It depends a lot on the size of the site you are looking after and what aspects you take into account. Chemicals have a lot of hidden costs that are often not discussed, such as the cost of certifications, storage, joining the OCR register, keeping stock up to date, PPE, equipment. Then there are the costs associated with removing chemicals from our drinking water, etc that are not directly associated with the application.
The labour and capital expenditure linked to Mechanical and Thermal weed management is often not as high as people imagine, especially after the first year. Once the existing soil build up is removed, ongoing maintenance becomes far quicker and far fewer reactive treatments are needed. This is because it typically reduces the weed burden.
Then there are things like the savings over time associated with mechanical weed removal, because brushing extends the life of the surfaces, meaning they won’t need replacing of fixing so frequently.