A wide range of chemicals are used in global agriculture under the perception that they are fundamental to achieving maximum crop yields. There is, however, a growing knowledge base developing that underpins the distribution and impact of chemicals in the environment and how they affect the human body. Furthermore, there is growing requirement for regulatory control and management procedures due to the specific challenges that are being recognised[sc:1].
Polluting practices of modern agriculture
Conventional agricultural practices are polluting soils, rivers and oceans with large amounts of harmful agricultural chemicals. These can include: nitrogen, nitrates, nitrites, phosphorous, phosphates alongside other pesticides and fertilizers[sc:3].
Where nitrate and phosphorous fertilizer is used, it creates runoff which flows into water bodies and develops algae blooms. Such chemicals are used to obtain maximum yields, but when the algae die the bacteria uses up all of the oxygen in decomposing it, thus creating an oxygen dead (or hypoxic) zone[sc:3].
Four commonly used pesticides include:
- Metam sodium
- Methyl bromide
- Telone II
Metam sodium is a biocide which can cause birth defects and is toxic to birds and fish. Methyl bromide can cause also birth defects, as well as cardiac arrest and nervous system damage. Telone II is a cancer-causing fumigant that has caused death to farmers. Chloropicrin can cause severe respiratory damage and is very toxic to fish[sc:3].
Other harmful chemical agents include:
They are all applied to crops in a similar fashion by spraying and ultimately aim to destroy insects, pests, diseases, weeds, rodents and other unwanted animals. In many cases, these chemicals are combined to enhance the effect they have on the target crop[sc:2].
Reducing chemical burden of our crops
Several initiatives and protocols exist to help protect the environment from harmful chemicals such as the Rotterdam (1998) and Stockholm (2001) Conventions; however the problems posed by their uses often exceed such decree. In continents such as Africa and Asia, the chemicals are predominantly used by poorly educated small-scale farmers and intentionally spread across large areas of the environment to increase yields. This not only leaves excess chemical burden on the crops which can be consumed by humans, but adversely impacts natural guardians of crops such as worms, bees and other insects[sc:1].
According to the Food and Agricultural Organisation (2013)[sc:1], the most effective way of reducing the negative effects of harmful chemicals on the environment is to simply reduce the amount of chemicals used. This can be achieved via a series of best-practice methods including Integrated Pest Management (IPM) which helps farmers produce crops in a cost-effective and sustainable manner. Such practice continues to grow globally as the concept of sustainable development becomes increasingly important to society and the natural world. Other alternatives are however very modest and simply include organic farming, which eliminates the need for chemicals and grows yields in the most natural and environmentally-friendly manner.