By Clifford Stanley
 IN considering the environmental benefits of organic agriculture, one must first consider air and climate change: Organic agriculture reduces non-renewable energy use by decreasing agrochemical needs (these require high quantities of fossil fuel to be produced).

Organic agriculture contributes to mitigating the greenhouse effect of global warming through its ability to sequester carbon in the soil.
Many management practices used by organic agriculture (for example: minimum tillage, returning crop residues to the soil, the use of cover crops and rotations, and the greater integration of nitrogen-fixing legumes), increase the return of carbon to the soil, raising productivity and favouring carbon storage.
The more organic carbon retained in the soil, the higher the mitigation potential of agriculture against climate change.

Sustainability over the long-term: Many changes observed in the environment are long-term, occurring slowly over time. Organic agriculture considers the medium- and long-term effects of agricultural interventions on the agro-ecosystem. It aims to produce food while establishing an ecological balance to prevent pest problems.

Soil: Soil-building practices such as crop rotations, inter-cropping, cover crops, organic fertilizers and minimum tillage are central to organic practices.
These encourage soil fauna and flora, improve soil formation and structure, and create more stable systems.
In turn, nutrient and energy cycling is increased, and the retentive abilities of the soil for nutrients and water are enhanced, compensating for the non-use of mineral fertilizers.
Such management techniques also play an important role in soil erosion control. The length of time that the soil is exposed to erosive forces is decreased, soil biodiversity is increased, and nutrient losses are reduced, helping to maintain and enhance soil productivity.

Water: In many agricultural areas, pollution of groundwater courses with synthetic fertilizers and pesticides is a major problem. As the use of these is prohibited in organic agriculture, they are replaced by organic fertilizers (e.g. compost, animal manure, green manure) and through the use of greater biodiversity (in terms of species cultivated and permanent vegetation), enhancing soil structure and water infiltration.

Biodiversity: Organic farming produces more biodiversity than other farming systems. Organic farmers are both custodians and users of biodiversity at all levels. At the gene level, traditional and adapted seeds and breeds are preferred for their greater resistance to diseases and their resilience to climatic stress.
At the species level, diverse combinations of plants and animals optimize nutrient and energy cycling for agricultural production.
At the ecosystem level, the maintenance of natural areas within and around organic fields and the absence of chemical inputs create suitable habitats for wildlife. The frequent use of underutilized species (often as rotation crops to build soil fertility) reduces erosion of agro-biodiversity, creating a healthier gene pool – the basis for future adaptation.

Genetically modified organisms: The use of GMOs within organic systems is not permitted during any stage of organic food production, processing or handling. As the potential impact of GMOs to both the environment and health is not entirely understood, organic agriculture is taking the precautionary approach and choosing to encourage natural biodiversity.

Ecological services: The impact of organic agriculture on natural resources favours interactions within the agro-ecosystem which are vital for both agricultural production and nature conservation. Ecological services derived include soil forming and conditioning, soil stabilization, waste recycling, carbon sequestration, nutrients cycling, predation, pollination and habitats.
By opting for organic products, the consumer, through his/her purchasing power, promotes a less polluting agricultural system. The hidden costs of agriculture to the environment in terms of natural resource degradation are reduced.

(To be continued…)