Sawad

Sawad was the name used in early Islamic times (7th–12th centuries) for southern Iraq. It means "black land" or "arable land"^[1] and refers to the stark contrast between the alluvial plain of Mesopotamia and the Arabian Desert. Under the Umayyad and Abbasid Caliphates, it was an official political term for a province encompassing most of modern Iraq except for the Syrian Desert and Upper Mesopotamia in the north.

As a generic term in Arabic, sawād (سواد) was used to denote the irrigated and cultivated areas in any district. Unmodified, it always referred to southern Iraq, the sawād of Baghdad. It replaced the earlier and more narrow term Rādhān.

The term sawad eventually came to refer to the rural district around a particular city; thus, contemporary geographers made references to the Sawad of Baghdad, of Basra, of Kufa, of Wasit, of Samarra, or of Anbar. This usage was exclusive to Iraq.^[2]:16

The enormous economic potential of the Sawad is reflected in early Abbasid revenue lists: the Sawad produced four times as much tax revenue as the second-highest-producing province, Egypt, and five times as much as Syria and Palestine combined.^[3]

During the medieval period, the lower Tigris followed a different course than it does today. It had shifted further west due to the floods of the early 7th century (before this, its course was the same as it is today). It passed the city of Wasit and entered the Batihah at the town of Qatr.^[4] According to Donald Hill, after about 1200, the Tigris and Euphrates started to gradually shift toward their present courses, which they finally reached during the 1500s.^[4] On the other hand, Stephen Hemsley Longrigg described the shift as taking place in the period between 1500 and 1650.^{[5][note 1]}

In Sasanian times, the Euphrates likely entered the swamps close to the site of the modern town of Shinafiya.^[6]:210

The Batihah (plural: Bata'ih) or great swamp was the medieval name for the vast marshlands of southern Iraq, along the lower courses of the Tigris and Euphrates.^[2] In the northwest, it stretched almost up to Kufa and Nippur, while in the northeast it began at al-Qatr, downstream from Wasit on the Tigris.^[2] Suhrab lists four great lagoons (Ḥawr) in the Batihah: Bahassa, Bakhmasa, Basriyatha, and finally al-Muhammadiyah, which was the largest.^[2] Below the Hawr al-Muhammadiyah, the channel called the Nahr Abi'l-As'ad finally carried the waters of the Batihah to the head of the Dijlah al-`Awra', or "one-eyed Tigris".^[2] The hydrography of the Bata'ih was not static.^[2]

Ibn Rustah described the Bata'ih as covered by reed beds crossed by water channels, where enormous amounts of fish where caught, then salted and exported to neighboring provinces.^[2] The water level was too shallow for most river boats to pass through, and only special pole-propelled vessels called mashhuf could be used for transport.^[2] Most of the marshes were covered by water, but there were some areas with good soil, where people formed settlements, grew crops, and dug canals for irrigation.^[2]

The vast, complex systems that emerged during the Sassanid period ultimately made local self-sufficiency impossible. Lack of maintenance on canals could have a strong adverse effect on faraway regions. This made state supervision of the infrastructure absolutely necessary to maintain this degree of settlement and cultivation.^[7]:82

Settlement in Iraq reached its apex during the late Sassanid period. The tumult surrounding the Islamic conquest led to a sudden, steep decline.^[8]:93 Fairly quickly, however, the Muslims were able to restore much of the Sassanid establishment. However, from the mid-800s onward, political instability in the Abbasid Caliphate led to a neglect of the rural economy and more corrupt exploitation of the peasantry in search of short-term profits.^[7]:84 This led to a long period of decline in population and in cultivated area over the centuries until the Mongol conquest.^[8]:93 The destruction accompanying the Mongol conquest was the dramatic final blow to the patterns of settlements in Iraq.^[8]:93[7]:84

