How farming affects parts of an ecosystem

Review questions Where does our food come from? How is our food supply dependent of ecosystems? How do current agricultural practices affect public health and the environment?

Soil The foundation of a farm’s ecosystem Foundation of food supply Sustains plants by providing: Water Nutrients Root support

Organisms in the Soil Bacteria Arthropods Earthworms Fungi Nematodes Protozoa Mammals 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 health Cycling nutrients which crops can use Soil stores nutrients and releases them slowly Soil stores water Soil can suppress plant disease Some soils can purify water by breaking down pollutants

Problems in Agriculture Industrialization of agriculture changed how food is grown From 1950 to 2000, production of US farms more than doubled with a fraction of human labor From 1950 to 1970 new varieties of grain was introduced to developing nations- The Green Revolution

The Green Revolution Genetically 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 populations Lead to outbreak of disease and trouble handling that many animals

Problems in Agriculture Fertilizers 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 environments Can cause deformities and in fish and amphibians Decline pollinator populations Compromised immunity of sea life

More Problems with Agriculture Wild 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 Loss Low genetic diversity in our crops Globally, 90% of our food supply is grown from only 15 plant and 8 animal species Climate Change Changes in temperature and weather patterns affect how, when and where certain crops can be grown

Resource Depletion Natural 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 Farmland Every minute, more than an acre of American farmland is loss to development Well managed agricultural land provides many ecosystem services

Loss of Farmer Equity Decisions 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 companies Farmers may be pressured into practices dictated by industry

The Treadmill Effect Target insects develop resistance to pesticides There 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 Assignment Go through the provided list of problems and answer the questions on the handout Tomorrow you will work with a group on one of these issues