Interaction of drought stress and potassium deficiency on soybean vigor and leaf temperature

Potassium (K) nutrition and drought stress affect soybean (Glycine max (L.) Merr.) vigor and productivity through the combined impacts on water regulation. A study was conducted with soybean grown in 18.9‐L buckets under a rain out shelter to determine how the interaction between these crop stresses at various growth stages influences the crop leaf K concentration, biomass production, total K uptake (TKU), grain yield, and temperature of the uppermost fully expanded trifoliate. Treatments included soybean grown with and without preplant fertilizer K, soil moisture at 50% (drought) or 80% (well‐watered) field capacity, imposed drought during vegetative growth (V3–V7), flowering (R1–R3), pod development (R4–early R6), and seed development (R5–mid‐R6) on two different silt loam soils. Widespread K deficiencies were observed during the study across all treatments. Drought stress significantly (p