Nitrogênio e potássio em bananeira via fertirriga??o e aduba??o convencional-atributos químicos do solo

摘要

A field experiment was carried out in Pindorama (Sao Paulo State, Brazil) in which it was evaluated the effects of N and K application through fertirrigation and conventional fertilization on soil chemical properties in a banana plantation, during two cycles of production. Nutrient (P, K, Ca and Mg) availability and movement in soil profile and some chemical properties (organic matter, pH and base saturation) were evaluated through samples carried out in the experiment implantation and at the end of the first and second production cycles. The most important treatment effects were on soil pH and on exchangeable K. Fertilizers, applied by fertirrigation or conventional fertilization, increased soil pH specially in soil layer depth of 0 to 20 cm. It was observed that the impact of pH soil fertilization via fertirrigation was proportional to fertilizer rate. The conventional fertilization also caused a pH decrease on soil, and it was more intense near the plants, reflecting the effect of fertilizer local application. The application of solid fertilizer on the soil surface determined a significant accumulation of exchangeable K on layers until the depth of 20 cm and in the region nearer the plant pseudo-stem . The effects of fertirrigation on soil chemical properties were more diffuse because fertilizers were spread in a larger area than the application of conventional fertilization.