Soil carbon stocks and nitrous oxide emissions of pasture systems in Orinoquía region of Colombia: Potential for developing land-based greenhouse gas removal projects

Improving grassland conditions under grazing has the potential not only to accumulate carbon in soils, but also reduce nitrous oxide (N 2 O) emissions from animal urine deposition. However, measurements developing countries are still scarce. In Orinoquia region, permanent grasslands (PG; this unimproved, native pasture is considered as at some state of degradation) based on unimproved grasses found due extensive, inefficient combined with annual burning pastures. We hypothesized that, compared PG, improved (IG) managed through rotational introduced, productive and deep-rooted grass species promote soil organic (SOC) accumulation N O emission deposited by cattle. determined SOC soils an area PG a 6.5 year-old IG Urochloa (Syn. Brachiaria ) humidicola beef cattle ranch Orinoquía region (Colombia). both areas, we sampled for chemical/physical analysis, measured simulating deposition over 21 days. applied two-way analysis variance considering type depth fixed factors. Estimated stocks (0–100 cm) were range 224.8 Mg C ha −1 259.0 IG, significant ( p < 0.05) average 2.0 y (0–20 area. 10 times lower PG. The introduction U. influenced probably its more abundant root system greater turnover together higher (14%) forage dry matter production reduced observed patches attributed biological nitrification inhibition ability nitrogen uptake grass. Compared reference default value IPCC for, stock was almost 40% higher, whereas factor (5%) within uncertainty (0.7–6%). shows storage pastures deep systems. Thus, scaling implementation land-based practices/projects could significantly contribute reducing net region.