Studies on allelochemical and mineral compounds for sustainable weed control in a pavement filler from brick recycling material

ABSTRACT

Here, organic and inorganic compounds, most of them naturally occurring, were selected on the basis of their potentially high resistance to leaching, in order to explore their potential to prevent the germination of weed seeds in inert substrates as well as in pavement filler based on brick wall recycling material (BRC). Using the weed species Lolium perenne, Poa pratensis, and Plantago lanceolata, it was shown that the susceptibility to either alkaline or allelochemical environments was plant species-dependent with regard to seed germination. In a cumulative leaching test, where a total of 53 L of water was rinsed through 1 L of filler material, the organic compounds juglone, lactic acid, pelargonic acid, and pelargonaldehyde all lost their initial inhibitory effect within a short time. In contrast, the suppressive effect of 2% w/v boric acid and 20% w/v sodium silicate (with a molar ratio of Si/Na of 3.35) was as persistent as that achieved by the sodium silicate-enriched commercial joint filler Dansand®. Results reveal sodium silicate as the most promising tested compound to achieve a long-term weed-suppressive effect in BRC with the lowest potential harm to soil invertebrates.

KEYWORDS:

• Alternative joint filler
• boric acid
• sodium silicate
• unbound pavement
• weed prevention

Acknowledgements

We would like to thank the Weimar Institute of Applied Construction Research (IAB Weimar) for project coordination, and the Bauhaus University of Weimar for chemical analysis of the recycling material. We thank the editors and the reviewers for their constructive comments, and Robert Koebner (Norwich, UK) for his editorial work on this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Federal Ministry for Economic Affairs and Energy (BMWi), and the German Federation of Industrial Research Associations (AiF) as part of the Central Innovation Programme SME (ZIM) [grant number KF 2043510KI1].