Definitions and Trivia in Soil Science Flashcards
Refers to the quality of a soil that enables it to provide essential chemical elements in quantities and proportions for the growth of specified plants.
Soil fertility
Refers to the capacity of a soil for producing a specified plant or sequence of plants under a specified system of management.
Soil productivity
The most fertile part of a soil profile.
Topsoil
Was a Greek historian who first recorded the merits of green manure crops.
Xenophon
In what age were the following discovered:
o Manure increased productivity ad prolonged land use - the green manure crops (i.e., legumes) enriched the soil,
o Liming increased productivity,
o Wood ashes and salt peter (KNO3) are beneficial, and
o Saline soils can be detected by taste.
Golden Age of Greeks
In the 13th century A.D., this Roman, published a book on agricultural practices (horticulture and agronomy)
Pietro de Crescenzi
He performed the Willow Tree Experiment in which he concluded that the Willow tree grew by drinking water and water was the sole nutrient of plants.
Jan Baptista Van Helmont
He thought soil small particles were ingested by plants. He concluded that cultivating the soil made it easier for plants to take up soil particles.
Jethro Tull
He is the father of the modern fertilizer industry.
Justus Von Liebig
This states “If one of the essential nutrients is deficient, growth will be poor even if all other elements are abundant”.
Liebig’s Law of Minimum
He established the experimental garden of bluffs of Savannah River in Georgia to produce exotic food crops during 1733.
James E. Oglethorpe
He demonstrated the value of gypsum which improves soil physical and chemical properties.
Benjamin Franklin
Who wrote “Agriculture is our wisest pursuit, because it will in the end contribute most to real wealth, good morals and happiness.”
Thomas Jefferson
He is the Father of Soil Chemistry in the US.
Edmund Ruffin
Number of nutrient elements that are considered essential for plant growth.
18
It is a process in which nutrient enters the cellular material of the plant following same pathway as water.
Plant nutrient uptake
The three mechanisms of plant nutrient uptake are…
mass flow, diffusion, and root
interception.
This happens when water absorbed by the root creates a water deficit near the root this will in turn create more water movement to the root carrying nutrients.
Mass flow
refers to the movement of nutrients due to an imbalance of concentration or diffusion gradient, i.e., movement of nutrients from higher concentration to lower concentration.
Diffusion
Also known as contact exchange which happens upon exposure of the roots to the soil and new supplies of nutrients. The roots could contact 3% of the soil nutrients.
root interception
An equation which can describe nutrient uptake is the _______?
Mitscherlich’s equation
Mitscherlich’s equation formula?
DY/DX = (A-Y)c
where: DY = increase in yield
DX = increase in input
A = maximum possible yield
Y = actual yield
c= constant depending on the nature of x
________ saves the soil through harsh weather and stops erosion.
Soil conservation
Nitrogen is being supplied to the plants through _________ and when lightning converts it to NO3-.
biological nitrogen fixation
Potassium can be found in minerals like _________ which contains 90% of soil K.
feldspars and micas
_______ another macronutrient can be found in organic matter which contains about 1%. It is also present in minerals, i.e., gypsum and pyrite.
Sulfur
– this element can be found in hornblende, plagioclase, dolomite, and calcite.
Calcium
– this element can be found in hornblende, dolomite, and biotite.
Magnesium
____________ is among the most abundant micronutrients. It can be found in limonite, hematite,
goethite, etc.
Iron
_________ which can be found in minerals and maybe
also supplied from salt sprays from oceans and irrigation water.
chlorine
All nutrients move relatively easily from root to the growing portion of the plant through the ________.
xylem
Cause of Decline in Soil Fertility
The topsoil is rich in nutrients and organic matter. Loss of the fertile topsoil components through erosion by water and wind results in decreased fertility.
Loss of topsoil by erosion
Cause of Decline in Soil Fertility
Removal of more nutrients by crops than added through manures or fertilizers is called __________ or depletion. It results from the exhaustion of any nutrient required in moderate to large amounts.
Nutrient mining
Cause of Decline in Soil Fertility
______________ leading to poor structure, compaction, crusting, and waterlogging reduces soil fertility. Soil structure is a variable soil property that, from an agronomic point of view, can improve or deteriorate.
Physical degradation of soil
Cause of Decline in Soil Fertility
The decrease levels of organic matter cause a strong reduction in soil fertility as it plays several roles in soil. It can result to poor physical, chemical, and biological properties of the soil.
Decrease in organic matter content and soil biological activity.
