Nutrient uptake during the course of a year by sour orange trees growing in ambient and elevated atmospheric carbon dioxide concentrations

AbstractDuring the third year of a long‐term carbon dioxide (CO2) enrichment study, macro‐ and micro‐nutrient concentrations in leaves and roots of sour orange trees were analyzed. Data for yearly courses of the macronutrients Ca, Mg, N, P, K, Na, and S and the micronutrients B, Cu, Fe, Mn, and Zn are presented. Significantly higher concentrations of N, K, Ca, and Mn were found in leaves of the control trees. The degree of difference varied seasonally: the greatest differences occured in summer, whereas essentially no differences were found in spring and winter.