- "Global reserves of phosphorus are running out and, since plants need phosphate to grow, this poses an enormous challenge for global food production in the foreseeable future. A shortage of phosphate could ultimately result in large-scale famine and social-political turmoil. Surprisingly, phosphorus depletion did not seem to be on the political agenda some time ago.
- A key question is whether it will be possible to feed a growing global population in the future. Often it is simply assumed that resources necessary for increased food production will be just as available as they are today. This might not be the case for phosphorus (P) which is a macronutrient indispensable for plant growth, and also irreplaceable.
- In the pre-industrialised era, when there was a much smaller global population, crop production relied on natural phosphorus supplies in the soil, with or without additional supplies from organic manure. Human excreta were also used as input. Increased food production was necessary to feed the growing global population. This became possible from around 1850 onwards, based on the input of artificial fertilisers, which boosted agriculture tremendously. However, since phosphorus is an important component of artificial fertilisers, this also accelerated phosphorus use.Currently we are in a situation in which global food supply has become dependent on continual inputs of phosphate fertiliser to maintain soil fertility. However, phosphate deposits are finite. The problem of phosphorus depletion is further complicated by the fact that, similarly to fossil fuels, the control of phosphorus resources is in the hands of a limited number of countries. Most of the known reserves are in Morocco, the US and China and the latter recently imposed an export tariff on phosphate."
- Link to the website and leaflet to learn more.
- Here is a website that lists the states where phosphorus depleted soils may be present.
THE SOLUTION: Sustainable Use of Phosphorus
The authors of the phosphorus depletion report above "authors stress the need to re-use and recycle phosphorus." They created a list of recommendations that includes recycling human and agricultural organic matter (aka poop, treated sewage sludge, biosolids).
Here's where biosolids recycling comes to the rescue - at least for the approximately 1% of US agriculture that uses biosolids. Because biosolids contain phosphorus, using them to fertilize farms and gardens will replenish your soil without having to further deplete phosphorus mines.
THE CAVEAT: Phosphorus in Moderation
Phosphorus is necessary to grow food in soil, but it is a pollutant in water. Ensuring best management practices, applying at agronomic rates, and preventing agricultural run-off are critical in balancing the critical need to recycle phosphorus with the environmental degradation that occurs with too much phosphorus.
Mining the phosphorus from animal and human wastes can help (article on mining from sewage). However the cost for this equipment is energy (climate change) intensive and expensive. The return on investment based on current phosphorus pricing probably doesn't pan out for wide-scale mining, especially where phosphorus is not scarce yet.
It's interesting that some soils are rich in phosphorus and phosphorus retained in the soil can keep soils productive for years (Western Farm Press article).
Bottom-line?
We are already seeing the monitoring and controls of phosphorus increasing along with the incentives for recycling and renewable mining.
Let's ensure that the low-energy direct use of biosolids on farms and gardens continues to help this situation!
Support Biosolids Recycling, have your voice heard here: http://www.ipetitions.com/petition/biosolids/
http://wdict.net/word/phosphorus/
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