrogen distribution, soil samples were collected from a long term experimental field located in central part of Croatia (Popovaca). Soil sampling was conducted during vegetation of maize (June, 2007) on four fertilization treatments (0, 100, 200, 300 kg N ha-1) and at 8 depths (up to 2 m). Spatial variability was mapped using ArcView geographic information system (GIS). Ordinary kriging was used as interpolation method. To characterize spatial variability, spherical (with logarithmic transformation) model were fitted to calculate semivariograms. Also, results indicate that the content of nitrate-nitrogen significantly varied depending on the depth and treatment.

soil; nitrate-nitrogen; micro spatial distribution

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