Environmental Test 2

Removal of topsoil

"soil" becomes nothing but gravel where topsoil was removed. After 50 years, only lichens and a few stunted trees gave developed.

Contour farming and shelterbelts

(a) cultivation up and down a slope encourages water to run down furrows and may lead to server erosion. Problem is reduced by plowing cultivating along the contours at the right angle to the slope. (b) Shelterbelts-belts of trees and farm fields, break the wind and protect the soil from erosion.

Formation of Desert Pavement

1) as wing erosion removes the finer particles (humus and clay), larger grains and stones are concentrated on the surface. 2) the result is desert pavement, which protects the underlying soil from further erosion. However, traffic such as off-road vehicles break up the desert pavement and intuit further erosion.

Most well know genetically modified products

1) cotton plants with built-in resistance to insects that comes from genes taken from a bacterium (Bacillus thuringiensis) 2) Corn and soybean resistant to the herbicide Roundup 3)

Contribution to high food prices

1) the price of oil (used by farm machinery and in fertilizer manufacturing. 2) bad weather and poor harvests 3) rising demand for meat and animal products

Agricultural Biotechnology

1) to incorporate resistance to diseases and pests that attack important tropical plants 2) to increase tolerance to environmental conditions, such as drought, and high salt level, which stress most plants 3) to improve the nutritional value of commonly eaten crops 4) to produce pharmaceutical products in ordinary crop plants.

Apparatus for no-till planting

12 row planter is planting no-till cotton with minimal disturbance to the protective mulch layer on the surface of the soil. Apparatus creates furrows with cutting discs, applies herbicide and fertilizer, drops in seeds, and closes the furrows.

B Horizon

Also known as Subsoil. Deposition of minerals that have been leached from the A and E horizons, high in Iron, Aluminum, calcium and other minerals. Referred to as the subsoil. high in clay and is reddish or yellow in color from the oxidized. Rock mineral material, not good for raising plants. (not enough water/nutrients) soil more rich than it used to be.

Machinery

Array of farm machinery that handles every meed for working the soil: seeding, irrigating, weeding and harvesting. Farmers can cultivate more land then ever before.

Genetic Engineering

Artifical transfer of specific genes from one organism to another. Makes it possible to combine characteristics from genetically different plants and to incorporate desired traits into crop lines and animals.

Global Food Crisis

Between 2006 and 2008, the prices of food commodities on world market rose on average 100%, triggering food riots and emergency measures in many countries. Added 75 mil to the 848 million people still suffering from hunger and malnutrition in the world.

Saline soil

Buildup of salt in soil makes it impossible for the roots of a plant to get water. Water can even be drawn out of the plant if salt levels are high enough (osmosis) resulting in hydration and even death. Only plants with adaptations can survive salty soil and so far none of those are crop plants.

US crop yields

Corn, wheat and soybeans. have increased exponentially since 1975.

Sheet erosion

Decrease in infiltration results in water run off carrying away fine particles from the surface.

Castings

Earthworm excrements, relatively stable clumps of inorganic particles plus hummus. Kept loose because of the burrowing activity of organisms. Desirable characteristic of soil.

Concerns for Genetically engineered technology

Environmental concerns, food safety and access to new techniques.

Evaporative water loss

Evaporation depletes the soil's water reservoir without serving the needs of plants. The O horizon functions well to reduce evaporative water loss by covering the soil.

No-till agriculture

Farming practice in which weeds are killed with chemicals and seeds are planted and grown without resorting to plowing or cultivation. Technique that permits continuous cropping. Minimizes soil erosion. Routinely practiced over much of the United States.

Global Trade in Grain

Global trade of grain changing in the last 7 decades. In 1935, Europe was importing grain, Asia, Africa, Latin America were self-sufficient. By 1950, North America has become the major source of exportable grains. Most of this is used as a protein supplement for animal feeds. Asia and Africa have developed an increased dependence on imported grain. These places have also experienced continued population growth.

Weathering

Gradual physical and chemical breakdown to the point where often it is impossible to tell just what kind of rock the soil came from.

Global population and grain and meat production

Grain production has kept up with the population increase, and meat production has greatly outpaced it over the last 35 years.

Soil erosion

Highly undesirable process. Sediment causes large bodies of water and reservoirs to fill up with sediment over tine. Also, a natural geological process, land surfaces undergo weathering and sediment form over geological time, eventually becoming think layers that form into sedimentary rock. So some erosion is bond to occur, no matter the farming practices.

