Nutrient recycling 10

BY4125

Hydrogen (H)

Basic building block of life, major component of water and organic molecules

Carbon (C)

Basic building block of life, forms the backbone of organic molecules

Nitrogen (N)

Essential macronutrient, component of amino acids, proteins, nucleic acids, and chlorophyll

Oxygen (O)

Basic building block of life, component of water and organic molecules

Sodium (Na)

Macronutrient, involved in osmotic balance, required by some plants

Magnesium (Mg)

Macronutrient, essential for chlorophyll synthesis

Phosphorus (P)

Macronutrient, essential for ATP, DNA, RNA, photosynthesis, N fixation, root and reproductive development

Sulphur (S)

Macronutrient, needed for protein synthesis

Chlorine (Cl)

Macronutrient, necessary for osmosis, ionic balance, and photosynthesis

Potassium (K)

Macronutrient, enzyme activator, important for energy metabolism, starch synthesis, nitrate reduction, photosynthesis

Calcium (Ca)

Macronutrient, strengthens cell walls and stems, applied via lime

Iron (Fe)

Micronutrient, essential for chlorophyll synthesis

Manganese (Mn)

Micronutrient, activates enzymes in chlorophyll formation

Zinc (Zn)

Micronutrient, participates in chlorophyll formation and enzyme activation

Boron (B)

Micronutrient, involved in carbohydrate transport and metabolic regulation

Copper (Cu)

Micronutrient, component of some enzymes and vitamin A

Molybdenum (Mo)

Micronutrient, used to reduce nitrates into usable forms

Cobalt (Co)

Micronutrient, important for nitrogen fixation in legumes

Nickel (Ni)

Micronutrient, essential for normal grain-filling and maturation in barley

Nitrogen fixation

Conversion of atmospheric N₂ into NH₃, biologically usable forms

Mineralization

Conversion of organic N into mineral forms (NH₄⁺, NO₂⁻, NO₃⁻)

Nitrification

Biological oxidation of NH₄⁺ → NO₂⁻ → NO₃⁻, generates protons (H⁺)

Denitrification

Microbial reduction of NO₃⁻/NO₂⁻ → N₂ or N oxides (N₂O, NO, NO₂)

Phosphorus cycle

Movement of P through inputs (fertilisers, manures, residues), transformations (mineralisation, adsorption, precipitation, dissolution), and losses (leaching, runoff, erosion)

Potassium cycle

Movement of K through mineral K → exchangeable K → soil solution → plant uptake → crop harvest → losses (leaching, runoff, erosion)

Sulphur (S) uptake

Taken up in large amounts, required for protein synthesis

Calcium (Ca) function

Strengthens cell walls and stems, applied as lime

Magnesium (Mg) function

Essential for chlorophyll synthesis, supplied via dolomite or Epsom salts

Micronutrient function

Elements required in small amounts for enzymatic and physiological processes

Law of the Minimum

Plant growth is limited by the scarcest essential nutrient

Nutrient uptake

Nutrients must be soluble and at the root surface for absorption

Nutrient movement to roots

By root extension, mass flow, and diffusion