Assessing nutrient uptake by field-grown orange trees

摘要: Abstract Mineral nutrients applied to crops are a cost growers and could represent cause of air water contamination, especially when supply exceeds nutrient needs. Assessing the amount that trees need absorb in order successfully complete vegetative reproductive growth is therefore fundamental step for developing rational fertilization strategies orchards. In this paper, estimation cumulative yearly needs dynamics uptake along season “Tarocco” orange [Citrus sinensis (L.) Osbeck] orchards Southern Italy were studied. first experiment, allometric relationships between branch circumferences wood or leaf biomass obtained. These used quantify patterns above ground organs. Woody organs accounted majority (AGB). Although leaves total less than 21% AGB biomass, they included more 38% N, 31% P, 44% K, 32% Ca 33% Mg. case-study represented by mature citrus orchard, most annual increase was fruits shoots. Calcium absorbed with highest rate, followed Mg P. Most recovered abscised leaves, while P K fruits. Nitrogen distributed equally among fruits, pruning leaves. Seasonal data indicate from April November, net almost summer. From December February present tree canopy either remained stable decreased, indicating no during period, and, as case N internal translocation perennial