KEEPING LIVING roots in the soils all year round to build fertility and improve resilience, is the goal at Balbirnie Home Farms, AHDB’s Strategic Cereal Farm in Scotland.

With cover crops an increasingly important part of their farming system, the effects of this are monitored with the aid of the Soil Health Scorecard.

Speaking at the soil health technical workshop presented by AHDB and SRUC at Balbirnie Home Farms, farm manager David Aglen, said: “Cover crops are starting to drive our system. I liken them to solar panels, allowing farmers to harvest sunshine, through plants, to produce food and energy.

Read more: Week-long cereals webinars to hear from AHDB's strategic farms

"As long as we can keep growing in the soil then our solar panels can work all year round, the plants are pumping energy into the soil which keeps the soil biology thriving, albeit at a slightly slower pace in the winter, and then, come spring when it warms up it is all ready to go. In contrast, in a bare stubble field you just have all that biology sitting there, hungry.

"We are lucky that we can feed cover crops to the livestock, drill through them in the spring and leave them as a mulch which allows us to keep the soil biology alive.”

At Balbirnie, cover crops are drilled as quickly as possible after harvest which can be late in the season. Because of this, Mr Aglen has found that the only cover crops that do well on his farm are large, seeded crops.

He continued: “We use winter peas, which we have multiplied up to keep the costs down, rye in front of broad-leaved crops and veg as well as beans as cover crops.

“The most important thing that we’ve learnt from our soil baselining studies has been that we need to pay attention to soil compaction, we are seeing pans creeping in," he continued.

"It has reinforced our aim to keep a living root in the soil all the time. We have no fields that have been harvested that don’t either have the following cash crop or a green cover crop growing in them. This should help reduce the impact of rain on the soil surface and might lessen the ponding which occurs in some fields over winter because of a very small pan that forms on the surface with rainfall. We are now direct drilling as much as we can to minimise soil movement and we'll continue monitoring our soils annually going forwards.”

AHDB environment scientist, Dr Amanda Bennett, who leads the Soil Biology and Soil Health Partnership said: “To measure soil health we have to take an integrated approach involving chemical, physical and biological assessments.”

The result is the Soil Health Scorecard, which aims to provide information on key indicators of the condition of the soil to help guide soil and crop management decisions. It combines physical observations of topsoil and earthworm counts in the field, with the results from analysis of soil samples sent for laboratory testing for pH, nutrients and soil organic matter, all done at the same time from the same 20cm x 20cm block of soil dug with a spade.

Dr Bennett said: “For routine soil health monitoring on farm, sampling should take place once per rotation and at the same time of year, in the autumn as the soil wets up and at the same place. Growers should mark a GPS point in an area which is representative and relatively uniform, and work within a 10m radius of that point.

"The idea behind the scorecard is that all the indicators have threshold values - benchmarks - and these have been given traffic light coding. If they come back red, outside of the expected range for that indicator, it means there is something to investigate. If the indicator falls in the amber region, then this is borderline and so an area to review more frequently. If the result is in the green area, then continue the rotational monitoring. The results involve interpretation, and knowledge of the field’s history.”