Recognizing Nutrient Deficiency Symptoms in Soybeans
May 17, 2013
Featured Seedsman: Doug Mueth, Illinois, (firstname.lastname@example.org)
Nutrient deficiency is one of many factors that can affect soybean plant growth and development throughout the growing season. Soybean plant age, environmental conditions, and soybean product selection can all impact the nutrient deficiency symptoms you may observe in the field.
Soybeans require at least 13 elements from the soil and three (C, H, O) supplied primarily by air and water. The nutrients most likely to be deficient are nitrogen (N), phosphorus (P), and potassium (K) as they are the major or primary nutrients needed in greater amounts. The secondary nutrients calcium (Ca), magnesium (Mg), and sulfur (S) are still needed to be taken up in fairly large quantities. The remainders are micronutrients needed in small amounts.
Nutrient deficiencies are one of the causes of leaf discoloration and/or chlorosis observed in soybean fields at this time of the year. This article describes symptoms of some of the most common nutrient deficiencies in soybeans to help you to understand some of the symptoms you may be seeing out in your field.
Nitrogen (N). Lower leaves turn pale green. One of the causes of chlorotic leaves is ineffective N fixation under cooler and wet soil conditions. Drainage tiles instillation in heavy soils can alleviate N deficiency.
Phosphorus (P). Older leaves begin to show deficiency symptoms of growth stunting, dark green coloration of the leaves with necrotic spots, and leaf cupping. Additionally, P deficiency can delay blooming and maturity. Cool and wet soils decrease P uptake by the root system.
Potassium (K). Similar to P deficiency, K deficiency symptoms occur first on older, lower leaves, although under severe deficiency all but the very young, newly developed leaves may show symptoms. Leaf margins and between the veins show signs of yellow and brown coloration. The causes of K deficiencies are insufficient application of K fertilizer and cool/wet conditions.
Apply the required K rate based on soil analysis and plant soybean in warmer conditions.
Iron (Fe). Chlorosis between the veins of young, upper leaves is the typical Fe deficiency symptom. Calcareous soils with high Ca levels and high pH cause Fe to tightly bound to the soil particle and become unavailable for the plant. Deficiency can be managed by installing drainage tiles in heavier soils and planting high tolerant varieties.
Manganese (Mn). Deficiency symptoms appear on high pH, sandy, or high organic matter soils. Symptoms are similar to Fe chlorosis. Plants are stunted with interveinal chlorosis.
Your Channel Seedsman can work with you to determine if nutrient deficiencies may be affecting your soybean crop and what management steps should be taken.
To learn more on how to recognize nutrient deficiency symptoms in soybeans contact Doug Mueth from Illinois (email@example.com) or your local Channel Seedsman.
Source: Diaz, D. 2008. Nutrient deficiency symptoms. Agronomy e-Updates, K-State Ext.
Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible. ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Channel® and the Arrow Design® and Seedsmanship At Work™ are trademarks of Channel Bio, LLC. Leaf Design® is a registered trademark of Monsanto Company. All other trademarks are the property of their respective owners. ©2012 Monsanto Company. ELW051313.