Islamic

Archaeological evidence indicates that there was "a precipitate retreat from a vast central area of the Sawad" during this period, only reversing itself in modern times.^[6]:214 After the golden age of the Abbasid Caliphate during the reign of Harun al-Rashid from 786 to 809, imperial revenues from the Sawad plummeted from 100 million dirhams to only 20 million by the early 10th century. The sharpest decline took place between the records of Ibn Khordadbeh in the mid-9th century and Ali ibn Isa in 915: in many formerly prosperous districts, a drop by 90% or more took place "in this period of less than a single human life span."^[6]:215 In the intervening years, there had been several decades of rural unrest and conflict, provoked by years of increasing tax burdens and abuses by state officials, as well as outright looting by Turkish mercenaries.^{[6]:215–216} The single greatest precipitating event was the Abbasid civil war and Siege of Baghdad (865), which "wiped out any notion that the government's reciprocal function of protection could be honoured".^{[10][note 2]} The Zanj rebellion lasted for 15 years before finally being quelled in 883, and the Qaramita movement that followed it was even larger and longer-lasting, leading to the area under state control shrinking dramatically and "prospects for any constructive, long-term approach to the agrarian economy diminished to the vanishing point."^[6]:216 Contemporary sources report this as a time of administrative and economic collapse, with many villages destroyed, communications disrupted, robbery and brigandry were rampant, and cultivation was made practically impossible.^[2]:71 By the early 10th century, 62% of settlements in the area around Baghdad had become abandoned.^[7] Yet at the same time, a movement of popular nostalgia emerged, "glorifying indigenous 'Nabataean' achievements, especially those connected with the spread of civilization and the improvement of agriculture. Even as actual conditions were deteriorating intolerably, exhaustively detailed compendiums were appearing with elaborate botanical nomenclature and careful specifications of all the procedures and requirements of good husbandry."^[6]:216

The intentional breaching of the Nahrawan canal by Ibn Ra'iq in 937 led to a severe water shortage in the region, leading to widespread emigration. The repercussions were felt heavily in Baghdad, since there was a desperate lack of grain leading to starvation.^[7]:86

The lands of the Sawad were among the most fertile in the Islamic world, but this productivity was almost totally dependent on artificial irrigation: dry farming requires 200 mm of rainfall per year, an amount reached in almost nowhere in the Sawad. Basra, for instance, has 60 mm of rainfall per year. Without irrigation, agriculture here would fail.^[3]

The amount of water used in irrigation was crucial: excessive irrigation would cause a dangerous rise in the water table, as well as enabling capillary action to bring saline water up to the surface. Too little irrigation, on the other hand, left no extra water to leach the salts that had been deposited from previous irrigation.^[2]:93Robert M. Adams suggested that, after the opening of the Katul al-Kisrawi made water readily available to farmers in the lower Nahrawan region, over-irrigation caused the water table to rise dramatically. Today, much of this region's soil is too saline for irrigated agriculture, and the area is largely abandoned.^[7]:81

A similar phenomenon occurred in the Sawad of Basra. Insufficient gradient in local irrigation systems resulted in poor drainage of salts from the soil. To counter this, laborers, including the Zanj, were tasked with removing the salty topsoil and piling it up by the sides of the canals. As many as 45 million tons of soil were moved in this manner, but even this was insufficient. After Basra itself was sacked by the Zanj and then again by the Qarmatians, much of the fields were abandoned and never brought into cultivation again.^[3]

At its apex under the late Sasanian period, the irrigation system of the Sawad must have diverted virtually the entire flow of both the Tigris and Euphrates to agricultural purposes.^[11] Regarding the Euphrates, Robert M. Adams wrote that, "with a whole series of massive diversions upstream, it is not unlikely that in Sasanian times the Euphrates entered the swamps [at its lower end]... with very little if any residual flow."^{[6]:210[note 3]}

