The effect of sodium and potassium fertilizer on the mineral composition of sugar beet

Plants from salt and potash fertilizer trials at Bothamsted were harvested at intervals throughout the growing seasons of 1942 and 1943 and analysed for N, K, Na, Ca, Mg and Mn. The uptake of nutrients is discussed with respect to field methods of fertilizer application. Salt increased beet yield in both years, but it did not act by mobilizing soil potassium reserves and increasing the potassium status of the plant. Potash fertilizer, although increasing the potassium status of the plant, did not increase yield. Sodium and potassium were differently distributed in the plant. At harvest, only 6% of the plant's sodium content was in the root compared with 33% of the potassium. The potassium, but not the sodium content of the petiole, was higher than that of the lamina until the end of August. Sodium thus is a nutrient for beet and not a potassium substitute.