Solutions to Environmental Problems Associated with Food Production

Ch. 12

BUT, I’m HUNGRY!What can we do?

Answer: 1. Adopt sustainable agriculture (low input

practices that cost less and are less damaging) 2. Change Food Subsidies 3. Coupled with genetic engineering. 3. Eat new foods

#1. What is sustainable agriculture?

Two major ways to increase world’s food production: 1. Increase crop yields2. Increase the amount of land used

Sustainable Agriculture

Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological pest control, and minimal use of nonrenewable fossil fuel energy.

Fig. 12-34, p. 310

Solutions

More Sustainable Agriculture

More Less

High-yield polyculture Soil erosion

Organic fertilizers

Biological pest control

Water pollution

Soil salinization

Aquifer depletion

Integrated pest management

Overgrazing

Efficient irrigation

Perennial crops

Loss of biodiversity and agrobiodiversity

Crop rotationFossil fuel use

Overfishing

Water-efficient crops Greenhouse gas emissions

Soil conservationSubsidies for unsustainable farming

Subsidies for sustainable farming

Organic Food

• Produced without synthetic pesticides, herbicides, & fungicides

• No GMFs

Organic meat/dairy- 100% organically grown feed- Outdoor pasture- No hormones/antibiotics

Produce Meat More Efficiently and Humanely

• Shift to more grain-efficient forms of protein

• Beef from rangelands and pastures, not feedlots

• Develop meat substitutes; eat less meat

Efficiency of Converting Grain into Animal Protein

Fig. 12-33, p. 309

Sustainable Practices

A. Diversifying products1. Crop rotation2. Conservation tillage3. Contour plowing

Sustainable Practices

B. Low input farming with water/energy conservation

Sustainable Practices

C. Natural predator/prey relationships over chemical pesticides

Sustainable Practices

D. Natural fertilizers from manure vs. commercial fertilizers

#2. Government Agriculture Policy

Government Assistance– Keep food prices artificially low– Give farmers subsidies– Eliminate most or all price controls and

subsidies and let farmers/fishers respond to market demand

Environmentalists think…

Use subsidies to reward farmers/fishers/ranchers who:

- Protect the soil- Conserve water- Reforest degraded land- Protect and restore wetlands- Conserve wildlife- Practice more sustainable agriculture/fishing/ranching

#3 Genetic Engineering

• Crossbreeding and artificial selection• Genetic engineering (gene splicing)• Genetically modified organisms (GMOs)

Crop

Cross breeding

Desired trait(color)

ApplePear

Offspring

Cross breeding

Best results

Newoffspring

Desiredresult

Traditional Crossbreeding

1) Slow process

2) Can combine traits only from closely related species

What are Genetically Modified Foods? *

Genetic Engineering/Gene Splicing/GMFs*

Inserting alien/preferred gene into valuable plant for new traits, quick results, cheaper

Genetic Engineering

• Wild plants/animals genetic diversity• Domesticated plants/animals genetic

diversity as certain characteristics are selected for

• Genetic diversity means species are more susceptible to new strains of disease, increasing risk of total species loss.

Phase 1Make Modified Gene

Identify and extractgene with desired trait

Identify and removeportion of DNAwith desired trait

Remove plasmidfrom DNA of E. coli

Insert extracted DNA(step 2) into plasmid(step3)

Insert modifiedplasmid into E. coli

Grow in tissueculture tomake copies

cellgene

DNA

Plasmid

E. coliDNA

Geneticallymodifiedplasmid

plasmid

Phase 2Make Transgenic Cell

Transfer plasmidcopies to a carrier

agrobacterium

Agrobacteriuminserts foreignDNA into plantcell to yieldtransgenic cell

Transfer plasmidto surfacemicroscopic metalparticle

Use gene gunto inject DNAinto plant cell

A. tumefaciens(agrobacterium)

Plant cell

Nucleus

Host DNA

Foreign DNA

Phase 3Grow Genetically Engineered Plant

Transgenic cellfrom Phase 2

Cell division oftransgenic cells

Culture cellsto form plantlets

Transgenic plantswith new traits

1) Half the time as conventional crossbreeding

2) Cuts costs

3) Allows insertion of genes from almost any other organism

Fig. 12-18, p. 294

Trade-Offs

Genetically Modified Crops and Foods

Advantages Disadvantages

Need less fertilizer Unpredictable genetic and ecological effectsNeed less water

Harmful toxins and new allergens in food

More resistant to insects, disease, frost, and drought

No increase in yieldsGrow faster

More pesticide-resistant insects and herbicide-resistant weeds

May need less pesticides or tolerate higher levels of herbicides

Could disrupt seed market

May reduce energy needs

Lower genetic diversity

Advantages vs. Disadvantages

• may produce food plants that are more nutritious

• develop crops resistant to pests/disease/drought/hot/cold/herbicides/acidic-basic soils

• develop disease resistant vaccines for livestock

• DID YOU KNOW … 2/3 of food products in US markets contain GM crops!

#4 Try New Foods

Ant Larvae, waterbugs, caterpillers, cockroaches, butterflies, fried ants

I DON’T WANT TO EAT BUGS…

Can we cultivate more land instead?

Not really – most land is marginal land with poor fertility/steep slopes and would require high inputs of fertilizer/water/energy which are expensive.

How can we increase crop/stock yields?

• In developed countries: – Fertilizer– Pesticides– Selective breeding– Machinery

GREEN REVOLUTION: increase food production per acre

Increase Livestock Yields by:

hormone and antibiotic injections.

European Union (EU) banned use due to health concernsBUT US/Canada still use practice

Should we continue Green Revolution techniques?

– Without fertilizer, water, and pesticides green revolution varieties are no more productive than traditional varieties

– Green revolution varieties and their needed inputs cost too much for subsistence farming.

– Grain yields are increasing at a much slower pace.– Actual gains from green and gene revolutions may be

overstated.– Crop yield may start dropping for a number of

environmental reasons.– Increased loss of biodiversity can limit genetic raw

material.

Tools to reduce hunger & malnutrition

• Slow population growth• Reduce poverty• Sustainable agriculture