Nitrogen compound‘s alternation in groundwater by fields manuring in large livestock enterprises

ISSN 1822-3230 (ankstesnių spausdintų leidinių)Livestock enterprises are the biggest source of point pollution, whose effect on groundwater quality has not been researched enough, so it is not enough to make sound conclusions about their effect on the groundwater quality. The aim of this research was to determine what effect annually manure fertilised fields of large livestock enterprises have on groundwater quality. The experiment was carried out in the Middle Lithuanian Lowland in Kėdainiai district. The groundwater quality research was conducted during 2008–2012 in a manure fertilised field of a livestock enterprise. There were higher Ntotal and NO3-N concentrations (2.4 and 2.8 times respectively) determined in the borehole, which was situated in a manure fertilised field. As groundwater level rises in the boreholes, the Ntotal and NO3-N concentrations increase: in the manure fertilised field – r=0.46 and r=0.53, and in the sheds territory – r=0.41 and r=0.48, respectively. NH4-N concentrations in the boreholes have a tendency to fall as the water level rises – r=0.10 and r=0.28 respectively. Air temperature, rather than the precipitation level and Nmin reserves in the soil, had a bigger impact on the increase of NO3-N and NH4-N concentrations in the borehole, while the mentioned factors had no effect on Ntotal and NO2 - N concentrations. Ntotal, NO3-N, NO2-N and NH4-N concentrations (r=-0.31) in borehole, installed in the sheds territory had a tendency to increase when air temperature was lowVytauto Didžiojo universitetasŽemės ūkio akademij