Wheat Productivity and Economic Implications of Biochar and Inorganic Nitrogen Application

Nitrogen loss via volatilization, leaching, and surface runoff is a major problem in coarse-textured and alkaline soils of Multan, Pakistan, impacting the economic and environmental sustainability of wheat (Triticum aestivum L.) production systems in the region. Soil amendments with biochar in combination with optimal levels of inorganic N could improve wheat productivity, but sustainable adoption will depend on economic profitability. We evaluated the effects of biochar produced from green waste (GW-450) and poultry waste (PW-450) feedstock and different rates of inorganic N (0, 60, and 120 kg N ha(-1)) on wheat productivity and economic profitability. The PW-450 improved wheat yield, quality, and nutrient uptake compared with the GW-450, which was attributed to a lower C/N ratio and higher essential nutrients and specific surface area that enhanced adsorption properties of the former. Soil amendments with biochar in combination with inorganic N improved wheat grain yield, quality, and N uptake over non-amended soils. On average, biochar increased wheat grain yield, protein content, and N uptake by 55 to 355 kg ha(-1), 3.7 to 6.9 g kg(-1), and 15 to 41 kg ha(-1), respectively. Despite the benefits of biochar on wheat yield, it was not economically profitable within the two growing seasons due to high application rates and price. However, the effects of biochar may last longer and potentially make biochar profitable in the long term. Overall, biochar holds promise for use in the wheat cropping system in Multan, Pakistan; further studies are recommended to better elucidate its benefit in the long term.