Soil biodiversity

Soil biodiversity reflects the variability among living organisms including a myriad of organisms not visible with the naked eye, such as micro-organisms (e.g. bacteria, fungi, protozoa and nematodes) and meso-fauna (e.g. acari and springtails), as well as the more familiar macro-fauna (e.g. earthworms and termites). Plant roots can also be considered as soil organisms in view of their symbiotic relationships and interactions with other soil components. These diverse organisms interact with one another and with the various plants and animals in the ecosystem forming a complex web of biological activity.

Soil organisms contribute a wide range of essential services to the sustainable function of all ecosystems. They act as the primary driving agents of nutrient cycling, regulating the dynamics of soil organic matter, soil carbon sequestration and greenhouse gas emission, modifying soil physical structure and water regimes, enhancing the amount and efficiency of nutrient acquisition by the vegetation and enhancing plant health. These services are not only essential to the functioning of natural ecosystems but constitute an important resource for the sustainable management of agricultural systems.

FAO and soil biodiversity

A series of activities on soil biological management and soil biodiversity were initiated by FAO in 2000 through the Netherlands-supported programme on agricultural biodiversity. The aims are: firstly, to increase awareness among the range of stakeholders of soil as a living entity and the importance of soil biodiversity for agricultural systems; and secondly, to catalyse the adoption of improved management practices and production systems to enhance soil biodiversity and its biological activity.

The Conference of Parties (COP) to the Convention on Biological Diversity (CBD) at its 6th meeting in Nairobi April 2002 decided (COP decision VI/5, paragraph 13) "to establish an International Initiative for the Conservation and Sustainable Use of Soil Biodiversity as a cross-cutting initiative within the programme of work on agricultural biodiversity, and invites the Food and Agriculture Organization of the United Nations, and other relevant organizations, to facilitate and coordinate this initiative".

For more information you can visit the soil biodiversity portal.

GEF is supporting a global research project  Conservation and Sustainable Management of Below Ground Biodiversity for characterisation of soil biodiversity in a range of ecosystems (mainly humid) which is expected to improve understanding of soil biota and  ecosystem functioning.

More work is needed to make available research findings on soil biota and their ecological functions into the public domain, in particular their beneficial functions in farming systems. Some opportunities that are well known but deserve to be more widely disseminated and applied include for example:

• The use of soil biota for nutrient cycling and improvement of soil fertility, for example:
  •  taking advantage of biological nitrogen fixation in leguminous plant species through adapted rhizobia species 
  • using certain types of fungi to increase the availability of phosphorus to plants
• Taking advantage of soil biota processes to improve soil structure while reducing tillage: conditions established under Conservation Agriculture and other farming technologies that increase organic matter in soils enhance the activity of soil biota, which in turn contribute to the formation of soil aggregates and soil pores.
• Using soil biota to contribute to pest and disease control: A healthy soil community has a diverse food web that keeps pests and diseases under control through competition, predation, and parasitism.
• Building soil fertility with the contribution of a healthy soil community associated with crop rotation and intercropping.