From these facts, organic agriculture may or may not lead to lower
soil-derived GHG emissions, as not only management characteristics
but site properties (soil characteristics, climate etc.) control soil GHG
fluxes as well. The generally lower N input level in organic agriculture
compared to non-organic however supports the expectation of lower
nitrous oxide emissions and enhanced methane uptake in organically
managed soils. There are some indications that organic agriculture
leads to less soil-born greenhouse gas emissions than conventional
agriculture (Niggli et al., 2009). This phenomenon has, however, never
been investigated systematically. Thus a comprehensive literature review
followed by a meta-analysis was conducted to compare non-CO2
GHG emissions fromsoils under organic and non-organic management.