The potential of two organic residues as sources of macro-nutrients in three types of soils of the third plateau of Paraná state was studied. Treatment consisted of a dose (38 t.ha-1) of fowl manure and sewage sludge neutralized by a 3:1 (CaO+MgO) mixture. Fowl manure was kept in natura. Maize (Zea mays L.)was reference plant. After 30 days of seeding, the aerial parts of the plants were cut. They were dried at 70 0C till constant weight was obtained, then weighted and ground. Analyses were undertaken after nitric-perchloric digestion of the samples. Macro-nutrient levels in soils and in plants were determined by atomic absorption spectrometry, flame technique. Results showed that production of dry matter was higher when fowl manure was used. Levels of macro-nutrients in Terra Roxa - TR were higher than those of Latossolo Vermelho Escuro - LE (Deep Red Latisol) and Podzólico Vermelho - PV (Red Podzolic), soils respectively. In aerial parts of maize plants collected in the soils treated with organic residues the concentrations of K, Ca, Mg, S and P were higher than those without treatment. The sewage sludge caused highest relation in Ca:Mg.
sewage sludge; macro-nutrients; maize culture; soil fertility
