Essential steps in soil chemical test

These tests require small quantities of soil to quantify availability of nutrients

Fertilizer trials in the researcher’s or farmer's fields are conducted to assess the effect of fertilizers

This is the process that results in the accumulation of soluble salt in the soil, mainly sulfates and chlorides of calcium, magnesium, sodium and potassium.

Refers to the total concentration of salts in the soil. It is usually measured by electrical conductivity (EC) of a saturated soil extract.

Soils which have an exchangeable sodium percentage (ESP) of more than 15.

Soils with an an electrical conductivity of the saturation soil extract of more than 4 dS/m at 25°C.

Soils that have both detrimental levels of neutral soluble salts (ECe > than 4 dS/m and a high proportion of sodium ions (ESP > than 15 or SAR > than 13.

This refers to the concentration of sodium.

Soils containing sufficient soluble salts to adversely affect the growth of most plants.

Meaning of SAR

An expression that tells how much sodium is adsorbed compared to two of the most common cations in the soil.

Effects of high concentration of salt on plant growth

The high concentration of salts outside the roots forces the water to move outside of the cells

How to test for salinity

What is the meaning of ASS

The meaning of PASS

Essential Ingredients for Pyrite Formation

A natural or artificial substance containing the chemical elements that improve growth and productiveness of plants.

Classification of Fertilizers

are those fertilizer which are the products of plant or animals.

Sometimes called artificial fertilizer, are minerals that have been mined or produced in a factory.

Indicates the proportion of N, P O and K O contained in 252

Are primarily used in the small fruit and nursery industries.

Are used primarily in the turf, sod and ornamental nursery industries.

The most important fertilizer properties

Air contains moisture as water vapour and therefore exerts a water vapour pressure (p H2O) that is determined by humidity and temperature

Arises due to the formation of strong crystal bridges and adhesive forces between granules.

volume weight (kg/m3) differs between fertilizer types.

Methods of Fertilizer Application

Different Fertilizer Application Methods

is the application method generally used for large field areas

This term generally refers to those fertilizer materials applied to the soil, (after the crop is up), during the early to mid-growth period of the crop.

This method is primarily used to apply small amounts of fertilizer as a plant starter.

nutrients are absorbed and used by the plant quite rapidly.

Nitrogen and potassium are sometimes sidedressed by applica- tion in the irrigation water that is applied to crop production systems at intervals during the growing season.

The practical goal is to determine how much nutrient material to add.

solid fertilizer materials blended together in small blending plants delivered to the farm in bulk

fertilizers that are present in the form of rather stable granules of uniform size

fluid fertilizers that contain essential elements in liquid forms either as soluble nutrients or as liquid suspension or both

two or more fertilizer materials mixed together, maybe as dry powders, granules, pellets, bulk blends or liquids

Materials that contain the three major plant-nutrient elements - nitrogen, phosphorus and potassium

the guaranteed minimum analysis, in percent, of the major plant nutrient elements contained in a fertilizer material or in a mixed fertilizer

refers to the relative percentage of N, P₂Os and K2O

An expression of the quantity and analysis of the material in a mixed fertilizer

One capable of increasing the acidity of the soil, which is derived principally from the nitrification of ammonium salts by bacteria.

one capable of decreasing the acidity of the soil.

one that is guaranteed to leave neither an acidic nor basic residue in the soil

the quantity of certain plant nutrient elements needed

The acidity developed in the soil by the fertilizer

The basic residues left in the soil by the fertilizer, expressed as equivalent calcium carbonate