Manejo do solo em estabelecimentos referência da agricultura familiar

Abstract

The Southwest region of Paraná is characterized by the presence of family farmers who develop diverse systems, such as the system "milk + grain" in crop-livestock integration (ILP) with the use of the same area for crop production annual summer and winter annual pastures. However, the introduction of animals in the area of crop ends up promoting changes in the characteristics of the soils, especially on the density, porosity, aggregation, soil organic matter (MOS) and nutrient cycling. Several studies have shown that when management practices are adopted in the appropriate ILP, there is no loss in relation to the maintenance or improvement of the chemical properties, physical and biological soil. This study aimed to evaluate the behavior of chemical and physical attributes of soils managed under ILP by five farmers, comparing them to summer pasture area (PV) and native vegetation (MA) in order to identify potential problems in maintaining quality of soils. The areas managed in ILP or PV have good levels of acidity and related (pH, V%, Ca, Mg and m%) and potassium (K) with medium to high levels, and phosphorus (P) that had lower nutrient levels, especially in subsurface. There was a possible transfer of nutrients from areas of ILP to the areas of PV, in function of the PV to be the point of maximum residence time of grazing animals or simple fallow throughout the year. The stocks of total organic carbon (COT) were lower in managed areas compared to native vegetation. For density and macroporosity, had managed areas, respectively, higher and lower values compared to MA, where the density levels showed no restrictive development of plants, but macroporosity values were restrictive in or near this level. For mean weight diameter (DMP) of aggregates, observed an effect mainly on the surface, with higher DMP in the areas of PV.