Effects of switchgrass biochar amendment rate on soybean growth, yield, and seed quality in peat-based substrate with and without complete fertigation

This study examined how adding switchgrass (Panicum virgatum L.) biochar to peat moss growing media in a greenhouse, affected soybean growth, yield, and seed quality. A one-year experiment was conducted with three biochar rates (0%, 5%, and 10% w/w) and two fertilization regimes (fertilized and unfertilized plants), using the soybean cultivar OAC Strive.

Plants were grown in pots with a modified Hoagland’s No. 2 nutrient solution and traits that measured were, total aboveground biomass, number of seeds, seed weight, number of pods, seed oil and protein content. Biochar was characterized for its properties, including nutrient content, SEM, metals, pH, electrical conductivity and ash content. Results showed that fertilized plants amended with 5% biochar produced significantly higher total seed weight (yield), total aboveground fresh and dry biomass, dry straw weight, and total number of seeds compared with the 10% biochar treatment.