Co-application of Boron, Sulphur, and Biochar for Enhancing Growth and Yield of Brassica napus under Calcareous Soil

The development of canola plant is sensitive to boron (B) and sulfur (S). A constant application of these nutrients is required at all canola stages, especially at the climax vegetative growth, budding, pod formation and seed maturation phases to attain maximum seed yield of canola. Biochar is an essential amendment that makes nutrients available for ‎canola plant for a longer period. Considering the importance of B, S, and biochar to canola crop, a ‎research trial was conducted with four levels of B (0, 0.5, 0.75, and 1 mg B kg−1) and ‎four levels of S (0, 5, 10, and 15 mg S kg−1) were applied, while biochar was applied at 1% (w/w). The results indicated that maximum increase in growth parameters, including shoot length (22%), root length (35%), shoot dry weight (37%) and root dry weight (40%) was obtained with the application ‎of 1 mg B kg−1 + 15 mg S kg−1 and 1% biochar. Yield parameters ‎such as the number of seeds ‎plant−1 (32%), 1000-grain weight (31%) and seed yield (39%) increased significantly by applying the highest level of B and S. Physiological parameters also showed a noteworthy increase as compared to control. Chemical parameters including nitrogen, ‎phosphorous, potassium, and B concentrations in shoots and roots (32, 37, 29, 31, ‎‎42, 34, 38, and 39%, respectively) showed an increasing trend. Therefore, it was ‎concluded that 1% biochar +1 mg B kg−1 and 15 mg S kg−1 performed best for improving the ‎growth and yield of canola.