Soil Degradation

Abstract

The growing population has exerted substantial pressure on the land and consequently on land productivity in Sri Lanka. The land: man ratio of the country is diminishing at an alarming rate. Degradation of soil and reductions of agricultural land extent jeopardize the agricultural production of the country seriously and put food security at risk. Soil degradation takes place through many physical, chemical, and biological processes. Soil erosion, fertility decline , lowering of soil pH (dystrification), increase of soil nutrients in soil (eutrophication), soil salinity , waterlogging and soil pollution are identified as the important processes among them. Ignorance of land users, unfavorable land tenancy conditions, poverty/subsistence farming, pressure for land, unfavorable political interferences, weak institutional framework, poor low enforcement efforts, incompatible economic and development policies, and lack of environmental concerns are the main drivers of soil degradation in the country. These drivers have led farmers to use inappropriate agricultural practices and various other land managers to resort to deleterious land management practices. Inadequate soil conservation efforts, overuse of agrochemicals, poor soil fertility management, blocking of drainage ways, deforestation, discharge of toxic materials to soil, improper garbage disposal, indiscriminate sand mining in rivers and streams are the main human activities responsible for the degradation. Loss of land productivity, depletion of water resources, loss of biodiversity, downstream sedimentation, increased cost of production, water pollution , loss of productive lands, and increased rural poverty are the serious impacts experienced. Land-use management functions are devolved among many institutions with overlapping responsibilities often leading to conflict in their decisions creating a complex situation in the management of lands.