Rationalization of Irrigation Water Using Potassium and Foliar Spraying with Salicylic Acid of Soybean

A field experiment was carried out during 2023 and 2024 seasons at the Agricultural Research Station Experimental Farm in Shandaweel Island, Sohag Governorate to study the effect of spraying soybean (Var. Giza-111) with different concentrations of salicylic acid (SA) and potassium sulphate under different levels of water stress on some vegetative and crop yield characteristics. The experiment was laid out in randomized complete block design (RCBD) using strip plot arrangement within split with three replicates. Three irrigation water amounts (2400, 2000 and 1800 m3/fed/season) were distributed vertically while the four SA concentrations (control, 25, 75, and 100 ppm) were allocated horizontally and, potassium sulphate rate (control, 48 and 72 kg/fed,) as soil applications were arranged in sub plot. The results showed that adding potassium at a rate of 72 kg per fed and spraying soybeans at a rate of 100 ppm had a significant effect on the growth (plant height and number of branches/plant) and soybean productivity (number of pods/plant, weight of 100 seeds, weight of seeds/plant and seed yield/fed). The interaction results showed that adding potassium at a rate of 72 kg /fed. and spraying salicylic acid at a rate of 100 ppm saved the amount of irrigation water from 2400 m3 to 1800 m3.