AgricultureWhat are some concerns about

conventional agriculture?

Goals:

• To understand some of the major concerns with conventional agriculture, and why conventional agriculture began and prospered

• To explore how growing corn and raising meat affect ecosystems, and how to combat some of these concerns through agroecology practices

• To consider our future options for growing food for a planet of 9+ billion

Major Concerns with Conventional Agriculture (an incomplete list…)

• Water pollution – animal waste, pesticides, herbicides, fertilizers

• Water use - dams, irrigation canals, groundwater• Land use changes – habitat loss, erosion, wetland loss,

desertification• Animals – animal welfare, waste, medication overuse,

feed requirements, introduction of invasive species• Genetic modification & ownership of plant genomes• Energy use & greenhouse gases• Human health

What is conventional agriculture?

• Large farms• Lots of inputs: $,

fertilizer, energy, water, pesticides

• Monocultures

What is organic agriculture?• A farm using methods that avoid most synthetic

materials (pesticides and antibiotics)• There ARE large, industrial-scale organic operations• Many small-medium sized farmers cannot afford the

organic label

vs

What is agro-ecology?

The application of ecology to the design and management of sustainable agro-ecosystems

Agro-ecology is a whole-systems approach to agriculture and food systems development – it incorporates– Traditional knowledge– Local food systems experience– Sustainable agriculture practices

Green Revolution

1. Plant monocultures of new hybrids (disease resistant and higher yielding)

2. Produce high yields by using chemical inputs & water

3. Mechanize irrigation, planting, harvesting

Started in 1950s with development of fertilizers and wide-spread availability of pesticides and farm equipment

Africa: the Green Revolution’s next iteration

Agricultural companies are buying up or leasing large tracts of land in Africa to grow soy, corn, and other export crops, often displacing small farmers.

Let’s look at one problem…nitrogen from fertilizers and animal waste

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1900 1960 1980 20001920 19401900 1960 1980 20001920 1940

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Source: Compiled from Landsat Thematic Mapper satellite imagery, Iowa Dept. of Natural Resources.

Nitrogen…so what?• Plants and animals

need nitrogen• But…there can be too

much of a good thing!• Too much nitrogen

results in: eutrophication of aquatic systems …which leads to…

There is both cultural (human) and natural eutrophication

• 1960s = 40 global dead zones• Today = more than 400

Why care about nitrogen?

We should care because it causes…• Water pollution (eutrophication, dead zones)• Acidic precipitation (rain, snow, fog)• Climate change (nitrous oxide)• Air pollution (nitric oxide=smog)

Agroecology solution: legumes!

Bacteria in the root nodules of legumes naturally fix inorganic atmospheric nitrogen , providing nutrients to the plant while receiving sugars in return

Many other chemicals are used (that we aren’t talking about today)!

• Pesticides/herbicides such as atrazine and neonicotinoids

• Genetically engineered crops and pesticides – “Roundup Ready”

Agroecology solution: Integrated Pest Management

– Disrupting Reproduction• Female Sex Pheromones• Male Sterilization

– Natural Predators

Nitrogen also comes from animal waste…

CAFOs (Concentrated Animal Feeding Operations)

In the US, the percentage of our meat products that come from factory farms:

• 99.9% of chickens for meat• 97% of laying hens• 99% of turkeys• 95% of pigs• 78% of cattle

• http://www.factoryfarmmap.org/

Global Impacts of Livestock • Produces 18% of greenhouse gas emissions

• Uses 30% of the Earth’s total land surface

• Good videos: Fresh, Food Inc., King Corn, Frontline’s Harvest of Fear

A double quarter pounder: uses 3000 liters of water

Worldwide Picture• As income increases, meat consumption also increases• Consequences: water, chemical inputs to grow grain,

animal abuse, transportation costs, monocultures

Fig. 8.5Benefits of eating lower on the food chain

Agroecology solution

• Smaller farms with fewer animals• Using animal waste as fertilizer is OK in small

amounts• Rotating animals• Eating less meat!

Note: if you eat dairyyou are still part of the meat system

Organic vs Conventional

• Organic yields match conventional yields & outperforms conventional in years of drought

• Organic farming systems build rather than deplete soil organic matter, making it a more sustainable system

• Organic farming uses 45% less energy• Conventional systems produce 40% more

greenhouse gases• Organic farming systems are more profitable

than conventional

Can organic farming “feed the world”?

Some takeaway considerations:– We waste 30-40% of our food– There are currently enough calories produced for

everyone (2,700 calories/person)– Of the ice-free land on earth, almost 40% is already

dedicated to agriculture

Perhaps the question should be instead: should conventional agriculture feed the world?

Solution: Agroecology

Recognize the farm as an ecosystem:– Grow lots of different crops, use heritage seeds– Rotate crops & animals– Implement integrated pest management– Use legumes or small amounts of animal waste for

fertilizer– Use wetlands to reduce runoff and eutrophication

What you can do:Buy local, buy organic, ask questions!

www.LocalHarvest.org – Find a CSA www.EatWellGuide.org - Find local farms