Biochar (BC) application as a viable soil amendment strategy has drawn much interest recently. However, limited information is available on the effect of BC application rates on plant growth, yield, and mineral composition in arid and semi-arid agroecosystems. Therefore, we investigated the effect of BC applications on winter canola (Brassica napus) performance and mineral composition in a greenhouse pot experiment. Two soils, clay loam and sandy loam, were used in this study as strip tests with five treatments in four replications within each soil type. Treatments included control, 0.1% BC, 0.3% BC, 0.5% BC, and 1.0% BC on a weight-by-weight (w/w) ratio with soil. Research results showed that 1.0% BC had the highest biomass and biomass water use efficiency (BWUE) compared to all other treatments in both soil types (p <= .05). Above-ground tissue N, Mg, and Fe were greater for the 0.5% BC treatment in both soil types, while below-ground tissue N, K, S, Mg, Zn, Fe, Cu, B, and Mo were greater in the 0.5% BC treatment compared to control and other treatments. N concentrations were generally low for the 1.0% BC in both soil types. Overall, the study indicated that the BC amendments have potential to improve plant performance in irrigated arid and semi-arid agroecosystems. However, a long-term field experiment is needed to confirm the results of current study.