In the state of the world assessment at the start of the new millennium academics found that two thirds of the delicately balanced ecosystems they studied have suffered badly at the hands of man over the past 50 years. Some 15 of the 24 ecosystems vital for life on Earth have been seriously degraded or used unsustainably. Through synthetic fertilizer use, the release of free nitrogen and phosphorus – important mineral nutrients for plant growth – has triggered massive blooms of algae in the freshwater and marine environments. This is identified as a potential “tipping point” that can suddenly destroy entire ecosystems. “The millennium assessment finds that excessive nutrient loading is one of the major problems today and will grow significantly worse in the coming decades unless action is taken”
Policies need to be established that require natural costs to be taken into account for all economic decisions. A tremendous amount can be done in the short term to reduce degradation – for example the causes of some of the most significant problems such as fisheries collapse, climate change and excessive nutrient loading are clear. Many countries have policies in place that encourage excessive harvest, use of fossil fuels or excessive fertilization of crops. To switch this trend we require significant investments in new technologies and significant changes in behaviour!
Synthetic versus Organic Fertilizers
Quote: “If you let soil degrade, the life it supports will degrade to the same extent – that includes plants, animals and humans” (Extract from ‘The Secret Life of Compost’ by Malcolm Beck).
What is Fertilizer?
Let’s start at the Origin
All fertilizers are chemical. Nutrition of plants, animals and humans is chemistry in action. The distinction is, are these chemicals natural (organic) or man made (synthetic)? As this will differentiate their effect on the soil.
Organic Fertilizers are created by nature, usually waste recycled from living systems (plants, animals or manures). They are built on a carbon structure, and would not have been radically altered from their natural state, for example they might have been composted, sterilized, milled or blended for consumer acceptance. Nutrients are released by microbes and plant exudes, and are therefore not easily lost through leaching.
Although some are obtained from natural mineral deposits their chemistry is altered through acid treatment to make unavailable plant nutrients accessible to plants e.g. superphosphate. Others are waste products of the petrochemical industry which are purified and nutrient is bound to a carrier salt to make it water soluble and therefore an artificial compound. Nutrients are supplied to plants though solution in water.
Although often sold as organic fertilizers compost seldom contains nutrient levels sufficient to stimulate vigorous plant growth in South Africa’s low nutrient soils. The value of compost is in its humus, which is food for microbes, improves soils water retention and structure, and humic acids which stimulate healthy plant growth.
Certified Organic Fertilizers
Fertilizers from natural sources they supply a buffet of plant nutrients (NPK & trace nutrients) to replenish nutrients in soil. IFOAM (International Federation of Organic Agriculture Movements) sets worldwide standards for certified organic growing to prevent soil and water pollution so inputs may not harm eco-systems. No synthetic pesticides, fertilizers or herbicides are allowed. Annual inspection assures compliance to these stringent standards. Certified Organic fertilizers should be used in the edible garden as produce will be nutritious and free of toxins, especially important in cancer patients, allergic or sensitive people and children. They are the first choice for the environmentally conscious, as soil health is promoted. Sustained release of nutrients ensures longer feeding, no burning and stronger plants less prone to pests and disease.
Synthetically Enriched Organic Fertilizers
An organic base, usually chicken manure which is enriched with synthetic fertilizer to boost nutrient levels. Plants, leaves and roots can burn if incorrectly applied.
Most of these fertilizers are salt based to make nutrients water soluble. Nutrients are highly concentrated. Plants show quick growth response, but fertilizer needs to be re-applied frequently (every 6 weeks). Most feed one to three nutrients only with the exception of products like Multifeed, which contains all nutrients. As nutrients are watersoluble they are easily leached, especially from sandy soils. With long term use or overuse, soils degrade and soil life declines. Addition of generous quantities of compost will slow degrading of soil.
To sum up, another quotation from ‘The Secret life of Compost’. “The study of history and civilization shows that those who took care of the soil survived, while those who mistreated the soil didn’t!”
Basic principals of organic growing:
- Work with natural systems rather than dominating them.
- Encourage biological cycles involving micro-organisms, soil flora and fauna,
plants and animals.
- The maintenance or development of valuable existing landscapes features and adequate habits for wildlife with particular regard to endangered species.
- Consideration of animal welfare
- Avoidance of pollution
- Consideration of wider social and ecological impact of growing.
- A fertile, balanced soil needs less fertilizer, and plants growing in it are healthier, requiring less pesticides.
- Important management steps to improve soil quality include:
- Use organic matter that stimulates microbial growth
- add microbial inoculants when needed
- keep tillage to a minimum
- increase ground cover
- increase plant diversity
In closing Organic, or sustainable methods of growing plants or fields is the way of the future. More and more large commercial farms are moving toward reduced and friendlier methods of farming as they discover that they can no longer do things the way they used to.