August 31, 2014

Identifying Nutrient Deficiencies in Alfalfa

What is your alfalfa trying to tell you when leaf discoloration, stunting or scorching become visible? And, can you tell a potassium deficiency from a sulfur deficiency?

In your alfalfa, signs of a deficiency can vary depending on the nutrient that's deficient in your soil. This article will identify some common signs of deficiency*, but preventing any of the following signs from developing is the key. Because once you see any indication of a deficiency, the damage has been done.

Potassium – signs of a deficiency in alfalfa include leaf spotting and or yellowing (Shown above) along the leaf margins. It also generally starts to appear on older leaves first. In addition, a potassium deficiency can make your crop more susceptible to disease.

Sulfur – plants deficient in sulfur typically appear a light green color with yellowing generally occurring in younger leaves first (Shown below). This is one way you can visually tell it's different from a potassium deficiency.

Phosphorus – a stunted plant can be a sign of a phosphorus deficiency. More severe signs include distorted leaf shapes, and a dark green coloration of the tissue. Dead areas on the leaves are also a symptom.

Nitrogen – this deficiency visually manifests in the form of dark green coloration in the leaves, then yellowing on the leaves. Another sign includes a stunted, spindly plant. Additionally, a nitrogen deficient plant will mature early, but have a lower yield and crop quality.

Soil and tissue testing will verify the deficiency involved, but your best bet is to be pro-active and avoid a problem altogether. For more information on the signs and symptoms of nutrient deficiency, visit the International Plant Nutrition Institute or contact your crop consultant, retailer or Great Salt Lake Minerals Company.