Symptom Identification Key for Nutrient Deficiencies in Soybeans

Use the following key to help identify nutrient disorders observed in Nebraska soybeans and drybeans.

Select the best descriptor for your plant symptoms. (Photos courtesy of the International Plant Nutrition Institute (IPNI) Image Collection © Version 2017-08-24, except as noted.) BACK to Soils page

Nutrient Deficiencies in Soybean
A1. Symptoms appear first or are more severe on older and/or fully expanded leaves. Select B1 or B2 d
A2. Symptoms appear first or are more severe on younger leaves. Select C1 or C2 d
B1. B1. Symptoms are uniform across leaves. Go to D d
B2. Symptoms are localized on leaves. Go to E d
C1. Pale green to yellow plants, often with pale brown or bronze necrosis. Go to F d d
C2. Dark green to bluish green leaves, often with interveinal, small lesions; dry bean may have marginal chlorosis.

Phosphorus deficiencyField with and without phosphorus deficiency

Left: P applied; right: P deficient
Source: Luiz Antonia Zanao Junior (IPNI)

d
D1. Pale green plants, pale yellow leading to brown older leaves, veins are not prominent. Symptoms appear first or are more severe on older and/or fully expanded leaves. Symptoms are uniform across leaves. Nitrogen deficiency
N deficiency in soybean
N deficiency in soybean
D2. Pale green plants; interveinal mottling (or interveinal chlorosis in dry bean) of older leaves leading to bronze necrosis; green veins. Symptoms appear first or are more severe on older and/or fully expanded leaves. Symptoms are uniform across leaves.

Zinc deficiency

d
E1. Green plants with chlorosis along the leaf margins leading to brown interveinal necrosis in soybean; veins stay green. Symptoms appear first or are more severe on older and/or fully expanded leaves. Symptoms are localized on leaves. Potassium deficiency
Soybean potassium deficiency
Potassium deficiency in soybean
E2. Pale green plants with interveinal pale yellow mottling of the leaves followed by interveinal necrosis - or necrosis along the underside of the main veins in dry bean. Symptoms appear first or are more severe on older and/or fully expanded leaves. Symptoms are localized on leaves. Magnesium deficiency



Soybean with magnesium deficiency
F1. Symptoms are prominent interveinal chlorosis or necrosis; veins are prominent over length of leaf. Pale green to yellow plants, often with pale brown or bronze necrosis. Iron deficiency


(photo by UNL staff)
Iron deficiency in soybean
F2. Pale yellow leaves with mottled interveinal chlorosis leading to dark brown necrosis. Pale green to yellow plants, often with pale brown or bronze necrosis. Manganese deficiency

Manganese deficiency in soybean(Click on image for a close-up view)

Manganese deficiency in soybean
F3. Pale green to yellow leaflets without prominent veins or necrosis. Pale green to yellow plants, often with pale brown or bronze necrosis. Sulfur deficiency

Soybean with sulfure defiency

d