Fifteen UK hop-growers are taking part in a new field lab looking at alley cropping. Led by Hutchinsons, working with the British Hop Association and East Malling Research, the growers want to develop practical ways to improve soil structure and organic matter through cover crops.
The soil challenges faced by hop-growers are unique: plants are grown from perennial stock, live for up to twenty years, and are cut back to 6 inch stumps when harvested. This means virtually no organic matter is returned to the soil during the cropping cycle, and soils can easily become depleted. Soil compaction can also be a problem, with the alleys being subjected to regular traverse by heavy vehicles.
There are plenty of thheories about the benefits of cover cropping in hop orchards, but a lack of evidence can hold growers back from trying them. Many import and spread organic matter as a way of maintaining soil health, but this is both expensive and time-consuming. By growing organic matter in situ and measuring the effects on soil health, the group hope to prove tangible outcomes that will encourage wider adoption of cover cropping.
Initially, baseline assessments of the soil will be taken to determine water infiltration rate, earthworm populations, organic matter content and soil mineral nitrogen content. Cover crops will then be established and comparative assessments taken after their removal. This will help to inform future cropping and develop best practice.
Ali Capper is one of the growers leading the group, she said: “Cover cropping could bring big benefits to hop growers. By increasing the soil organic matter you can improve fertility, improve crop health and – ultimately – improve yield. We’re hoping to see increased earthworm populations, less soil erosion, better water management and as a result a more nutrient-rich setting for the hops in successive years.”
The group are now looking at which cover crops to use. They need to be easy to establish, fast growing, suitable for a late summer or autumn sow, and easily manageable. It is thought that using a mix will be more resistant to pest and disease than a single species, and the crops being considered include Rye, Black Oat, Buckwheat and Vetch.
Baseline assessments and sowing are scheduled for autumn 2017, with initial evaluation in spring 2018.