Minerals and Nutrients in Food Systems

Study Notes

Essential minerals for agriculture: phosphorus, nitrogen, potassium, calcium, magnesium.
Minerals originate mainly from mines; nutrients pertain to function in plant production.
Limited mineral availability results in reduced crop yields and livestock production.
Deficiencies of iodine, selenium, and zinc in soils can impact human health.
Soil types affect mineral content; tropical soils are typically mineral-poor, while recent sediments are rich.
Bioavailability of nutrients matters more than total nutrient content; factors such as soil pH and microorganisms influence this.

Minerals can be supplemented in food systems through fertilizers, feed, or direct human consumption.
Approximately 18 essential minerals are crucial for both plants and humans.
Nitrogen can be fixed from the air, while other minerals are mined.
Global nitrogen fixation for synthetic fertilizers was about 120 Tg in 2005.
Food systems heavily depend on agriculture for macronutrient use (P, K, S).

Current mineral reserves may last 50-500 years depending on consumption rates and potential new discoveries.
Nutrient deficiencies in diets relate to low intake of varied food sources like meat and vegetables.
Soil nutrient deficits can cause severe health issues, impacting both crop quality and human nutrition.

Minerals typically flow linearly from rural to urban areas, with minimal recycling back to agriculture (4% for nitrogen and phosphorus in 2000).
Nutrients are lost during processing and consumption, with livestock retaining only 10-30% of consumed minerals.
Improper nutrient management leads to environmental issues, including eutrophication and pollution of water systems.

Fertilizer use is projected to rise due to population growth and increased livestock production.
Higher fertilizer consumption could exacerbate nitrogen and phosphorus surplus issues and environmental losses.

Inefficient mineral use has multiple consequences:
- Low soil nutrient status correlates with reduced crop yields.
- Insufficient mineral concentrations, like zinc and selenium, lead to human health problems.
- Continuous need for ‘fresh’ minerals depletes current stocks and heightens fossil fuel use.
- Environmental losses from nutrient runoff lead to eutrophication and ecosystem disturbances.

Biodiversity encompasses genetic, species, and ecosystem variety essential for food production.
Food systems are significant contributors to biodiversity loss, with approximately 60% of terrestrial biodiversity decline attributed to food production.
Intensive food production uses large land areas, degrading original ecosystems through practices like monoculture and pesticide use.

Unsustainable practices threaten ecosystem services (e.g., overgrazing, deforestation) and contribute to biodiversity loss.
Increased reliance on monocultures limits genetic diversity in crops, risking ecosystem stability.
Climate change impacts ecosystem function and agricultural productivity.

Human diets significantly affect resource use and environmental impacts, with distinctions between animal and plant-based foods.
Animal products generally entail higher land usage and greenhouse gas emissions due to feed inefficiencies.
Beef production requires the most land, compared to other protein sources, highlighting the resource-intensive nature of animal agriculture.

Natural resources are often unsustainably managed, creating risks for future food production and contributing to 24% of global greenhouse gas emissions.
Increased population, wealth, urbanization, and climate change will heighten pressures on natural resources, necessitating careful management of cropland and ecosystems.