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Very sustainable? "Food production requires application of fertilizers containing phosphorus, nitrogen and potassium on agricultural fields in order to sustain

Very sustainable? "Food production requires application of fertilizers containing phosphorus, nitrogen and potassium on agricultural fields in order to sustain crop yields. However modern agriculture is dependent on phosphorus derived from phosphate rock, which is a non-renewable resource and current global reserves may be depleted in 50–100 years." Raising animals to eat is a much less efficient use of non-renewable phosphate than eating plants ourselves. Source: Dana Cordell, Jan-Olof Drangert, Stuart White. 2009. The story of phosphorus: Global food security and food for thought. Global Environmental Change, Volume 19, Issue 2, Pages 292-305. http://www.sciencedirect.com/science/article/pii/S095937800800099X http://www.sciencedirect.com/science/article/pii/S0959378008...

Turing_Machine 14y ago
The phosphate doesn't actually get used up. It winds up back in the ocean from whence it came (most phosphate rock is limestone formed from krill and the like). There's no reason we couldn't use krill directly. It would be more expensive, but also 100% renewable.
- bendmorris 14y ago
  We don't really have the infrastructure in place for doing that at the necessary scale, so it would be so much more expensive as to cause food prices to skyrocket. I'm sure that as supplies get lower more research will be done on recycling phosphate efficiently, though.
  - Turing_Machine 14y ago
    You don't need a lot of infrastructure. Krill nets are pretty low-tech. Also, it's not like we're going to wake up one morning and all the phosphate rock is gone (which is the usual unstated assumption with "peak" this or that). The price will go up gradually until the point where alternative sources become more economic.
    - Turing_Machine 14y ago
      For that matter, you could probably create engineered organisms that do a better job of extracting the phosphate from seawater. Animal kidneys are pretty good at this already. Before we were able to process phosphate rock on an industrial scale, animal waste was the primary source of agricultural phosphate and nitrate. There was a thriving industry in mining bird droppings (guano) from various islands all through the 19th century. The birds would eat the sea life, concentrate the minerals, and deposit them on land. There's no reason we couldn't cut out the middle man (or middle bird, in this case).

Turing_Machine 14y ago

The phosphate doesn't actually get used up. It winds up back in the ocean from whence it came (most phosphate rock is limestone formed from krill and the like). There's no reason we couldn't use krill directly. It would be more expensive, but also 100% renewable.

bendmorris 14y ago
We don't really have the infrastructure in place for doing that at the necessary scale, so it would be so much more expensive as to cause food prices to skyrocket. I'm sure that as supplies get lower more research will be done on recycling phosphate efficiently, though.
- Turing_Machine 14y ago
  You don't need a lot of infrastructure. Krill nets are pretty low-tech. Also, it's not like we're going to wake up one morning and all the phosphate rock is gone (which is the usual unstated assumption with "peak" this or that). The price will go up gradually until the point where alternative sources become more economic.
  - Turing_Machine 14y ago
    For that matter, you could probably create engineered organisms that do a better job of extracting the phosphate from seawater. Animal kidneys are pretty good at this already. Before we were able to process phosphate rock on an industrial scale, animal waste was the primary source of agricultural phosphate and nitrate. There was a thriving industry in mining bird droppings (guano) from various islands all through the 19th century. The birds would eat the sea life, concentrate the minerals, and deposit them on land. There's no reason we couldn't cut out the middle man (or middle bird, in this case).