Agricultural Practices — Food, Soil & Pesticide

Major food sources

Wheat, rice, and corn provide most of the world's required nutrients.

Global Big Three

Wheat, rice, and corn are the three major global food crops.

Most consumed fruit

Bananas are the most consumed fruit.

Regional food differences

Different regions rely more heavily on certain crops and nutrients.

Global meat consumption

Meat consumption has increased worldwide over the past 50 years.

Chicken consumption

Chicken consumption has increased greatly over time.

Pork consumption

Pork consumption has remained relatively similar over the years.

Nutritional value of meat

Meat provides concentrated protein, iron, fats, and other nutrients.

Meat as an indicator of wealth

Meat consumption can indicate wealth because meat is expensive to produce.

Feed conversion

The amount of feed needed to produce 1 kg of edible animal weight.

Meat energy input

Producing 1 kg of meat requires at least 16 times more fossil fuel than producing 1 kg of plants.

Livestock methane

Livestock produces about 35% of U.S. methane emissions.

CAFOs

Concentrated Animal Feeding Operations; large enclosures where livestock are fed for rapid growth.

CAFO animals

Cattle, hogs, and poultry are commonly raised in CAFOs.

CAFO concern

CAFOs require heavy use of antibiotics and can create environmental concerns.

Green Revolution

Research and technology that greatly increased worldwide agricultural production beginning in the 1940s–1960s.

High responders

Crops that show increased yields only when given fertilizers and protection from pests.

High responder disadvantage

They can be expensive because they require fertilizers and pest protection.

U.S. corn production

More corn is grown in the U.S. than is directly eaten by people.

Genetic engineering

The removal of DNA from one organism and insertion into another organism's chromosomes.

GMO

Genetically Modified Organism; an organism whose DNA has been altered to produce new traits.

GMO concern: superweeds

Heavy pesticide use can lead to pesticide-resistant weeds called superweeds.

GMO concern: biodiversity

GMOs and associated farming practices may reduce natural biodiversity.

GMO concern: wealth

Some GMO technologies may be more accessible to wealthy farmers than poor farmers.

GMO concern: family farms

High costs may make small family farms less competitive.

GMO concern: food safety

Food safety is one concern associated with genetically modified foods.

Soil

Soil develops through weathering of rocks and accumulation of organic material.

Topsoil

The upper soil layer containing organic material and many soil organisms.

O Horizon

The soil layer made mostly of organic material such as leaf litter.

A Horizon

Surface soil containing mineral particles and organic material.

Subsoil

The soil layer below topsoil.

B Horizon

A soil layer rich in clays.

Parent material

The underlying material from which soil develops, often bedrock.

Most productive soils

Soils that develop under moderate temperatures and rainfall are often highly productive.

Soil as a resource

Soil is renewable, but it replenishes extremely slowly.

Soil formation rate

Soil can form at roughly 1 mm every 1,000–10,000 years.

Farming and soil depletion

Farming can deplete soil through erosion and removal of organic material.

Soil degradation

The decline in soil quality caused by processes such as erosion and nutrient loss.

Row crops and erosion

Row crops leave soil exposed after harvest, increasing erosion.

Lack of crop rotation

Not rotating crops or allowing fields to rest can contribute to soil degradation.

Windbreak removal

Removing windbreaks can increase wind erosion.

Ground cover

Plant material that covers soil and protects it from erosion.

Cover crops

Crops such as clover planted after harvest to protect and improve soil.

Interplanting

Growing two different crops in the same field to help protect soil.

Mulch

Organic material placed on soil to protect it and add nutrients.

Nitrogen (N)

Nutrient needed for chlorophyll and an essential component of proteins and enzymes.

Phosphorus (P)

A nutrient essential for photosynthesis.

Potassium (K)

A nutrient involved in building proteins and photosynthesis.

Fertilizer runoff

Excess nitrogen and phosphorus from farms can enter waterways and cause pollution.

Dead zone

An area of water with very low oxygen levels caused by excess nutrients.

Algal bloom

Rapid growth of algae caused by excess nutrients such as nitrogen.

Hypoxia

Low oxygen levels in water.

How dead zones form

Excess nutrients cause algae blooms; algae die and decompose, using up oxygen.

Effects of hypoxia

Low oxygen water supports fewer organisms and can cause massive fish kills.

Pesticides

Chemicals used to kill or control biological pests.

Natural pesticides

Pesticides such as sulfur, mercury, and arsenic that have been used for thousands of years.

Chlorinated hydrocarbons

Fast-acting, highly toxic synthetic pesticides that can persist in the environment.

DDT

The first synthetic organic pesticide; persistent and can concentrate in food chains.

Pesticide persistence

Some pesticides remain in the environment and become concentrated in food chains.

Organophosphates

Among the most widely used synthetic pesticides; many degrade relatively quickly.

Roundup

A pesticide/herbicide that breaks down relatively quickly compared with persistent pesticides.

Neonicotinoids

Pesticides more toxic to many invertebrates than higher animals.

Neonicotinoid properties

They are water-soluble and can be taken up through plant roots.

Neonicotinoids and bees

Neonicotinoids may affect bees' ability to forage.

Fumigants

Small molecules delivered as gases to penetrate soil or other materials.

Fumigant uses

Used to control fungi and pests in crops and stored materials.

Fumigant danger

Fumigants can be extremely dangerous to farm workers.

Termite fumigation

A treatment where an enclosed structure, such as an entire house, is fumigated.

Pesticide resistance

When pests evolve resistance to pesticides used against them.

Chemical arms race

The repeated development of stronger pesticides and pesticide-resistant pests.

Non-target species

Organisms unintentionally affected by pesticides.

Pesticide effect on natural enemies

Pesticides can kill or repel natural enemies of pests.

Pesticides and honey bees

Pesticides can harm beneficial species such as honey bees.

Causes of insect decline

Habitat loss and pollution are major causes of insect decline.

Organic agriculture

Farming that avoids synthetic pesticides, fertilizers, hormones, antibiotics, and genetic modification.

Organic agriculture and soil

Organic agriculture can leave soil healthier than intensive chemical monoculture.