Nutrients uptake of corn plant as affected by rock dust addition treated by heating and humic material

Silicate rocks are a natural substance that contains many essential nutrients for plants, but the applications of silicate rocks dust as fertilizer in agriculture are very limited. The nutrients derived from silicate rock dust were very slowly available. As a result, its effect on plant growth is not significant. The effort that can be done to accelerate the availability of nutrients from silicate rocks dust fertilizer is through heating treatment and giving humic materials. This research was conducted using a split-plot designed by three factors; namely, the heating temperature (at 25°C, 300°C, and 700°C) as the main plot, rock types (Trachyte, diorite, and basalt), and the solvent (KOH 0.1 N, rainwater, lignite humic and peat humic) as the subplot. The results showed that the rock dust fertilizer treated with peat humic significantly influenced the plant height 14 days after planting (DAP). Besides, basalt rock dust fertilizer can significantly influence plants' height at 21, 28, and 35 DAP. The highest dry weight of corn plants was obtained in the treatment of basalt rock dust treated by heating to a temperature of 700°C with the solvent peat humic. Nutrient uptake of potassium (K) in corn plants tended to be higher in the treatment within the rock dust treated by heating to a temperature of 300°C using lignite humic solvent.