SOIL COPPER ACCUMULATION IN COFFEE PLANTA TION TREATED WITH COPPER FUNGICIDES

Field study was conducted to evaluate the effect of continuous applica tions of copper fungicides used for the control of coffee leaf rust on soil copper accumulation. The two field studied have been treated for 8 and 10 years with copper fungicides at rate of 4g/tree/appl, with 5 applications per year in the period from January to May. Continuous a pplications of copper fungicides increase double acid extractable copp er contents of sandy and clay soils from 14 to 49 ppm and from 28 to 1 49 ppm, respectively. The order of extractability was: 0.05N HCl + 0.0 25N H2SO4 (double acid) > HCl 0.1N > EDT > DTPA. The results indicated that there was considerable accumulation of copper in soil. Copper ac cumulation decreased organic matter mineralization, and consequently i ncreased soil organic carbon, Ca, Mg and pH, and decreased Al and P.