Overview of soils and nutrients for food production
In this course, we describe food systems as a coupling between human societies and natural earth systems and environments. This coupling is especially clear in the activities of food production that rely on crop and livestock raising. Crops and livestock production (and to a similar extent, fisheries, and aquaculture) require food producers bring together human management with soil conditions and soil nutrients (this module), water (next module), as well as sunlight for energy and adequate climate conditions (temperature, humidity, adequate growing season). To understand these human-natural interactions across the entire course, and to build your capacity to understand natural factors as part of your capstone projects and other chapters of your education, this module describes basic soil properties and the role of soils in creating adequate conditions for crops to grow, which underlies most aspects of food production. It’s therefore very important that we understand soils as the “living skin of the earth” in their properties and history, the global patterns of soil fertility and soil limitations, and then its role in supplying nutrients to plants, and how soil fertility is regenerated by the human societies and management knowledge that allows them to continue supporting food production. Our goal is not to condense an entire course in soil science, although we hope that many of you will go on to take such a course. Rather, we want to sketch out major factors and determinants of the opportunities and limitations posed by soils to a human food production system.