Identifying Nutrient Deficiency Symptoms In Field Crops

Jun 10, 2016

By George Silva

Mobile and immobile nutrients differ where their symptoms appear in the plant.

A useful step in identifying nutrient deficiency symptoms is to determine whether the deficiency is the result of a mobile or immobile nutrient based on where the symptoms first appear in the plant. Mobile nutrients include nitrogen (N), phosphorus (P), potassium (K) and magnesium (Mg). Mobile nutrients are able to move out of older leaves to younger plant parts when supplies are inadequate. Because of their mobility inside the plant, visual deficiencies will first occur in the older or lower leaves (see photo). If the deficiency continues, then the symptoms will spread throughout the plant.

Generalized diagram showing the portion of the plant where nutrient deficiency symptoms are first observed. Courtesy of the 4R Plant Nutrition Manual, IPNI 2012.

In contrast, the relatively immobile nutrients do not readily move within the plant. As such, their deficiency symptoms first appear in new growth or young leaves and can be localized. Some of the common immobile nutrients include manganese (Mn), sulfur (S), copper (Cu), iron (Fe), calcium (Ca) and boron (B).

Macro nutrients such as N, P, K and Mg are needed in large quantities, so they are best applied to the soil. The micronutrients are needed in small qualities and can be soil and foliar applied.

Source: msu.edu

Video: Residue Management

Residue Management conservation practice manages the amount, orientation, and distribution of crop and other plant residue on the soil surface year-round while limiting soil-disturbing activities used to grow and harvest crops in systems where the field surface is tilled prior to planting. This video explores how Ryan McKenzie implemented this conservation practice on his farm in Samson, Alabama.

Practice benefits:

• Increases organic matter

• Improves air quality

• Decreases energy costs

• Reduces erosion

• Improves soil health

The Conservation at Work video series was created to increase producer awareness of common conservation practices and was filmed at various locations throughout the country. Because conservation plans are specific to the unique resource needs on each farm and also soil type, weather conditions, etc., these videos were designed to serve as a general guide to the benefits of soil and water conservation and landowners should contact their local USDA office for individual consultation.