Why Soil Matters

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In 2011, the global population flew past seven billion people. It is now on pace to reach eight billion by 2024. The rapid pace of our population growth underlines the need for healthy and productive farmland. Yet as our population increases, the amount of arable land on the planet is decreasing. Human activity and climate change are degrading once-productive farmland, decreasing the amount of food that can be grown. The United Nations Convention to Combat Desertification estimates that 3 to 5 percent of the world’s agricultural yield is lost due to land degradation every year.

How can we feed more and more people on less land? International experts agree with urban farmer Will Allen. He knows that soil is the key to stopping land degradation and increasing productivity. In this QUEST video, Will Allen explains how increasing soil fertility will ensure our future food security.

Pre-activity Questions

  • How much land did it take to grow your breakfast today?
  • What is the difference between productive land and degraded land?
  • What causes land to degrade?

Focus Questions for Viewing

  • How is farmland being lost today?
  • Why is soil fertility important?
  • How can leftover food and waste be converted to soil?

Post-viewing Questions

  • How do your actions contribute to land degradation?
  • How could your actions reduce land degradation?
  • How can you convert food waste into soil?

Extension Activity

  • Explore the soil profile in your community using the USDA’s map. http://websoilsurvey.sc.egov.usda.gov/. Compare and contrast how the land has changed over time. What might have caused these changes? Using the data from the map, predict changes that may occur in the future.

Links to Learn More

  • Urban Farming, Growing Power, Inc.See how Will Allen’s organization is empowering communities to grow their own food.
  • Land Degradation, Institutional Food Policy Research InstituteLearn about the potential of integrated soil fertility management to slow land degradation.
  • Real Time Population Statistics, WorldometersSee world population data in real time.
  • Food Security, United Nations Convention to Combat DesertificationRead the 2014 report on food and land security from the United Nations Convention to Combat Desertification.

Next Generation Science Standards

  • Performance Expectation: Evaluate the evidence for the role of group behavior on the chances of individuals and species to survive and reproduce. HS-LS2-8
  • Disciplinary Core Idea: Ecosystems have carrying capacities, which are limits to the number of organisms and populations they support. These limits result from such factors as the availability of living and nonliving resources and from challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem. HS-LS2-A
  • Crosscutting Concept:Scale, proportion, and quantity: The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.
  • Science and Engineering Practices:Constructing explanations and designing solutions