Soils and Society

Abstract

Humans and soils have been intricately linked since antiquity, for soil touches people’s lives in many ways, including serving as the source of food and clothing, and for its multiple ecological services, such as filtering drinking water and maintaining environmental health (for which it is often called ‘a geologic kidney’ by environmentalists). It has influenced the rise and decline of many civilizations across the world. However, improper use and management of this basic natural resource have led to its gradual degradation with consequent loss in capacity to function. It influences human life in many ways that include, but not limited to, wealth, nutrition (quantity as well as quality of food), and health. It affects human health directly or indirectly and positively or negatively. The indirect effects come from the food produced on soils since the nutritional value of many foods is markedly influenced by the soil’s ability to supply essential nutrients to food systems and most of the elements that are essential for plants are also essential for human health. The direct effects could come from the exposure of humans to soil contaminated by various chemicals and pathogens through ingestion, inhalation or absorption. Geophagy, the habit of eating soil, is often one way through which humans ingest soil. The harmful substances and pathogens as well as deficiencies of nutrients could be causes of many diseases of complex nature. The soil materials to which humans could be exposed include heavy metals, organic pollutants, toxic materials in fertilizers and other agro-chemicals such as pesticides and herbicides, radioactive materials, pathogens, and polluted water. On the positive side, soils have been the origins of a large number of medicines (e.g., antibiotics) that are used for curing or treating a large number of human health problems. In Ethiopia, where agriculture is the main stay of the economy and supports the livelihood of about 79% of the population, soil is a strategic resource. However, unwise use and improper management have exposed it to degradation of intense nature, reducing its capacity to support life systems and exposing the country to persistent struggles to ensure food security. Fertility depletion is among the challenges the country has been facing since many decades, leading to the production of food that is both insufficient and nutrient-poor. Most of the beneficial physical, chemical, and biological soil attributes are below their expected threshold levels and thus the soils are unhealthy. The country carries the greatest burden of many of the soil-transmitted diseases such as helminths and podoconiosis. Most of the cultivated soils require restoration interventions that help them regain their quality.