A pot experiment was conducted to study the differences between clovers (Trifolium repens Linn) in biomass, nutrient uptake, physical, chemical, and biological properties of substrates among various mixtures with clay, topsoil, or sandy soil, in order to obtain the optimal mixture ratio. The results showed that the substrates with different mixture proportions significantly influenced clover productivity; the biomass varied with the type of substrate and was in the range of 26.5-40.0 g/pot (average=31.2 g/pot) for the clay and topsoil combinations and in the range of 14.9-20.3 g/pot (average=18.9 g/pot) for the clay and sandy soil combinations; the biomass was 9.0 g/pot, 5.4 g/pot, and 41.7 g/pot for the clay, sandy soil, and topsoil, respectively. Similarly, the highest N acquisition was 1071 mg/pot of clover in the clay and topsoil combinations, which was 1.62, 3.34, and 5.64 times higher for the clay and sandy soil combination, clay, and sandy soils, as were P and K acquisition, which was significantly altered by the difference in root diameter, root length, root surface area, and tip numbers. In comparison with the clay and sandy soil, the soil bulk density and maximum moisture holding capacity were significantly decreased by 7.4%-21.5% and 24.5%-71.8%, respectively, whereas the infiltration rate, porosity, normalized mean weight diameter, total N, organic matter, Olsen P, available K, electric conductivity of the clay with topsoil and clay with sandy soil combination were markedly enhanced by 26.9%-96.3%,45%-218%, 34%-72%, 23.0%-88.3%, 25.1%-146%, 44.0%-91.5%, 70.3%-114.8%, and 3.5%-59.3%; the activities of phosphatase, urease, nitrate reductase, invertase, and nitrogenase were significantly increased by 45.5%-105%, 65.2%-172.3%, 160%-252%, 53.4%-62.7%, 197%-374%; the numbers of fungi, bacteria, and actinomycetes were also increased by 119%-142%, 93.5%-107%, and 83%-147%, respectively. Significant positive correlations were observed between clover productivity and soil physicochemical or biological properties via correlation analysis; overall, the effect of substrates occurred in the order clay+topsoil=topsoil > clay+sandy soil > clay > sandy soil. Thus, the clay and topsoil or sandy soil mixtures provided significantly enhanced substrate conditions; in particular, the 1:2 clay and topsoil ratio was the optimum choice in the opencast coal mine in the eastern steppe of China.