People in the world go hungry because:Food production has not been increasing as fast as the human population has increased.
Manypeople worldwide are malnourished, in part because food production is:Sufficient, but distribution is inconsistent
Some places on Earth do not have enough food due to famine.Factors that can lead to famine are:1. Crop failure and soil loss2. Unequal distribution of food3. Drought
The human body uses food for:1. A source of energy2. Asource of materials for building and maintaining body tissues
If a person does not receive enough food or the right types of food they will become malnourished.Typical types of malnutrition are:1. Amino-acid deficiency2. Diet of mostly vegetables and grains3. Low calorie consumption
Humans have certainnutritional requirements thatneed to be met. One of thoserequirements are:They must receive 8 essential amino acids from the proteins they eat.
What people eat in developed countries is different than what people in developing countries eat.People in developed countries eat more food and a larger portion of proteins and fats than people in developing countries.
Different types of food require different amounts of energy to produce:A plot of land can produce more food when it is used to grow:Plants such as grains and vegetables because it requires less energy compared to raising animals for food consumption.
Researchers hope to improve the efficiency (raising more food on less land) of food production by:Studying plants and other organisms that have a high yield (The amount of a crop produced per hectare or acre)
The types of organisms that researchers are interested in studying to improve efficiency are:Organisms that can thrive in various climates and that do not require large amounts of fertilizers, pesticides, or fresh water
The reasons why people suffer from malnutrition vary, depending upon where they live.Malnutrition usually occurs because of:1.Poverty2.War and political strife3.Transportation problems
Tobe able to feed the people of the world in 2050:1.Produce more food2.Abolish poverty3.Increase the productivity of subsistence farmers
Positive and negative affects of the Green Revolution (increasing the production of food without increasing the area of farmland used) are:Positive1.New varieties of grains.2.Large yield crops.3.Reduce the price of food.4.Improve the lives of millions of people.
Negative1.Soil degradation (harming the soilso that it can no longer support thelocal ecosystem)2.Overuse of water, pesticides, andfertilizers.
The difference between traditional and modern farming techniques are:Traditional1.Plows pushed by farmer or livestock.2.Organic fertilizers are used to enrich the soil.3.Fields are irrigated by water flowing through ditches.4.Weeds are removed by hand or machine.
Modern1.Machinery is now used to plow the soiland harvest crops.2.Syntheticchemical fertilizers are usedinstead of manure and plant wastes.3.Avariety of overhead sprinklers and dripsystems may be used for irrigation.4.Synthetic chemicals are used to killpests.
Earth’s available arable land isbeing reduced by:1.Fast growing human populations.2.Soil erosion.3.Desertification.
For crops to grow and be plentiful, they need fertile soil.Fertile topsoil is composed of:1.Rock particles2.Water and air3.Organic matter, such as dead and decomposing organisms
Most soil forms when rock is broken into smaller and smaller fragments by:1.Wind2.Water3.Chemical weathering (when the minerals in the rock react chemically with substances such as water to form new materials)
Other processes that help to produce fertile topsoil are:1.Rock particles – supply minerals2.Fungi and bacteria – decompose dead plants and organic debris3.Earthworms, insects, and small animals – break up the soil and allow air and water into it
Layers of topsoil from the top to the bottom:1.Surface layer – fallen leaves and partially decomposed organic matter2.Topsoil – organic matter, living organisms, and rock particles3.Zone of leaching - dissolved or suspended materials moving downward
4. Subsoil – larger rock particles with organic matter, and inorganic compounds5. Rock particles – rock that has undergone weathering6. Bedrock – solid rock layer
Unfortunately topsoil is being lost due to erosion.Factors that can lead to erosion are:1.Modern farming techniques – using any type of machinery loosens the soil which can then be washed away2.Irrigation – washes away any soil that is loose
Not only can soil be lost to erosion it can also become like a desert over the years.Farmland may become desertified if:1.Domestic animals are allowed to overgraze the land2.Too many crops are grown on the land3.Over time the land gradually looses it fertility4.No soil left due to erosion
The following can be done to helpprevent desertification:Lettingthe land lie fallow or toremain unplanted for several years.