Cause of Decline in Soil Fertility
_____________from soil can be caused by soil erosion, leaching, crop removal by soil erosion, leaching, or in the form of gases, e.g., in case of N and to a lesser extent S. Nutrient removal by crop products compared with external nutrient inputs can be similar, higher, or lower.
Loss of nutrients through various routes
Cause of Decline in Soil Fertility
_____________causes reduction in soil fertility, and eventually lead to problems of nutrient deficiencies, toxicities, and imbalances.
Soil acidification, salinization, and alkalinization
Cause of Decline in Soil Fertility
Poor or ___________ such as improper crop rotations leading to nutrient mining may decrease the soil fertility tremendously. Excessive soil tillage leads to erosion of the topsoil.
Inefficient soil management
Cause of Decline in Soil Fertility
________ caused by indiscriminate use of agro-chemicals and heavy metals reduces fertility of the soil by affecting its biological properties. The growth of soil organisms is affected adversely and will cause decline of biological soil fertility.
Soil pollution
8 Causes of Decline in Soil Fertility
- Loss of topsoil by erosion
- Nutrient mining
- Physical degradation of soil
- Decrease in organic matter content and soil biological activity.
- Loss of nutrients through various routes
- Soil acidification, salinization, and alkalinization
- Inefficient soil management
- Soil pollution
Knowing ___________ within the plant is useful in diagnosing plant nutrient deficiencies.
nutrient mobility
Nutrient management practices formulated to achieve economically optimum plant performance as well as minimal leakage of plant nutrients from the soil-plant system can only be optimized after _______
soil fertility evaluation
- A method of soil fertility evaluation wherein abnormality in plants are being used to determine which nutrients are low or lacking in the soil is?
Nutrient Deficiency Symptoms
- Which of the following element does not involve in minus-one element technique?
a. N
b. Si
c. Zn
d. P
b. Si
- Which nutrient is deficient when leaves has graying cast?
a. S
b. Fe
c. Zn
d. P
c. Zn
- Which of the following nutrients shows deficiency symptoms at older leaves?
a. N
b. Ca
c. S
d. Fe
a. N
- When collecting tissue for plant analysis the leaves that must be collected must be?
a. young
b. damaged
c. oldest
d. latest matured
d. latest matured
- Aspergillus niger are used to evaluate which nutrient element?
a. K
b. N
c. Ca
d. S
a. K
- Which of the following methods are used to determine nitrogen?
a. Ammonium acetate method
b. Kjeldahl Method
c. Bray Method
d. Olsen Method
b. Kjeldahl Method
- If the soil pH is 4.5 which method to determine phosphorus is used?
a. Ammonium acetate method
b. Kjeldahl Method
c. Bray Method
d. Olsen Method
c. Bray Method
- The method of applying fertilizer before or during planting is?
a. broadcasting
b. basal
c. side dress
d. top dress
b. basal
- Which solid fertilizer has the highest nitrogen content?
a. Anhydrous ammonia
b. Ammonium sulfate
c. Urea
d. Ammonium phosphate
c. Urea
_______ is defined as the net long- term balance of all processes that detach soil and move it from its original location
Soil erosion
________ can happen when the chemicals absorbed into cause the levels of nitrogen and phosphorus in water bodies. It can cause eutrophication.
Sediment pollution
________ is characterized by excessive plant and algal growth due to increase availability of one or more limiting growth factors needed for photosynthesis.
Eutrophication
_______ is an estimate of the ability of soils to resist erosion, based on the physical characteristics of each soil.
Soil erodibility
The two general types of erosion are _________
water and wind erosion.
This form of water erosion refers to the movement of soil from raindrop and runoff water. It occurs evenly over a uniform slope and goes unnoticed until most of the productive topsoil has been lost. Eroded soils
are deposited at the bottom of the slope or in low lying areas
Sheet erosion
This form of water erosion results when surface water runoff concentrates, forming small and well-defined channels. The channels are called rills and are small enough not to interfere field machine operations. As part of tillage operations, rills are filled in many cases.
Rill erosion
This form of water erosion is an advanced of rill erosion where surface channels are eroded to the point where they hamper tillage operations
Gully erosion
This form of water erosion is the progressive undercutting, scouring, and slumping of natural streams and constructed drainage channels.
Bank erosion
Soil erosion has a three-phase process consisting of ___________
detachment, transport,
and deposition.
The factors controlling soil erosion are ____________
the erosivity of the eroding agent, the erodibility and slope of the land, and the nature of plant cover.
