The article said that this has historically been used for nitrogen-demanding crops, so it must have some value. "Pigeon towers became a crucial part of the agr

The article said that this has historically been used for nitrogen-demanding crops, so it must have some value. "Pigeon towers became a crucial part of the agricultural economy, providing much-needed fertilizer for melons, cucumbers, and other nitrogen-demanding crops—cornerstones of Persian cuisine."