The research was accomplished in the Caetés watershed, municipal district of Paty do Alferes (RJ), from January to March of 1997, in the crop cycle of cucumber (Cucumis sativus L.). The research took place in an area of Yellow-Red Podzolic soil (Udult), of clayey texture, at a slope of 60%, where Wischmeier plots for studying soil erosion were installed. The treatments applied were: (a) MAQ - down hill mechanical tillage, and burning of crop residues; (b) MANQ - contour mechanical tillage, with plant residues remaining on the field; (c) AA - contour tillage, with animal traction and strips of grasses placed every 7,0 m; and (d) CM - minimum tillage. Soil samples were collected in crop rows, and planting pits, in the plow layer, before planting and after harvesting. After each rain that resulted in production of sediments, the material was collected, dried, weighed, and kept for analyzes of total P; labile, organic and inorganic P; organic carbon; and pH in water. The CM treatment reduced P losses and influenced the distribution of labile and organic forms of P. MAQ treatment implied in loss of 12.4% of the total applied P, while the CM lost only 1%. The remaining of the plant residues among the crop rows, on the MANQ plot, decreased in 40% the total P loss, when compared to MAQ. The plots MAQ and MANQ showed clay increase in the sediments, which favored the highest losses of P sorbed in the clay fraction.
soil tillage; P fractionation; erosion losses
