The effect of biochar–organic fertilizer combinations on the physical properties of post–mining type C soil after maize cultivation

Abstract

C Quarry mining causes significant soil degradation due to the loss of topsoil, resulting in land with poor physical structure, low pH and minimal nutrient content. Post-mining soil fertility recovery encourages the implementation of amelioration with materials such as coal fly ash (CFA), biochar and organic matter. This study aims to evaluate the effectiveness of CFA, biochar, and organic matter applications on the physical properties of post-C Quarry mining soil after corn planting. The study was conducted from July to November 2025 using a completely randomized design (CRD) with 7 treatments of a combination of biochar and CFA (5% of the soil weight of 15 kg) with organic fertilizer (chicken manure, goat manure and compost 20 t/ha). Corn cultivation was carried out, and observations were made on the physical properties of the soil bulk density, particle density soil porosity and soil water holding capacity at harvest. Analysis of variance with advanced BNT tests. The results showed no significant differences in soil bulk density, particle density, and porosity but significantly different in soil water holding capacity. The BCM treatment showed the lowest bulk density (1.09 g /m3), the CCM treatment showed the lowest particle density value (g/cm3), the CGM treatment showed the highest porosity (56%) and the BGM treatment showed highest water holding capacity (88%).