Mechanism

Nüzül was designed as a form of requisitioning from farms, to feed Ottoman armed forces; large quantities of food were needed to support Ottoman armies in the field. Flour

Flour

Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...

 was a major constituent in the 16th-17th century. Producers were expected to deliver nüzül to the required destination, and were not paid for this. Nüzül was supervised by the local kadis

Qadi

Qadi is a judge ruling in accordance with Islamic religious law appointed by the ruler of a Muslim country. Because Islam makes no distinction between religious and secular domains, qadis traditionally have jurisdiction over all legal matters involving Muslims...

, an official who acted as both a judge and a tax-collector; Ottoman central government determined the kadi's jurisdiction, and set the levels of taxes to be collected - they were even required to arrange supplies of ship biscuit, in parallel with nüzül provision.

A waqf

Waqf

A waqf also spelled wakf formally known as wakf-alal-aulad is an inalienable religious endowment in Islamic law, typically denoting a building or plot of land for Muslim religious or charitable purposes. The donated assets are held by a charitable trust...

 might be founded to help a specific community pay their nüzül and avariz

Avariz

Avariz was a tax in the Ottoman Empire, an annual cash tax paid by households registered in a defter.-History:In early Ottoman history, the state depended on the timar system of feudal dues; but over time - especially due to the need to hire professional soldiers rather than peasants serving a...

 obligations. Frontier areas, such as Bosnia, might be exempted from these tax obligations (much as some pastoral groups in the marcher-land were given tax exemptions on the understanding that they would raid enemy territory).

History

Nüzül collection, as an irregular tax, began at least as early as the start of the 16th century. Initially, Nüzül was seen as an alternative to avariz

Avariz

Avariz was a tax in the Ottoman Empire, an annual cash tax paid by households registered in a defter.-History:In early Ottoman history, the state depended on the timar system of feudal dues; but over time - especially due to the need to hire professional soldiers rather than peasants serving a...

, which was a cash tax; in times of war, villages might be required to supply food to army supply points, or they might be required to supply cash; but never both. Over time, this relationship changed, and both might be demanded. As with other Ottoman taxes, what was originally a requirement for payment "in kind" became a cash tax over time. A related concept was sursat

Sursat

Sursat was a form of food requisitioning with price controls, used by the Ottoman Empire to provide consumables for its armed forces. It was related to nüzül; sursat was initially an obligation for the public to provide food and other supplies at a pre-fixed price which was unlikely to be...

, which was an obligation for food producers to sell food at prices dictated by central government.

Detailed Ottoman tax registers

Defter

A Defter was a type of tax register in the Ottoman Empire. The information collected could vary, but tahrir defterleri typically included details of villages, dwellings, household heads , ethnicity/religion , and land use.The defter-i hakâni was a land registry, also used for tax...

survive which show the levels and details of taxation in different provinces. Although the tax burden was very variable, nüzül and avariz were very important taxes in the 17th century - for instance, they represented 58% of all tax revenue in Manastir in 1621-1622 - but by the 18th century their importance had declined, and more money was collected through other taxes.