Long term soil fertility management practices for nutritional security

Abstract

Southern Asia's soils provide nearly 1.8 billion people with food, but are vulnerable to many sustainability problems. The ever-increasing population has placed tremendous pressure on the natural resources available (land/soil and water) that are threatening food security in the future. Urbanization is encroaching on the fertile farmlands. Declining groundwater levels, increasing micronutrient deficiencies, the use of fertile soil for brick making, degrading soil structure, and global warming are serious sustainability issues in Southern Asia. The extensive production of cereals and conventional soil management practices are increasing soil erosion; depleting soil organic matter, soil fertility, water resources, and increasing salinization. The restoration and management of soil organic matter, rainwater harvesting, and the efficient use of water and sustainable nutrient management are essential to sustain the long-term productivity of agricultural soils. Diversification of monocropping systems and the adoption of conservation agriculture may enhance the sequestration of soil carbon and increase biodiversity. However, site-specific technologies must be identified and made available to farmers. Prime agricultural land must be protected against urban encroachment. Communication and collaboration between scientists, farmers, and policymakers are needed to manage soils for ensuring food security in Southern Asia. The objective of this review is to deliberate the causes of soil degradation in Southern Asia and suggest soil management options to reverse the degradation trends and ensure long-term food security in the region.