The purpose of the study is to determine an effective technological method for the complete anaerobic processing of agricultural waste. It also aims to create and implement an effective technological method of sufficiently complete anaerobic processing of agricultural waste, including taking into account biologically active additives. A new technology for the disposal of organic agricultural waste and the influence of Mephosphone on the process of methane formation using a biogas unit at a processing facility developed at Kazan State Agrarian University is considered. The results of theoretical and experimental studies are presented, which made it possible to significantly reduce the utilization time, and reduce the cost of electricity and fuel. The experiments were carried out in a low-capacity biogas unit (LCBU) without air access in a heat-insulated reactor filled by 2/3. The results of numerical studies of the products of conversion of cattle manure are presented. Manure was kept in the reactor for 7 days. The use of Mephosphone in ultra-low concentrations (10-4) made it possible to obtain a useful product in the form of high-quality organic biofertilizer and biogas. The results of microbiological analysis of experiments in the test center of the Tatar Interregional Veterinary Laboratory are shown.