Assessment of Annual Nutrient Uptake of Macro- and Micro-Elements for Mango Trees Based on Whole-Tree Analysis

Elucidating nutrient requirements is crucial for the fertilization management of fruit trees. The current study explored the nutrient uptake and allocation patterns of macro- (N, P, K, Ca and Mg) and micro- (Fe and Zn) elements during the vegetative and reproductive periods of 15-year-old ‘Keitt’ mango trees in Southwest China. The contents of N, P, K, Ca, and Mg were significantly higher in young organs than in perennial organs, while Fe and Zn exhibited the highest accumulation in perennial branches. For yielding 100 kg of fruit in each mango tree, the annual total uptake of N, P, K, Ca, Mg, Fe, and Zn was 601.32, 93.45, 275.74, 541.50, 88.68, 21.22, and 1.35 g, respectively. Nutrient allocation showed element-specific patterns during the annual growth cycle. Nutrient losses from pruning and fallen flowers and fruits accounted for 27.74–38.94% of the total nutrient uptake of each tree. The harvested fruits contained 3.79–32.89% of the total nutrient uptake of each tree; furthermore, K and Mg were the two highest amounts in the fruit. The Ca requirement was significantly higher than those of P and K in mango trees; however, only 2% of the total Ca in each tree was distributed in the fruit. These findings can contribute to in-season fertilization strategies for mature mango orchards according to nutrient uptake per tree and fruit yield.