It is a spectacular sight: the helicopter flying close to treetops and unloading a cubic meter of rock dust every two minutes. That rock flour is a soil improver and fertilizer in one and should improve the Dennendijkse Forests near Asten. “The soil here could use a boost,” says Roel van Haandel, project leader of Bosgroep Zuid Nederland.
The municipality of Asten has received almost one million euros in subsidies from the province and the European Agricultural Fund for Rural Development. Roy Heymans from the municipality of Asten: “This is really necessary. You can see the decline in some areas of the forest: how the tree tops are slowly dying.”
“It is quite an operation. There is a lot involved: contact with Eindhoven Air Base and the paths have to be closed. People have to know where we are going to fly. It is a very fun, complicated puzzle,” he says, beaming. “I’m very proud.”
Project leader Roel van Haandel: “In recent decades, the soil here has become acidified due to the precipitation of nitrogen and acid rain. Many species have disappeared and have not returned. You see fewer and fewer deciduous trees and more and more pine trees. So the soil here can We do need a boost and rock flour is the product we use for this. This reduces soil acidification, making it easier for other plants to grow again.”
“We are also going to plant new tree species with more digestible leaves, which will give us more soil life,” adds Roy Heymans of the municipality of Asten. “We hope to eventually have a more beautiful, more varied forest here with more animal species.”
Project leader Roel van Haandel explains what rock dust is. “It is a residual product from mining in Norway. It is a mixture of volcanic material and crushed basalt. It is very rich in lime and potassium. It takes about thirty years to improve the acidified soil,” Roel explains. He worked for two years towards this moment. “It’s very nice to see that the helicopter is finally in the air.”