Effect of potassium application on morphophysiological two varieties of soybean under drought stress

Abstract

Domestic soybean production is getting weaker due to drought stress which affects all aspects of plant growth and metabolism, besides using adaptive plant varieties, increasing plant nutrition, especially potassium, also affects increasing plant tolerance to drought. The research aimed to examine the effect of potassium application on the morphophysiological of two varieties of soybean under drought stress. The research was conducted in a plastic house, Deli Serdang Regency, North Sumatra, using a randomized block design with three factors. The first factor was soil water content condition, which consisted of 80% and 40% field capacity. The second factor was variety, consisted of Grobogan and Dering-1. The third factor was the application of potassium, consisted of without potassium 100, 200, 300 kg KCL ha-1. Result showed that drought stress decreased potassium uptake, the relative water content (RWC) of leaf and plant height. Grobogan variety more adaptive to drought stress with the highest plant height (71.49 cm), K content (1.77%), K uptake (43.85 mg/plant), and leaf RWC (37.91%). Application of K at a dose of 200 kg ha-1was the most appropriate to encourage the growth of soybean plants under drought stress with the highest total K (1.76%) and leaf RWC (44.40 mg/plant).