Cedar
A tree native to mountainous regions from North America to Asia, cedar is known for its strong properties. There are many species of cedar but western red is commonly used for gardening purposes.
Pros
Cons
- Whilst native to areas outside of the UK, the species was introduced to Britain, planted in the UK for timber. British red cedar wood will be locally sourced and reduce emissions in terms of transport.
- Whilst some species of cedar are endanger, the western red cedar in Britain is not.
- The wood is durable and naturally resistant to fungi, due to natural preservatives.
- Cedar woods can be found FSC certified.
- The wood is usually reasonably priced.
- Imported red cedar tends to be more durable than locally sourced, but not by too much. Imports will also have more impact on the environment due to the amount they will travel.
- Cedar imported from non-certified sources and from abroad may have further environmental impacts, threatening habitats along with indigenous cultures.
Synthetic Fertiliser Minerals
Plants need many different nutrients and elements to ensure a healthy growth, however, they need three core nutrients more than others, Nitrogen, Phosphorus and Potassium. Synthetic fertilisers, used heavily in agriculture, but also gardening, ensure they have these elements to help plants grow, but the sourcing of these elements can be problematic.
Phosphorus
Most phosphorus is obtained from mined phosphate rock. (ref) Mining has many consequences for the environment but also the resource itself, and there are many things to consider with phosphate rock:
- It is estimated that 170 million tonnes of the rock is extracted each year. (ref) More than 85% of this goes into fertiliser. (ref)
- The resource is only located in a handful of countries, such as Jordan, America, Morocco and Egypt. Some countries do have untapped resources, however. (ref) Due to this, the resources needs to be transported, increasing the amount of carbon used to obtain the fertiliser and increasing its carbon footprint.
- It has been mentioned that mines produce around 150 million tonnes of waste each year, with 37 million of this leaking into the environment, significantly impacting waterways. (ref)
- Some argue we are at peak phosphorus, (ref) meaning the resource is beginning to run low, and it is not sustainable in the long run.
- The most common method of mining is open cast mining, (ref) this has a major impact on the existing environment and habitat of organisms that lived near the mine.
- Phosphorus mines also impact the surface water, with wastewater, (ref) which may produce radioactive chemicals and dust contaminating water sources.
Nitrogen
The biggest elemental influence on plant cells and life, nitrogen is needed by plants in order to grow. The air contains large amounts of nitrogen, and processes exist which can extract nitrogen from the air by making ammonia, meaning that it does not need to be mined like Phosphorus or Potassium. However, there are issues associated with nitrogen:
- Along with biodiversity and climate change, the nitrogen cycle is another aspect of the planet which humans have impacted so badly. (ref)
- On farms in the US, 80 million tonnes are spread on the fields each year, but only 17 million goes into the plants, the rest goes missing in a sense, ending up in the worlds water systems. This causes major environmental degradation as organism die from vegetation growing so quickly and absorbing oxygen from water. (ref)
- Whilst garden usage will not have the same amount of damage as agriculture, nitrogen run off from synthetic fertilisers could contribute to the degradation of the environment.
Potassium
The biggest source of potassium worldwide is from potash salts which are mined. This mining has a large impact on the environment, however:
- The UK does have potash mines, (ref) meaning there are potential local sources for fertiliser, however, most of the world's potash comes from Canada, along with Russia and Belarus. (ref)
- In the design for a potash mine, infrastructure is needed to house workers and to transport goods. (ref) These will impact the environment as areas are destroyed to make way for human need.
- The mining requires water being pumped underground. This uses a lot of water (a limited resource) but also may cause pollution of water sources, (ref) and change the flow of them. (ref)
Synthetic Fertiliser Minerals Summary
In summary, all of the chemicals involved to make synthetic fertilisers have environmental costs, some, such as nitrogen and phosphorus, having more impact. To mitigate the damage these processes have, organic fertilisers can be a solution and help to reduce the environmental impact a garden has.
