In a 12-month field study, different types of biochar made from pine chips and peanut shells were added to soil to see how they affect nitrogen emissions and plant growth. When no extra nitrogen was added, using pine biochar increased nitrogen emissions by 48%, while peanut shell biochar increased it by 131% when nitrogen was added. Pine biochar boosted plant yield by 25–27% when nitrogen was added and increased nitrogen uptake by 47%. The study shows that using biochar can affect how much nitrogen is released into the air, especially when nitrogen is added. Pine biochar might increase emissions by helping soil retain more water, while peanut shell biochar might do so by providing more nitrogen and increasing soil pH. This is important to consider when using biochar to help cut nitrogen emissions.