- Many fertilizers that ensure the world’s food security are supported by minerals. For years, these compounds came from various countries and have recently been discovered in the Amazon.
- The large deposits were discovered as part of other infrastructure work in the Amazon.
- Potash, phosphorus and agricultural lime improve the performance of farmland, but are also generating new demands and criticism from Indigenous communities as well as environmental activists.
The ongoing expansion of Brazil’s industrial farms has created a robust market for the mineral feedstocks used for the manufacture of chemical fertilizers. Historically, demand was met largely by imports, but a combination of cost and geopolitical considerations has motivated agribusiness and government to invest in domestic fertilizer production. Most of this investment will be in mines and manufacturing plants in other parts of Brazil; however, the Brazilian Amazon has mineral resources that are cost-competitive and strategically vital. Andean countries also rely on imports and, although there is interest in Peru to enhance domestic sources, fertilizer feedstocks would not be of Amazonian origin. The Guianas do not have agricultural economies sufficient to justify investment in fertilizer factories, nor, apparently, sufficient mineral reserves to create an export industry.
Potash: A new mineral resource in the heart of the Amazon
Brazil is the world’s largest single importer of potash fertilizer and it is almost entirely dependent (95 per cent) upon imports from three countries: Canada, Belarus and Russia. The fertilizer supply chain is about to undergo radical change, however, because of an ongoing effort to develop a world-class potash reserve located directly underneath the Amazon River floodplain.
The potash was discovered by Petrobras geologists when they were exploring for oil in the Amazon and Solimões basins in the 1980s. The deposit consists of a 400-kilometer-long band of sedimentary rock that is one to four meters thick buried 650 to 900 meters below the surface of the Amazon floodplain. The ore body is a salt and clay mineral, known as ‘sylvinite,’ which is located within the Nova Olinda stratum formed during the Cretaceous Era about 100 million years ago. It is essentially a layer of salt that formed in a shallow-water marine habitat located in an estuary of the Proto Amazon River during a period with a strong evaporative climate. The deposit is estimated to contain at least 250 million tonnes of ore with an average purity grade of 31.5 per cent potassium chloride (KCl).
This is what potash, the mineral that sources have been found when searching for oil in the Amazon basins, looks like. Image via brazilpotash.com.
The resources are being developed by a subsidiary of a Canadian merchant bank, Forbes and Manhattan, which specializes in greenfield mining ventures. The company, Brazil Potash, acquired the mineral rights in 2010 and has since documented the dimensions of the mineral resource, while conducting feasibility and environmental studies. The project proposal is based on an underground mine that will employ conventional room and pillar methods to extract an estimated 8.5 million tonnes per year of ore.