Complex sentence: The immediate impact of paying this poor rate fell on the landowners of the parish concerned, who naturally sought other means of dealing with the poor that would reduce both this impact and the aggravating features, such as the workhouse funded through parish unions.
Split into simpler sentences: The immediate impact of paying this poor rate fell on the landowners of the parish concerned. They then sought other means of dealing with the poor, such as the workhouse funded through parish unions.