Response of ‘Açúcar’ orange trees to mineral and organic fertilization in Western Santa Catarina, Brazil

Abstract

The aim of this study was to investigate the influence of organic and mineral fertilization on orange
yield (Citrus sinensis Osbeck cultivar Açúcar) grafted on Rangpuor lime (Citrus limonia Osbeck). The experiment was carried out in a 2 years old ‘Açúcar’ orange orchard. A complete randomized block design was used, with a split-plot distribution of the treatments and three replications. The treatments were pig slurry and broiler litter
house in the plots, and doses of NPK mineral fertilization in the subplots. Fruit yield was evaluated from 2003 to
2006, while leaves and soil (zero to 10cm) were analysed in 2006. Significant yield responses to manure and mineral fertilizer were observed. The positive response to organic and full mineral fertilizer dose can be attributed mainly to N. Liming, P and K application before planting were sufficient to provide adequate foliar nutrient concentration and fruit yield. Nutrient levels in the leaves were high in all treatments. Annual surface application
of manure and mineral fertilizer increased nutrient availability in the top soil layer (zero to 10cm) and poultry manure increased also soil pH and organic matter.