Pilot young trees

Do young trees grow better when Kaumera is mixed into the soil to retain moisture longer? Trials by gardening company Hoefakker from de Bilt in their nursery were promising. In spring 2022, a pilot started in the forest near Loenen Falls, an area where water board Vallei and Veluwe operates. Now, six months after planting, we are seeing the first positive results.

Young growth thrives

The Water Systems Management Department of the Vallei and Veluwe Water Authority plants about 500 trees every year to improve the ecology around the water system. These young plantings, on high sandy soils among others, require manual care such as extra watering in the first three years after planting. Often, this is also on difficult terrain. In dry seasons, such as in 2018-2020, this care is even more intensive. Initial trials have shown that Kaumera's properties include retaining soil moisture longer. In addition, it can potentially provide additional nutrition in the early stages of growth.

How did we go about it?

In March 2022, a total of 60 new trees were planted with Kaumera as a soil conditioner in two different concentrations and a control group (0%). The Kaumera used comes from the water authority Rijn and IJssel plant in Zutphen. Soil moisture sensors allow good monitoring of soil moisture levels. The starting point of the study is to determine whether there is a positive effect of Kaumera on the growth of the planted trees, so that additional care can be limited in the early stages.

Measuring the effects

Hoveniersbedrijf Hoefakker (de Bilt) and Flexyz B.V. from Harderwijk, an Internet-of-things (IoT) company, have developed the innovative concept SmartCityTrees©. Here, tree care takes place based on data from soil moisture sensors. These are placed near the trees and provide a real-time measurement of soil moisture levels. In Loenen, these sensors are incorporated into tree poles so that they are optimally protected and can do their work for several years.

The first results

In the first six months after planting, we see a clear difference in soil moisture levels. Especially the planting circles where 10% Kaumera was mixed in show significantly higher moisture contents compared to the 0% and 5% planting circles. This is a nice result that more than meets expectations. Furthermore, we only had to water for the first time just under five months after planting. This is much less than you would normally expect.

Other factors such as location of the trees and weather conditions can also influence the results. Therefore, we monitor the trees daily using the moisture sensors and analyse the measurement results in combination with environmental factors.

Want to know more?

For more information, please contact us through the contact details at the bottom of the page.

60 trees were planted in Spring 2022

Sensors measure realtime moisture levels