Mechanical irrigation

Buzjani outlined five main mechanical devices used for irrigation purposes in the Sawad. The first, the nā'ūr, was a waterwheel powered by the flow of the stream itself. They were used extensively in the area of the Nahrawan Canal, in the region of Anbar on the Euphrates, and in the western part of the Baduraya district, west of Baghdad. The second, the dūlāb, was another type of waterwheel; it was powered by animals (typically horses or oxen, although in the area of Anbar they were powered by camels) instead of water thrust. These were commonly used around Baghdad and Anbar. The third was the daliya; it was a waterwheel powered by human labor. The fourth, the shādūf, was a bucket operated by four people; it was in use in the area of the Sarsar canal. Finally, the bakra was a simple animal-powered device used to transport water taken from wells.^[2]:46–51

Ibn Wahshiyya wrote a detailed book on agronomy called Kitab al-filaha al-Nabatiyya, or The Nabataean Agriculture, which documents many of the agricultural practices of the Sawad in the 3rd century AH.^{[2]:110–111}

The techniques used by farmers in the medieval Sawad were mostly the same as those used by twentieth-century Iraqi farmers.^[2]:110 Buzjani and Ibn Wahshiyya both wrote extensively on such practices. Several different ploughs were in use, including the sikkah, or iron coulter. An instrument called the mijrad was used to level a field after it had been ploughed.^{[2]:122–123}

Grafting was practiced extensively: most fruit trees were grown this way rather than from seeds. Ibn Wahshiyya wrote a detailed description of the practice. Layering was done with vines if there was enough space for it.^{[2]:107–108}

Ibn Wahshiyya described two general types of manure used to fertilize crops in the Sawad. The first was "natural" manure, which consisted of either dried plant matter, feces (both animal and human), or ash and cinders. Ibn Wahshiyya preferred this kind. The second kind was "composite" manure, which consisted of a mixture of several types of "natural" manure along with earth and water, and was left to decompose after mixing. Different crops called for different kinds of manure, and some needed no fertilization at all. Manure was traded and sold locally, according to several sources, including Ibn Wahshiyya, Ibn Bassam, and Yaqut al-Hamawi.^{[2]:109–110}

The Abbasid government played a role in supervising cultivation. It would sometimes loan money to farmers to help them buy seed and livestock. Some poorer farmers were directly given seeds. The government expected repayment in full after the harvest.^[2]:156

At the maximum extent under the late Sasanian dynasty, the Iraqi countryside would have been under "virtually continuous cultivation", supporting a much larger population than in previous periods.^[6]:180 During the time of the caliphs Harun al-Rashid and al-Ma'mun, the total winter acreage for cereal crops has been estimated at 3 million hectares in cultivation during a single winter.^[11] (Since land was fallowed every other year, the actual amount of land set aside for grains would have been twice that.)^[11]

Major crops

Wheat and barley

Wheat and barley were grown in every district of the Sawad. In most of these districts, the kharaj tax was paid mostly in the form of those two grains. Tabari described the four districts surrounding Baghdad as extremely productive, which is partly why the caliph al-Mansur chose Baghdad for the site of his new capital.^{[2]:121–122}

Breads made from wheat and barley formed the main food for most Iraqis, especially in major urban areas such as Baghdad, Wasit, Basra, and Kufa. An especially popular dish was al-tharīd, which consisted of pieces of bread with either vegetable soup or a combination of olive oil and vinegar. Dishes such as burghul, habbīya, and disheesh were made from boiled and peeled wheat. Other dishes consisted of a paste made from mashed meat and pearl wheat. Most Iraqi peasants ate more barley-based breads, which were often made with millet and beans mixed in. Additionally, a kind of alcoholic beverage was prepared from a mixture of barley and millet.^{[2]:125–126}

According to Ibn Wahshiyya, six different kinds of wheat were grown in the Sawad.^[2]:125 The most important wheat-growing areas were located around Kashkar and Anbar, although both districts experienced a steep decline in wheat production by the end of the 3rd century AH.^{[2]:123–124}

