Influence of mid-field afforestation on the changes of organic nitrogen compounds in ground water and soil

Different forms of nitrogen (total, organic, amino acids in dry mass and in humic acids) as well as humus substances, dry mass, activity of ureasein ground water and in soils under mild-field deciduous afforestation were measured. Experiments were carried out during an entire year. Afforestation decreased total organic substancesin ground waters, as well as total nitrogenand free and bound amino acids to humic acids. In soil under afforestationthe decreaseof pH, activity of urease,and the content of amino acids in humic acids was observed.