Soil Sci Lec (1.1 - 1.3) Flashcards
It is a living, dynamic system which forms at the interface between the atmosphere and lithosphere
Soil
What are the factors of soil?
- climate
- living organisms
- parent material
- topography/relief
- time
Soil is composed of?
- solid phase (45% mineral particles, 5% OM)
- air/gaseous phase (25%)
- water/liquid phase (25%)
Exert significant direct and indirect influences on the supply and availability of most nutrient elements.
soil minerals
The fraction of the soil that consists of plant or animal tissue in various stages of decomposition
organic matter
Not the reservoir of nutrient ions except for those that are not adsorbed by the solid phase or incorporated in the organic matter
liquid phase
- contains a number of gases of which nitrogen, oxygen, carbon dioxide and water vapor are the most important
- constantly moves from the soil pores into the atmosphere and from the atmosphere into the pore space
gaseous phase
Functions of soil as far as plants are concerned
- Provides anchorage to root
- Acts as a store house of water and nutrients for plant growth
- Acts as home of flora and fauna
- Provides space for air which creates healthy environment for the biological activity of soil organisms
the supply and absorption of chemical compounds needed for growth and metabolism
Nutrition
chemical compounds required by an organism
Nutrients
takes into account the interrelationships of mineral elements in the growth medium as well as their role in plant growth
Plant Nutrition
the mechanism by which nutrients are converted to cellular material or used for energetic purposes
Metabolic Processes
encompasses the various reactions occurring in a living cell in order to maintain life and growth
Metabolism
- the quality of a soil that enables it to provide essential chemical elements in quantities and proportions for the growth of specified plants
- the capacity of the soil to provide crops with essential plant nutrients in right amount and available forms
Soil Fertility
the capability of soil to produce specified crop yield under well defined and specified systems of management of inputs and environmental conditions
Soil Productivity
it is the nutrient enrichment of bodies of water
Eutrophication
In Greek, Mesopotamia means ____
land between two rivers
what were built for irrigation of crops in mesapotamia
canals
involves clearing of land—usually with the assistance of fire— followed by phases of cultivation and fallow periods
Shifting cultivation
used as a common method in clearing and preparing lands
Slash and burn
in the golden age of greeks, ____ was used to increased productivity and prolonged land use
manure
____ was used to increased productivity of soils
marl
Saline soils could be detected by?
taste test
true or false
in the golden age of greeks, wood ashes & saltpeter were found to be harmful
False
They were found to be beneficial
published a book on
agricultural practices
pietro de crescenzi
true or false
Sir Francis Bacon believed that water is
the main plant nourishment and that soil kept plants upright and insulated from extreme temperatures
True
his willow tree experiment “proved” that water was the sole nutrient of plants
Jan Baptista Van Helmont
believed that plant growth is influenced by something other than water
John Woodward
believed that roots ingest soil particles and cultivating the soil made it easier for plants to take up soil
Jethro Tull
Jethro Tull wrote the book ____ and developed the horse hoe and the seed drill
Horse and Hoeing Husbandry
true or false
de Saussure believed that soil provides only small amounts of nutrients required by plants and that plants obtain C from the air.
true
true or false
John Woodward introduced the Humus Theory, wherein plants live on humus-derived extracts (C, H, O, N) from which they are able to rebuild more complex plant tissue. He also believed that fertilizer salts and lime are good because they promote humus and organic matter breakdown.
false
The correct answer is Albrecht Thaer
believed that the increase in mass of the plant as it grows could not be due only to uptake of CO2, but also to the uptake of H2O
de Saussure
what is the name of the theory that Albrecht Thaer introduced?
Humus Theory
A student of Thaer, concluded that salts in humus extracts were real plant nutrients. He also came up with a list of compounds
required for plant growth and discussed the idea of fertilizers
Philip Carl Sprengel
Popularized the Law of the Minimum
Justus Von Liebig
states that growth is controlled not by the total of resources available, but by the scarcest resource (limiting factor).
law of the minimum
who developed the law of the minimum?
Carl Sprengel
Dry matter is composed of?
5% mineral elements & 95% C, H, O
true or false
Plants are composed of 10% dry matter and 90% water
true
- are the fundamental materials of which all matter is composed
- any substance that cannot be decomposed into simpler substances by ordinary chemical processes
elements
The term essential mineral element was proposed by?
Arnon and Stout
what are the criterias for essentiality
- Plants cannot complete their life cycle without the element
- Deficiency symptoms for the element can be corrected only by supplying the element in question
- The element must be directly involved in plant metabolism or a component of an essential plant constituent
- Most plants need this element to survive
required by bacteria responsible for nitrogen fixation in legumes
cobalt
Two ways to classify the essential elements
- Classified by whether it is used in large or small amounts
- Classified by its function in the plant
what are the primary nutrients
- Nitrogen
- Phosphorus
- Potassium
what are the secondary nutrients
- calcium
- magnesium
- sulfur
what are the micronutrients
- zinc
- copper
- manganese
- iron
- boron
- molybdenum
- chlorine
- nickel
what are the elements that belong in group 1
- C
- H
- O
- N
- S
true or false
the elements P & B belong to group III
false
they belong to group II
what are the elements that belong to group III
- K
- Mg
- Ca
- Mg
- Cl
- Ni
what are the elements that belong to group IV
- Fe
- Cu
- Forms the organic components of plants
- Plants assimilate these nutrients via biochemical reactions involving oxidation and reduction
group 1
a component of plant structural parts
Ca
Nonspecific functions, involved in establishing osmotic potential
group 3
- Esterification with native plant alcohol with importance in stabilizing cell walls and bio membranes
- Phosphate esters are involved in energy transfer
group 2
Present predominantly in a chelated form in prosthetic group, enable electron transport by valency change
group 4
Constituent of carbohydrates; necessary for photosynthesis
carbon
Maintains osmotic balance; important in numerous biochemical reactions; constituent of carbohydrates
hydrogen
Constituent of carbohydrates, necessary for respiration
oxygen
Constituent of proteins, chlorophyll and nucleic acids
nitrogen
Constituent of many proteins, coenzymes, nucleic acids and metabolic substrates; important in energy transfer
phosphorus
Involved with photosynthesis, carbohydrate translocation, protein synthesis, etc.
potassium
A component of cell walls; plays a role in the structure and permeability of membranes
calcium
Enzyme activator, component of chlorophyll
magnesium
Important component of plant proteins
sulfur
Believed to be important in sugar translocation and carbohydrate metabolism
boron
Involved with oxygen production in photosynthesis
chlorine
- A catalyst for respiration; a component of various enzymes
- Component of cytochromes and nitrogenase
copper
Involved with chlorophyll synthesis and in enzymes for electron transfer
iron
Controls several oxidation-reduction systems and photosynthesis
manganese
Involved with nitrogen fixation and transforming nitrate to ammonium
Molybdenum
Necessary for proper functioning of the enzyme, urease, and found to be necessary in seed germination
Nickel
involved with enzyme systems that regulate various metabolic activities
Zinc
Important Plant nutrition principles
- Plants require nutrients in balanced amount
- Sufficient concentration of nutrients should be present in plant leaves at any time
true or false
At early growth stages, the highest concentration of nutrients are found in leaves, and the lowest in leaves near harvest
true
Pattern of nutrient uptake
follows a ____
sigmoid curve
