If you have never had your own horses, or looked after them 24/7 365 days plus a leap year, in all seasons, then don't do it. Use the land for something else, or as a PP poster suggested rent it out and enjoy the income.
Horses are hard work. They need routine care including new shoes every 5 to 8 weeks at nearly £100 a pop. More if they need special shoes. They need worming. You need to muck out at least once a day, clear the paddocks of poo, remove and manage your muck heap, repair fencing constantly, ensure a constant supply of grazing or hay, skip out beds if they are kept in during bad weather on top of your muck out, they need exercise, they need their weight managing, they need monitoring for injury/colic/general health twice a day ideally.
And that is before you start to factor in the costs of lessons to learn to ride them, competitions, tack, rugs, clothes appropriate for riding, developing an unhealthy obsession for finding the perfect set of wellies and winter coat to suit the changeable seasons. There is also more mud and grooming required than you could ever think possible.
And all this on a good day. Factor in things like injury, box rest, the day the little monkeys don't want to be caught and brought in but there is a storm brewing and you need to get to your child's nativity etc etc etc etc... and it is a whole lot worse.
In essence they are a lifestyle choice and then some. They always come first. They eat up your income as if they are a black hole.
I wouldn't be without them but they are very definitely not something to play with. And my advice would be to spend a long time (good couple of years) of try before you buy at a well run riding school or livery yard. Most people start with horses when they are young. Older riders tend to have children that have flown the nest or had them as kids and return to riding and horse ownership at a later stage. Few start from scratch, on their own land, as adults.