Best to double check:
a) has the manure and/or straw been treated with herbicide (particularly aminopyralid or another one with a similar name) - this can persist in the soil for more than a year, and has impacts on certain plants such as spuds, beans and tomatoes; and
b) does your plot tenancy agreement allow you to leave it fallow for a year? With mine, you'd get kicked off for non-gardening.