Responses of forage sorghum early growth, biomass production, and mineral nutrient composition to biochar and manure amendments in a semi-arid environment
Abstract The overuse of inorganic fertilizers to meet the increasing demand for food supplies has mounted enormous pressure on agroecosystems, especially in the arid and semi-arid regions, leading to soil quality deterioration and eutrophication problems. Therefore, we investigated the effect of the application of organic soil amendment materials (biochar (BC), manure, and their combinations) on forage sorghum (Sorghum bicolor (L.) Moench.) performance in a two-year field experiment. The experiment consisted of six treatments: Control, Manure 100% (45 Mg ha−1), BC 5% + Manure 95% (% w/w), BC 15% + Manure 85%, BC 25% + Manure 75%, and BC 100% (11 Mg ha−1), randomized in four replications. Research results revealed that total biomass, total water use, and biomass water use efficiency (BWUE) showed no significant differences among the treatments (p < 0.05). All plant tissue macro and micronutrient concentrations were unaffected by amendment treatments. However, the year × treatment interaction effect was evident on all nutrients. Additionally, a decrease in nutrient concentrations was observed in all treatments in the second year compared to the first year, which demonstrated the environmental effect. Overall, the application of organic amendments did not statistically affect the overall yield and tissue nutrient availability during the two-year study period; it is essential to investigate the long-term effects of biochar in combination with manure on plant growth, yield, and plant nutrient uptake. CORE IDEAS Different proportions of biochar and manure, along with their sole applications, were tested in forage sorghum production Forage sorghum biomass production and biomass water use efficiency showed similar results across all treatments Forage sorghum tissue mineral nutrients were unaffected by the tested soil amendments