In this module, we have introduced the basics of soil properties and the nature of soil as a key resource for food production, which following modules will build upon to show how soils can be managed sustainably. We hope that you have understood the fundamental composition of soil as minerals, organic matter, water, and air as an essential part of earth's natural systems. We also have tried to illustrate the way in which key properties of soil, like its pH, nutrient content, and retention of water, affect how plants grow and produce food. On the human system side, we also presented the way in which human efforts have managed soil for sustained production of food, including the addition of nitrogen and phosphorus to replenish soil stores that are removed by crop harvests, and the protection of soils from erosion losses. However, a surplus of soil nutrients generated by over-applying N and P is also a problem, as illustrated in the nutrient balances in this module's summative assessment. We will continue to deepen your knowledge of sustainable soil management, as it supports sustainable food systems, during the next modules.
Reminder - Complete all of the Module 5 tasks!
You have reached the end of Module 5! Double-check the to-do list in the Module 5 Roadmap to make sure you have completed all of the activities listed there before moving on to Module 6!
- Brady, N.C. and Weil. R.R. 2016. The Nature and Properties of Soils. Columbus: Pearson. A very readable and visual textbook that gives an extremely comprehensive treatment of soil science.
- Dybas, C.L.,2005 "Dead Zones Spreading in World Oceans" Bioscience 55(7): 552-557 - freely available article in Bioscience journal.
- Scoones, I. (2010). Dynamics and Diversity: soil fertility and farming livelihoods in Africa, case studies from Ethiopia, Mali, and Zimbabwe. Earthscan.