Potassium content in soil and plants in a long-term potassium fertilization experiment

ABSTRACT: The assessment of nutrient content in soil and plants plays a fundamental role in determining soil fertility and plant nutritional status. This study evaluated potassium content in soil, plants, and crop productivity in an experiment with a history of potassium fertilization since 1991. Results indicated that grain yield, dry mass, grain size, 100-grain weight, and potassium levels in soil and soybean plants significantly responded to soil potassium levels. Additionally, it was possible to determine the soil potassium content necessary to achieve 95% of maximum soybean (51.3 mg kg-1) and combined crops yield (51.3 mg kg-1), to achieve the largest grain size (48.6 mg kg-1), and the maximum K concentration in grains (45.2 mg kg-1), providing valuable information for nutritional management and agricultural productivity optimization.