methods using draglines and bucket wheel excavators. Once it is ground and impurities are removed, water and sulfuric acid is added to the phosphate rock which generates gypsum crystals, a way of getting rid of what we don't want, leaving phosphorus as an acidic liquid. To raise phosphorus levels, impurities are precipitated out and any excess water is evaporated. Then vapor ammonia is applied to the liquid phosphorus and the end products are phosphorus granules. List of other raw materials used in agriculture Apatite - a major source of slow release of phosphate in acidic soils. Carbonate - contains liming materials used to solve problems of acidity and related toxicities. Malachite – useful for correction of copper deficiencies Scoria – useful as a mulching material to conserve soil water and provide slow release of nutrients. Zeolite – useful in conserving nitrogen and releasing phosphorus from apatite couple reaction, also raises pH Future Using raw materials could drastically improve agricultural production as it is both cost-effective, easily accessible, and sustainable. Agrogeology, although still in development, is proving to be of agronomic importance for crop cultivation and yield, resulting in solving issues regarding food shortage and the economy associated with farming. Scientists who specialize in agrogeology are termed agrogeologists. See also Dietary mineral Edaphology Essential nutrient Micronutrients References External links Rocks for Crops: Agrominerals of sub-Saharan Africa book in pdf format by Peter van Straaten Project Site Agricultural soil science Agriculture Subfields of geology