Fertility of agricultural soils close to native forest fragments

Abstract

The government strategy to increase native forest coverage has frequently been to punish land owners that do not abide the environmental legislation. The advantages of the forest presence in agricultural areas are rarely discussed, as is the soil fertilizing potential of close forests. The influence of edge forest in the soil fertility in agricultural areas was verified in five forest fragments of Londrina - State of Paraná. The soil of the area is originated from basaltic rocks, presenting differences in agreement with the intensity of the weathering. The Latossolo Vermelho Distroférrico (oxissol) presenting on the weathered palteaus, Nitossolo Vermelho Distroférrico (ultissol) on the hillsides and small pockets of Neossolo Litólico (entissol) on the most hilly sites. The soil fertility was evaluated, through its components, organic matter (OM), pH, potential acidity, Ca, Mg, K and P, in 5 m intervals to the distance of 50m of the edge forest towards the agricultural area. The organic matter content was higher until 10m from the forest edge, what is a demonstration of the positive effect of forests to the agriculture. Large forest fragments showed larger influence in the amount of nutrients than smaller fragments.