In recent years, the municipality of Leeuwarden has worked fairly closely with Rinagro on various projects. Wonderful results have been achieved within these projects and special discoveries have been made. For example, the trial with roadside grass as a soil improver was successful, and the mineralization with Compost-O® retained the nutrients. With a washout of 0!

Particularly interesting is also the reason why we ended up at the municipality. Within composting, Rinagro’s liquids proved to be able to completely remove the germination capacity of (unwanted) weed seeds. The germination capacity of the seeds in the mass is an important matter within composting, because compost in which (weed) seeds still have germination capacity is not favorable for the sale thereof. If one fills the garden with compost for soil improvement and all of a sudden weeds and grasses emerge, then that is far from pleasant. In addition, weeds can have a negative impact on our biodiversity, because they simply grow very dominantly.

For example, the Japanese knotweed is a headache for both municipalities and many private individuals because the plant, or rather this weed, is difficult to remove from gardens, beds and fields. Solutions for this tenacious plant so far include:

Placing the plant under extremely high voltage, which would electrocute the plant.

Digging up the soil up to 4 meters deep, so that the root system is also removed as much as possible. The soil is then removed and destroyed.

And the last option is to treat the plant and the soil with pesticides, so that the plant will die.

However, there are objections to these options…

For example, the smallest piece of root would retain germination if it is not reached with the high tension, remains in the ground when it is dug up or is not reached by the pesticide.

Moreover, the consequences with regard to the climate are also an area for improvement. A lot of fossil fuels are currently used in the excavation, removal and destruction of the soil. In the case of pesticides, both the soil and its soil life, the groundwater and the surrounding plants then have to endure a lot.

All aspects together have motivated us to set up an experiment to see if we can process the plant in a sustainable way. The idea is that the Japanese knotweed may be very anaerobic. When these are completely, root and all, penetrated with Compost-O® or our pure bacteria, so they are composted, that the plant is no longer viable. If this is successful, we will do tests with an “contaminated” soil that we will then treat.

The photo below shows the composting setup as it was set up at the end of 2022. We hope that in the next newsletter the organic material has been completely mineralized and that the compost has already been used in a test setup.