Low carbon soils and grassland
Sam Adams - 12 March 2013
On a beautiful spring afternoon in March, 20 farmers and advisors gathered at Duchy Home Farm in Gloucestershire. The reason for the gathering was to learn about low carbon farming and particularly its application to soil and grassland management. I think many of us were also there to enjoy the tour of the farm and the networking with other farmers.
Charlie Morgan, aka ‘The Grassmaster’, reminded us that carbon emissions are only a fraction of agriculture’s contribution to global warming and climate change. Methane, with a global warming potential (GWP) 21 times that of carbon dioxide, is of far greater importance. This was very relevant for our meeting, as the farm has significant dairy and beef enterprises.
We were also reminded that nitrous oxide (N2O) has a GWP of 296 times that of carbon dioxide, making it even more of an important focus. N2O is released as part of the nitrogen cycle. As with the production of methane through enteric fermentation, these are natural processes that you cannot cancel out. Instead, we learnt that low carbon farming is about limiting their release.
Low carbon farming looks at increasing the efficiency of farming systems. This is to the benefit both of the environment, through lowering carbon emissions, as well as to the farm business. Increased efficiency and lower wastage means more profitability.
We saw this in operation at Duchy Home Farm, as David Wilson, the farmer, showed us the farm’s 100KW solar PV installation. The renewable energy goes to all parts of the farm, including the farm house, and excess is sold back to the grid. David also showed us a German-made min-till machine that he was using. In a single pass, it breaks the soil and plants up to three varieties of seed.
Low carbon farming is about innovations such as these. However, we were reminded in a presentation from Dr Jennifer Dungait from Rothamsted, that it is also about getting the basics right. This means understanding your soil through counting earthworms and soil testing. She emphasised the importance of soil biology and the need to regularly feed our soils with organic matter.
It was an excellent and informative event. Much was learnt through the two presentations, the farm walk, and the hub of activity around the delicious buffet that was served. We left with a deeper understanding of how higher soil carbon levels have both environmental and economic benefits for our farms.
Sam Adams runs the Low Carbon Farming project, part of the SWARM Hub. He is based at the Soil Association. More information on the project and future events can be found at www.soilassociation.org/lowcarbon