All crops are inclined to be grown in monocultures. That's because even if you'd get more yield pairing with other species — as in these studies — pragmatically

All crops are inclined to be grown in monocultures. That's because even if you'd get more yield pairing with other species — as in these studies — pragmatically the time and cost of sowing, harvesting and separating multiple species outweighs the theoretical yield gain per unit area of a monocrop.