N, P, and K Percentages in Soybean (Glycine max (L.) Merrill) Plant Parts¹

Field experiments were conducted with N fertilizer applications for nodulating and non‐nodulating soybean isolines, with P and K fertilizer applications for the nodulating isolines, and with 8 varieties. Percentages of N, P, and K in the plant parts at successive stages of plant development were determined. Composition of plant parts from different varieties usually were similar. N, P, and K concentrations in each plant part, except the seeds, usually decreased as the season progressed. Fertilizer applications resulted in increased concentrations of the fertilizer nutrient applied in all plant parts. N deficiency resulted in late‐season increased P concentrations, especially in leaves, petioles and seeds. Nutrient translocation to the developing seeds resulted in severe nutrient depletion in other plant parts irrespective of fertilizer applications.