Nitrate levels in soil profile after the first N application on coastcross pasture, grown on a dark red latosol (Hapludox), in Sao Carlos, SP, Brazil, under tropical altitude climate, were measured at 7-day intervals, to monitor possible losse in depth. Soil nitrate rates varied with high rates of N-ammonium nitrate (200kg ha per cutting) in surface layers. Danger of environmental impact was low in the studied conditions.