it’s a nutrients deficiency symptoms.
go for following treatment
1)the leaves of the standing soybean crop appear excessively yellow, immediately mix 10 kg of ferrous sulfate (micronutrients) and 100 kg of manure per acre into the soil before tilling.
-2)For management through spraying, use 20 grams of micronutrients + 30 ml of amino acids/seaweed extract + insecticide if needed, based on the intensity of the pest infestation.
3)To quickly address foliar deficiencies and, if there is some nitrogen deficiency, spray 2% DAP or urea (200 grams/10 liters of water).