Earth as a Living Planet - Food

How did modern agriculture develop?

• Until about 10,000 years ago, we were a hunter gather society, limiting the number of humans on Earth

• Agriculture, cultivating plants and domesticating animals for consumption, resulted in a larger population and a smaller amount of land needed to support a person

Historical Agriculture Practices

• HUmans have learned how to create domesticated varieties of many crops, such as wheat and corn

• Domestication of animals began with dogs for hunting and then animals such as cattle, chicken, and pigs for consumption

• About 6,000 years ago Egyptian and Mesopotamian societies constructed canals and dams along rivers to irrigate crops, and in China they learned to fertilize using organic matter

• More than 2000 years ago, the Roman Empire rotated crops between fields and allowed fields to remain unplanted or fallow to help restore the soil

• Indigenous communities enriched soils with fish and practiced companion planting

• Until the 1950s, most farms raised a variety of animals as well as crops, which provided ready sources of manure for fertilizer, muscle power for farm implements, and edible protein such as meat, eggs, and dairy

• New tech led to Green Revolution

  • Gas and diesel powered plows and harvesting equipment replaced human and animal powered tools

  • Irrigation

  • Pesticides

  • Fertilizers

  • Genetic modification

Modern Irrigation

Large-scale dams and reservoirs, electric aquifer pumps, long-distance canals and pipelines, and automated sprinkler systems have allowed the area of farmland irrigated globally to increase to 20%

Synthetic Pesticides

• Use of syntheic pesticides has also increased globally

• Synthetic pesticides are industrially produced chemicals applued to combat insect and weeds

• These pesticides have been found to harm pollinators, 70 to 100 of the top food crops rely on pollinators

Synthetic Fertilizers

• Global use has increased from 14 million tons in 1950 to more than 177 million tons today

• These fertilizers are industrially produces chemicals that have one or more of the primary nutrients for plant growth, many soils are limited in these nutrients

Genetic Manipulation

• We have cross-bred wheat, corn, and rice for thousands of years, more recently to create varieties that thrive with intensive irrigation and fertilization while resisting common diseases

• Genetic engineering is splicing genetic material from one species into the DNA of another, developed in the 1970s and used for GMO’s

• Modification of rice in the 1980's to add beta-carotene

Soil Erosion

• When land is intensely cultivated, large areas of bare soil are vulnerable to erosion, where water and wind redistribute soil particles acorss Earth’s surface

• Bare soil erodes 100 times more rapidly than soil with plant cover and results in removing soil that took centuries to form

• Dust Bowl

Loss of Agrobiodiversity

• Green Revolution selected certain crop varieties for production over others and reduced agrodiversity

• Loss of crop varieties leads to genetic erosion

• The resultant crop or livestock monoculture temporarily have higher yields but are more vulnerable to pests and diseases

Pesticides

• In 1940s, synthetic fertilizers and intensive monocultures resulted in agricultural pest infestations

• Widespread use of pesticides caused toxic bioaccumulation in species above insects in the food chain

• Overuse of pesticides creates chemical resistance and poses risks for humans

Genetically Modified Organisms

• Constiture 88% of corn and 94% of soybean acreage in US

• “Round-up ready” crops are GMOs that allow broadfield spraying to control weeds without affecting crops

• GMOs creating resistant weedsand insects through natural selection

• Not required to be labelled in US

Soil Loss and Degredation

• Irrigation systems speed up erosion

• Intensive irrigation speeds of leaching

• Irrigation also causes salinization, where mineral salts dissolved in soil water concentrate after evaporation, eventually building up to amounts that damage or kill plants

Water Availability

• Agriculture draws on most water resources and uses 2/3 of all freshwater

• Due to drilling and pumping, groundwater supplies 40% of irrigation water globally

• As an aquifer dries up

Desertification

• Globally, lose around 360,000 hectares of land each year to desertification, when drought, extreme erosion, and soil infertility causes land to lose more than 10% of its productivity

• Big tree planting efforts to try and reverse desertification

Meat Production

• Generations ago, farms raised livestock, along with crops in a connected system

• Both global meat consumption and annual seafood catch have more than doubled since 1950

• Most hogs are artificiallt inseminated artificiallt

• One major US meat producer propogated a genetic line of pigs on thousands of farms to standardize production

Chicken Production

• CAFO’s began with chicken production, where the industy bred chickens called broilers for meat production, enhanced with animal protein, amino acids, vitamins, and minerals (crowded conditions in CAFO’s led to use of antibiotics to prevent diseases and artificial light to stimulate growth)

• Less feed are bigger broilers with less feed and fewer deaths before slaughter

Aquaculture

• Seafood is also raised in high concentrations within controlls ponds, tanks, or pens, requires specialized foods and antibiotics to prevent spread of diseases

• More than 50% of seafood consumed in the US

• Biggest cause of mangrove loss globally

Impacts of Seafood Production

• Overfishing is where quantity of fish caught exceeds the productive capacity of a species and causes population decline and even collapse

• Exceed max sustainable yield

• Bycatch is where non-food species are incidentally captured in fishing nets and lines, killion millions of tons of sea turtules, marine mammals, and fish

Challenged with Food Production Today

• Increasing scale and shrinking diversity

• Drive for efficiency and increased productivity

• More than half of the food production in the US comes from just 10 states in the Midwest and California, with production of some foods concentrated in the hands of a small number of companies

• Over past 100 years, varieties of cultivated food crops have declined 90% with more than half of the global varieties having gone extinct (standardization)

Food Consumption

• Consume significantly more meat and processed foods and prodice than previous generations and portion sizes have also greatly increased

• Processed foods are produced to optimize ease of preparation, consumption, and storage, and often remove fiber but add sweeteners, salt, fats, colors, artificial flavors, and preservatives

• Average American eats 60% more sugar, double the amount of fat, and 3.4 times the salt

Overnourishment and Obesity

• Overnourishment, when energy use does not match the food energy consumed, leads to obesity, which is a condition of being substantially overweight due to excessive fat accumulation

• For the first time in history, more people are overweight and obese than suffering from hunger

• Half of US adults are overweight

Organic and Sustainable Agricultural Practices

• In the US, certified organic foods must pass inspections ensuring crops are grown without synthetic fertilizers, pesticides, or sewage sludge and are not genetically modified, while livestock must be raised with organic feed and not treated with hormones or antibiotics

• Organic farmers must employ crop rotation, cover crops, and use animal and plant waste to add nutrients and conserve the soil

• Can still use synthetic compounds

Fair-Trade Certification

• Asure costumers that the price of a product provides adequate wages and environmentally sustainable production that helps farming communities thrive, market-based program

Global Equity

• Moving away from modern agriculture and toward sustainable farming practices will require economic incentives

• Some grocery stores and restaurants now highlight items grown locally (reduced greenhouse gas emissions from transporting food over long distances)

Reducing Food Waste

• 1/3 of world’s agricultural output is lost as food waste

• In Us, more than 60% of food waste occurs because consumers buy food that they don’t eat, costs US 165 billion dollars/year