Nutrient Deficiency in Plants Laboratory Exercise #12

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.

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. ElementSymbolSource OxygenOAir/Water HydrogenHAir/Water CarbonCAir/Water NitrogenNSoil PhosphorusPSoil SulfurSSoil PotassiumKSoil CalciumCaSoil MagnesiumMgSoil

Macronutrients – Form Used By Plants NutrientForm Used CarbonCO 2 OxygenH2OH2O HydrogenH2OH2O NitrogenNO 3 -, NH 4 + PhosphorusH 2 PO 4 & HPO 4 2- PotassiumK+K+ CalciumCa 2 + MagnesiumMg 2+ SulfurSO 4 - Charge on the molecule

Micronutrients Macronutrients are needed in relatively small amounts by plants. They are usually supplied by fertilizers. ElementSymbolSource IronFeSoil ManganeseMnSoil BoronBSoil MolybdenumMoSoil CopperCuSoil ZincZnSoil ChlorineClSoil

Micronutrients – Form Used By Plants NutrientForm Used IronFe 2+ ManganeseMn 2+ BoronH 2 B0 3 - MolybdenumMoO 4 2- CopperCu 2+ ZincZn 2+ ChlorineCl - 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 & Soils ElementSoil Factor Causing Deficiency N & KExcessive leaching on coarse-textured low organic matter soils PAcid low organic matter soils Cold wet soils such as occurs during early spring Newly cleared soils SExcessive leaching on coarse-textured low organic matter soils in areas where air pollution is low (minimal levels of SO2 in the air) Ca & MgExcessive leaching on coarse-textured low organic matter soils Soils where large amounts of K have been applied

Micronutrient Deficiencies & Soils ElementSoil Factor Causing Deficiency FePoorly drained soils, Low organic matter soils, pH>7.0, Soils high in P ZnCold wet soils low in organic matter and highly leached, High pH soils (pH>7.0), Soils high in P, Exposed subsoils CuPeat and muck soils, High pH, sandy soils, Soils heavily fertilized with N BExcessive leaching on coarse-textured low organic matter soils, Soils with pH>7.0 MnExcessive leaching on coarse-textured low organic matter soils, Soil with pH>6.5 MoSoils 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. ciency_Pages/soy_def/SOY-N1.JPG

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. iculture/04octobernovember/photo3.jpg

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. EndRot.JPG

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. cies/-Mgcq.jpg

Deficiency Symptoms - S Leaves uniformly light green, followed by yellowing and poor spindly growth. Uniform chlorosis does not occur ogy/ndsucpr/Years/2007/june/7/soils.jpg phics/sulfur2.jpg

Deficiency Symptoms - Cu Leaves wilt, become chlorotic, then necrotic. Wilting and necrosis are not dominant symptoms. ing_Small_Grains/Grain_images/fig4.jpg&usg=AFQjCNE2 vzRwrqp65VR_xKRlo2LQOgWI3g

Deficiency Symptoms - Fe Distinct yellow or white areas appear between veins, and veins eventually become chlorotic. Symptoms are rare on mature leaves. tx.tamu.edu/HomeHort/F1Column/2003Article s/Graphics/iron%20chlorosis.jpg

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. rient_Deficiency_Pages/corn_def/CORN- ZN1.JPG s/Mirror/Nutrient%20Def_files/slide24.jpg

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 Deficiencies ElementCrops MnSoybean, Small Grain & Peanuts CuWheat & Corn ZnCorn MoSoybeans & Cauliflower BAlfalfa, Apples, Peanuts, Tobacco & Tomatoes FeOrnamentals, Fruit Trees, Soybeans, Grain Sorghum & Some Grasses

Questions?