The use of waste from the production of gravel as fertilizer for cultivation of technical energy crops

Abstract

The object of research is the process of management and treatment of crushed stone production waste. Modern approaches to the disposal of crushed stone production waste are analyzed. It is revealed that crushed stone production wastes are mainly used in the construction industry, and their volumes of use are insufficient to neutralize the impact of dumps on the environment. The chemical composition of crushed stone production wastes was analyzed and an experiment was carried out to determine the possibility of their use as fertilizers for the cultivation of industrial energy crops. For the experiment, an energy crop was chosen – sorghum. Sorghum seeds were placed in two types of soil: regular peat substrate and peat substrate with the addition of rock in a ratio of 60:40. Waste from crushed stone production – rock, which includes: quartzite – 90–98 %, pyrophyllite – 1–9 %, ore mineral – 0.3–1 %. The results of the experiment showed an increase in the biomass of sorghum grown on a peat substrate with the addition of rock, 1.5 times, compared with that grown on a conventional peat substrate. Accordingly, the energy yield of sorghum per hectare of field will also grow by 50 %. In addition to increasing the biomass of sorghum, as a result of the experiment, an increase in the number of secondary and tertiary roots was found when it was grown on a peat substrate with the addition of rock. A more developed root system allows the plant to receive more moisture and nutrients, thereby increasing its endurance and drought resistance. The results obtained can be explained by the positive effect of silica, of which more than 90 % of the rock is composed, on the growth and development of plants. It is proposed to increase the level of environmental safety of mining regions through the use of crushed stone waste as fertilizers for industrial energy crops and the transition to alternative energy sources, in particular biofuels made on the basis of these crops.