The prospect of compiling a soil-improving mixture based on local natural resources with their chemical activation with nitric acid

In agrochemistry, a promising direction can be considered the preparation of soil-improving mixtures consisting of local, relatively cheap natural resources. These include phosphorites and phosphate rock prepared from them, limestone, dolomites, and can also include loam (overburden rock). One should expect an increase in their agrochemical efficiency when using modifying acids, in particular nitric acid, for the purpose of chemical activation (as a result of nitrate decomposition) of nutrients while simultaneously enriching soil-improving mixtures with nitrogen. The purpose of the research is to study the chemical activation of loam and phosphate rock with nitric acid (65%) when preparing a soil-improving mixture (SUMS). We proceeded from the composition of the PUUS with the ratio phosphate rock: dolomite: PS: nitric acid as 1:0.6:1:0.8. The work was carried out based on materials from laboratory experiments. In the experiments, the chemoactivating effect was considered at the level of individual components. This is due to the lack of appropriate GOST standards for a multicomponent mixture. Therefore, the data on the chemical composition have approximate values, because eliminated the influence of the components on each other and the immediate influence of nitric acid on them. However, it is possible to indicate the approximate values of the main agrochemical indicators of the PUUS: the content of total nitrogen 9,0%, total phosphorus – 19%, digestible and water-soluble forms of phosphorus 7,0 and 3,5% (according to the FM + dolomite + double treatment with HNO₃), total potassium 0,2% (approximately based on cover loam).