Net zero and net negative emissions in brazilian biomes by no-till system.

No-till systems (NTS) predicated on the tenets of conservation agriculture principles are a viable agricultural paradigm to achieve net zero or net negative emissions. We assessed the carbon dioxide equivalent (CO₂e) emissions based on soil organic carbon (SOC) stock changes in 1-m depth by plow-based tillage (PBT) and the mitigation potential through a no-till system (NTS) across 26 sites in the Cerrado biome and 37 sites in the Atlantic Forest biome. These sites comprise 86,411 ha (ha), encompassing four climate zones in Brazil. The investigation revealed a range of CO2e emissions, with the lowest recorded value of 74.2 Mg CO2e ha-1 observed in the tropical equatorial climate zone and the highest recorded value of 470.1 Mg CO2e ha-1 detected in the subtropical humid climate zone. The total CO2e emissions in the tropical equatorial, tropical central, subtropical humid and subtropical temperate climate zones were calculated to be 5.51, 3.88, 3.21, and 4.20 Tg CO2e, respectively, with a cumulative value of 16.80 Tg CO2e with 6.7 % of uncertainty (i.e., 1.12 Tg CO2e). Adoption of NTS demonstrated a high capacity for offsetting CO2 emissions, achieving 5.40 Tg CO2e in the tropical equatorial zone (recovering 98 % of the total emissions), 2.57 Tg CO2e in the tropical central zone (68.7 %), 2.67 Tg CO2e in the subtropical humid zone (83.2 %), and 2.88 Tg CO2e in the subtropical temperate zone (68.6 %). The percentage of net zero and net negative emissions contributed by the SOC stock for 1-m depth was 73.63 % and 26.37 %, respectively, and it played a pivotal role in integrating agriculture as a part of the climate solution.