Period of performance:
In agriculture, the most widely used compound for potassium fertilization is KCl (potassium chloride). Combined together, Canada, Russia and Belarus account for more than 85% of the total production of KCl. Therefore, while cheap and easily available in the northern hemisphere, supplies of KCl in the Global South can be expensive and/or scarce, mainly due to the logistics required for North-South transportation. Additionally, KCl is not necessarily the right product for all the soils of the world, which exhibit remarkably different properties and fertility depending on geological history and age. As an example, in tropical soils the high solubility of KCl results in non-negligible leaching losses and low residual effect, meaning that the poorest farmers need to pay a prohibitive price for a product that does not benefit their soils. Here, we propose and test a novel potassium fertilizer derived by hydrothermal processing of K feldspar in presence of CaO. The proposed research leads to both the characterization of the hydrothermal material and the evaluation of its potential as a potassium fertilizer for tropical soils alternative to KCl. The availability of starting resources and a preliminary cost model reveal the opportunity to positively impact low-yield, tropical agriculture of the African continent.