5.2 Agriculture and food

• 70% ice-free land for agriculture and forestry

• Human population increasing, requires feeding

• Needs not accounted for in land-use decisions

• Indigenous peoples, low socio-economic groups

• World agriculture produces enough for 8 billion

• Not equitably distributed, ~1/3 wasted

• Due to different soils and climates

• Outputs: arable, pastoral, mixed, monoculture, diverse

• Reasons: commercial, subsistence, sedentary, nomadic

• Inputs: intensive/extensive, irrigated/rain-fed, organic/inorganic

• Nomadic pastoralism, slash-and-burn agriculture

• Sustained low-density populations

• Less sustainable with modernization and higher density

• High-yielding crops, improved irrigation, synthetic fertilizers, pesticides

• Increased food security but criticized for consequences

• Fossil-fuel dependent

• Needed in intensive systems for productivity

• At expense of sustainability

• A variety of techniques can be used to conserve soil, with widespread environmental, economic and sociocultural benefits

• Soil conservation techniques are very varied and can be classified in a number of ways

• Conservation from erosion—water and wind a

• Water—terracing, contour ploughing, bunding, drainage systems, use of cover crops b

• Humans are omnivorous, and diets include fungi, plants, meat and fish

• Diets lower in trophic levels are more sustainable

• The yield of food per unit of land area is greater in quantity and lower in cost with crops rather than livestock

• Consider: to what extent plant-based diets could make agriculture more sustainable

• Current global strategies to achieve sustainable food supply include reducing demand and food waste, reducing greenhouse gas emissions from food production

• Examples include plant-based meat substitutes, reducing nitrogen loss to the atmosphere, low methane rice, reducing methane release by ruminants, extended shelf life for food

• Food security is the physical and economic availability of food, allowing all individuals to get the balanced diet they need for an active and healthy life

• Consider: the current extent of food security within differing regions of the world

• Contrasting agricultural choices will often be the result of differences in the local soils and climate

• Consider: one pair of contrasting agricultural choices from one biome

• Examples: cereal vs. ranching in prairie mollisols; soya beans vs. cattle ranching in tropical forest oxisols

• Soil regeneration, rewilding, permaculture

• Non-commercial cropping, zero tillage

• Mixed farming techniques

• Improve and diversify productivity

• High-tech greenhouses, vertical farming

• Supply food to urban areas

• Not always sustainable (fossil fuel dependent)

• Supply chain efficiency, food miles

• Farming type and techniques, diet changes

• Example: planetary health diet (PHD)

• Traditional methods may be more sustainable

• Examples: Brazil nuts, truffles, bamboo, honey

• Evaluate sustainability claims

• Must produce enough for global population

• Uneven distribution → malnutrition

• Undernourishment and overnourishment

• Famine from distribution problems and crop failure