Farmers could access environmental benefits such as reduced nitrate leaching and improvements in soil health by adding biochar, a type of charcoal, into cattle diets.
Farm-based research on a beef enterprise in Lincolnshire has indicated that feeding biochar to cattle can decrease nitrate levels in manure.
Richard Colpey, who runs an 80-head suckler herd of Beef Shorthorn cross Limousins over 80 hectares (200 acres) near Grantham, got involved in the trial at its inception a year ago, but has been feeding biochar, a charcoal type product, in rations himself for several years.
The ongoing trial, which is looking to test whether feeding cattle biochar can reduce nitrate leaching and improve soil health, is being led by Innovative Farmers, a not-for-profit network which enables farmer-led research and is now set to extend on to a number of farms in Wales.
Mr Copley, who runs a tree surgery business in addition to his suckler herd, explained that the concept was one he had a particular interest in as it provided a way to sustainably manage foliage and other waste products this produces.
He says: “Producing biochar turns brash and other off-cuts into a useful product that locks away carbon.
“It is produced in a specialist chamber via pyrolysis, at a temperature of 375 degrees celsius, and after a period of about eight hours will leave you with biochar as the end product.”
He then feeds the biochar to cows and finishing stock, originally in chunks but more recently after it has gone through a roller mill. This substance is scattered and fed on top of the cattle’s existing barley and protein based ration.
Mr Copley says: “The cattle seem to like it and will hoover it down quickly when it is put in front of them.
“We definitely noticed positive side effects while we were undertaking the trial, and the groups which had been fed the biochar seemed to have a calmer temperament overall.
“Although it was not an outcome we were able to measure in-depth, ammonia levels in manure from animals fed biochar also seemed to reduce, which was clear from its smell.”
Donna Udall, researcher at Coventry University has a background in biochar research and worked alongside Mr Copley during the trial.
In the knowledge that biochar is able to store carbon in the ground, her wider work has seen research and investigation into what effective use of biochar on-farm would mean for farmers.
Feeding it has been found to be one way of achieving this, which led Ms Udall to this research into whether there are any wider benefits to animal and soil health, as well as the environment.
She explains that dung samples are used to determine the impact biochar is having on the health of the cattle but also the impact it is likely to have on the soil once it is spread within manure.
She says: “Results from the manure tests show that levels of nitrate went down in the samples from cows which had been fed biochar, but the small sample size [five cows] means that more results are needed to draw real conclusions from.”
Pot trials have been carried out to see whether biochar-fed manure has any impact on grass growth and soil health, results from which show no difference in the yield of grass between pots fertilised with biochar-fed manure and manure alone, although it is noted that biochar is being fed at a low rate.
Anecdotally it has also been suggested that biochar could benefit cattle in reducing parasitic worm burdens, as well as reducing ammonia emissions, and these were parameters Dr Udall is hoping to investigate further now that the trial is set to widen.
Dr Udall says: “Richard and others farmers have felt that cows fed on biochar are more comfortable, eat better and seem more settled which we think is because of an alteration of pH in the rumen.”
Wider research and more time is needed to provide more definitive answers, but Dr Udall says that by increasing carbon in the soil, improving its health is a given.
She says: “Initial results are hopeful but biochar is not perfect and there is a lot more we need to find out.”