Assuming the land is currently agricultural:
Where is it in relation to your house? If adjoining, be careful it is not seen an extension to a garden, or you will run into change of use issues (agricultural <-->domestic) with planning. You only need one person who gets jealous and sees it as you using it to boot a residential property value for things to become a faff.
It might be an issue if you claimed BPS grant. Don't know much about that.
Other than that, is it a private orchard or a community orchard? If other people are involved, even as volunteers, it may require a change in your insurance.
Consider if you might want to revert back to grazing - there's a difference in planting trees as a shelter belt than for orchard.