Flashcards
Environmental Science - FINAL - Soil and Agriculture
Flashcards do conjunto (48)
- 1What does soil consist of?mineral matter, organic matter, air, water
dead and living microorganisms, decaying material
bateria, algae, earthworms, insects, mammals, amphibians, and reptiles - 2What is Parent Material?the base geologic material of soil
lava, volcanic ash, rock, dunes, bedrock - 3Physical (mechanical) WeatheringWind and rain, no chemical changes in the parent material
- 4WeatheringThe physical, chemical, biological processes that break down rocks to form soil
- 5Chemical WeatheringSubstances chemically interact with parent material
- 6Biological WeatheringOrganisms break down parent material
- 7Erosionthe dislodging and movement of soil by wind or water
occurs when vegetation is absent - 8What are some biological processes that affect soil?biological activity includes deposition, decomposition, and accumulation of organic matter
- 9Humusa dark, spongy, crumbly mass of material formed by partial decomposition
a very complex system of strange molecules, abundant in oxygen
humus, overall, contains a negative charge. Since nutrients are positively charged, humus is good at holding onto them. - 10What is Lignin and what is it's role with bacteria & humus?Lignin is a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae
Bacteria cannot digest the humus' lignin polymer because Its too large, so some will release a lignin modifying enzyme, which will turn it into a monomer - 11Soil Profile HorizonsOstriches --> O Horizon: Litter
Always --> A Horizon: rich in nutrients
Eat --> E Horizon: poor because of leaching (Elluviation)
Bananas --> B Horizon: very rich in nutrients/minerals (Illuviation) - 12Soil profilethe cross section of soil as a whole
- 13Topsoilinorganic and organic material most nutritive for plants
- 14Leachingdissolved particles move down through horizons
- 15What are the properties that classify soilscolour
texture
structure
pH - 16Soil Colourindicates its composition and fertility
black/dark brown : rich in organic matter
Pale grey/white : indicates leaching - 17Soil Texture Classificationthe size of particles
Clay = smallest
silt = middle
Sand = largest - 18Loama soil with roughly equal proportions of sand, silt, and clay.
influences how easy it is to cultivate and let air and water travel through the soil - 19Which types of soils are best for plant growth and crop agriculture?Silty soils with medium sized pores, or loamy soils with mixtures of pore sizes
- 20Soil Structuresa measure of soil's "clumsiness", facilitates bioactivity
large clumps can discourage plant roots
repeated tilting compacts soil - 21Plow Pana subsurface horizon or soil layer having a high bulk density and a lower total porosity than the soil directly above or below it as a result of pressure applied by normal tillage operations
- 22Soil pHinfluences a soil's ability to support plant growth
soils that are too acidic or basic can kill plants - 23Soil ClumpMix of sand, silt, and clay that are held together by organic matter and microbes, host bacteria, and contains water and air
- 24What is Cation Exchange?process that allows plants to gain nutrients
negatively charged soils hold cations of calcium, magnesium, and potassium - 25What is Cation Exchange Capacity?A soils ability to hold cations, preventing them from leaching, therefore increasing their availability to plants
a useful measure of soil fertility
greatest in fine soils - 26How is cation exchange vital for plant growth?The higher the CEC, the higher the negative charge of the soil and the more cations that can be held.
CEC indicates how well your soil will hold onto anything, including nutrients and water
the negative charge not only holds nutrients, but it can also hold toxic metals
The lower the CEC of a soil, the faster the soil pH will decrease with time. - 27AgriculturePractice of raising crops and livestock for human use and consumption
- 28Croplandthe land used to raise plants for human use
- 29Rangeland / Pastureland used for grazing livestock
- 30Soila complex plant-supporting system consisting of disintegrated rock, organic matter, water, gases, nutrients, and microorganisms
- 31How does consumption and population effect/degrade soil?feeding the world's rising human population requires changing our diet or increasing agricultural production
mismanaged agriculture turns grasslands into deserts, removes forests, diminishes biodiversity, and pollutes soil, air, and water
population dense regions have the highest rates of degraded soil ( due to deforestation, agriculture, overgrazing) - 32Green RevolutionIntensive plan of the 1960s to add new technology, crop varieties and farming practices to increase crop yields in developing countries by introducing higher-yielding strains of plant and new fertilizers.
