Effects of soil diversity loss

Written By: / Articles / Wednesday, 24 February 2021 17:25

Soil is a mixture of organic matter, minerals, gases, liquids and organisms that together support life. Earth’s body of soil, called the Pedosphere, has four important functions viz, as a medium for plant growth; as a means of water storage, supply and purification; as amodifier of Earth’s atmosphere and as a habitat for organisms. All of these functions in their turn modify the soil and its properties. The health of soil is dependent on the mix of living organisms they contain, including bacteria, fungi, protozoa, insects, worms, other invertebrates and vertebrates. This variety of organism present in soil is known as soil diversity. Soil diversity drives the carbon, nitrogen and water cycle upon which life on earth depends. The productivity of land is therefore determined to a large extend by its soil diversity. When land is degraded, it loses its soil biodiversity. Soil which takes hundreds of years to form, can be eroded easily by wind and water when soil biodiversity lost, causing land to produce less food, store less water and release carbon into the atmosphere. The correlation of soil and biodiversity can be observed spatially. Traditional agricultural practices have generally caused declining soil structure. Soil erosion leads to a loss of top soil, organic matter and nutrients, it breaks down soil structure and decrease water storage capacity, in turn reducing fertility and availability of water to plant roots. Soil, erosion is therefore a major threat to soil biodiversity. About a third of the World’s land has already been degraded, with two-third of this degradation attributed to the agricultural sector, particularly chemical fuelled, intensive agricultural production. According to the assessment Report on Land Degradation and Restoration, produced by Intergovernmental Science-Policy platform on Biodiversity and Ecosystem Services (IPBES), land degradation is currently undermining the wellbeing of at least 3.2 billion people and represents an economic loss of 10% of annual global gross product. By the year 2050, the global population is projected to surpass nine billion people. These people will be wealthier than ever and will demand more agricultural products, placing even greater demand on soils and undermining the long-term productivity of land. The Food and Agriculture Organization of UN (FAO) has estimated that based on current trajectories, the world only has 60 harvests left.
Globally, soil diversity has been estimated to contribute between1.5 billion US dollar and 13 trillion annually to the value of ecosystem services –the good and services provided by healthy ecosystem, including the provision of food, hydrological services and regulation of climate . Soil organism regulates nutrients availability and uptake of nutrients by plants, maintain soil structure and regulates hydrological processes. The loss of healthy soil reduces agricultural yields and could result in a food production shortfall of 25% by 2050. It is estimated that increasing soil biodiversity could contribute up to 2.3 billion tons of additional crop production per year, valued at 1.4 trillion US dollar. Research in Argentina, India and west African sahil has also found that crop yield can be increased by 20-70 kg/ha for wheat,10-50kg/ha for rice and 30-300kg/ha for maize with every 1000kg/ha increase in soil organic carbon around the plant root. Soil stores two-thirds of the fresh water on planet and this function is determined by the level of organic matter in the soil. This water from soil support 90% of the world’s agricultural production. The losses of soil biodiversity reduce the infiltration capacity to store water, lowering food production and worsening the impact of draught. By 2050, an estimated 1.8 billion people will be living under water stressed conditions. One estimate suggests that the loss of 1gm of soil organic matter decreases soil available moisture by 1 to 10 gm.
Soil biodiversity represents one of the largest carbon stocks on Earth and plays a major role in mitigating climate change. It is estimated that there is more carbon stored in the soil than the total carbon in both the atmosphere and above-ground vegetation. When soil is lost in the form of greenhouse gases (GHGs), contributing to climate change. Increasing soil biodiversity could provide at least half of emission reductions needed to limit the global average temperature increase to well below 20C above pre-industrial levels set by the Paris Agreement. Target 15.3 of the UN 2030 Agenda for Sustainable development aims to halt the world’s net land degradation. Healthy soil is both a natural resource and public good underpinning sustainable development. The target of the 2030 Agenda for food, water and energy security, biodiversity conservation and climate change mitigation, all hinges on healthy soils. For instance, research has estimated that restoring only 12% of degraded agricultural land by 2030 could boost small holders’income by 35-40 billion US dollar per year and help to feed an additional 200 million people annually, while increasing resistance to draught, water scarcity and reducing GHG emission.
It is preferable to avoid degradation in the first place by adopting sustainable land management practices and sustainably managing agricultural landscapes. Farming practices that increase soil biodiversity include sustainably managing soil, water and nutrients. Controlling erosion and maintaining ground cover. Once such method is agroforestry which involves planting trees alongside crops. Government should support land users in adopting sustainable land management practices for instance through subsidies and other means. Land users should be paid for conserving the public good rather than purely for the individual foods and other commodities they produce. Government should also promote private investment in sustainable land management for instance by facilitating financial opportunities for small and medium agribusiness that engage in sustainable land management. The services, healthy soil provides should be incorporated into land-use planning. This planning requires input from a number of sectors to ensure the delivery of collective goals, for example food production, water supply and biodiversity conservation. Government should also strengthen land tenure and resource rights to enable local communities manage land more sustainably.

About the Author

Sanjenbam Jugeshwor Singh

Sanjenbam Jugeshwor Singh

Sanjenbam Jugeshwor Singh is a regular contributor of Imphal Times. Presently, he is teaching Mathematics at JCRE Global College. Jugeshwor can be reached at: [email protected] Or WhatsApp’s No: 9612891339.

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