SOIL CONSERVATION

As the soil reserves of the world are finite, and within the human lifespan are nonrenewable resources, except at great cost, the case for soil care is very strong. soil is one of humanity’s most precious assets: it allows plants, animals and people to live on the Earth’s surface. Soil is a limited resource that can easily be destroyed by poor management or thoughtless action. Silt loams, sand, loamy sand, fine sandy loam and cultivated organic soils are vulnerable to wind erosion and water erosion. Considerable effort has been expended in developing theoretical models to help counter erosion, such as the Universal Soil Loss Equation in the United States and the Soil Loss Estimation Model for Southern Africa in South Africa. If conservation techniques known since the AD 1930s were to be applied worldwide, the present impact of erosion would be greatly reduced.

Until the past decade, soil conservation was synonymous with measures to prevent soil erosion, but recently, the term has come to embrace protection against chemical and physical damage as well. Inappropriate use of pesticides and overuse of fertilisers in the developed world by factory-type agriculture (see agricultural intensification) is causing problems, just as poor soil management caused by ignorance and poverty affects developing countries. Society uses soils for a variety of purposes, such as industry, housing and transport. With the rising world population, it is necessary to develop policies of landuse and soil conservation that take into consideration the nature and properties of soils as well as the present and future demands of society.

[See alsoconservation, mechanical soil conservation measures, sustainability]