Perhaps due to its greater resilience to the increasing soil salinity, barley was a more common crop than wheat in the medieval Sawad.^[2]:124Ibn Hawqal notes the region surrounding Wasit in particular as an important barley producer.^{[2]:122–123}

Rice

Rice was grown in the parts of the Sawad that were warm and humid – two conditions necessary for it to thrive. Qudama noted that four districts paid taxes in barley and rice instead of the usual barley and wheat, indicating that rice was a particularly widespread crop there. These districts were Sura and Barbisama, Furat Badaqla, Nistar, and Kashkar. The rice plantations around Jamida, as described by Qadi Tanukhi, constituted some of the richest rice-producing areas in the Sawad, which enticed government officials to compete for the control of the region.^{[2]:126–128}

Ibn Wahshiyya wrote a detailed description of the cultivation of rice in the Sawad. There were two growing seasons for rice in the Sawad: a summer season, which was entirely dependent on irrigation, and a winter season, which was supported by rainfall. Summer rice was planted during the second half of July (Tammuz) and harvested in December (Kanun al-Awwal). Winter rice, meanwhile, was planted at the beginning of January (Kanun al-Akhir) and harvested in May (Ayyar and June (Haziran). Rice farming required meticulous preparation, fertilization, irrigation, and labor for harvesting and threshing.^[2]:128

Rice, and particularly rice bread, was a dietary staple in southern Iraq, especially in the Bata'ih and Basra regions. Rice was often served with fish and/or vegetables. Various recipes called for rice to be cooked with milk, butter, oil, or fat, and seasoned with salt. Rice-based pastries were also eaten, and a type of rice wine called nabīdh was produced in many districts, including Abdasi, Badaraya, Bakusaya, and Junhula.^[2]:128–9 Rice bread, like barley, was cheaper than wheat bread, which resulted in it gaining a reputation as being food for poor people. Nonetheless, rice remained the single most important food for many people, especially the poor, in southern Iraq due to its low price.^[2]:129

Other cereals

Described as a summer crop by Ibn Wahshiyya, sorghum (dhura) was grown in large quantities throughout Iraq. Bread made from sorghum flour, especially when mixed with wheat and barley flour, was regarded more highly by Southern Iraqis than rice bread. Sorghum was also grown for use as fodder; Ibn Wahshiyya considered it the ideal fodder for livestock, especially cows and goats.^[2]:130

Oats, rye, and millet were also grown for use as fodder in the Sawad. Ibn Wahshiyya recorded the nahiyahs of Saqī dijla, Asfal iqlīm Bābil, Jūkhī, and al-Jarāmiqa as producing these crops in large quantities. Ibn Khordadbeh wrote that, in the Rustuqbadh district, millet was used alongside barley to pay taxes, indicating its local importance. Alfalfa and clover were also grown as fodder as well as to replenish soils, but their importance appears to have declined after the second century AH.^{[2]:130–131}

Textile crops: cotton, flax, and hemp

The most important textile crop in Iraq, cotton was especially cultivated in the Sawad of Basra. Ibn Wahshiyya considered the ideal soil for growing cotton to be clayey and free of salt. It was sown between late April and late May, and harvested in June and July.^[2]:131

Flax (kattān) was especially grown in the central part of the Sawad, where, besides being used for textiles, it also formed a dietary staple; flaxseed flour was used to make bread. Flaxseed oil was also used to light lamps.^{[2]:131–132}

Hemp was grown both for its textile use as well as for hashish. It was planted in late February and in March, and harvested in June. Hemp was woven into a rough but durable cloth; its fibers were also used to make ropes.^[2]:132

