Agriculture & Food Production

Food Production• Agriculture began 10,000-12,000 years ago

• Enough food to meet basic nutritional needs

• 1 out of 6 people in less developed countries are not getting enough to eat

–Why?

–ACCESS

• 2007 study

–By end of the century 50% of the world’s population will face food storages

Important Nutrients

Different Diets• Poor (less developed countries)

– Low protein (to vegetarian)

– High carbohydrate• Wheat

• Rice

• Corn

• More developed countries– More protein & fats

– In US, ½ consumed calories are from

meat, fish, & oil

Nutrition CategoriesUndernutrition – hunger

Malnutrition

Nutrition CategoriesMalnutrition – lack of sufficient nutrients

•One out of three people suffers from a deficiency in one or more vitamins/minerals

•Three main deficiencies:–Vitamin A

•Blindness

–Iron•Anemia/fatigue

•Increase chance of death during

childbirth

–Iodine•Thyroid disorders

Reason for Under & Mal Nutrition

• Poverty – top cause– Lack of resources for access

• Political/economical factors– war

• Diverted resources– More grain to feed livestock (40%)

– In US, corn & soybeans are primarily grown to feed livestock

Nutrition CategoriesOvernutrition - Excess fat from too many calories

• Health problems (similar to underfed)– Lower life expectancy

– Greater susceptibility to illness• Type 2 diabetes, hypertension, heart disease

– Lower productivity

Three Food Supply Systems• Croplands

– Grains (corn, rice, & wheat = 60% human intake)

– 77% of world’s food on 11% of its land

• Rangelands (pastures)– Meat

• Amount of intake increases with income (wealth)

– 16% of world’s food on 29% of its land

• Fisheries– 7% of world’s food

Agriculture Map

Green RevolutionGrow more food on less land

Increase crop yields

• 1st :1950-1970ish– Monocultures of high yield crops

– Large amounts of pesticides, fertilizers, & water

– Multiple cropping

• 2nd :1970-present– Fast growing dwarf varieties

• Changes led to industrialized agriculture

Green Revolution ResultsGrow more food on less land

Increase crop yields

• Less human labor

• More machinery = more fossil fuels

• More irrigation = water shortages

• Increase use of fertilizers

• More monocropping

• More pesticides

Green Revolution Outcome

Croplands• Industrialized Agriculture

– Uses: heavy equipment, financial capital, fossil fuels, water, & heavy fertilizers & pesticides

– Goal: Increase crop yield

– 80% of food

• Plantation Agriculture– Growing cash crops in less development countries to

export

– Monocultures

– Examples: sugar cane, bananas, coffee, soybeans

Croplands• Monocropping

– Main agricultural practice in the US

– Benefits:• Large expanses of land can be planted at once

• Can apply the same pesticides

• Can harvest at the same time

– Problems:• Soil erosion – harvest at once = exposed soil

• Higher vulnerability to pest attacks

Case Study: Hydroponicsan alternative to croplands

Hydroponics – growing plants by exposing roots to a nutrient rich water solution

Case Study: HydroponicsAdvantages

• Grown indoors: anywhere & year-round– increase total yields

• Grow in urban areas

• Recycle water & fertilizers

• Little to no pesticides

• No soil erosion

Case Study: HydroponicsWhy not?

• Expensive to begin

• Need Technical knowledge

• Threatens current farming business– Pesticide companies, farm equipment, etc.

Traditional AgriculturePracticed by 39% of world population

• Traditional subsistence agriculture– Use human labor & draft animals to grow family food

• Traditional intensive agriculture– Increase labor in addition to increased water & fertilizer

(manure) use to feed family & sell some for profit

PolycultureGrowing several crops on the same plot simultaneously

•Reduces chance of losing crop due to pest or weather, etc.

Slash & Burn• Clear & burn a small plot of land

• Advantages:– Fertile soil

– Less water (roots)

– Less pesticides (predator habitat)

• Disadvantages:– Use for few years

– Depletes soil nutrients

– Deforestation

– 10-30 recovery

Increasing Crop Yields • Crossbreeding

–Artificial selection

–Slow process• 10-15 years sometimes

–Good results

Increasing Crop Yields • Genetic engineering (GMOs)

–2nd gene revolution

–Gene splicing

–Plants resistant to:• Heat or cold

• Herbicides

• Insect pest

• Parasites

• Viruses

• Drought

Advantages of GMOs

• Half the time to develop

• Cost less (usually)

