Nitrogen transformation and migration in the soils of Zitny ostrov [Czechoslovakia]

agricultural chemicals checoslovaquia chemistry chimie chimie du sol czechoslovakia engrais europa europe fertilizantes nitrogenados fertilizers fisiologia fonction physiologique inorganic compounds metabolism metabolisme metabolismo nitrate nitrates nitratos nitrogen fertilizers nitrogen metabolism physiological functions physiologie physiology pollution pollution de l'eau produit agrochimique sales salts sel soil chemistry water pollution