ORGANIC AGRICULTURE AND SOIL BIODIVERSITY

Nadia El-Hage Scialabba

 

LIVING SOILS FOR AGRICULTURE

Soils contain enormous numbers of diverse living organisms assembled in complex and varied communities. Soil biodiversity reflects the variability among living organisms in the soil - ranging from the myriad of invisible microbes, bacteria and fungi to the more familiar macro-fauna such as 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. Environmental factors, such as temperature, moisture and acidity, as well as anthropogenic actions, in particular, agricultural and forestry management practices, affect to different extents soil biological communities and their functions.

Soil organisms contribute a wide range of essential services to the sustainable functioning 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 emissions; 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 critical to the functioning of natural ecosystems but constitute an important resource for sustainable agricultural systems.

HEALTHY SOILS FROM AGRICULTURE

Capturing the benefits of soil biological activity for agricultural production requires adhering to the following ecological principles:

Improvement in agricultural sustainability requires, alongside effective water and crop management, the optimal use and management of soil fertility and soil physical properties. Both rely on soil biological processes and soil biodiversity. This calls for the widespread adoption of management practices that enhance soil biological activity and thereby build up long-term soil productivity and health.

Adaptation and further development of soil biodiversity management into sustainable land management practices requires solutions that pay adequate consideration to the synergies between the soil ecosystem and its productive capacity and agro-ecosystem health. One practical example of holistic agricultural management systems that promote and enhance agro-ecosystem health, including biodiversity, biological cycles and soil biological activity is organic agriculture.

ORGANIC AGRICULTURE NURTURES SOIL BIODIVERSITY

Scientific research has demonstrated that organic agriculture significantly increases the density and species of soil's life. Suitable conditions for soil fauna and flora as well as soil forming and conditioning and nutrient cycling are encouraged by organic practices such as: manipulation of crop rotations and strip-cropping; green manuring and organic fertilization (animal manure, compost, crop residues); minimum tillage; and of course, avoidance of pesticides and herbicides use.

Benefits of organic management on soil biological activity are summarized below1:

MAINSTREAMING ORGANIC AGRICULTURE

In line with the Convention on Biological Diversity, organic agriculture can enhance the value of biological diversity by linking conservation efforts with social and economic benefits. Decision III/11 on Conservation and Sustainable Use of Agricultural Biological Diversity "encourages the development of technologies and farming practices that not only increase productivity, but also arrest degradation as well as reclaim, rehabilitate, restore and enhance biological diversity and monitor adverse effects on sustainable agricultural biodiversity" such as "inter alia, organic farming".

Target 12 of the Global Strategy for Plant Conservation of the Convention on Biological Diversity (i.e., "30 per cent of plant-based products derived from sources that are sustainably managed") identifies organic agriculture as a main indicator to monitor progress towards this target.

Organic agriculture meets precise standards which are verified through certification; in 2002, the International Federation of Organic Agriculture Movements has included "organic ecosystems", with specific biodiversity parameters, within its International Basic Standards for Organic Production and Processing.

Improved awareness on the potential of organic agriculture to provide food while conserving biodiversity offers both a practical option to implement commitments made by governments to the Convention on Biological Diversity as well as more coherence to national policies (and related support) to agriculture and environment schemes.

 


1 Extracted from Organic Farming Enhances Soil Fertility ad Biodiversity: Results from a 21 Year Old Field Trial, Research Institute of Organic Farming (FiBL), Frick, Switzerland, August 2000.

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