Fertilizer and organic farming
Organic farming is an approach to crop and livestock production that promotes the use of natural inputs, in order to benefit human health and the environment. The organic matter found in typical organic fertilizers, like manure and compost, plays a critical role in soil and plant health.
This is why all good farming practices encourage the use of available organic materials. However, solely relying on organic sources of plant nutrients leads to the following difficulties:
- High volumes are required due to low nutrient contents.
- There is often a lack of steady supply and the nutrient composition is inconsistent.
- Nutrients are imbalanced which can lead to crops experiencing nutrient deficiencies and toxicities.
- Soil and environmental responses are unpredictable.
Numerous scientific studies have shown that a combination of inorganic and organic resources of plant nutrients are the most beneficial, used together they improve both soil fertility and crop yields. Through the addition of inorganic fertilizers, and subsequent higher yields, other limited resources like land and water are also used more efficiently.
Both the International Federation of Organic Agriculture Movements (IFOAM) and the Codex Alimentarius (a FAO/WHO body that sets guidelines for food products) have acknowledged the need for inorganic fertilizers in organic farming systems. In fact, the only aspect of IFOAM and Codex requirements that is not met by commercial organic fertilizers is acceptable transformation processes, which rules out nitrogen fertilizers, but allows the use of a wide range of other inorganic products. However, there is no scientific justification to the restrictions, and permitted organic fertilizers are not necessarily safer.
Generally, fertilizers and soil ameliorants sold to organic farmers are not subjected to the same rigorous standards for food and environmental safety as inorganic fertilizers. For example, heavy metals contamination is often a greater risk in organic than inorganic sources. Ideally, inorganic and organic fertilizers should be subjected to the same standards, as the characteristics of nutrient products are more important than their origin.
Frequently Asked Questions
Are inorganic fertilizers artificial?
No, the raw materials used are found in nature e.g. atmospheric nitrogen and mineral deposits of phosphate and potassium. They are merely processed to make them more available to plants.
How are plants affected by inorganic fertilizers?
Plants take up nutrients in their inorganic forms! Organic fertilizers first need to undergo chemical reactions in the soil in order to be useful to crops. These processes are affected by a wide range of environmental factors, which makes the availability of nutrients from organic sources highly unpredictable.
Are organic fertilizers safer?
Not necessarily. Both organic and inorganic fertilizers can negatively affect soils and ecosystems if used incorrectly. Organic fertilizers carry an additional risk of potentially harbouring human pathogens.
Do we need inorganic fertilizers?
Yes, research has shown that vitamins and anti-oxidants are lower in organically grown crops, most likely due to the inability of organic fertilizer programmes to meet crop nutrient requirements. Also, as land and water become limiting, inorganic fertilizers are needed to achieve the yields that are required to feed a growing world population.