Soil can be conserved in several different ways.Some methods of soil conservation are:1. No-till farming2. Contour plowing3. Building terraces4. Drip irrigation
No-tilling farming methods include:1.Crops being harvested without turningover the soil2.Seedsof the next crop are plantedamong the remains of the previous crop
Advantage and disadvantages of no-tillfarming include:Advantages1.Theremains of the first crop hold the soil inplace while the new crop develops2.Saves time compared with conventionalmethods3.Can also reduce soil erosion to one-tenth ofthe erosion caused by traditional methods
Disadvantages1.May not be suitable for some crops2.Soil that becomes too denselypacked3.Lower crop yields over time
Irrigation water usually comes from:Rivers and groundwater
Over the years the soil can build up aconcentration of salts, known assalinization.Salinization usually occurs because of: long-term irrigation because when thegroundwater evaporates it leaves behindsalts
Ways to reduce salinization include:1.Usingrainwater instead of groundwateron crops, because of less salts2.Useorganic fertilizers in place ofchemical fertilizers, which containexcess salts and nitrates
Even if a person is successful in obtaining a high yield of crops, using the least amount of land, they may still have to deal with pests.Major crop pests include:1.Plants, such as weeds2.Fungi3.Microorganisms
Pest populations damage plants by:1.Breeding more rapidly in warmer climates2.Becoming resistant to pesticides via natural selection3.More successful at ruining crops than wild plants
Reason why it is easier for pests to invade crops instead of wild plants are: Wild plants grow throughout the landscape and have a variety of pest predators that live on or near the plants, whereas crops grow densely packed together which makes it easy for pests to wipe them out faster
To help get rid of pests, farmers have turned to using pesticides.Human health concerns regarding pesticide use include:1. Cancer rates among children is higher in areas that use pesticides2. Nervous system damage3. Accidental chemical leaks in factories that make pesticides
Environmental problems associated with pesticides include the following:1.Accumulate in the soil and water2.Donot break down rapidly into harmless chemical when they enter the environment
In order to avoid the problems with pesticides, farmers are turning towards biological pest control.Biological pest control works by:1. Releasing a pathogen to control insect larvae2. Breeding plants with natural defenses3. Interrupting reproductive methods
Tools of biological pest control include:1. Pathogens – used to kill the organism that is the pest2. Chemical compounds – repel the pest and physical barriers – tougher skin3. Plant’s defensive chemicals - biodegradable
Farmers are also using another type of pest management known as integrated pest management.The goal of integrated pest management is:Reduce pest damage to a level that causes minimal economic damage
Integrated pest management can include:1. A mix of farming methods2. Biological pest control3. Chemical pest control
Through advances with technology, farmers are now able to grow crops with desirable traits. The do this through a process known as genetic engineering. Farmers choose to use genetic engineering: In order to get a faster result tha
Genetic engineering of food crops:Continues to be debated among scientists
The following are advantages and disadvantages of genetic engineering:Advantages1. Tastier fruit2. Pest resistance
Disadvantages1.Products have not been fully tested forenvironmental impacts2.Geneticallyengineered traits areaccidentally passed on to the wildplants
An alternative to genetic engineering include:Sustainable agriculture
Not only do people get their nourishment from vegetables, they also get vitamins and minerals from animals. Animals can be wild, domesticated, or farm raised. Just like plants, animals can be overharvested.
To combat overharvesting, especially fish, governments have created: No-fishing zones, so that fish populations can recover
A highly used method of harvesting fish and seafood is known as aquaculture. The most common method of aquaculture is:Fish farming
The different types of aquaculture include:Fish farm – many individual ponds that each contain fish at a specific stage of developmentRanch – fish raised until they reach a certain age and then released
The environmental damages that canoccur from aquaculture are:1.Alarge amount of waste, which can be asource of pollution2.Requires so much water that they candeplete local water supplies
Animals, known as livestock, are raised for certain products.Products obtained from livestock include:1. Leather2. Wool3. Eggs and meat
People in developed and developing countries use livestock for different reasons. The differences between developed and developing countries and their use of livestock are:Developing countries use livestock for manure and fuel, also for plowing and pulling carts
Another type of livestock raised is poultry or chickens, ducks, and geese. Chickens are raised for:Meat and eggs, which are a good source of essential amino acids
Chickens, ducks, and geese are usually raised in factory farms.The criticisms against raising poultry in factory farms are: They live in cramped, artificial environments
Ducks are being used as part of an integrated system in which some of their products are used to help another crop.Ways in which ducks are used as part of an integrated system are:1. Droppings are used to fertilize fields of rice2. Rice fields are flooded several times a year with nearby ponds3. Mulberry trees are irrigated by the ponds
The integrated system is beneficialbecause:1.Uses little fresh water2.Recycles waste3.Produces ducks, silk, rice and fish