Cover crops are often promoted for their benefits, including providing protection and adding organic matter into the soil.

However, in Scotland, they don’t come without their challenges, with the cost of establishment often cited as a barrier to uptake. They can also be hard to establish and can promote volunteers in the following crops.

As part of the Farming for a Better Climate Initiative, the Soil Regenerative Agriculture Group has been investigating the nutritional value of cover crops in a bid to integrate livestock onto arable farms, as well as trying to offset some of the cost against wintering sheep.

Traditionally, this isn’t a new idea, with stubble turnips often planted after harvesting early crops to provide winter forage. However, a broader mix of species is likely to have a greater benefit on soil health, prompting some members of the group to try something different.

Hugh Black, at Backboath Farm, has invested in electric fencing so he can manage sheep across his arable farm which has no permanent fencing. However, after experimenting with cover crop mixes, he soon realised he was altering the feeding value, as well as the benefits he could bring to the soil.

In the autumn of 2020, Hugh established a mix containing phacelia (6%), mustard (20%), oilseed radish (30%), vetch (30%) and fenugreek (14%). He left this mix to grow until the beginning of January when he introduced sheep.

Hugh said: “The snow arrived with the sheep and as my primary aim was to graze my cereal crops, I had to put the sheep onto the cover crops which had enough biomass to stand out above the snow.

“We analysed the covers as we were concerned about how much of them had died back with the cold weather, but they still provided a surprising amount of grazing.”

As one of the group facilitators, we at SAC Consulting found that some of the cover crops analysed had a metabolizable energy of 9.9 to 10.7 MJ/kg DM and a protein of 296 g/kg DM to 335 g/kg DM.

The cover crops at Backboath provided a range of grazing days per hectare from just 37 lambs, up to 390 lambs days/ha, based on dry matter intake assessed at 2% of lamb body weight. Alongside the grazing, this mix provided a variety of root structures to improve Hugh’s soils.

Work within the Soil Regenerative Agriculture Group is ongoing, with different mixes established so it can continue the on-farm trials throughout this winter.

For more information visit: www.farmingforabetterclimate.org, or follow the group on Twitter @SACFarm4Climate.