Among the elements of mineral nutrition, the leading place belongs to the macronutrient phosphorus. The first mineral phosphorus fertilizer was developed by Looz at the Rothamsted Experimental Station in the 1840s. Before the beginning of the twentieth century manure applied to the fallow field was the main source of increasing soil fertility and crop yields. Phosphorus, as an element, came in the composition of organic matter. In the 1930s, the search for natural sources of phosphorus fertilizers was widely launched in our country, among which the leading place belongs to phosphorites – ores of natural origin that do not require industrial processing. In various areas of the country, positive results were obtained with the use of phosphorous flour of natural origin. In the mass experiments of the Novozybkov experimental station for 1925–1929, the increase in oat grain from phosphorite was 2.3 c/ha. When applying 5 kg/ha of phosphorous flour, the increase in the yield of winter rye grain amounted to 2.8 kg/ha, the sources of phosphorus fertilizers were examined in the western part of the Southern Urals, which subsequently formed the Ural phosphorous-bearing basin, where the Ashinskoye field took the leading place. This deposit was first discovered by N.P. Varlamov and G.V. Yakovlev in 1953, and was developed under the leadership of A.M. Mulmenko. The study of Ashinsky phosphorites for suitability as a phosphorus fertilizer began with the participation of the staff of the Department of Agrochemistry under the leadership of Professor Yu.A. Usmanov. Laboratory, vegetation, field and production studies were carried out with various agricultural crops. The average composition of phosphorites of the deposit was determined by laboratory: phosphoric acid – 24.43 %; one and a half oxides (Fe2O3 + A2O3) – 7.9 %; calcium oxides (CaO) – 45 %; insoluble residue – 11.0 %. It has been established that Ashinsky phosphorite phosphates are insoluble in water, up to 20 % of them are presented in lemon-soluble form, i.e. available to plants in the first year of use. In field experiments, the increase in the yield of winter rye grain ranged from 33.6 % to 54.3 %. Cereal crops had a different reduction in the growing season by 4–65 days. With high rates of phosphorite application, the sparsity of winter rye crops decreased to 9.2 %. The proportion of phosphorus (P2O5) in the grain of cereals increased. The use of phosphorous flour was justified as a phosphorus fertilizer both agroeconomically and agrochemically. Currently, the return of mineral nutrition elements to the soil together with fertilizers is at the level of half of the removal with the harvest. Therefore, it is necessary to increase the supply of mineral fertilizers and the introduction of organic ones. As phosphorus fertilizers, it is necessary to resume the application of phosphorous flour from the Ashinsky deposit, as it is economically feasible to increase the productivity of field crops in the farms of the Republic of Bashkortostan as in previous years.