Soil is a vital resource for both humans and living organisms, serving not only as a habitat for various life forms but also as a repository of biological diversity. Its significance extends to maintaining the balance of ecosystems and is linked to human existence. This is particularly evident in the four essential factors for sustaining life, all of which originate from the soil—namely, food, shelter, clothing, and medicine.
Soil - primary repository of global biological diversity
Based on the findings of scientists globally, it is evident that more than 40% of life in terrestrial ecosystems has a life cycle directly associated with the soil. This ranges from single-celled organisms to non-vertebrate animals, such as earthworms, insect larvae, insects, myriapods, as well as mammals, reptiles, and amphibians that primarily live underground. Additionally, there are diverse algae and fungi. In the soil, there are intricate biological relationships between soil bacteria, algae, fungi, mosses, and plant roots, as well as non-vertebrate animals. These living organisms are integral parts of a complex food web that facilitates the cycling of energy and nutrients to support life above ground.
Interconnection of biodiversity in the soil and above-ground
Preserving soil biodiversity is crucial for maintaining and enhancing the overall biodiversity above ground. This is achieved through the transfer of nutrients and energy from organic matter in the soil to various living organisms, which is a vital aspect of life on Earth. Furthermore, it helps alleviate environmental issues, such as cleansing of polluted soils. Biological processes in the soil stimulate filtration, decomposition, and the sequestration of target pollutants. The use of living organisms, including bacteria, plants, and worms, plays a role in remediating soil contaminated with hydrocarbons. On the other hand, larger soil organisms, such as earthworms, termites, and ants, play a significant role in improving soil structure, making it more resistant to erosion caused by wind and water.
Organisms in the soil contribute to the creation of nutrients for plants
Organisms in the soil actively contribute to the generation of essential nutrients vital for plant growth. It has been found that the total carbon content of all bacterial cells in the soil is equivalent to the carbon content of all plants on Earth. Additionally, the combined amounts of nitrogen and phosphorus within these organisms are also greater than the carbon content of all plants. Therefore, soil bacteria and various small organisms serve as indispensable sources of essential nutrients for life on Earth. Furthermore, plants require both primary and secondary nutrients absorbed from the soil to build biomass and transfer nutrients and energy to sequester carbon from the atmosphere. Soil bacteria and small organisms depend on various factors such as temperature, pH, and moisture levels to facilitate the transformation into necessary nutrients for these plants. Moreover, several types of soil bacteria also play a role in nitrogen fixation, thereby reducing costs and dependency on synthetic nitrogen fertilizers in agriculture. By enhancing soil fertility and reducing greenhouse gas emissions resulting from the energy-intensive production of nitrogen fertilizers, these bacteria offer an avenue for sustainable agricultural practices.
Healthy soil – high carbon sequestration
Organisms in the soil play a direct role in the carbon cycle within the soil, making it crucial for overall reduction in greenhouse gas (GHG) emissions from agricultural activities. Approximately 10-12% of greenhouse gas emissions from human activities come from global agriculture each year. Notably, an estimated 38% of these emissions arise from the release of nitrous oxide gas in the soil, and 11% from methane emissions related to rice cultivation. Soil bacteria are involved in every stage of the processes leading to the production of these greenhouse gases. The biodiversity in the soil plays a vital role in combating global climate change. Healthy soil has the capacity to sequester more carbon what exists in both the atmosphere and plants combined.
Organisms in soil – a source of many drugs and vaccines
Since the beginning of the year 1900, a significant number of drugs and vaccines have been discovered from living organisms in the soil. These include antibiotics, drugs used to treat cancer, and medications for fungal infections. Ongoing research efforts aim to develop new drugs that combat antibiotic-resistant bacteria, addressing a growing concern in modern medicine. Furthermore, the biological diversity in the soil and healthy soil contribute to reducing the risk of foodborne illnesses by enhancing plant resistance to infections. The relationship between plant roots and the biological diversity in the soil allows plants to produce free radical-scavenging compounds that protect them from plant pests. When we consume these plants, we receive antioxidant compounds that stimulate our immune system and help regulate hormones. It is evident that the biological diversity in the soil supports human health directly and indirectly through disease control and food production.
Threats to the biodiversity in the soil
Living organisms in the soil may be threatened by human activities and natural disasters, especially intensive agricultural practices involving the use of pesticides and chemical fertilizers that disrupt soil life. This also leads to changes in essential nutrients in the soil and excessive fertilizer use, resulting in a decreased ability of soil bacteria to thrive. Significant negative impacts on soil biodiversity also arise from wildfires, which greatly affect the variety of life in the soil. Further consequences arise from deforestation, pollution, urban expansion, soil compression due to logging, and changes in oxygen release in the soil. These activities lead to surface sealing, nutrient imbalance, fluctuations in soil pH levels, loss of species or groups that have adapted to specific environments, and an increase in species or groups that can survive in diverse conditions. There is a decline in predator species, a reduction in soil diversity, and a loss of soil benefits and the process of soil restoration under such circumstances may take several decades.
Conservation of biodiversity in the soil
Guidelines for conserving biodiversity in the soil are crucial processes for maintaining the environment and the long-term sustenance of living organisms in the soil. These guidelines include:
- Planning and controlling land use to reduce threats to soil organisms and soil structure, with designated conservation areas or nature reserves play a role in preserving soil biodiversity.
- Preserving natural areas that serve as habitats for both soil-dwelling and surface-dwelling organisms. Preventing deforestation and wildfires significantly contributes to the conservation of soil biodiversity.
- Adopting sustainable agricultural practices by reducing the use of chemical pesticides and controlling plant diseases that may harm soil conditions and decrease soil biodiversity. Proper fertilizer use, tailored to reduce the risk associated with high-chemical-content fertilizers, also contributes to soil microbial diversity.
These practices align with good practices in rice cultivation that are in line with the conservation and utilization of soil biodiversity. They provide guidance for farmers to actively participate in conserving soil biodiversity. Additional information can be found at source link: https://chm-thai.onep.go.th/?p=5588
Conserving biodiversity in the soil requires continuous collaborative efforts from all sectors to contribute to maintaining the balance of the ecosystem. This has implications for both water and air systems and other benefits, allowing all living organisms to thrive and coexist harmoniously.
Source of information:
- https://www.fao.org/publications/en/
- https://www.globalsoilbiodiversity.org/
Source: TEI
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