Effect of Fertilizer N, P, K, Ca, Mg, and Si on Tomato Yields in an Oxisol

Abstract

The effect of different levels of N, P, and K with and without Ca, Mg and Si, was studied on tomato cultivar Floradel at the Isabela Experiment Substation. The results obtained revealed that 224 Kg N and P/ha appear to be adequate for tomato production in a Coto clay, an Oxisol. A fertilizer-yield equation was employed to describe the relationship between applications of nitrogen, phosphorus and potassium and the yield in metric tons/ha of marketable tomatoes, in an experiment conducted in the same soil. The equation fitted very well the yield data obtained with nitrogen and phosphorus, but not so well mth that obtained with potassium. The poor fit of the potassium equation may have been due to the high level of potassium in the soil.