Just because you farm dark, level soils doesn’t mean you won’t see a nutrient deficiency. Agronomists say it depends on how soils have been cared for in the past. Especially if you don’t know what recent soil-test levels are, nutrient deficiency symptoms could show up. Would you know them if you saw them?

Jamie Bultemeier, with A&L Great Lakes Labs, Fort Wayne, is an Indiana certified crop adviser who can recognize deficiency symptoms when he sees them. This is a good time of year to look for nutrient deficiency symptoms, he notes. Plants are using lots of nutrients to make seed. If nutrients are deficient in the soil, now is when those symptoms could appear.

Nutrient by nutrient

Bultemeier points out the most common nutrient deficiency symptoms observed in soybeans:

Nitrogen. Look for pale, yellow leaves.

Potassium. This leads to chlorosis and necrosis of the leaf margins and interveinal tissue of soybean leaves. Visual symptoms of potassium deficiency can often be confused with various leaf diseases.

CLOSE-UP OF K DEFICIENCY: These symptoms appear on leaves when potassium is deficient in the soil and the plant.

Phosphorus. This simply leads to a smaller plant. It can be difficult to identify visually.

Sulfur. This one mimics a nitrogen deficiency and often occurs in conjunction with nitrogen deficiency.

Multiple micronutrients. Manganese, magnesium and iron deficiency all display variations of a pale green leaf with interveinal yellowing within the leaf. Differences are subtle.

MANGANESE SYMPTOMS: Manganese shortages caused these symptoms in soybean plants.

Boron. If this micronutrient is low, it doesn’t often produce distinct visual symptoms. However, it can lead to reduced pod counts on soybean plants.