Dr. Raza Ullah Khan:Soil is one of the most precious natural resources providing 98.8% of the food needs of human beings on planet earth. It sinks about 2,500 gigatons of carbon, more than the atmosphere and vegetation combined. Besides food availability, soil also plays a significant role in delivering ecosystem services like filtered water, regulation of geochemical cycle such as Greenhouse circulation, carbon sequestration and hydrological cycle. The total value ecosystem services is estimated at US $11.4 trillion. However, it is being realized that due to growing world population, global soil resources are under tremendous pressure. The productivity and fertility of soil resources are highly endangered.
One-fourth of the world population lives in South Asia on just 4.5% of the world land area. Agriculture is the main stay and plays a pivotal role in Economy of the region by contributing more than18% to GDP of South Asia. Livelihood of over two-third population living in the rural areas depends on Agriculture and related activities. Consequent upon high population density, urbanization, climate change, intensive cultivation, soil as primary producer are exposed to issues like degradation, contamination, salinity and waterlogging.
Soil degradation includes erosion by water and wind as recurring floods and dust storms respectively, secondary salinization, water logging, and groundwater depletion. Water erosion is a major degradation agent that covers 21% of land area costing as much as US$10 billion to SA annually. Soil erosion by wind and water in hilly areas and coastal areas respectively resulted in loss of upper surface fertile soil. The deterioration of soil resources in the SAARC region is alarming and pose a consistent threat to livelihood and food security. It is estimated that since 70’s the Padma River eroded 29,390 ha of land, while far more by such as 87,790 ha by Jamuna River hence riverbank erosion in Bangladesh is leading to public displacement and land loss. In Nepal average annual soil erosion stands 25 t/ha, significantly higher than the global average. Erosion is particularly severe in the Middle Mountain region, with rates of 38.4 t/ha per year. According to an estimated in 2021 in Pakistan national average annual soil erosion rate increased from 1.79 t/ha in 2005 to 2.47 t/ha in 2015, more pronounced in hilly area and jumped to 28 t/ha from earlier 14 t/ha.
Other degradation processes included depletion of SOC content, imbalance nutrient use causing mineral mining, soil microbial and biodiversity losses, surface sealing and scalping, urban encroachment, landfilling of contaminants and industrial/urban wastes, and denudation of sloping land by deforestation. Current agriculture practices such as burning crop residues, monocropping, increase crop intensity and imbalance nutrients application further aggravated soil health and productivity. Low soil organic matter due to intensive all around the cultivation had deteriorated soil health and productivity.
To protect soil a non-renewable natural resource, there is need for more inclusive and intensive community-based interventions. Farmers need to practice conservation agriculture and switch over to agroecological approaches. Instead of monocropping, broad based legume-cereal cropping patterns, apply balance and integrated nutrients-based fertilizer to avoid greenhouse gases emission, and enhance soil organic matter content by incorporation of left over crop residues.
The management or mismanagement of soil can contribute to climate resilience or vulnerability. Now it is our hand how to manage it.
-The writer is a Senior Program Specialist (NRM), SAARC Agriculture Centre
