Degraded soils: Origin, types and management

Abstract

The cultivated lands are continuously degrading and the extent is increasing because of different natural environmental and anthropogenic activities. Soil degradation due to salinization, erosion, water logging etc. makes environment difficult for plant growth resulting in reduced agricultural production. Soil physical, chemical and biological properties are affected due to alteration in hydraulic conductivity, bulk density, osmo-deregulation, poor aeration and specific ion toxicities. A number of management and reclamation technologies are available to counter these problem but the major concern is to optimize the most economical and eco-friendly technologies. Saline soils can be cultivated growing different halophyte plants and using modern irrigation practices. Conservation and effective and efficient use of good quality water help proper leaching of soluble salts in saline soils. Saline-sodic and sodic soils can be rehabilitated with different amendments, which can provide soluble calcium to replace exchangeable sodium adsorbed on clay surfaces. Different amendments can provide calcium directly to the soil or indirectly dissolving native calcium from calcium carbonate already resent in the soil. The eroded soils can be reclaimed by providing proper soil surface cover either in the form of mulching or vegetative cover by fodder or wild shrubs. Different studies demonstrate that under adverse conditions where chemical treatments are uneconomical tree plantations provide positive net returns to investment and significant net benefit and social outcomes from these lands. These findings suggest that there is great opportunity for capital investment in afforesting abandoned degraded soils with multipurpose approaches. This chapter covers the introduction to origin, extent and sources of degraded soils, along with their management and reclamation options.