Dates

In much of the Sawad, the date was a crucial crop, almost as important as cereals like wheat, barley, and rice. Basra alone grew 300 varieties at the time of Caliph Al-Mu'tasim. In the Sawad of Basra, dates were the main dietary staple for much of the population. Dates were not only eaten plain: they were used in producing a strong type of vinegar as well as various beverages, and, despite Islamic prohibition, they were used to make a type of intoxicant. Ibn Wahshiyya praises the myriad uses of the date palm, remarking that every part of the tree was useful – it provided timber for construction, its fronds could be used to make furniture as well as boats, and it produced a sweet syrup that was highly valued.^[2]:128

Contemporary financial records seem to imply that the palm trees themselves were exceptionally spread out in early Islamic orchards. The tax schedules say that date orchards paid 5–10 dirhams per jarib in taxes, which at a rate of 1/2 dirham per ordinary tree and 1 dirham per finer "Persian" tree implies a density of about 95 date palms per hectare. Today, on the other hand, the typical practice in the area around Basra is to pack 450 trees into a hectare. The Neo-Babylonian standard of 227 trees per hectare is also much denser. The apparent low density of early Islamic date palm orchards remains an unsolved problem. It's possible, however, that this is just an artifact of how the contemporary taxes were set: they may have been intentionally set low in order to encourage more date palm production, and that in practice the actual density was much higher.^[6]:217,351

Grapes

These were used to produce raisins and currants.^[2]:138

Citrus

At first only the citron was grown in Iraq, with Ibn Wahshiyya and al-Dinawari each distinguishing between two varieties of citron: sweet (aṭrunj ḥulū) and bitter (aṭrunj ḥāmuḍ). Later, in the early 4th century AH, citrus trees such as the lemon, orange, and bitter orange were introduced to Iraq from India.^[2]:140

Other fruits

According to Ibn Miskawayh, melons and watermelons were the most popular fruit in Iraqi markets. Ibn Wahshiyya wrote that they were widely cultivated in Iraq and listed eight different varieties of them, but said that it would be difficult to list all the varieties grown at the time.^[2]:140

Figs were another commonly grown fruit. The district of Hulwan was especially known for growing figs. Al-Dinawari distinguished between four basic types of figs: bustānī, grown in gardens and orchards; barrī, or wild; sahlī, grown in flat areas; and jabalī, grown in the mountains. He also described ten different specific varieties of fig, with varying size, taste, and color.^[2]:139

Ibn Wahshiyya listed the following as fruits grown widely in most parts of Iraq during his lifetime: apricots, peaches, pears, prunes, damsons, quinces, apples, pippins, bananas, mulberries, black mulberries, raspberries, blackberries, and olives.^{[2]:139–140}

Herbs

These included mint, chicory, capers, fennel, dill, parsley, sage, basil, etc.^[2]:135

Other crops

Plants grown for use in dyes included madder (fuwwah), which produced a red dye, saffron (za'farān), which produced a yellow-orange dye, indigo (nīla), which produced a deep blue dye, and henna, which produced a dark orange dye and was also used for cosmetics.^[2]:133

Asparagus was introduced to Iraq from the Jordan valley, and was grown in the regions of Bājarmā, Saqī Jūkhā, Bābil, and Khaṭarnīyya.^[2]:133

Sesame was grown to make sesame oil, which in Iraq was far more widespread than olive oil. Ibn Wahshiyya warned that sesame should not be grown in back-to-back years because doing so would deplete the soil's nutrients. Al-Muqaddasi described the environs of Tikrit as ideal for sesame cultivation. Wasit was also an important sesame producer in the early 4th century AH.^{[2]:133–134}

Various types of flowers were grown, mainly for use in medicine. Ibn Wahshiyya singled out roses in particular; they were used to make rose oil and rosewater.^{[2]:141–142}

Ibn Wahshiyya also enumerates 35 different kinds of "unfruitful trees" which were planted to supply wood.^[2]:142

