Thank you all very much for the replies - very helpful
We have plenty of chickens and they'll be there as soon as they see a spade being wielded. Have also found several mentions on the web about trapping wireworm using sliced potato, so may give that a try.

Hello there, we are running out of space in our veg plot and are planning to dig up part of a paddock to grow larger crops of onions and potatoes
I seem to remember there is a pest in grassland that could cause problems. Is there anything we could do in advance to prevent problems later?