created new problems, and worsened old ones (ex. The use of chemical fertilizers and synthetic herbicides and pesticides dramatically influenced the environment by increasing pollution and erosion) - 33Solutions to soil degradation- soil conservation
- restoring plant cover
- preventing salinization (the process of increasing the salt content)
- better fertilization practices
- better grazing practices - 34Examples of how regional differences in soil traits affect agriculturerain forests have high primary productivity (the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances), however, the nutrients are in the plants, not the soil.
Temperate grasslands have lower rainfall and less nutrient leaching - 35What causes erosion?primary causes of erosion due to urban development. Habitat replacement often results in an increase in the amount of impervious surfaces. Normally, vegetation would slow surface water flow. Impervious surfaces increase water flow. Water can travel faster and in greater quantities. This action causes water to overflow stream banks, thus triggering erosion in vulnerable parts of the ecosystem.
there is also natural causes to erosion, such as wind erosion & water erosion - 36What are the impacts of erosion on ecosystems and agriculture?Erosion removes the topsoil from the ground, often removing the seed bank that exists within soils. Further, this can introduce toxins from pesticide and fertilizer applications into waterways.
- 37What is Desertification?A type of land degradation by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture.
affects 1/3 of the planet's land area
most prone areas are arid (area having little or no rain) and semiarid lands. - 38What is the dust bowl and how did it happen?an area of land where vegetation has been lost and soil reduced to dust and eroded, especially as a consequence of drought or unsuitable farming practice.
Native prairie grasses originally held erosion-prone soils in place, this grass was removed due to cultivation of wheat and grazing, caused erosion - 39crop rotationgrowing a series of dissimilar or different types of crops in the same area in sequenced seasons. It is done so that the soil of farms is not used for only one set of nutrients
- 40Contour farminggrowing crops across or perpendicular to a slope rather than up and down the slope in order to conserve rainwater and to reduce soil losses from surface erosion
- 41Intercropping and agroforestryintercropping: to grow (a crop) among plants of a different kind, usually in the space between rows.
Agroforestry: agriculture incorporating the cultivation and conservation of trees. - 42Terracingmake or form (sloping land) into a number of level flat areas resembling a series of steps.
- 43Shelterbeltsa line of trees or shrubs planted to protect an area, especially a farm field, from strong winds and the erosion they cause.
- 44Reduced tillagea practice of minimising soil disturbance and allowing crop residue or stubble to remain on the ground instead of being thrown away or incorporated into the soil.
- 45Irrigationartificially providing water to support agriculture
- 46waterloggingover-irrigated soils which suffocates roots
- 47What is Salinization, what does it cause, and how can it be prevented/corrected?the buildup of salts in surface soil layers
inhibits production of 20% of all irrigated cropland, costing more than $11 billion a year
can be prevented by choosing crops appropriate for the area, irrigate with low-salt water - 48What are fertilizers, and what are the pros/cons of them?fertilizers are substances that contain essential nutrients
inorganic fertilizers : mined or synthetically manufactured mineral supplements
organic fertilizers : the remains/wastes of organisms
Fertilizer affects plant growth by supplementing plant nutrients, which allows plants to grow faster and thicker. However, this applies only if the soil is deficient in nutrients.
When the excess nutrients from all the fertilizer we use runs off into our waterways, they cause algae blooms
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- O usuário eliminou as informações de disciplina FlashCards sobre Environmental Science - FINAL - Soil and Agriculture, criado por Usuário eliminado em 01-04-2018.
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- Criado por abby Radske · 31 mar 2018
- Copiado por abby Radske · 1 abr 2018
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