During the Sasanian period, and probably continuing into the Early Islamic period, large-scale industrial operations were carried out even in the countryside, far from the major cities.^[6]:211–2 For example, one newly-dug Sasanian canal in the area north of Uruk was studded with sites that specialized in glass manufacturing. At these sites today, there are vast mounds, hundreds of meters long, consisting mainly of glass slag. There are also numerous remains of what were once glass furnaces. This indicates the large scale of the glass industry here. Where the raw materials serving this industry came from is unknown, but Robert M. Adams provided one possible explanation: by late Sasanian times, the area to the south of this canal was increasingly becoming part of the great swamp. Here, there would have been large numbers of snails as a source of calcium carbonate (they are still found in swampy areas around here today in "almost unbelievable numbers").^[6]:211 Plants native to the area may have supplied sodium carbonate, and sand may have been supplied from here as well, deposited by the water.^[6]:211

In the year 105 AH (723–4 CE), the caliph Yazid II commissioned Umar Ibn Hubayra to undertake a general land survey of the Sawad, in order to make the taxation of the Sawad more centralized. Taxpayers resented this land survey.^[13]:254

In practice, tax collectors often took far more than the official rate. According to Jahshiyari, in some cases, tax farmers demanded a payment greater than a farmer's entire harvest for the year, driving them to seek protection from higher officials. Abu Yusuf condemned the injustices against taxpayers in the Sawad, saying that tax farmers were breaking the law for their own financial benefit. He said that they "rob the taxpayer by imposing on them taxes they do not owe and punish them in repulsive ways to secure their own profit". Tax farmers often tortured people who refused to comply with their demands. Abu Yusuf describes some of these tortures. Tax farmers would severely beat taxpayers, or make them stand out in the hot sun on one foot for a long time. The punishments for defaulters were even more severe: tax collectors would hang heavy stones or buckets filled with water around their necks, or tie them up with ropes and left to starve. Yet, despite these condemnations, the punishments and torture continued for a long time thereafter, sometimes even with official sanction. In 847, Muhammad ibn Abdul-Malik al-Zayiyat, the vizier for the caliph al-Mutawakkil, introduced a "furnace of iron which had protruding nails inside it" to be used to punish tax evaders.^{[2]:256–258}

The accounts of Qudama ibn Ja'far and Ibn Khordadbeh describe the general administrative setup of the 9th-century Sawad. It was divided into 12 districts (astān; there were only 10 at Ibn Khordadbeh's time), each of which consisted of several sub-districts (tassūj). There were 60 tassujs in total (48 at Ibn Khordadbeh's time). Many of these divisions bear Sasanian names, indicating that they had originally been established before the Islamic conquest of Iraq.^[2]:61–64

The total rural population of the medieval Sawad can be calculated from the extent of the farmland.^[11] Assuming 3 million hectares of winter cereal crops in the late 8th/early 9th century, and the ability of a person to reap 3 hectares during the 2-month-long harvest season using contemporary technology, the total labor requirement would have been 1 million people.^[11] Assuming an average family size of 4 people, the total agricultural population of rural Iraq at that time would have been 4 million people.^[11] This is in addition to an assumed non-agricultural population in Iraq (also including cities) of 1.8 million.^[11]

Under this model, the hypothetical annual net output per worker would be 2757 kg of grain.^[11] An average agricultural family of 4 is assigned a subsistence income of 1000 kg of grain per year, which would be equivalent to 154 dirhams per year, or 13 per month.^[11] This means that out of net production, 36% was kept by the peasants, while taxes were 26% and rents were 38%.^[11] Thus almost 2/3 of the Sawad's total net production went to supporting the urban population and upper classes.^[11]

From the Sasanians to the Abbasids, the peasants of the Sawad formed "a legally subordinate class, working the estates of large landlords, and from which surplus in the form of taxes, rents, and labor were extracted".^[13]:252

The jurist Sharik wrote that "the inhabitants of the Sawad are servants and slaves."^[2]:65

