THE ADAPTATION OF CERTAIN COLORIMETRIC METHODS TO THE ESTIMATION OF NITRATES, PHOSPHATES AND POTASSIUM IN PLANT SOLUTIONS

Abstract

Qualitatively, the usual chemical microscopical tests were found to be incapable of use in the establishing of low, medium, and high nutrient levels in crop plants. Quantitatively, the following methods were found applicable to determinations with plant solutions: (a) nitrate-N[long dash]phenol di-sulphonic acid method; (b) phosphate-P[long dash]coeruleo-molybdate method; and (c) K[long dash]reduced chloroplatinate method. The application of these methods to the establishing of optimum nutrient levels of the 3 fertilizer elements within the plant as indicative of a normal crop is discussed.