The investigations were carried out from 1997 to 2001. It was shown the function of the leafy shelter-belt as biogeochemical barrier of total length 114 m by changes of different forms of nitrogen in soil (total, nitrate, ammonium and organic) and in the ground water under shelterbelt and also activity of urease in soil. This shelterbelt is located on two kinds of soil. It was found the impact of the edge of the shelterbelt on the changes of different forms of nitrogen in soil and in ground water and also activity of urease in soils. It was observed that the significant impact on the decrease of nitrogen in ground water and in soils exerts the distance from the edge of shelterbelt. The highest decrease of analyzed compounds was observed in the first sector of shelterbelt (16.5 m). Additionally the effect of eluted cations Ca+2 and Mg+2 on the compensation of pH value of the ground water was also observed.