Biochar trials hit a hole in one at Okehampton Golf Club

The Okehampton trials

Locations and issues:

The 5th green – a very sandy newly-extended area of the green, which leaches nutrient heavily.

The 12th green – the ‘disease indicator’ green, placed in the Ockment Valley. It is surrounded by trees and receives very little winter sunlight.

Application:

Enriched Biochar Lawn Improver was applied in March 2017. Both greens were 13mm hollow tined to a depth of 100mm. 1kg per m2 of Carbon Gold’s Enriched Biochar Lawn Improver was brushed in – in the same way, sand is commonly brushed into the turf – over an area of 100m2 per green.

Outcomes reported by Okehampton

Fertiliser inputs

Okehampton currently fertilises the greens five times a year.

The trial areas were continued at the same fertiliser rate as the rest of the greens initially. The 5th green looked healthier through the summer and appeared to be holding nutrient more efficiently, so the team decided to miss one feed application on the trial area. Three weeks later it was not evident that the feed application had been missed, and the trial area looked as healthy as the rest of the green. Okehampton reported a 20% reduction in fertiliser use across the trial area over the year.

Fungicide inputs

The fungal disease being managed in the Okehampton trial was fusarium patch (Microdochium nivale), common to golf courses across the world. The club typically applies a fungicide to all of the greens on the course twice a year, sometimes up to four times. Treating the whole 7,000m² course costs approximately £700 per application, with an annual fungicide bill that can reach £2,800.

Okehampton reported that no fungicide was required on either of the trial areas across the trial year, a 100% reduction in fungicide use on those areas over that period.

Water retention and drainage

Water retention and drainage were further factors that David and Stuart wanted to address. Summer 2017 was relatively wet, but the treated greens performed well in the trial team’s assessment. The trial areas drained better and faster than before when needed, and also held moisture in prolonged hotter weather.

The trial greens were reported as more resilient over the course of the year. During the hot dry periods they held onto moisture better and were visibly healthier. In wetter periods they did not flood, were firmer and drier, and remained playable. This is a significant advantage for the club during wet months: course flooding can lead to greens becoming unplayable, closures and lost revenue.

Next steps

David planned to scale up the trial to cover two entire greens, monitored across 2018. Applications would normally take place during spring and autumn maintenance windows. With the reduced fungicide, fertiliser and irrigation requirements reported by Okehampton on the trial areas, David expected a return on investment within a reasonable timeframe.

At the optimum application rate of 1kg per m² reported in the trial, enriched biochar is a single application that contributes long-term to soil function in the rootzone. The combination of reduced fungicide use and reduced fertiliser inputs reported on the trial areas at Okehampton makes biochar of practical interest to Course Managers.

David has expressed confidence in the approach. He said he would “highly recommend the use of Carbon Gold’s enriched biochar to all Greenkeepers and Groundsmen for the wider benefits of the product.” He added, “I believe that biochar will be used throughout this industry in the not too distant future.”

Substantiation note

The outcomes described on this page are as reported by Okehampton Golf Club from their 2017 trial on two greens. Quantitative figures (100% reduction in fungicide use on the trial areas, 20% reduction in fertiliser use on the trial areas) reflect Okehampton’s reported experience on the specified trial plots, not a controlled multi-site scientific trial. Outcomes at other sites will depend on biochar specification, soil and climate conditions. Carbon Gold does not currently publish product-level lifecycle assessments.