Environmental concerns to GM

If pest have a broad exposure to the toxin, it can develop a resistance that would make the toxin ineffective as an independent pesticide. Genes for herbicide resistance or for tolerance to drought and other environmental conditions can also spread by pollen to ordinary crop pal ants and their relatives, creating "super weeds"

Splash erosion

Impact of falling raindrops breaks up the clumpy structure of the topsoil. Results in decreased infiltration and aeration.

Soil aeration

Land plants depend on the soil being loose and porous enough to allow the diffusion of oxygen into, and carbon dioxide out of the soil.

Detritus

Leaves, stems, flowers, seeds, derived from plants (continual deposition) Biological breakdown of ___ to hummus.

Mollisols

Middle aged to young, very fertile, dark brown. Dakota's, parts of Oklahoma. Found in temperate grassland biomes. Worlds best agricultural soils and are encountered in the midwestern United States. Across temperate Ukraine, Russia and Mongolia, pampas (broad grassy region) in Argentia. Deep A horizon and are rich in humus and minerals. Rainfall is too insignificant to leach the minerals downward towards the E horizon.

Impact of the Green Revolution

More varieties of high yielding crops Modern research has focused on resistance

Organisms in Soil

Most important organisms in soil detritus based ecosystem are the bacteria. Millions of bacteria are present in a gram of soil.

Developing World + GM

New technologies have not been made available in developing countries yet. Yet to help alleviate hunger and improve well-being of farmers in developing countries.

Green Revolution

Norm Borlaug was sent to Meico to help with the serious food problem. They introduced a crop (bred a dwarf hybrid with a large head and a thick stalk). Hybrid did well in warm weather when provided with fertilizer and sufficient water. Some of the most populous countries that struggled to feed their populations became wheat exporters. However it is not a total success because the crops needs adequate water and fertilizer.

Leaching

Nutrients may literally be washed from the soil as water moves through it. Not only lessens fertility of the soil but also contributes to pollution when materials removed enter water ways.

C horizon

Parent material: Partially broken-down inorganic minerals.

Mineral particles

Parent materials leached minerals Weathered clay, sand, silt from bedrock, glacial deposits, wind and alluvial deposits.

Parent material

Partially broken-down inorganic materials. mineral material of soil, has its origin in the geological history of an area. Could be rock or sediment deposited by wind, water or ice.

A Horizon

Partially decomposed organic matter (humus), living organisms, and some inorganic matter. Mixture of mineral soil from below and the hummus from above. Fine roots from overlaying vegetation permeate this layer. Usually dark because of hummus present, may be shallow or thick depending on overlying ecosystem.

Bt corn

Pollen from ____ can be spread by the wind to adjacent natural areas where beneficial insects may pick it up and be killed by the toxin.

Desertification

Process of erosion of topsoil. Refers to a permanent reduction in the productivity of arid, semi-arid, and seasonally dry areas. Process of land degradation degradation with a number of possible causes, including extended droughts, overgrazing, erosion, deforestation and over cultivation. Serious because it is extremely permanent.

Genetically Modified (GM)

Researchers no longer limited to genes that already exist within a species or that could arise via mutation; its now possible to exchange genes among bacteria, animals and plants. Can help developing world produce more food.

Humus

Residue of partially broken down organic matter. Found in high concentrations at the bottom of the O horizon. Really black or dark brown spongy material found in the middle of rotting log is an example. Very good for plant growth, Good because it has extremely good holding capacity for water and nutrients. 100 times greater than the capacity of clay on the basis of weight.

Soil separates

Sand, silt and clay

Soil Classification

Similar to a biological classification. You find the order first and then work your way down through the taxonomic categories. (suborders, groups, subgroups,families) until you come to the soil classes.

low-till farming

Similar to no till farming, except instead of using herbicides, farmers plow just once over residues of a previous crop and plant their new crop.

Detritus-based ecosystem

Soil contains, soil fungi, wood roach, rove beetle, centipede, snail, slug, milipede, carpenter ant, sow bug, soil protozoans, wireworm, earthworm, etc.

Topsoil formation

Soil production involves a dynamic interaction among mineral particles, detritus, and members of the detritus food web.

Nutrient holding capacity

Soil's capacity to bind and hold nutrient ions until they are absorbed by roots.

Water holding capacity

Soils ability to hold water after it infiltrates. Poor ____ means that most of the infiltrating water percolates on down below the rah of the roots. If soil does not have a good _____, the plants will have to depend on frequent rains or irrigation or else they will suffer consequences of drought. Sand soils have a poor______, whereas clayey and a silty soil are good at holding water.

