Soil compaction is an invisible threat to trees in the city. As people, cars, trucks, mowers and other heavy vehicles constantly compress the soil, soil compaction occurs.
Soil compaction is an invisible threat to trees in the city. As people, cars, trucks, mowers and other heavy vehicles constantly compress the soil, soil compaction occurs.
Without the help of soil life, trees can absorb less nutrients and water. This stunts their growth and makes them vulnerable to diseases and pests. Soil improvement and sensor company Soilmania is working hard on an innovative methodology to address soil compaction and restore gas exchange between soil and atmosphere. This is a basic prerequisite for obtaining soil life and healthy trees. Ecological engineer Nadina Galle sat down with Soilmania and tells us more.
In fact, soil compaction prevents trees from taking root properly, making them blow over more quickly. Soil compaction occurs when the soil is compressed: the structure changes and the pores become smaller. New hair roots can no longer develop and a lot of soil life dies off. This limits the ability of trees to absorb nutrients and water. Often this is not enough for a mature tree.
Soil compaction also limits water infiltration. Project manager and co-founder of Soilmania, Didy Arnold, says, "A lot of water runs off as a result and doesn't reach the tree. Even after a wet period, trees then still quickly run dry." Soil compaction also interferes with gas exchange between soil and atmosphere. At the bottom of the soil, anaerobic (oxygen-free) conditions can therefore develop. Sometimes toxic gases also accumulate here, creating unfavorable conditions for tree roots and aerobic soil life. As a result, tree roots are less well protected against diseases and pests.
Counteracting soil compaction requires structural measures when creating growing sites to deal with the pressure exerted on the soil. But what to do with existing growing sites that are already compacted? To eliminate the resulting soil compaction more efficiently, Soilmania has developed an innovative machine in collaboration with contracting company De Mulder-Strijbosch.
After Willy removes the lance, he fills the holes with a compost mixture. This consists mainly of nutrients for soil life. He determines the composition of the mixture on the basis of Soilmania's soil analysis, called "Soil Insight 2.0. This analysis distinguishes itself from classic soil analyses by focusing on three factors: the soil environment (including the pH and oxygen levels in the soil), the soil chemistry (available nutrients) and the biological processes (bacteria and fungi) taking place there. This analysis provides insight into soil biology, structure and fertility. All of these factors have a major impact on the growth and health of a tree.
To monitor soil recovery after "plopping," Willy installs a soil life sensor from Soilmania. This sensor measures soil moisture, soil temperature, dissolved nutrients, acidity (pH) and field oxygen levels. The sensors are continuously connected to the cloud where all measurement data can be seen at a glance on the dashboard, so that additional measures can be taken in the field when needed.
In Mönchengladbach, a compact city in the German state of North Rhine-Westphalia, this method worked very well. In the centrally located Schmölderspark, after the extremely dry summers of 2018, 2019 and 2020, the mature trees became less and less vital. One beech after another was dying. The municipality thought this was due to soil contamination and that the soil needed to be remediated.
Read more about this caseIn a previous thud treatment in another park, the results were also quite striking. Six weeks after the treatment, a doubling in the tree's resilience was noticeable. The tree had much more growth speed and growth inhibition had been reduced by 80% due to organic breakdown. Willy was able to meticulously track these improvements all in his dashboard.
Most surprising? Willy says, "These results! With the traditional method, where a small cycle is started on the soil surface, it takes years to get these results. Now we're seeing results in six weeks." And that, according to Willy, is unprecedented. By efficiently removing soil compaction and feeding the soil, the soil environment recovers and people can enjoy beautiful healthy trees for generations to come.
