Muqasama had been common practice in the Mamluk empire, and much of the Middle East, even before the spread of Islam; a similar system had been used in Sassanid Persia.
Muqasama was a tax directly applied to agricultural output, taking a proportion which varied between areas and between producers.
These discriminatory rates caused inefficiencies; as farmers reacted to locally varying taxes on different farm products, this increased variations in agricultural output between areas, or even between villages.
early forms of öşür were enforced in transit, with watchtowers on transport routes, and checkpoints at bottleneck locations such as bridges and passes.
[3] There was very wide variation between different regions, and the tithe was extended to cotton, fish, honey, and silk as well as the usual fruit and vegetables.