No-tillage systems linked to reduced soil N2O emissions in Mediterranean agroecosystems
Most emissions of nitrous oxide (N2O) are linked to the use of nitrogen (N) fertiliser in agriculture, highlighting a need for agricultural management practices that reduce emissions while maintaining agronomic productivity. A new study has assessed the long-term impact of conventional tillage (CT — where soil is prepared for agriculture via mechanical agitation) and no-tillage (NT) systems on soil N2O emissions and crop productivity in rain-fed Mediterranean conditions.
The findings show that, over a period of 18 years, mean yield-scaled (i.e. per unit grain yield) soil N2O emissions (YSNE) were 2.8 to 3.3 times lower under NT than CT. The researchers therefore recommend NT as a suitable strategy by which to balance agricultural productivity with lower soil N2O emissions in rain-fed Mediterranean agroecosystems.
N2O is a greenhouse gas (GHG) with significant global warming potential. Most N2O emissions originate from soils treated with N fertiliser as a result of nitrification and denitrification processes. Different agricultural management practices can modify these processes, influencing N2O emissions. If the population’s rising food needs are to be met in a sustainable way, management practices must contribute to reduced N2O emissions without damaging agronomic productivity.
In CT systems, land is tilled, causing crop residues to become buried. In NT systems, land is untilled and crop residues remain at the soil surface, enhancing water storage.
Source: Plaza-Bonilla, D., Álvaro-Fuentes, J., Bareche, J. et al. (2018). No-tillage reduces long-term yield-scaled soil nitrous oxide emissions in rainfed Mediterranean agroecosystems: A field and modelling approach. Agriculture, Ecosystems & Environment, 262: 36-47. DOI: https://doi.org/10.1016/j.agee.2018.04.007. Contact: daniel.plaza [at] pvcf.udl.cat