Efeito residual da adubação mineral e orgânica na composição química do solo e na composição de folhas de cafeeiro cultivado em Mococa

Abstract

Estudos realizados com matéria orgânica em solos cultivados com cafeeiro mostraram efeitos benéficos nas características físicas do solo, como a temperatura, e a umidade, e proporcionaram aumentos nas concentrações de fósforo das folhas, e aplicação de matéria orgânica no solo provoca redução da concen- tração de manganês das folhas, comparada com o tratamento sem adubo ou com a adubação mineral.O presente trabalho visou conhecer os efeitos residuais da adubação mineral e os da adubação orgânica, na composição química do solo e das folhas de cafeeiro.A study was made in Ortho-Red Yellow Podzolic soil on the residual effect of two years of fertilization with NPK and farm yard manure. The principal object was to observe the effects on the chemical characteristics of the soil and leaves, using coffee 'Mundo Novo'. The soil analysis showed that those treatments that received mineral fertilization lowered the pH. It also lowered the calcium and magnesium content of the soil when compared with check or with treatments that received farm yard manure. Leaf analysis demonstrated a marked residual effect of farm yard manure as a source of nitrogen. Mineral fertilization, on the other hand, showed a greater residual effect of potassium. Due to the soil pH reduction by the application of mineral fertilization, there was an increase of manganese and aluminum content of the leaves. The correlation between soil pH and the above mentioned elements showed: r = 0,92** and r = —0,66**, respectively.