YIELDS AND ELEMENTAL COMPOSITION OF ALFALFA PLANT PARTS AT LATE BUD UNDER TWO FERTILITY LEVELS

Abstract

The current study was initiated to ascertain distribution of elements in various parts of alfalfa (Medicago sativa L.) and whether differential accumulation occurred when a fertilizer was applied. Rows of Vernal alfalfa were fertilized in late April with a mixture of K2SO4, KCl, K2HPO4, MgSO4, MnSO4, Na2B4O7, CuSO4, and ZnSO4. Control rows were not fertilized. Shoots were removed at late bud and separated by 10-cm segments into leaves and stems. Upper 15 cm of roots also were sampled. No significant difference existed between unfertilized and fertilized plants in dry weights of comparable plant parts, except for significantly more leaves on next-to-bottom segment of fertilized shoots. Total leaves at both fertility levels contained higher concentrations of S, P, Mg, Ca, Zn, Mn, B, N, and Cu than total stems or roots. Total stems were highest in K and Cl. Total roots at both fertility levels contained higher concentrations of Na, Fe, and Al than total stems or leaves; roots contained no measurable Cl. In shoot segments, largest differences in concentrations due to fertilization occurred for K and S in upper stem segments, for Cl in lower stem and lower leaf segments, for Zn in lowest stem segment and stubble, for Mn in middle-to-lower stem segments and stubble, and for B in middle stem segment.