Migration of nitrogen in soil as a consequence of acceleration of pentachlorophenol degradation
2000
Madaras, M. | Barancikova, G.
The paper evaluates distribution and leaching of mineral nitrogen as a consequence of acceleration of PCP degradation in five soil types. On the basis of received results, we can conclude: mineral nitrogen was intensively leached in the case of soil with good water permeability connected with higher inundation (Planosol in this experiment). In field conditions it means higher probability of underground water contamination. Penetration of nitrogen to discharges was not observed in soils with restricted movement of soil solution; retention of mineral nitrogen was found in the top layer of all accelerated variants. The retention was negatively correlated with overall drainage volume; different behaviour of studied soil is not a consequence of different soil types, but was caused by different physical state of soils, mainly by the presence of layers with low hydraulic conductivity. Nitrogen balance is only quantitative in this evaluation. To make qualitative assessment of fate of mineral nitrogen forms, 15N should be used. Recent research shows that only lower portion of leached nitrogen has its origin in the applied fertiliser. This resulted of so-called priming effect (Ondrisik et al., 1998). In addition, experimental conditions were extreme with respect to nitrogen movement in soil: high dose of soluble fertiliser, absence of vegetation, lower evaporation. Although undamaged soil lysimeters are good approximation of natural conditions, they don't reflect all characteristics of field soils. Important phenomenon, which are not considered in laboratory lysimetric experiments, are variability of hydrophysical properties, macropore flow, torrential rains and variable temperature
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