Effect of Biochar on CO2 Sequestration and Productivity of Pearl Millet Plants Grown in Saline Sodic Soils

The use of biochar to increase the soil carbon sequestration is a vital tool to reduce greenhouse gas emissions. Biochar was added to pearl millet (Pennisetum glaucum L.) to investigated its role in carbon sequestration and increasing the plant productivity. In these 2-year filed studies, biochar was added to a saline sodic soil at five rates: 0, 5 (BC5), 10 (BC10), 15 (BC15), and 20 (BC20) ton ha(-1). Biochar raised the soil organic carbon and improved the availability and uptake of N, P, and K compared with the non-amended soil. BC5, BC10, BC15, and BC20 increased the forage yield by 36, 45, 27, and 18%, respectively, above the control in the first year and by 45, 65, 35, and 25%, respectively, in the second year. Biochar significantly minimized the proline, phenolic compounds, Na+, and Cl- in the leaf tissue of pearl millet. BC20 increased CO2 emissions by 15, 13, and 10%, respectively, compared with the control in the first, second, and third cuts. Biochar had a positive effect on increasing CO2 emissions from saline sodic soils. The total amount of organic-C sequestered by the pearl millet was 6.00-9.45 ton C ha(-1) per season, while the total CO2 emissions were 1.62-1.82 ton of organic-C ha(-1) per season. The application of biochar enhanced the nutrient availability and uptake; moreover, it mitigated the salinity effects in the leaves tissues. Carbon sequestration by pearl millet amended with biochar is an effective strategy to mitigate gas emissions from saline sodic soils.

Automated summary

The use of biochar is crucial in enhancing soil carbon sequestration and improving nutrient availability in saline sodic soils. Biochar application significantly increased forage yield and reduced salinity effects in pearl millet leaves. Additionally, biochar positively influenced CO2 emissions, with organic carbon sequestration ranging from 6.00 to 9.45 ton C ha(-1) per season.