Nutrient Deficiency in Plants

Objectives

Know the definition of element, compound, macronutrient and micronutrient.

Know the 16 essential nutrient elements. Learn how to use the "Key to Nutrient

Disorders ".

Important Definitions

An element is a pure chemical that contains only one type of atom. A compound is a molecule that contains one or more elements.

“Mineral”: An inorganic element Acquired mostly in the form of inorganic ions from the

soil

“Nutrient”: A substance needed to survive or necessary for the synthesis of organic compounds

Essential Elements

The 16 elements required by plants are obtained from the soil, water and air.

Thirteen of these elements must be supplied by the soil.

Six of the soil elements required by plants are needed in relatively large amounts and are usually added to the soil through fertilizer or lime. These are called macronutrients.

The remaining 7 elements supplied by soil are required in very small amounts and are termed micronutrients.

Macronutrients Macronutrients

are needed in relatively large amounts by plants.

Element Symbol Source

Oxygen O Air/Water

Hydrogen H Air/Water

Carbon C Air/Water

Nitrogen N Soil

Phosphorus P Soil

Sulfur S Soil

Potassium K Soil

Calcium Ca Soil

Magnesium Mg Soil

Macronutrients – Form Used By PlantsNutrient Form Used

Carbon CO2

Oxygen H2O

Hydrogen H2O

Nitrogen NO3-, NH4

+

Phosphorus H2PO4 & HPO42-

Potassium K+

Calcium Ca2+

Magnesium Mg2+

Sulfur SO4-

Charge on the molecule

Micronutrients

Macronutrients are needed in relatively small amounts by plants.

They are usually supplied by fertilizers.

Element Symbol Source

Iron Fe Soil

Manganese Mn Soil

Boron B Soil

Molybdenum Mo Soil

Copper Cu Soil

Zinc Zn Soil

Chlorine Cl Soil

Micronutrients – Form Used By PlantsNutrient Form Used

Iron Fe2+

Manganese Mn2+

Boron H2B03-

Molybdenum MoO42-

Copper Cu2+

Zinc Zn2+

Chlorine Cl-

Charge on the molecule

Nutrient Deficiency Symptoms Nutrient deficiency symptoms usually appear

on the plant when one or more nutrients are in short supply.

In many cases, deficiency may occur because an added nutrient is not in the form the plant can use.

Deficiency symptoms for specific elements are included on the "Key to Nutrient Disorders".

Nutrient Deficiencies

Every soil is not susceptible to the same nutrient deficiencies.

For example, coarse-textured soils low in organic matter are susceptible to sulfur deficiencies whereas sulfur is usually in adequate supply in clayey soils or soils high in organic matter.

Macronutrient Deficiencies & SoilsElement Soil Factor Causing Deficiency

N & K Excessive leaching on coarse-textured low organic matter soils

P Acid low organic matter soils

Cold wet soils such as occurs during early spring

Newly cleared soils

S Excessive leaching on coarse-textured low organic matter soils in areas where air pollution is low (minimal levels of SO2 in the air)

Ca & Mg Excessive leaching on coarse-textured low organic matter soils

Soils where large amounts of K have been applied

Micronutrient Deficiencies & SoilsElement Soil Factor Causing Deficiency

Fe Poorly drained soils, Low organic matter soils, pH>7.0, Soils high in P

Zn Cold wet soils low in organic matter and highly leached, High pH soils (pH>7.0), Soils high in P, Exposed subsoils

Cu Peat and muck soils, High pH, sandy soils, Soils heavily fertilized with N

B Excessive leaching on coarse-textured low organic matter soils, Soils with pH>7.0

Mn Excessive leaching on coarse-textured low organic matter soils, Soil with pH>6.5

Mo Soils high in Fe oxides, high adsorption of molybdenum, Soil cropped for a long time

Deficiency Symptoms - N

General chlorosis. Chlorosis progresses

from light green to yellow.

Entire plant becomes yellow under prolonged stress.

Growth is immediately restricted and plants soon become spindly and drop older leaves.

Deficiency Symptoms - P

Leaves appear dull, dark green, blue green, or red-purple, especially on the underside, and especially at the midrib and vein.

Petioles may also exhibit purpling. Re striction in growth may be noticed.

Deficiency Symptoms - K

Leaf margins tanned, scorched, or have necrotic spots (may be small black spots which later coalesce).

Margins become brown and cup downward.

Growth is restricted and die back may occur.

Mild symptoms appear first on recently matured leaves.

Deficiency Symptoms - Ca

Growing points usually damaged or dead (die back).

Margins of leaves developing from the growing point are first to turn brown.

Deficiency Symptoms - Mg

Marginal chlorosis or chlorotic blotches which later merge.

Leaves show yellow chlorotic interveinal tissue on some species, reddish purple progressing to necrosis on others.

Younger leaves affected with continued stress.

Chlorotic areas may become necrotic, brittle, and curl upward.

Symptoms usually occur late in the growing season.

Deficiency Symptoms - S

Leaves uniformly light green, followed by yellowing and poor spindly growth.

Uniform chlorosis does not occur

Deficiency Symptoms - Cu

Leaves wilt, become chlorotic, then necrotic.

Wilting and necrosis are not dominant symptoms.

Deficiency Symptoms - Fe

Distinct yellow or white areas appear between veins, and veins eventually become chlorotic.

Symptoms are rare on mature leaves.

Deficiency Symptoms - Mn

Chlorosis is less marked near veins.

Some mottling occurs in interveinal areas.

Chlorotic areas eventually become brown, transparent, or necrotic.

Symptoms may appear later on older leaves.

Deficiency Symptoms - Zn Leaves may be abnormally small and necrotic. Internodes are shortened.

Deficiency Symptoms - B

Young, expanding leaves may be necrotic or distorted followed by death of growing points.

Internodes may be short, especially at shoot terminals.

Stems may be rough, cracked, or split along the vascular bundles.

Crops Highly Susceptible to DeficienciesElement Crops

Mn Soybean, Small Grain & Peanuts

Cu Wheat & Corn

Zn Corn

Mo Soybeans & Cauliflower

B Alfalfa, Apples, Peanuts, Tobacco & Tomatoes

Fe Ornamentals, Fruit Trees, Soybeans, Grain Sorghum & Some Grasses

Questions?