loose surface of the earth as distinguished from solid bedrock

material which nourishes and supports growing plants

mixture of mineral matter, organic matter, water and air

collection of natural bodies of the earth’s surface

Components of the Soil

Is the fraction of the soil that consists of plant or animal tissue

The Solid phase

Not the reservoir of nutrient ions except for those that are not adsorbed by the solid phase

The soil air contains a number of gases of which nitrogen, oxygen, carbon dioxide and water vapor are the most important.

Functions of soil as far as plants are concerned

The quality of a soil that enables it to provide essential chemical elements

The capacity of the soil, in its normal environment to support plant growth.

The supply and absorption of chemical compounds needed for growth and metabolism.

Is the nutrient enrichment of bodies of water.

The mechanism by which nutrients are converted to cellular material or used for energetic purposes

Chemical compounds required by an organism

Is a term that takes into account the interrelationships of mineral elements in the growth medium as well as their role in plant growth.

Encompasses the various reactions occurring in a living cell in order to maintain life and growth.

“Land between two rivers”

Refers to any temporal and spatially cyclical agricultural system that involves clearing of land

The Golden Age of Greeks

Used to increased productivity of soils (liming material)

Was used to increased productivity and prolonged land use.

Saline soils could be detected by?

What is KNO3?

Published a book on agricultural practices.

Believed that water is the main plant nourishment

His willow tree experiment "proved" that water was the sole nutrient of plants.

Believed that roots ingest soil particles and cultivating the soil made it easier for plants to take up soil. He wrote the book “Horse and Hoeing Husbandry” and developed the horse hoe and the seed drill.

Believed that plant growth is influenced something other than water

Believed that soil provides only small amounts of nutrients required by plants and that plants obtain C from the air.

A student of Thaer, concluded that salts in humus extracts were real plant nutrients.

Introduced the Humus Theory,

Popularized the Law of the Minimum stating that, if one of the essential nutrients is deficient, growth will be poor even if all other elements are abundant

Beneficial Elements

Is essential for N-fixing organisms, irrespective of whether they are in the free-living or symbiotic form. is required for N-fixation in root nodules of legumes and non-legumes.

The beneficial effects of this on plants include increase in yield that can result from increasing leaf erectness, decreasing susceptibility to lodging, decreasing incidence to fungal infections and preventing Fe and Mn toxicity.

Is not essential element for crop plants, although it is beneficial for crops such as sugar beet and it is considered to be essential for the growth of a halophyte Atriplex vesicaria at levels in the range of a micronutrient.

A chemical element necessary in large amounts

What are the Macronutrients?

A chemical element necessary in only extremely small amount

What are the Micronutrients?

It is essential for energy storage and transfer in plants.

Imparts deep green color of the leaves.

leaves become purplish or reddish

Provides strength to plant cell walls and contributes to greater canopy photosynthesis and crop growth.

Needed in low concentrations in membranes to maintain their proper structure and differential permeability characteristics.

It is a constituent of chlorophyll and is involved in photosynthesis.

Is an essential activator for one or more enzymes catalyzing reactions involved in chlorophyll synthesis.

It is required for protein synthesis, plant function, and plant structure.

It activates many enzymes which is an important function in plants.

Is essential for several biochemical processes in the rice plants.

It is an electron carrier when present in certain enzymes necessary to convert nitrate to ammonium ions.

It has a role in carbohydrate translocation.

Necessary for proper functioning of the enzyme, urease and was found to be necessary in seed germination.

It stimulates photosynthesis by acting as an enzyme activator for one or more reactions in which water is split and oxygen released.

Are nutrients that is readily transported from old leaves to new growth

Are nutrients that move slowly from cell to cell

Refers to dissolved nutrients, like calcium and nitrate, that move toward the root in soil water that is flowing in that direction.

Occurs when nutrients move from higher concentrations in the bulk soil water solution to lower concentrations at the root.

Root moves through the soil and comes into contact with the nutrient on the colloid.

Factors affecting nutrient availability

The rate of ion movement in the soil, whether by mass flow or diffusion depends highly on soil moisture.

Refers to a particular soil's distribution of mineral particles within certain size ranges. Relative amounts of sand, silt and clay

Is an expression of the soil’s ability to hold and exchange cations.

This soil property affects the positional availability of nutrients and root proliferation.

Measures of Availability of Nutrients

The amount of nutrients that is adsorbed or exchangeable.

Ability of the soil to maintain nutrient intensity

The concentration of nutrients in the soil solution

German chemist, formulated a relationship between limiting nutrient and yield

Recognizes that yield response to a limiting growth factor are usually nonlinear.

“The amount of plant growth or yield is regulated by the nutrient present in minimum amounts relative to its optimum nutrient requirement and yield rises or falls accordingly as this nutrient is increased or decreased in amount, the other growth factor being present in adequate quantities”.

“As the mobility of a nutrient in the soil decreases, the amount of nutrient needed in the soil to produce a maximum yield increases from a variable net value, determined principally by the magnitude of the yield and the optimum percentage composition of the crop, to an amount whose value tends to be a constant”.

Methods of Soil Fertility Evaluation

Deficiency symptoms

Yellowing in between leaf veins, yet veins remain green.

General yellowing of plant tissue; lack of chlorophyll

Refers to symptoms limited to one leaf or section of the leaf or plant

Refers to symptoms not limited one area of a plant, but rather spread over the entire plant.

Refers to the death of plant tissue

Presence of irregular spots in a plant leaf or body in an inconsistent pattern

Measures nutrient levels in the plant during their growth.

Refers to the decreased growth, in terms of height, of plant.

Types of Plant Analysis

This is sometimes called “troubleshooting” or problem-solving type of plant testing

This is done to assess the adequacy of current fertilizer practices and related management factors

This may be used in three ways: a) analysis of samples collected during early crop development and is used to predict the likelihood of nutrient deficiencies occurring before reaching crop maturity, b) analysis of fruit is used to predict its likely behavior in storage, and c) analysis of seeds or grains is used to predict probable deficiencies in succeeding crops.

What not to sample in Plant tissue analysis

Interpretation of plant tissue test results

This happens when the level of an essential plant nutrient is below that required for optimum yields or when there is an imbalance with another nutrient.

It occurs when an essential element is at a low concentration that severely limits yield and produces more or less distinct deficiency symptoms.

It occurs when the concentration of an essential plant nutrient is sufficiently high to result in a corresponding shortage of another nutrient.

It takes place when the concentration of an essential nutrient is present in adequate amounts for optimum crop growth.

When the concentration of either essential or other elements is sufficiently high to reduce plant growth severely.

Methods of Interpreting Results of Plant Analysis

offers significant advantages over the use of critical values.

Have been defined as the concentration at which there is a 5-10% yield reduction

In its simplest form, the use of ratios in the interpretation of plant analysis results involves the evaluation of two essential elements together,

Is a rapid method of determining the amount of nutrient elements essential for plant growth in the soil at the time of determination