Food and Nutrition World Food Problems Principle Types of Agriculture Challenges of Producing More Crops and Livestock Environmental Impact.

Food and Nutrition

World Food Problems

Principle Types of Agriculture

Challenges of Producing More Crops and Livestock

Environmental Impact of Agriculture

Solutions to Agricultural Problems

Fisheries of the World

Carbohydrates Sugars and starches metabolized by cellular

respiration to produce energy Proteins

Large, complex molecules composed of amino acids that perform critical roles in body. Must get essential amino acids from food.

Lipids Include fats and oils and are metabolized by

cellular respiration to produce energy. Most energy.

Vitamins (molecule) and Minerals (elements – iron, calcium)

Annual grain production (left) has increased since 1970

Grain per person has not (right) South Asia and Sub-Saharan Africa

Growing population Rising temperatures Falling water tables

and droughts Ethanol production More grain is going

towards feeding livestock. ▪ Ex: 1 kg of beef

requires 7 kg grain

VEGETARIANS

More sustainable land use

Harder to get essential amino acids

NON-VEGETARIANS

Easy source of protein – meat, milk, eggs

Livestock requires more land, more energy, more water

Risk of heart disease

Rice and beans = nutritious

Just rice = not nutritious

Poverty and Food 1.3 billion people are so poor they cannot

afford proper nutrition Undernourished vs. malnourished▪ Kwashiokor – protein deficient

More common in▪ Rural than urban areas▪ Infants, children and the elderly

Economics and Politics Cost money to store, produce, transport

and distribute food Getting food to those who need it is political

High-input High yields Fossil fuels:

machinery, inorganic fertilizers, pesticides, irrigation

HDC

Industrialized agriculture

Subsistence Agriculture Low yields (enough for family) Energy from humans/work animals Require lots of land

Examples: Shifting cultivation Slash and burn agriculture (deforestation) Nomadic herding

No pesticides, synthetic fertilizers genetically modified crops

Domestication causes a loss of genetic diversity▪ Farmer selects and propagates

plants/animals with desirable agricultural characteristics

• Many high yielding crops are genetically uniform

• High likelihood that bacteria, fungi, viruses, etc. will attack and destroy entire crop

Increasing Crop Yield• Developed

countries:• fertilizers• Pesticides• Selective

breeding

Graph = wheat

1960s – more grain (wheat/rice) per acre

Selective breeding Use of fertilizers and irrigation made

it possible to grow crops in more places

Started in Mexico, spread to US, India, China

Problems: High energy costs▪ Require fossil fuels to make fertilizers,

build/run tractors, construct dams/canals, pump water from groundwater

Environmental degradation due to inorganic fertilizers and pesticides

Led to overpopulation

4 – 3 – 2 - 1 -

CAFOs (concentrated animal feeding operations): less land, but more antibiotics. Waste disposal

Increasing Livestock Yields: Antibiotics▪ Problems with increased bacteria resistance

(evolution) Hormone supplements (rBGH)▪ US and Canada do this: increase growth and milk

production. ▪ Europe does not citing human health concerns

(Precautionary Principle)

High use of fossil fuels Air pollution

Untreated animal wastes and agricultural chemicals Water pollution Harms fisheries

Insects, weeds, and disease-causing organisms developing resistance to pesticides Contaminate food supply Kills beneficial soil organisms

Land degradation Decreases future ability of land to support

crops or livestock▪ Erosion – decreases soil fertility, sediments

pollute water▪ Compacting soil, waterlogging, salinization

Habitat fragmentation, deforestation habitat loss erosion Decreases biodiversity and gene pool

Cultivating marginal lands Irrigating dry land Cultivating land

prone to erosion Water consumption

Ex: Ogallala Aquifer = nonrenewable resource b/c water so old

Drip irrigation!

Examples: Pest control: natural Predator-prey

relationships instead of pesticides, crop selection

Reduce erosion: conservation tillage and contour plowing

Reduce fertilizers – crop rotation, animal manure, supplying nitrogen with legumes

Integrated Pest Management (IPM) Limited use of pesticides by using

knowledge of the life cycles of pests, pheromones, trapping, and then targeted pesticide use; allowing some pests is fine

Organic agriculture No pesticides, synthetic fertilizers

genetically modified crops

4 – I can cite at least 2 methods for each of the farming issues below

3 – I can cite at least 1 method to farm sustainably for each of the following farming issues: pesticides, synthetic fertilizers, erosion, soil salinization, water consumption

2 - I know a few examples, but not one for each issue.

1 – I know what sustainable means.

Transferring genes of desirable trains from one organism into the DNA of another

Faster than selective breeding 1st GM food on market – Flavr Savr

Tomato Typical goals

Increase nutrition – ex: golden rice Pest resistance – ex: Bt corn Resistant to other environmental stress –

drought, salty or acidic soils GE in animals

Create hormones to increase growth

Determined safe by FDAConcerns: allergies, reduced

biodiversity if introduced to wildLabeling: none in US

4 – I can explain the pros and cons of GE food.

3 – I understand multiple reasons why GE food is developed AND multiple reasons why people are concerned about it.

2 - I understand either why GE food is developed or why people are concerned about it, but not both.

1 – I know what GE food is.

No nation lays claim to open ocean susceptible to overuse Tragedy of the

CommonsOverharvesting

Many species are at point of severe depletion

Food for growing human population

Technological advances in fishing gear

Longlines – thousands of hooks

Purse-sein nets

Trawl net – dragged along the bottom

Spotter airplanes

• Overfishing reduces gene pool of existing fish

• By-catch DIE

Magnuson-Stevens Fishery Conservation and Management Act▪ EX: Set quotas, limits # of boats

• Marine Mammal Protection Act

Ocean Pollution - dumping ground Oil Heavy metals Deliberate litter dumping Stormwater runoff from cities and

agricultural areas – biggest pollution source

Coastal areas degraded by development (many fish depend on tidal marshes, mangrove swamps, estuaries for spawning and feeding)

Raising of aquatic organisms for human food Protein!! Negatives:▪ Locations of fisheries may hurt natural habitats –

compete for shore space, destroy mangroves, destroy breeding grounds for fish

▪ Produce waste that pollutes adjacent water▪ Often fed fish from the wild▪ Expensive facility▪ Easy spread of disease antibiotics

4 – I can teach the next class. 3 – I understand at least 2 fishing

techniques that may lead to overfishing, the laws that serve to protect fisheries, and the pros and cons of aquaculture.

2 – I understand but need to re-read my notes.

1 – I know why overfishing is bad.