Greenhouse Gas Emissions and Yield Production from an Organic and Conventional Fertilization on Quinoa

The high nutritional properties of quinoa have resulted in a production increase worldwide. The resistance to environmental stresses renders this crop suitable for sustainable farming systems. Few studies have examined the impact of different agricultural management strategies and its contribution to climate change. In this work, we quantify soil greenhouse gas (GHG) emissions, in terms of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and crop productivity (yields and biomass) under conventional (urea) and organic (digestate) fertilization. Significant differences (p < 0.05) in N2O cumulative emissions are reported between digestate (50–100 kg N ha-1), urea (50–100 kg N ha-1) and the control (0 kg N ha-1). Higher cumulative GHG emissions are observed under 100 kg N ha-1 of digestate (337.8 kg C ha-1 CO2 and 0.23 kg N ha-1 for N2O) compared to treatments with lower nitrogen (N) inputs. However, yield and biomass production do not show significant differences (p > 0.05) with increasing nutrient application. Hence, this study opens the discussion about the pros and cons of increasing fertilization to improve yields besides providing agricultural extension workers with additional information to promote sustainable quinoa production worldwide.