A new meta-analysis from Rothamsted Research reviewed 422 studies on conservation agriculture and found that its climate benefits are not uniform. Reduced and zero tillage consistently lowered carbon dioxide and nitrous oxide emissions, and sometimes boosted methane uptake. But mulching and some fertilizer strategies increased emissions in certain environments, especially with high rainfall or specific soil types. The study also shows nitrogen application rate remains a key driver of N2O emissions, pointing to precision nutrient management as a critical lever. Crop rotations with legumes reduced CO2 compared to continuous cereals. The authors call for more long-term field trials, particularly in Africa, and for evaluating practices locally rather than treating conservation agriculture as a one-size-fits-all solution.
