There is an ethical problem behind using pigeon lofts. I can build a pigeon loft to house hundreds of pigeons on a tiny patch of
land. They fly large distances foraging - including over other farmers' fields. The birds fatten up for me to harvest, and produce fertilizer for me to use on my land - but it comes at the expense of those around me.
In the UK they used to be the exclusive privilege of the wealthy landowners, who enjoyed squab on the table regularly while the pigeons foraged the fields of their tenant farmers.
Now pigeons are recognised as a pest species and hunted here, to protect crops. It is not unusual to see flocks of 200+ birds descending on a single field. They tend to hit freshly seeded land, or when crops are sprouting with tender new shoots.