FEED TREES TO SHEEP TO CUT GREENHOUSE GASES , STUDY SUGGESTS
Introducing tree leaves to a sheep ’ s diet could play an important role in reducing harmful greenhouse gas emissions , suggests research presented at this today ' s Intercropping for Sustainability conference .
Scientists from the Game & Wildlife Conservation Trust ( GWCT ) monitored four groups of six Aberfield x lambs , half of which were fed around 200g of goat willow leaves each per day . When their urine patches were monitored , they found significant reductions in both nitrous oxide and carbon dioxide in those groups which fed on willow leaves . The work , partfunded by the Woodland Trust , also found lower emissions of ammonia from urine patches where lambs were fed willow .
While cutting branches to feed to livestock is labour intensive , a move towards agroforestry with livestock ( also known as silvopasture ) would allow the direct browsing of coppiced trees if livestock access is managed to ensure sustainability . The use of tree fodder as an alternative source of food during periods of drought may become increasingly relevant as the climate changes , but these results suggest that a supplementary benefit of incorporating willow into grazing ruminant systems may be a contribution to climate change mitigation , as well as air quality improvement .
The Committee on Climate Change estimates that agroforestry could result in carbon emissions savings of 5.9 MtCO2e per year by 2050 , approximately 13 % of the total current emissions from the agriculture sector .
Professor Chris Stoate undertook the research and is encouraged by the findings : “ This study is a novel application of the specialist expertise and equipment we have at the Allerton Project and builds on our recent research on grass and livestock systems . The results are preliminary , but they provide an exciting indication that feeding willow leaves to ruminants may contribute to national targets for both climate change and air quality . It certainly warrants further investigation .”
Despite decreasing by 16 % since 1990 , farming in the UK contributes 10 per cent of the country ’ s emissions . Any ambition to reach net zero , which the NFU has set as a goal for 2040 , will require novel solutions . It is estimated that one kilogramme of N2O warms the atmosphere about 300 times the amount that one kilogramme of carbon dioxide does over a 100-year timescale , so any potential reduction is worth serious consideration . The benefits to air quality of the apparent reduction in ammonia is an added bonus .
Defra has recently made it clear that agroforestry is eligible for support through the Basic Payment Scheme ( BPS ), including both silvoarable ( trees planted at wide spacings and intercropped with a cereal or bio-energy crop ) and silvopasture ( trees combined with forage grassland and livestock production ).
22 | Rural Life