The point of this study was to find out how two types of biochar—hard and soft—made from locally made corncob waste (by slowly breaking it down at 500°C with little oxygen) improved sandy soil and helped radishes grow. We added biochar to the sandy soil in rates of 0, 1, 3, and 5% (w/w). It was incubated for one month at room temperature (25±2 °C) and rewetted every seven days to field capacity. The soil mixture was saved to cultivate the seeds into the pots, then collected the mature plants. The samples were washed, cut into pieces, and prepared to be subjected to analysis. The biochar experiment was conducted as a split-split plot in Randomized Complete Block Design (RCBD), with three replications in the open greenhouse of the Faculty of Agriculture, Saba Basha, Alexandria. The irrigation schedule consisted of five treatments (20, 40, 60, 80, and 100% of potential evapotranspiration), which was the primary factor in the experiment.