Effect of biochar on soil CO2 production

Abstract

The study focuses on looking for answers to the following questions: 1. Is biochar application a suitable solution for reducing CO2 emissions? 2. What application rate significantly reduces CO2 production to the atmosphere? 3. Does have the application of enriched biochar a justification in relation to reducing CO2 production? The experiment was established on Haplic Luvisol at the experimental site of SUA in Nitra (Dolná Malanta), where we measured CO2 emissions from the soil to the atmosphere under the following treatments: different rates (0, 10, 20 t ha-1) of pure biochar (B0, B10 a B20) and enriched biochar (EB10, EB20) combined with different levels of mineral nitrogen at doses of 0, 40 and 80 kg ha-1 (N0, N40, N80). Overall, the average values of CO2 emissions were lower by 19.8 %, 13.3 %, 12.9 %, 9.4 % and 8.7 % in B10N0, B20N40, B20N0, B20N80 and B10N40 treatments as compared to B0N0 (control) during the studied period. On the other hand, the average values of CO2 were higher by 20% in B10N80 treatments as compared to control (B0N0). Application of enriched biochar whether individually (EB10N0, EB20N0) or with additional N (EB10N40, EB20N40, EB10N80, EB20N80) increased average CO2 by 29.7 %, 34.6 %, 36.0 %, 44.9 %, 45.8 % and 53.6 % as compared to control (B0N0). The cumulative CO2 emissions for the whole studied period (2014) were in the following order from the lowest one B10N0 < B20N0 < B20N40 < B20N80 < B10N40 < B0N0 (control) < B10N80 < EB20N40 < EB20N80 < EB10N80 < EB20N0 < EB10N0 < EB10N40.

Keywords

• biochar
• enriched biochar
• N-fertilization
• CO2 emission