‘Via sand channels, we want to get nutrients into the soil at a greater depth.’
Moving towards chemical-free management, VGR is developing a maintenance method that consists of cultivation and natural soil-improving products. The motto is Healthy Soil Better Turf. To support this, VGR is working on trials using a compost product as the basis for good soil. A golf club, one of VGR’s earliest customers, is participating in one of these trials, using VGR's GreenGood product on a green and tees to improve turf quality.
In developing a chemical-free maintenance method that also requires less fertiliser and irrigation, VGR has focused for 22 years on a combination of adapted precision mechanical operations and natural soil-improving products. The GreenGood compost product is part of this constantly evolving method.
GreenGood products are made from composted green waste and come from the VGR site in Almkerk. In fact, the VGR Group chain organisation consists of three mutually reinforcing parts: the VGR Composting Plant, VGR Equipment and VGR Services. VGR Equipment generates green waste streams during the maintenance of green areas, in particular sports facilities. The VGR Composting Facility processes these into new soil-enhancing products and wood chips. These products are used by VGR Services to improve the growing conditions of the turf being maintained. The GreenGood compost is naturally dried in Almkerk and enriched and stabilised by fermentation.
A fine fraction of GreenGood is used for green areas and a coarser fraction for sports fields. Both GreenGood products are fully matured, and once injected into the soil by the VGR TopChanger, the dry material is gradually converted by soil life into nutrients that grass plants can absorb. “Composting is an organic process that provides a natural means of improving soil resistance and grass growth,” said Arwin Verschoor, soil specialist at VGR.
Customer for twenty years
The test site golf club became a customer soon after VGR was founded 22 years ago. Verschoor started with scarifying and aerating and later expanded the work to include cleaning ditches and pond edges and overseeding bare areas. The VGR TopChanger has already injected GreenGood into the ground on several occasions. In recent years, VGR has been scarifying the course with the contour following Maredo MT200 Flex-Verticutter.
The head greenkeeper, who has been with the club for almost 20 years, explains how the GreenGood products are used at this golf club. “On the tees, we repair divot damage on a weekly basis with a mixture of sand and Greengood.” Ruud de Deugd, who worked with VGR’s greenkeeper, said. “On the 4th green, we injected a mixture of 95% sand and 5% VGR GreenGood, a very fine, high-quality compost - 1-2 millimetres. By introducing this stable organic matter, we are trying to get the food web of soil life going to make the soil more resilient.”
The proportion of Growth Food compost in the mix can be adjusted to suit. Ruud already reports that grass germination is good and seedling dehydration is low, as the compost retains moisture.
Trial on the 4th Green
In 2019, the golf club, together with VGR and a consultant, started a trial on the 4th green. A mixture of sand and a fine fraction of mature GreenGood compost, specially developed for golf greens, was injected at a depth of 10 to 15 centimetres. Ruud: “When this course was built 20 years ago, the greens were 100% sand. We found that they were subject to a lot of leaching, and as a result, the CEC in this green is tremendously low. In the top layer, the organic matter content is fine, but at a depth of 1.10 metres, it is low, less than 2%.”
Ruud: “Through the sand channels the TopChanger creates to reach further into the soil, we want to get nutrients into the soil at greater depths. By creating a more active soil life, we want the felt layer to break down naturally. Green four suffers a lot from dollar spot. With the fungi and bacteria from the compost, we want to strengthen the grass plant to fight disease and ensure a faster recovery from dollar spot.”
Patience for results
“We have to be patient to see results”, says Ruud. “This kind of development is gradual and must be done meticulously, in combination with the fertilisation schedule that the consultant has written for us. Because of injecting and aerating with the TopChanger, we can apply compost on only 3% of the green area. So, several tillage sessions are needed to introduce compost into the soil over the entire green. The golf club wants to run this trial on the 4th green until around 2023. Through the application of compost, we hope to eventually need to fertilise less and use less water and pesticides.” Since there was a lot of damage from grubs on the fairway in 2020, on the advice of another consultant, the golf club will start working with compost there too.
The fact that compost can be introduced per application on only 3% of the total green area is put into perspective by Verschoor: “The difference between 3% and nothing is a lot. The advantage of enriching 3% each time with compost is not only that added three per cent, but also the progressive effect due to the synergy created in the soil. As the bacteria and fungi in the compost do their work, the activity of the soil life goes up considerably and increases soil resistance. It rebalances the soil, and the turf benefits from that.”