Soil fertility

Soils ability to support plant growth. Can refer to the presence of proper amounts of nutrients

Importance of Humus to topsoil

Topsoil is the result of a balance between detritus additions and humus-forming processes as well as their breakdown and loss. If additions of detritus are insufficient, soil will gradually deteriorate.

Modern Industrialized Agriculture

Traditional approaches included crop rotation, variety in crops grown. animal wastes were turned into soil. Farming was good that enough people could leave the farms and join the growing ranks of merchants and workers in the city. Because of the industrial revolution in mid 1800's efficiency of farming increased dramatically. Since 1930's number of farms have decreased by 2/3rds. While the size of farms has grown 4-fold. Things that have lead to change: Machinery, Land Under Cultivation. Fertilizers/Pesticides/ Irrigation, High-yielding plant varities.

Safety issues of GM

Transgenic crops contain proteins from different organisms and might trigger unexpected allergic reactions in people who consume the food. Transgenic crop could convey the resistance to pathogens and prevent the antibiotic from being used effectively in an individual who has consumed the food. Plants could create new toxic/allergenic substances in their tissues in response to the presence of foreign genes.

Transpiration

Water evaporates from leaves of a plant, a vacuum is created that pulls the water up through the plant tissues. The roots draw water from the soil to replenish the evaporated water. Sun's energy drives transpiration via the initial evaporation process.

Plant soil- water relationships

Water lost from the plant by transpiration must be replaced from a reservoir of water held in the soil. In addition to the amount and frequency of precipitation, the size of the reservoir depends on the soil's ability to allow water to infiltrate, hold water and minimize direct evaporation.

Alfisols

Widespread, moderately weathered, forest soils. Middle aged, relatively fertile, medium brown soils. Good for agriculture, most suitable if supplemented with organic matter or mineral fertilizers to maintain . Indiana, Illonios parts of Oklahoma and Texas. Not deep but have very well developed O, A, E and B horizons. Typical of moist, temperate forest biome.

Gully erosion

With more extreme runoff the water with converges into streams greater volume, velocity and energy and greater capacity to pick up and remove soil. Eroded soil is less able to support regrowth of vegetation and is exposed to further erosion. Making it even less able to support vegetation.

Tilt

ability of the soil to support plant growth.

PH

acidity or alkalinity of any solution. Solution that is neutral is said to be a 7. Runs from 1 to 14. Different plants are adapted to different __ranges. Most animals and plants do best with a ___ near neutral. But some do better in distinctly more acidic or alkaline soils. Blueberries love more acidic soil.

12 soil textures

alfisols (Middle aged, relatively fertile, medium brown soils) , andisols, aridisols (middle-aged dessert soils, low in organic matter) , entisols (very young, under-developed solid, pale yellow to reddish brown). Histosols (very young organic peats and micas, dark brown to black). Inceptisols (young, few or faint horizons, gray to red). Molisols-Middle

Surface litter

also referred to as O horizon. Freshly fallen leaves and organic debris and partially decomposed organic matter. Where roots are often dark in color. Detritus is high in organic content.

Sorghum

an african crop, resistant to a parasitic plant known as witchweed, which infects many crops in Africa.

Clay

anything finer than .004 millimeters. Water filtration poor. Water holding capacity is good.

Inorganic fertilizer

chemical formulations of required nutrients, without any organic matter included. Much more prove to leaching than organic fertilizers.

O Horizon

consists of dead organic matter (detritus) deposited by plants:leaves, stems, fruits, seeds, etc. High in organic content, primary source of energy for the soil community. Toward the bottom the O horizon the processes of decomposition are well advanced, and original materials may be unregonizable. Material is dark and called hummus

Soil profiles

creates a vertical gradient of layers that are often (but not always) quite distinct. Horizontal layers are known as horizons. Topmost layer is the O horizon,A Horizon, E horizon, B Horizon, C horizon.

Wilting

cuts of photosynthesis by closing the stomata and preventing gas from being exchanged. If condition is too severe or prolonged, the plant dies.

Humus

dark brown or black, spongy residue of organic matter that remains after the bulk of dead leaves, wood or other organic matter has decomposed. Does oxidize but slowly. Very valuable in enhancing the physical and chemical properties of soil.

Overcultivation

first step, in growing crops is plowing. But soil is then at risk of being over exposed to wind and water weoaion.

overgrazing

grasslands that receive too little rainfall to support cultivated crops have traditionally been used for livestock. When grass production does not keep up with consumption. Land becomes barren.

marker assisted breeding

identifies desirable traits in crop plants or their wild ancestors and locates the genes with DNA sequencing.

Bedrock(R)

impenetrable layer.

