Role of Soil Organic Matter and Balanced Fertilisation in Combating Land Degradation and Sustaining Crop Productivity

摘要

Land degradation means reduced potential productivity of soils/; at a fixed level of output. It is a widespread problem throughout the tropics and subtropics and a major issue because of its adverse impact on agricultural productivity and sustainability. Cultivated lands are being degraded by salinity and sodicity and irrigation through poor quality ground waters. Unsustainable activities including inadequate soil conservation, minimum use of animal manure, imbalances-fertiliser use and improper irrigation management have a devastating impact on the land resources in arid and semiarsd regions. The soils of dry areas are very deficient in organic matter. As per estimates the extent of degraded lands is around 168 million hectares in India. Restoration of these lands is of prime importance, for both economic and ecological reasons in irrigated and rain-fed eco-system as well. Economic rationale for restoration of degraded soils is related to productivity and income. Important among ecological reasons are carbon sequestration in. soil to mitigate the greenhouse effect and minimizing risks of pollution, contamination and eutrophtcation of natural water. There is a tremendous potential to sequester C through restoration of degraded ecosystems and more so-through reclamation of salt affected lands.