Concentrations of some macro and micronutrients in trees growing on the campus of Escola Superior de Agricultura "Luiz de Queiroz"

Abstract

Five trees growing on the campus of Escola Superior de Agricultura "Luiz de Queiroz" were analysed in relation to their macro and micronutrient concentrations. These trees belong to the following species: Aspidosperma polyneuron Mitell, Tabebuia roseo-alba, Aleurites moluccana Willd, Cariniana estrellensis Randü, and Piptadenia rigida. Three samples of young, intermediate and old leaves were collected from each of the above species. The 15 samples obtained, were washed for micronutrient analysis, dried in an incubator at 70°C, macerated and analysed for N, R, K, Ca, Mg, Cu, Fe, Mn and Zn. Each analysis was repeated three times. The differences between treatments (trees and leaf types were analysed according to the completely randomised statistical design. The following observations were made: a) At least one of the trees differed from the others in relation to nutrient concentration. b) The nutrients that appeared in higher concentration were N and Ca in all trees, but Aleurites mollucana Willd, presented higher concentrations of N and K. c) Piptadenia rigida and Corinmna estrellensis Raddi, showed higher concentrations of Fe than other species. d) Young leaves showed a tendency to have high concentrations of N, R, K and Cu.