Maximum Yield USA 2015 April | Page 87

The Guano Wars: The War on Poop Before human civilization, plants obtained phosphorus from the flooding and weathering of soils, as well as the natural composting of organic matter. After the dawn of agriculture, humans eventually figured out that adding manure and compost to their crops would increase their harvests. This was furthered by the addition of the inedible remains of animals, including bones and fish. After the famines of the 18th century, a surge in farm production was necessary to revamp the withered populations of Western Europe. Then in 1802, explorer Alexander von Humboldt (yes, the namesake of Humboldt County) documented the agricultural techniques used by the indigenous people of Peru, who used seabird guano as a fertilizer. The local inhabitants understood the value of the phosphorus-rich guano, as harm to the seabirds was punishable by death. Islands off South America containing large seabird guano reserves as deep as 300 ft. were soon coveted by the Western world. The guano reserves peaked and declined, and political and military battles broke out over control of the resource. This culminated in the Guano Wars of the mid1860s between Spain and an alliance between Chile and Peru. Yes, it was a war over piles of bird poop. The guano reserves were mostly depleted and unattractive to market demands by 1900, and the world found a new source of phosphorus: mined rock phosphate. of available phosphorus must be developed and our entire system of global food production must be re-evaluated. The Phosphorus Cycle: From Mine to Fork The current system of getting phosphorus to a plant and then to humans is extremely inefficient. For example, 80% of the rock phosphate mined for agricul