Food and Ecosystems How farming affects parts of an ecosystem

Review questionsWhere does our food come from?How is our food supply dependent of

ecosystems?How do current agricultural practices affect

public health and the environment?

SoilThe foundation of a farm’s ecosystemFoundation of food supplySustains plants by providing:

WaterNutrientsRoot support

Organisms in the SoilBacteriaArthropodsEarthwormsFungiNematodesProtozoaMammals All play a role in the foundation of soil

Soil Food Web Soil food webs offer many services that

promote and abundant food supply and human healthCycling nutrients which crops can useSoil stores nutrients and releases them slowlySoil stores waterSoil can suppress plant disease Some soils can purify water by breaking down

pollutants

Problems in AgricultureIndustrialization of agriculture changed how

food is grownFrom 1950 to 2000, production of US farms

more than doubled with a fraction of human laborFrom 1950 to 1970 new varieties of grain was

introduced to developing nations- The Green Revolution

The Green RevolutionGenetically engineered rice, grain and corn

was introduced and produced higher yields per acre

These crops needed many nutrients the soil did not provide naturally so fertilizers had to be used

Many of these crops were expensive so poorer farmers could not afford them

Livestock was raised in larger populationsLead to outbreak of disease and trouble handling

that many animals

Problems in AgricultureFertilizers

Nutrient runoff promotes algal blooms and dead zones

Dead zones common in Gulf of Mexico, Chesapeake Bay and other coastal regions

Synthetic nitrogen fertilizers and increased intensity of meat production are among the greatest contributors to nutrient pollution

Pesticides Impact surrounding environmentsCan cause deformities and in fish and

amphibiansDecline pollinator populationsCompromised immunity of sea life

More Problems with AgricultureWild biodiversity loss

Heavy use of insecticides impact pollinators and predators of other pests

Where are all the bees? Monoculture and biodiversity loss

Replaces bio-diverse habitats with fields of genetically uniform organisms – open to disease

Pollinators may not have enough variety of food to survive

Monoculture- only growing one type of crop- Depletes soil of

nutrients- Decreases

amount of pollinators

Strip-cropping – planting multiple crops in alternating rows- Better for the soil

because each crop uses different nutrients

- Allows for more biodiversity

Domestic Biodiversity LossLow genetic diversity in our cropsGlobally, 90% of our food supply is grown from

only 15 plant and 8 animal speciesClimate Change

Changes in temperature and weather patterns affect how, when and where certain crops can be grown

Resource DepletionNatural resources like fertile soil, freshwater

and fossil fuels are being depleted faster than natural rates can restore them

Modern agriculture is dependent on all these resources

Loss of FarmlandEvery minute, more than an acre of American

farmland is loss to developmentWell managed agricultural land provides many

ecosystem services

Loss of Farmer EquityDecisions about food production- who, how and

where- have shifted away from the farmer and into industry More than half of the corn seeds sold in the US are

controlled by 2 companiesFarmers may be pressured into practices

dictated by industry

The Treadmill EffectTarget insects develop resistance to

pesticidesThere is a need to apply more or stronger

chemicals Chemical fertilizers can degrade the soil

quality over time Farmers continually need to apply more

chemicals to achieve the desired results

If they can’t breath it ….do you want to eat it?

Your AssignmentGo through the provided list of problems and

answer the questions on the handoutTomorrow you will work with a group on one

of these issues