Things could be tough in the countryside back then, and in times when work was short, labourers (agricultural or otherwise) could find themselves utterly destitute, with no prospect of relief. As you say, these poor people were sometimes driven to crime simply as a means of survival. Sadly, starvation was not infrequent, especially in areas where there was no alternative to farm work, and where the enclosures of the commons had removed any scope for a little private enterprise. Projects such as the Royal Military Canal must have been very welcome to fit labourers.
Agriculture in the UK has a turbulent history, with cheap imports from the empire often causing slumps in demand for local produce from the 1700s right up to the 20th century. There was at first no social care beyond the awful Poor Laws, whose workhouses effectively imprisoned and enslaved those without the means to live otherwise, and which were shunned even by some of the few who qualified for Poor Law relief. Benevolent landlords often began allotment schemes, to ensure that their villagers would have at least some means of producing their own food.