MINERAL NUTRITION

• Plants are:

  ✔ Capable of making all necessary organic compounds from inorganic compounds and elements in the environment (autotrophic)

  ✔ Supplied with all the carbon, hydrogen, and oxygen they could ever need (CO2, H2O)

  ✔ Required to obtain all other elements from the soil so in a sense plants act as soil miners.
• Nutrient

  • any substance that can be metabolized by an organism to give energy and build tissue
  • growth and development
  • source of nourishment, especially a nourishing ingredient in a food
  • providing nourishment
• Categories of Plant Nutrients

  • Based on Function
  • Essential
  • Beneficial
  • Based on amount required by crop
  • Macroelements
  • Microelements
  • Based on capability to move from one part of the plant to another
  • Mobile
  • Immobile
• CRITERIA OF ESSENTIALITY

  1. If the nutrient is absent, then the plant is unable to complete its life cycle
  2. The function of the nutrient must not be replaceable by another element
  3. The nutrient must act directly in the metabolism of the plant
• Functions of the Essential Elements

  • Structural
  • Catalytic
  • Osmotic
• Functions of the Essential Elements

  • Structural - important components of biomolecules (e.g. N, P, Ca, Mg, S)
• Functions of the Essential Elements

  • Catalytic - as co-factor of enzymes (e.g. most micronutrients)
• Functions of the Essential Elements

  • Osmotic - regulation of cellular hydration (e.g. K)
• The Essential Nutrients

  • Macronutrients:
  • Nitrogen
  • phosphorus
  • potassium
  • calcium
  • sulfur
  • magnesium
  • oxygen
  • carbon
  • hydrogen
• The Essential Nutrients

  • Micronutrients:
  • Iron
  • boron
  • copper
  • zinc
  • manganese
  • molybdenum
  • chloride
• Macroelements / Macronutrients

  • Required in relatively large quantities like one to 10 milligram per gram of dry matter
• Microelements/ Micronutrients

  • Required in minute quantities like 0.1 mg per gram of dry matter
• The essential nutrients- plants take up only INORGANIC nutrients
• Beneficial Elements

  • Elements which promote plant growth in many plant species but are not absolutely necessary for completion of the plant life cycle
  • Silicon, sodium, cobalt, and selenium
• Beneficial Elements

  • Silicon
  • sodium
  • cobalt
  • selenium
• Decline in Soil Fertility

  • Soil erosion
  • Crop removal
  • Conversion of nutrients to unavailable forms
• Soil erosion

  • physical loss and displacement of the fertile topsoil
  • Geological erosion
  • Wind erosion
  • Water-borne erosion
  • Accelerated erosion due to human activity
• pH affects the growth of plant roots and soil microbes
• Root growth favors a pH of 5.5 to 6.5
• NUTRIENT DEFICIENCIES

  • ____ ____ deficiencies occur when the concentration of a nutrient decreases below its typical range
  • Deficiencies of specific nutrients lead to specific visual, often characteristic, symptoms reflective of the role of that nutrient in plant metabolism
• NUTRIENT DEFICIENCY SYMPTOMS

  • Chlorosis
  • Necrosis
  • Lack of new growth,
  • Accumulation of anthocyanin
  • Stunted leaf growth
• NUTRIENT DEFICIENCY SYMPTOMS

  • Chlorosis (uniform or interveinal) or yellowing of the leaves due to chlorophyll degradation
• NUTRIENT DEFICIENCY SYMPTOMS

  • Necrosis (tip, marginal, or interveinal) or death of leaf tissue
• NUTRIENT DEFICIENCY SYMPTOMS

  • Lack of new growth, which may result in death of terminal or axillary buds and leaves, dieback, or resetting
• NUTRIENT DEFICIENCY SYMPTOMS

  • Accumulation of anthocyanin resulting in reddish coloration of leaf tissues
• NUTRIENT DEFICIENCY SYMPTOMS

  • Stunted leaf growth with green, off-green, or yellow color
• Patterns of deficiency

  • _____ ___ _____ are important in identifying which nutrient is deficient or lacking
  • The location where a deficiency reflects the mobility of a nutrient
  • Nutrients are redistributed via movement through the phloem
• Patterns of deficiency

  • If the deficiency is seen in old leaves = nutrient is mobile
  • If the deficiency is seen in young leaves =nutrient is fixed or immobile