Living in the Environment Chapter 13

What are the three systems humans depend on for food supply?

Cropland, rangeland, and fisheries

What are the three major crops that provide 50% of the world's calories?

Wheat, rice, corn.

Annuals

Plants whose seeds must be replanted every year

Monoculture

Community of a single crop

Polyculture

Community of a mixture of crops

What are the two major agricultural systems?

Industrialized and Traditional

Industrialized Agriculture

Also known as high-input. Uses larges amounts of energy, water, fertilizer and pesticides to create huge quantities of one crop. Spreading across countries.

Plantation Agriculture

Form of industrial agriculture that is practiced in tropical developing countries where cash crops are grown on monoculture plantation.

Traditional Agriculture

Consists of traditional subsistence agriculture and traditional intensive agriculture.

Traditional Subsistence Agriculture

Typically uses human and animal labor only to produce enough crop or livestock for the family of the farmer to survive.

Traditional Intensive Agriculture

Farmers increase human and animal labor input to get a higher yield so that they can sell food and make an income while also feeding their family.

How do farmers produce more food?

Farming more land or getting higher yields per unit of area

Green revolution

A process that increase crop yield. Three steps are developing and planting monocultures that were selectively or genetically bread, multiple cropping, and using lots of fertilizer, pestides and water.

First Green Revolution

1950-1970, rapid increase in crop yield in developed countries

Second Green Revolution

1967-present. Increased crop yield as a result of growing new varieties of rice and wheat in developed countries. Depends on fossil fuels to run machinery, produce fertilizers, and pump water.

Agribusiness

Family owned farmers or big companies controlling 3/4's of US food production.

Why has industrialization of agriculture been possible?

Cheap energy: oil.

Interplanting

Farmers growing several crops on the same plot per year. Reduces risk of losing food supply by bad luck.

Polyvarietal Cultivation

Form of interplanting where crop is planted with several varieties of the same crop

Intercropping

Form of interplanting where two or more different crops are grown at the same time on the same plot

Agroforestry (alley cropping)

Form of interplanting where crops and trees are planting together

Polyculture

Complex form of intercropping with many different plants that mature at various times planted together. Lowers fertilizer and water need, protects the plants from wind and water erosion, decreases need for insecticides or herbicides.

Macronutrients

Nutrients of which a large amount are required for life

Micornutrients

Nutrients needed in smaller amounts for life

Undernutrion

What people who can't grow or buy food to meet basic energy need suffer from.

Chronically Undernourished

People who consume 100-400 kcals less than they should, daily. Children are likely to suffer retardation and be less immune to disease

Malnutrition

Deficiencies of proteins and other key nutrients, many poor people suffer from this.

What are the most widespread micronutrient deficiencies in developing countries?

Vitamin A, Iron, Iodine

Overnutrition

One in seven adults in developed countries suffer from this. Condition where food energy intake exceeds energy needs and causes obesity. Causes lower life expectancy, greater susceptibility to disease, and lower life quality.

Why isn't food distributed equally in the world?

Because of differences in soil, climate, political and economic power, and average per capita income.

What is the principal cause of hunger and malnutrition?

Poverty

What will the ability to produce food be limited by in the future?

Soil erosion, desertification, waterlogging of irrigated lands, and water deficits and droughts.

Cross breeding

Artificial selection where genetically improved varieties of plants and livestock are developing by crossing two different organisms

What is the downside to cross breeding?

Slow process, can only combine genetically similar organisms, and the result is only useful for 5-10 years

Gene Revolution

Using genetic engineering to develop new strains of crop

Genetic engineering

gene splicing. Insertion of alien gene into commercially valuable plant or animal to give it a new trait. Outcome is genetically modified organisms

GMOs

Genetically modified organism, had an alien trait inserted into it.

Benefits of gene splicing

Shorter time required, cuts costs, allows insertion of a gene from contrasting organisms

Advance Tissue Culture Techniques

used to produce only desired parts of plants such as oils or fruits

Transgenomics

Artificially created DNA sequence is introduced to plant's to stimulate a mutation

Age of Genetic Engineering

2/3 of food products in US have been genetically engineered

GMF

Genetically modified food, potentially dangerous.

What are benefits of GMFs?

Food for everyone

What are negative effects of GMFs?

We know far too little about potential harm and modified organisms cannot be recalled.

Terminator Genes

Genes in specific crops that are modified so that one year after purchase, the seeds cannot reproduce unless buying a certain chemical from the original seller. This way the seed company can control farmers.

Microlivestock

Insects. Potential sources of protein, vitamins, and minerals. Flaws are consumers don't want to eat bugs and farmers are worried about the economic risk.

How would perennial crops help?

Eliminate need to till soil and replant every year, reduce energy use, save water, and reduce soil erosion

Marginal Land

Land with poor soil fertility, steep slopes or both. Cannot be used for planting

Rangeland

Land that is too dry, steeped or infertile to grow crops. Supplies forage or vegetation for grazing or browsing animals.

Pasture

Managed grassland or enclosed meadow planted with domesticated grasses or other forage

Open Range conditions

Low rainfall but fairly regular

Nomadic Herding Conditions

Sparse rainfall and irregular

Pastoralists

People who make their living tending animals on rangeland.

Feedlots

Where meat production increases. Animals are fattened for slaughter by grain or fish. Factory like.

Flaws with feed lots

Concentrates pollution problems, increase pressure or grain producers, requires fossil fuels input, and spreads infectious livestock diseases

Overgrazing

Occurs when too many animals graze for too long on grassland and exceed carrying capacity. Results in lower NPP, reduction of grass cover, compacted soil, and lets species invade.

Undergrazing

Absence of grazing for a long period of time, reduces NPP. More likely in arid areas or places where nomadic herding has reduced.

Rangeland Management

Characterized by controlling number, types, and distribution of livestock, deferred grazing, and rangeland restoration and improvement.

Fisheries

Earth's third largest food producing system where particular species of fish are commercially harvested.

Sustainable Yield

Size of the annual catch that could be harvested indefinitely without decreasing populations.

Why is it hard to determine sustainable yield?

Fluctuations in populations due to climate and because fish are mobile populations

Overfishing

Taking of so many fish that too little breeding stock is left to maintain numbers. Exceeds sustainable yield.

Commercial Extinction

Result of prolonged overfishing. Species declines to the point that it is no longer profitable.

Aquaculture

Fish and shellfish are raised for food, leader in this field is China

Fish farming

type of aquaculture where fish are cultivated in a controlled environment then harvested at desired size

Fish ranching

type of aquaculture where anadramous species are held in captivity for youth then released and harvested when the adults return to spawn

What are three approaches the government could apply to agriculture?

Keeping food prices artificially low, giving farmers subsidies to keep them in business and encourage food production, eliminate all pricing control and give no subsidies

Sustainable agriculture

Low input agriculture that will continue to keep population steady in the future.

Organic

Produced without pesticides, fungicides, and herbicides and cannot genetically engineered.

Components of sustainable agriculture

Lower carbon dioxide emissions, less energy required, more habitats available, more profitable for farmer, improves soil fertility