Corncob valorization: design-related engineering properties for the development of corncob crusher for soilless substrate production

Urbanization and soil degradation have placed significant pressure on agricultural sustainability and food security, prompting the exploration of alternatives to soil. The potential of corncob as soilless substrate, an innovative growing media for sustainable urban agriculture, has been preliminary established. Hence, this study investigated the design-related properties of corncob necessary for developing crusher for producing corncob substrate using standard methods. Corncobs from yellow and white corn varieties were used for the study at five moisture levels (9.71, 11.01, 14.29, 17.58 and 21.87% w.b). The results indicate that moisture content rise increased the major axes, angle of repose, surface area and static coefficient of friction. Sphericity decreased for yellow corncob from 0.50 to 0.47 but increased for white corncob from 0.63 to 0.65. Solid and bulk densities decreased: yellow corncob from 0.365 to 0.290 g/cm³ and 0.325 to 0.225 g/cm³, respectively; white corncob from 0.395 to 0.340 g/cm³ and 0.345 to 0.270 g/cm³, respectively. Rupture strengths decreased from 1.12 to 0.80 N/mm² and 1.12 to 0.80 N/mm² for yellow and white corncobs, respectively. Valorization of corncob will create new economic opportunities and give farmers more value for their corn. Hence, this work is pivotal in achieving that with the empirical data provided for developing a corncob crusher for soilless substrate production.