Recycling of selected fraction of municipal solid waste as artificial soil substrate in support of the circular economy

Regions with warm climate are poor in organic matter or have a deficit of soil. The purpose of the work was to select the optimal mix from biodegradable wastes such as cardboard (Cb), natural textiles (Tx) newspaper (Np), colored newspaper (Cp), and office paper (Op) for creating artificial soil by combining these materials with compost and sand. To select the optimum mix, 15 samples were taken (3 from each type of waste in the following proportions: 25%, 50% and 75%). The optimum mix was analyzed for grass germination rate and root development. Tests were performed in the laboratory with conditions similar to those of regions with warm climate and soil deficiency in a specially designed testing spot (bioterm). The effects of particular mixes on plant germination rate and growth were measured. Out of all mixes, the textile compositions Tx50 and Tx25 supported best the plant propagation. During the whole experimental process, the grass showed various growth tendencies. The best results for grass height were observed for mixes with textiles and colored newspaper. Based on this data and subsequent laboratory research, the best substrate composition was selected. For the whole period of the tests, germination rate in the pot with the mix was higher than the germination rate in the control sample with compost. Considering the experimental conditions of this research, the tested substrates can be used to aid in plant propagation, especially in regions with warm climate and soil deficiencies, and for restoration of damaged land areas.