A System of Routine Foliar Analysis of Sugar Cane Major and Trace Elements

A system of routine foliar analysis of sugar cane for N, P, K, Ca, Mg and S is discussed which, together with subsequent field soil analysis, is used as criteria for fertilizer recommendations on the estates and privately-owned sugar farms in the Rhodesian Lowveld. The sampling techniques and analytical methods described are reasonably rapid, economical and accurate. Furthermore, they do not require highly skilled analysts and our staff have been trained in a comparatively short time to perform these operations reliably. Briefly, after semi-micro H,SO,/H,O, digestion, aliquots are taken for: N by micro-distillation of NH, and titration with standard H,SO,; P by Vanando-Molybdenum complex colorimetry; K, Ca, Mg by atomic absorption; and S by tube furnace in a stream of oxygen at 1 OOO°C with titration of resultant H,SO, with standard sodium borate. The method for Fe, Mn, Zn, Cu, Ni and B is briefly discussed.