This picture, for me, encapsulates the case for Weed Suppressant Fabric. The net overhead and the collars around the plants give away that this was my brassica patch (in 2017). The strip to the left: no WSF. The rest to the right WSF applied in early spring. Which would you rather be faced with come the month of June? No contest. This trial evolved as a result of my wish to leave a strip in which to sow later brassicas that will not tolerate transplanting (Swedes, Pak Choi, Mooli) and was not staged to prove a point. None the less as I crouched on hands and knees under the net I thought it was worth taking this picture for the record, ready for that Autumn day when I would be warm indoors mulling over the lessons learned. 16 months later that day has arrived.
I do still have reservations. The fabric is made of woven plastic and is not biodegradable (although it lasts for years and is reused). It allows water through the weave but there are concerns for the effect it has on the soil/air interface. Do insects and worms like or abhor it and how does that affect the soil food web? I see the Garden Organic guidelines approve of it only on a limited basis for clearing weed patches although it is acknowledged as a longstanding tool for growing organic strawberries. A web search has plenty of rants against "landscaping fabric" in vegetable patches which surprises me some as I have not experienced the problems they describe. (Usually someone is renovating a recently acquired garden where the previous occupant has laid down a layer below soil level and weeds have grown on top. ) My piece follows (or rather precedes) the brassicas around the plot and has the bonus of already having the holes spaced out at just the right distance for planting.
For now, I will continue to use it on my brassica patch in order to reap the benefits, but I am now wary of leaving it down in one place for more than one season. I have just recently decided to carry out a worm survey of comparable patches with and without WSF to see if there is any discernible drop in numbers. If you can save me the trouble by pointing to any research on this topic - do please let me know. I don't know about you but I just find weeding a chore.