Nutrient deficiency in corn or soybeans can be seen just by looking at the plant. Problems in the upper and lower canopy can signify micro and macronutrient deficiencies, respectively. Discoloration can mean a shortage in potassium or nitrogen and stunted plant growth can also signify a nutrient shortage.
Nutrient deficiencies in corn and soybeans can result from a number of reasons, but should be diagnosed and fixed as soon as possible regardless of the cause. Identifying deficiencies early on allows you to take a corrective course of action to minimize damage and increase your bottom line.