COMPOSIÇÃO, PROPRIEDADES E USO DE RECURSOS SECUNDÁRIOS COMO FERTILIZANTES ORGÂNICOS DE SOLOS.

The paper discusses reserves of secondary raw materials, local organic fertilizers, and ameliorants (peat, sapropel, phosphogypsum, phosphorites, lignite coals, zeolites, gypsum, limestone) in the Republic of Bashkortostan. The effect of phosphogypsum and poultry manure on soil fertility and potato yields is studied. The use of gypsum to improve soil has been studied and used in agriculture and environmental restoration for many years. Most of the published literature is devoted to the influence of the use of gypsum on soil properties and not on yield. The paper presents the results of a field experiment on the use of phosphogypsum together with poultry waste, with detailed documentation of changes in the microelement composition of soils, the mode of precipitation, and the total yield after fertilizing. The results of the given work will be useful in determining gypsum application norms; there are also recommendations for future research on the use of gypsum for soil improvement. The yield improvement may be the result of an additive or synergistic effect; therefore, a metaanalysis of gypsum experiments is strongly recommended to improve recommendations for the use of gypsum in various environments. The optimal application rates of secondary raw materials are found. The soil humus сontent improves, and potato yield increases from 13.9 to 75.7 С/ha when phosphogypsum is applied separately and in combination with poultry litter. There is the nutritional value of the poultry manure, with the main elements as nitrogen, phosphorus, and potassium. Phosphogypsum is characterized with high content of strontium (14691 mg/kg) and rare earth elements (cerium - 1358 mg/kg, praseodymium - 123.9 mg/kg, neodymium - 418.5 mg/kg, samarium - 77.5 mg/kg, europium - 19.9 mg/kg, gadolinium - 58.9 mg/kg, terbium - 6.91 mg/kg and dysprosium - 25 mg/kg). The content of total element forms in phosphogypsum was determined by inductively coupled plasma mass spectrometry (IPC-MS) using a VG Plasma Quad and Elan-6100 mass spectrometer. [ABSTRACT FROM AUTHOR]