CIGR Handbook of Agricultural Engineering, Volume I Land and Water Engineering, Chapter 4 Land Reclamation and Conservation, Part 4.1 Soil Reclamation

First paragraph: There is an increasing awareness that the world’s resources are not boundless. In many countries, there is now a concern about husbanding and protecting the environmental resources upon which life depends. Among the most basic resources is the soil. Reclamation, in its broad sense, means modifying the physical, chemical, and biological characteristics of the soil to restore its capacity for beneficial use while protecting the environment. The soil could have lost its suitability for cropping or other use by means of natural or anthropogenic causes. In any case, we have to deal with an ecosystem in which normal biological processes are at a standstill. These processes must be restored so that a normally functioning ecosystem of soil, plants, and animals is reactivated, such that the natural processes of nutrient release, plant growth, and nutrient cycling proceed at a natural rate. However, the soil is a complex biological system built up over long periods of time. If we are to restore it, we must understand how it functions biologically, physically, and chemically. It also involves understanding the requirements of plants and the other organisms that interact with soil processes. Soil restoration can take a long time and generally depends on the actual conditions of the soil and on the processes employed in restoring it. Modern methods can hasten the process considerably. The key is the identification and correction of the problems that brought the soil into its degraded state. This identification process requires imagination and sensitivity as well as science. Drainage of wetlands, amendment of saline soils, restoration of soil contaminated with urban waste materials, and the rehabilitation of floodplains and tidal forelands are all reclamation processes. In some cases they may not lead to complete restoration of the soil and landscape, although a self-sustaining ecosystem always must be created.