• Can use genes from other organisms

Current State of GMOs• 12% of world’s cropland

– ½ in US

– Other major countries: Argentina & Brazil

• European Union (EU) restricts use of GMOs

GMOs in the US• 80% of corn, soybeans, & cotton

• 70% of food items and/or their ingredients

Disadvantages of GMOs1. Disrupts seed market

Few producers & investors controlling market

2. No significant increase in crop yields (US)(2009)

3. Decrease in genetic diversity of wild type

– Hybrids between GMOs & WT

4. More pesticide resistant insects & herbicide resistant weeds

5. New allergens in food

6. Harmful to organic farming

– Increase cost for testing & hybrid prevention

7. Too little known about long term potential harm

Meat Production• World meat production four fold from 1961-2007

• Average consumption person more than double

• Result: Increase need for grain

RangelandsUnfenced with grass grazing livestock

½ the world’s meat

Industrialized Meat Production• Two types

– Feedlots

– Concentrated animal feeding operations

• Feed grain/fishmeal that contains growth hormones & antibiotics

Environmental Impacts of Meat Production

• Use large amounts of fossil fuels & water

• Creates high concentrated amounts of animal waste

–Leads to air and water pollution

• Ex: Brazil – large exporter of beef

–High deforestation rate

2008 FAO report• 1/5 of world’s grasslands degraded by livestock

• Livestock responsible for 55% of erosion & sediment pollution

• 1/3 of water pollution result of excessive fertilizers

• Increase in antibiotic use – Leads to genetic resistant microbes

Environmental Impacts of Meat Production

Environmental Impacts of Agriculture

Biodiversity Loss• Loss of habitats

• Agrobiodiversity loss– World’s genetic variety of

animal & plant species used to provide food

– Since 1900, ¾ of crop genetic variety has been lost

Soil ErosionMovement of soil by wind or water

• Largest cause: flowing water

• Effects:– Loss of soil fertility

• Depletion of nutrients

– Water pollution• Can kill fish/shellfish

• Clog irrigation

DesertificationTop soil productive potential falls by 10% or more because of a combination of prolonged drought & human activities

(overgrazing or deforestation)

World Desertification

Irrigation Consequences

• Salinization – Accumulation of salts in soil

– Lowers crop yields

– Affects 10% of world croplands

• Waterlogging – Irrigation raises the water table

– Roots cannot get oxygen

– Affects 10% of world croplands

Air Pollution & Climate Change• Clearing of forest

• Livestock generate 18% of world’s greenhouse gases– Cattle methane/year = 33 million automobiles

• Manufacturing of fertilizers increase nitrous oxide

PestsAny species that interferes with human welfare

•Competing for food

•Invading lawns & gardens

•Destroying building materials

•Spreading disease

•Invading ecosystems

PesticidesChemical used to kill or control populations of

organisms we consider undesirable

•Insecticides

•Herbicides

•Fungicides

•Rodenticides

•Coevolution leads to resistance, so ever changing game…

Two Phases of Pesticides• First Generation Pesticides

– Natural chemicals borrowed from plants

– Ex: Nicotine sulfate (tobacco)

• Second Generation Pesticides– Chemical produced in a lab

– 1939 – DDT (Paul Müller)• Became most used pesticide

• 1948 Nobel Prize

– 1962 – Silent Spring (Rachel Carson)

– 1970 – biopesticides – copying nature

Characteristics of PesticidesPesticides can be

• Broad spectrum– DDT & Organophosphates

• Selective– Treating one or a few types of pest

• Persistent– Length of time they remain deadly in the environment

– Biological magnification

Pesticide Advantages• Save human lives

– Ex: DDT & malaria – prevent spread of diease

• Increase food supply & farmer’s profits– Every $1 spent on pesticide = $4 in crop yield

• Work fast

• When used properly: health risk < benefit

• More environmentally friendly– Biopesticides & GMOs

Pesticide Disadvantages

• Genetic Resistance

– Insect resistance: 5-10 years (shorter in tropics)

– Since 1945 – 1000 insects/rodents & 550 plants

• Farmers on financial treadmill

• Can kill natural predators & parasites

• Can spread to unwanted areas & pollute the environment

Reducing Exposure to Pesticides

Pesticide Alternatives

• Crop rotation– Fool the pest

• Polycultures– Home for pest enemies

• Use pheromones

• Intro natural predators– Ex: ladybugs

Food Sustainability• Reduce Soil Erosion

Soil Conservation• Methods:

– Terracing• Decrease erosion

• Decrease runoff

Soil Conservation• Methods:

– Contour planting• Decrease erosion

Soil Conservation• Methods:

– Alley cropping • Also called agroforestry

• Provides wind breaks = less erosion

• Helps restore nutrients

Soil Conservation• Methods:

– Conservation tilling farming• Leaving crop residue

• Roots hold soil in place

• Decomposition helps to restore nutrients

• Reduces evaporation

• Reduces need for fossil fuels

• Reduces air pollution (dust)

• Habitat for wildlife

• Identify erosion hot spots

Restore Soil Fertility

• Organic Fertilizers–Animal manure

–Green manure (grass clippings)

–Compost

• Inorganic Fertilizers–Nitrogen/phosphorus based

• Crop Rotation

Reduce…

• Soil Salinization–Prevention (better irrigation)

–Clean up (2-5 years)

• Desertification–Reduce:

• Population growth

• Overgrazing

• Deforestation

Aquaculture

More Efficient Meat Production• Grain efficient protein

• Rangelands instead of feedlots

• Less meat consumption

Organic Farming