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

Area of Science:

• Agricultural Science
• Environmental Science
• Climate Science

Background:

• Conservation agriculture principles, particularly no-till systems (NTS), are explored as a method for achieving net zero or net negative emissions.
• Soil organic carbon (SOC) stock changes in the top 1-meter depth are a key metric for assessing emissions.
• Plow-based tillage (PBT) serves as a baseline for comparison with NTS.

Purpose of the Study:

• To assess carbon dioxide equivalent (CO₂e) emissions based on SOC stock changes under PBT and NTS.
• To evaluate the mitigation potential of NTS across diverse Brazilian biomes and climate zones.
• To determine the contribution of SOC stock to achieving net zero and net negative emissions in agriculture.

Main Methods:

• Comparative analysis of CO₂e emissions using SOC stock changes in 1-m depth.
• Study conducted across 26 sites in the Cerrado biome and 37 sites in the Atlantic Forest biome, covering four climate zones in Brazil.
• Data aggregated from 86,411 hectares to calculate total emissions and NTS mitigation potential.

Main Results:

• CO₂e emissions varied by climate zone, ranging from 74.2 Mg CO₂e ha⁻¹ (tropical equatorial) to 470.1 Mg CO₂e ha⁻¹ (subtropical humid).
• Total cumulative emissions across all zones were 16.80 Tg CO₂e (± 6.7% uncertainty).
• NTS demonstrated significant CO₂e offsetting capacity, recovering between 68.6% and 98% of total emissions across different climate zones.

Conclusions:

• NTS is a highly effective agricultural paradigm for mitigating CO₂e emissions and enhancing SOC stocks.
• Adoption of NTS significantly contributes to achieving net zero (73.63%) and net negative (26.37%) emissions.
• Integrating agriculture through NTS is pivotal for climate change solutions.