Mineral Nutrition

Mineral Nutrients are

elements acquired primarily in the form of inorganic ions from the soil.

Why is absorption by plants very efficient

the large surface area of the roots and their ability to absorb inorganic ions at low concentration from the soil solution

enter the biosphere predominantly through

the root systems of plants

The study of mineral nutrition

the study of how plants obtain and use mineral nutrients

high agriculture yields

depend strongly on fertilization with mineral nutrients.

The complex nature of plant-soil-atmosphere relationship

studies in the area of mineral nutrition involve atmospheric chemists, soil scientists, hydrologists, microbiologist, and ecologists.

Essential nutrients are defined as

one whose absence prevents a plant from completing its life cycle or one that has clear physiological role

example of essential nutrients obtain from their gasses state

Hydrogen, Carbon, Oxygen

example of essential nutrients that are obtain from soil (Macro)

Nitrogen, potassium, calcium, magnesium, phosphorus, sulfur, silicon

example of essential nutrients that are obtain from soil (Micro)

Chlorine, Iron, Boron, Manganese, Sodium, Zinc, Copper, Nickel, and Molybdenum

Classified according to their biochemical role and physiological function

1. Organic compounds

2. Energy storage

3. Ionic compound

4. Electron transfer reaction

How to demonstrate that an element is essential

it requires that plants be grow under experimental conditions in which only the element under investigation is absent

Hydroponics

the technique etablished in the 19th century, of growing plants with their roots immersed in nutrient solution without soil.

A successful hydroponic culture requires

a large volume of nutrient solution or frequent adjustment of the nutrient solution to prevent nutrient uptake by roots from producing radical changes in nutrient concentration and pH of the medium.

Diagnosis of soil-grown plants can be more complex, due to

1. both chronic and acute deficiencies of several elements may occur simultaneously

2. Deficiencies or excessive amounts of one element may induce deficiencies or excessive accumulation of another

3. some virus-induced plant disease may produce symptoms sil=milar to those of nutrient deficiencies

Soil analysis

the chemical determination of the nutrients content in a soil sample from the root zone

the result of soil analysis vary based on

sampling methods, storage conditions for the samples, and nutrients extraction techniques

Plant tissue analysis

the levels of nutrients potentially available to the plants root from the soil, but the soil does not tell us how much of a particular mineral nutrient the plant needs or is able to absorb

proper use of plant tissue requires

an understanding of the relationship between plant growth and the mineral concentration of plant tissue samples

Chemical Fertilizers

contain inorganic salts of the macronutrients nitrogen, phosphorus, and potassium

Straight fertilizers

contain only one of these three nutrients

example of straight fertilizer

superphosphate, ammonium nitrate, and muriate of potash

Compound fertilizer

two or more mineral nutrients are

Organic fertilizers

originate from the residue of plants or animal life or form natural rock deposits

example of organic fertilization

plant and animal residues

Mineralization

the organic compounds must be broken down, usually by the action of soil microorganisms

Mineralization depends on

temperature, water, and oxygen

Foliar application

some mineral nutrients can be applied to the leaves as sprays

Saline

Excess mineral are present in the soil

the most common salts in saline soil

Sodium Chloride and Sodium Sulfate

how to cure saline soil

Rain / Adding water

When do plants encounter salt stress

In saline soil

Plants with salt glands

take up the mineral but excret them

to prevent toxic build up of mineral ions in the cytosol

many plants may sequester them in the vacuole

accumulation of heavy metals in the soil cause

severe toxicity in plants

Group 1 (organic compounds)

plants assimilate these nutrients via biochemical reactions involving oxidation and reduction

Group 2 ( Energy storage)

elements group is bound to hydroxyl group of an organic molecule

Group 3

Free ions or ions bound to substances

Group 4

Important roles in reaction involving electron transfer

N

(Group 1) Consists of amino acids, amides, proteins, nucleic acid, coenzyme, hexoamines, etc.

P

(Group 2) component of sugar phosphate, nucleic acids, nucleotides, coenzyme, phospholipids, phytic acid, ATP, etc.

K

(Group 3) Required as a cofactor for more than 40 enzymes. Principal cation in establishing cell turgor and maintaining cell electroneutrality.

Fe

(Group 4) Constituent of cytochromes and nonheme iron proteins involved in photosynthesis, N, fixation, and respiration.

Nitrogen (N) deficiency inhibits

Plant growth and showers chlorosis, especially in the older leaves near the base of the plant

Which deficiency is shown in the picture

Nitrogen (N) deficiency

Phosphorus (P) deficiency causes

Stunted growth in young plants and dark green coloration of the leaves, which may be malformed and contain small spots of dead tissue (necrotic spots). In some cases the steams are slender and the older leaves are dead

Which deficiency is shown in the picture

Phosphorus (P) deficiency

Potassium (K) deficiency cause

Mottled or marginal chlorosis, which then develops into necrosis primarily at the leaf tips, at the margin, and between veins. Symptoms occur on more mature leaf’s first and may appear crinkled or curled. The stems may be slender and weak, with abnormally short intermodal regions

In Potassium-deficient corn

The roots may have an increased susceptibility to root- rotting fungi present in the soil resulting in an increased tendency for the plant to be easily bent to the ground

Which deficiency is shown in the picture

Potassium (K) deficiency

Iron (Fe) deficiency causes

Intravenous chlorosis in younger leaves. Extreme or prolonged deficiency causes the veins to become chlorotic turning the whole leaf white

Which deficiency is shown in the picture

Iron (Fe) deficiency

Hydroponic growth system

Relationship between yield (or growth) and the nutrient content of the plant tissue. The yield parameter may be expressed in terms of shoot dry weight or height.

Avg. soil pH

5.5 -6.5