The latest interim results have been published from a Soil Association Innovative Farmers’ Field Lab project looking at the effects of living mulches in bush and cane fruit.
Coordinated by Harriet Prosser of Ribena’s owners SBF GB&I, growers Josh Berry of Kent and Rosie Begg of Norfolk have conducted the first full year of trials in 2024/25, with the results monitored and assessed by ADAS.
The aim of the project was to investigate different living mulch species/ mixes underneath blackcurrants to determine if they could offer a viable alternative method of weed control in bush and cane fruit. The mulch treatments used as comparisons in the trials are wild white clover, white clover & trefoil mix, woodchip and a herbicide treatment.
For the Kent trial the living mulch seed was sown in spring 2024 and they established very well. Woodchip and herbicides were applied late summer 2024 and the blackcurrant cuttings were planted in autumn 2024. However, in Norfolk a new field site was sown in in Spring 2025 Norfolk by Rosie as the original established blackcurrant crop where the trial was located had to be removed. This meant that Blackcurrant cuttings were planted in March 2025. Living mulch seed were sown in April 2025 and irrigation was used to aid germination and establishment due to the dry spring conditions.
According to ADAS, ‘The clover in the living mulch treatments [in Norfolk] was very vigorous and formed a good carpet of ground cover. The herbicide treatment has required some extra hand weeding as conditions were too dry for the residual herbicide alone. The woodchip treatment has provided good weed suppression but was starting to degrade and so by the late summer assessment weeds were present.’
“Results to date at the Norfolk site show that there were very minor differences in crop height between the treatments, with the woodchip treatment having slightly taller blackcurrant plants,” explained Dr Lynn Tatnell of ADAS. “There was total ground cover from both living mulch treatments, and these were visibly reducing the weed burden (100 per cent weed reduction in most plots) but may be competing with the crop. This will be monitored further in spring and autumn 2026. For the woodchip and herbicide plots there was mean of 78% and 80% weed ground cover for each treatment respectively. There will be more woodchip added to those treatments as they have now degraded over time and will allow weeds to emerge and establish if not topped up.
“Results to date from the Kent site show that the living mulch treatments have established so well that they have completely outcompeted the blackcurrants cuttings and prevented further crop establishment. Crop plants have been established in the woodchip and herbicide treatment plots. The weed burden is very high on this site, and some species have been able to dominate quickly including sow thistle, prickly lettuce, bristly oxtongue and phacelia. This is not commercially viable. The trial plots will now be adapted to make use of the established living mulch strips using rooted one-year old blackcurrants to monitor how well they can establish through the mulch.
“It has been a learning curve so far and we are still experimenting. We are trying to understand how best to manage the living mulches themselves to prevent them becoming too dominant to the crop but having a ground cover of clover has been positive in terms of weed suppression.”
