The environmental monitoring study, carried out by the Life-Seed Capital project and co-founded by the European Commission’s Life+programme, found that introducing rapeseed cake cuts methane emissions between 6 percent and 13 percent and carbon dioxide emissions between 6 percent and 13.6 percent.
Rapeseed cake is a byproduct produced after pressing the plant to extract its oil. The study also found that oilseed can improve the efficiency of livestock’s digestable organic matter between 4.4 percent and 10.1 percent and cuts the fermentation of the diet between 6.2 percent and 11.8 percent.
The Life-Seed Capital project aims to find ways to use rapeseed crops to improve agricultural productivity while cutting greenhouse gas emissions. The project advocates using the plant as a rotational crop because it’s capable of increasing cereal productivity and improving soil structure.
Once the rapeseed has been harvested, it can be used as a biofuel and added to diesel in varying proportion after simple cold pressing, according to Life-Seed Capital. The waste product of this process can then be used to produce animal feed.
Global greenhouse gas emissions from the agricultural sector totaled 4.69 billion tons of carbon dioxide equivalent in 2010, the most recent year for which data are available — an increase of 13 percent over 1990 emissions, according to the Vital Signs report released in May 2013 by the Worldwatch Institute.
The three most common gases emitted in agriculture are nitrous oxide, CO2 and methane. Methane accounts for around 50 percent of total agricultural emissions, the report says. Enteric fermentation — the digestion of organic materials by livestock — is the largest source of methane emissions and of agricultural emissions overall.
Laura Reynolds, Worldwatch food and agriculture researcher and the study’s author, says adding oils or oilseeds to feed can help with digestion and reduce methane emissions.
The switch isn’t without risks. A move from to a grain- and oilseeds-based diet often accompanies a shift from pastures to concentrated feedlots, which has negative environmental consequences such as water pollution and high fossil fuel consumption, Reynolds says in the report.