Secure dog fields are the future for anyone with a 1 - 3 acre field. £10 per hour, 8 hours a day 7 days a week - why would you farm??? Insurance and Planning permission definitely required but I would say worth it. However if land is rented you would need to secure a tenancy for quite a few years to make it worthwhile.
So - how many dogs /day do you reckon you'd get at £10/hour and 8 hours a day? 80? From one local area? (I assume you're not suggesting that anyone is going to pay £10/hour for exclusive use of the field on a daily basis?)
I don't believe there are that many people prepared to pay for somewhere to exercise their dogs every day.
And how would you charge them? A yearly fee of £365? Can see that going down well as a lump sum payment
Or would you spend your entire time collecting small amounts from people? Even collecting 80 payments once a month would be a hassle. And how would you police those that hadn't paid? I'm afraid that dealing with large numbers of the general public is incredibly stressful.
For the reasons already mentioned it is in practical terms a none starter. The field would soon be full of dog muck (because many people
don't pick up) It would be a reservoir for disease (because of the numbers involved), and the public liability aspect would be almost impossible to quantify (my dog wouldn't hurt
anything!)
In addition the field would require cutting regularly and I personally would not want my machinery coated in excrement
to be passed on to other fields where my livestock graze.
So I don't believe I'm alone in saying that as a farmer I can think of few uses for my land that carry less appeal. Farming isn't all about making money - it's about job satisfaction and way of life.