EDAFOLOGÍA, VOL 13. (2), PP 73-85 2006
CONSEQÜÊNCIAS DE DIFERENTES SISTEMAS DE PREPARO DO SOLO SOBRE A CONTAMINAÇÃO
DO SOLO, SEDIMENTOS E ÁGUA POR METAIS PESADOS
J.E.V. NÚÑEZ (1,2), N.M.B. AMARAL SOBRINHO(2,3); & N.
MAZUR(3,4)
1Instituto de Investigación Agropecuaria de Panamá (IDIAP). Apartado 58,
Santiago, Província de Veraguas.Panamá 2Departamento de Solos da Universidade
Federal Rural do Rio de Janeiro (UFRRJ). CEP 23890 000 Seropédica (RJ), Brasil
3Bolsista do CNPq 4Autor correspondente
The objectives of this study were to determine the influence
of different soil tillage me- thods on the loss of heavy metals by erosion,
and to evaluate the level of contamination in sediments and water from the
main stream in Caetés watershed, Paty do Alferes County, State of Rio de Janeiro.
The ex- periment was conducted from December of 1996 to March of 1997, and
cucumber (Cucumis sativus L.) was the cultivated crop. Four Wichmeier plots
were installed, with an area of 22 x 4 m. The treatments uti- lized were the
following: (i) tillage with machinery and operation down hill and burning of
the grassland (MAQ); (ii) tillage with machinery and operation down and without
burning of grassland between lines of crop (MANQ); (iii) tillage with animal
traction and following the natural contour of the hill, strip cropping grass
each 7 m (AA); and minimum tillage, (CM). Heavy metals concentration were also
determined in the samples of sediments and water from the main Caetés watershed
stream. The highest losses of heavy me- tals by erosion were in the MAQ treatment.
The bottom stream sediments showed an increase in the total concentration of
Cd, Ni, Pb, Zn and Mn, according to the sampling position, upstream and downstream,
showed Cd, Mn and Pb concentration above the maximum limits established for
tap water. The results ob- tained in this work allow to conclude that the intensive
use of agrochemistrys associated the high soil los- ses by erosion can determine
serious risks of contamination of the water from the main stream in Caetés
watershed that is used by the animals and for irrigation.
Key Words: contamination of soils, heavy metals, sediments, water, soil tillage methods, erosion.