Loam

important soil type. 40% sand- 40% silt and 20% clay. Best for agriculture.

Organic fertilizer

includes plants and animal wastes or both manure and compost (rotted organic matter). Leguminous fallow crops such as alfalfa, clover, lentils and pea cops, which fix atmospheric nitrogen.

undernourishment

lack of adequate food energy.

Hunger

lack of basic food required to provide energy and meet nutritional needs such that the individual is unable to live a health life.

Subsistence farming

live on small parcels of land, provide them with the food for their households, and it is hoped, a small cash crop. Labor intensive and lacks all the practicalities of industrial farming.

Subsistence farming in africa

low yields, rapid population growth, poverty and hunger, infant mortality. Because agriculture fails in many of these regions people are dependent upon imported foods, which cause the world food prices to soar.

aridisols

middle-aged, desert soils, low in organic matter. Dessert areas, bordering on grasslands. Thin and light colored and in some regions they may support enough vegetation for rangeland animal husbandry. Irrigation on these soils usually leads to salinization m high evaporation creates draw salts to surface horizons, where they accumulate to toxic levels.

Mineral nutrients

mineral nutrients- phospjate (PO3-4) postassium (K+), Calcium (Ca2+) and other ions- are present in various rocks, along with non-nutrient elements. Minerals first become available through the weathering of rock. However, it is much too slow to support normal plant growth.

biofuels

one way of mitigating the burning of fossil fuels which have triggered global climate change. ____ are derived from ethanol and other oils from crops. They do not release any new C02 into the atmosphere which makes them a form of renewable energy. Also less expensive then fossil fuels. Ethanol most common.

Compaction

packing of the soil, fills the air spaces in the soil preventing proper aeration. Reduces infiltration and increases runoff.

Sand

particles from 2.0 to .063 milimeters in size. Water infiltration good.

Stomata

pores of the plant, essential to permit the entry of carbon dioxide and exit of oxygen in photosynthesis.

Silt

range from .063 to .004 millimeters. Water filtration Medium.

Benefit to Bioengineered Foods

reductions in the use of pesticides because the crop is already resistant to pests, less erosion because no-till cropping is facilitated by the use of herbicide-restant crops and less environmental damage associated with bringing more land into production because existing agricultural lands will produce more food.

Soil structure

refers to the arrangement of soil particles. Loose _____ is ideal for infiltration, aeration and workability. Clumpy, loose, humus-rich soil is best for supporting plant growth. Represented by A-horizon, topsoil layer.

Soil texture

refers to the relative proportions of each type of particle in a given soil. If one predominates, the soil is said to be sandy, silty, or clayey.

Fertilizer

replenish the nutrients of the soil (lost when absorbed by plants into harvest material). Can be organic or inorganic.

glyphosate resistance

resistance found in number of weeds that infest soybeans, corn and cotton. Because ______ crops are planted so worldwide, resistant weeds could spread quickly and cause economic disaster for farmers.

Gain of humus

results in topsoil formation and consequent gain in -Water holding capacity -Nutrient holding capacity Water infiltration -Aeration

Loss of humus

results in topsoil mineralization and consequent loss of -Water holding capacity Nutrient holding capacity Water Infiltration Aeration

Bioturbation

reworking of soils and sediments by animals or plants. Effects include changing the texture of

Loam

soil that consists of roughly 40% sand, 40% silt and 20% clay. Sand particles will settle first, silt second and clay last. Water infiltration and water holding capacity is medium. As well as nutrient holding capacity

Infiltrate

soils ability to let water soak in. If water runs off the ground surface, it won't be useful to plants. Worse, it may cause erosion.

Soil

solid material of geological and biological origin that is changed by chemical, biological and physical processes, giving it the ability to support plant growth.

E Horizon

stands for eluviation- process of leaching or dissolving away. Also known as Zone of leaching. Usually paler than the 2 layers above it.

Ethanol

substitue for gasoline. 1/3 of us corn crap is now sold to the highest bider to become ____. Some think that it is criminal to divert corn from hungry people in order to produce _____. However, evidence that the demand for wheat, rice and soybeans has risen more than the price of corn.

Yield gap for cereals

the difference in yield in terms of tons per acre between sub-Saharan Africa and other regions continues to widen.

Malnutrition

the lack of essential nutrients, such as specific amino acids, vitamins, minerals,

Composting

the process of fostering the decay of organic wastes under more or less controlled conditions and the resulting compost is essentially humus.

Ultisols

very old, nutrient-poor, distinct, horizons, yellow to red. Around the Virginia area.