High metal contents in coffee plant organs developed in tubets with different proportions of biosolid composts and carbonized rice hulls

The objective of this study was to analyze the effect of biosolid composts (BC) and carbonized rice hull (RH) on the production of Coffea arabica L. cv Catuai Vermelho seedlings (IAC H 2077-2-5-99) gown in tubets. A totally randomized experimental design with five treatments and four replications was conducted in a nursery, to evaluate Co, Ni, Cr, Pb, Cu, Mn and Zn contents in roots, steins and leaves. Higher contents of Cr, Co, Ni, Pb, Cu and Zn were found in roots, while leaves carried the highest content of Mn. Zn in leaves went from average to high in plants developed in BC. In plants developed in RH. Mn content was about four times higher than the adequate concentration. Ni, Co, Cr, Pb and Cu contents found in leaves were considered normal, according to international standards. The best treatment for coffee seedling nutrition was 50% RH+ 50% BC.