Most of the inhabitants of the Sawad were called "Nabataeans". Although they converted to Islam, they maintained many pre-Islamic traditions and spoke a distinct dialect of Arabic.^[2]:77–78

According to Ibn Wahshiyya and Sabi, almost all the landlords of the Sawad lived in larger cities and towns, with their representatives, called al-quwam or al-wuhata maintaining the landlord's rural properties. These agents were responsible for overseeing daily work, providing necessities like seed and farm tools, and potentially hiring additional workers if needed.^[2]:78–79Alfred von Kremer compared this system with that of the Roman latifundia.^[7]:85

Slavery was practiced extensively in the Sawad. According to Umar's policy, any freeman was allowed to sell his Nabataean neighbor as a slave if they were in dire financial straits; this policy was upheld by the caliph al-Ma'mun.^[2]:83–85 According to Abu Ubayd, however, Umar I banned the purchase of dhimmi serfs because they were ahl al-karaj: subject to payment of the kharaj land tax.^[13]:252

The dihqans, or village chiefs, formed the lowest rung of the Sasanian landed elite.^[2]:79–80 They remained after the Islamic conquest, with their village estates formed "the prevailing form of land-tenure in post-conquest Iraq."^[13]:251 The government frequently consulted them on matters concerning land and irrigation, as well as for help with collecting taxes; the dihqans' local knowledge made them essential for this purpose.^[2]:79–80 In return, they were allowed to collect a special tax on local cultivators.^[2]:79–80 However, their importance began to decrease with the rise of new Arab landowners,^[2]:79–80 including Sasanian urban and military converts to Islam and their descendants; this process happened gradually, over the course of 60 or 70 years.^[6]:204

Under Persian rule, the Persian settlement had been heaviest in the area east of the Tigris, as well as in certain garrison cities.^[6]:204

Contemporary writers did not provide any extensive descriptions of rural villages.^[2] Ibn Wahshiyya gave only some details: he wrote that villages should be built on elevated ground such as hillocks, and if this was not naturally available then he said an artificial elevation should be built from wood and mud.^[2] This served two purposes: the first, he said, was for better health, and the second was to provide an elevated lookout point over the surrounding fields.^[2] Houses were built from either baked or sun-dried bricks, with high walls and many openings to provide ventilation and let sunlight in.^[2] (The walls were high to make space for all the openings.)^[2] Tree trunks were used either for columns or as rafters to support the ceilings, and the ceilings themselves were lined with wood from tamarisk, cypress, pine, and walnut trees and then covered with a mixture of mud and straw.^[2] Ibn Wahshiyya also described how plaster was used to cover walls and floors, especially in rooms and buildings used for storage.^[2] He said that isolated, independently standing houses were best, but if space was tight then they could be built adjoining each other as long as the necessary ventilation was provided.^[2] He also stressed the necessity of a blacksmith, carpenter, and potter in each village to supply residents with everyday items or building materials.^[2]

Ibn Wahshiyya disapproved of the unsanitary methods of obtaining drinking water that were prevalent in the Sawad: people would dig holes or use natural slopes to collect rainwater in ponds without making sure that either the ground or the water itself was clean—cattle manure was even used to cement the sides of the ponds.^[2] He said that these practices should be abolished and prescribed that drinking water should instead be provided by being collected on clean roofs of houses, and then directed down the sides of the houses into a cistern by wooden gutters.^[2]

• Schaeder, H.H. (1997). "Sawād". In Bosworth, C. E.; van Donzel, E.; Heinrichs, W. P. & Lecomte, G. (eds.). The Encyclopaedia of Islam, Second Edition. Volume IX: San–Sze. Leiden: E. J. Brill. p. 87. ISBN 978-90-04-10422-8.
• Michele Campopiano, “Land Tax Alā l-misāḥa and muqāsama: Legal Theory and Balance of Social Forces in Early Medieval Iraq (Sixth to Eighth Centuries)”, in Journal of the Economic and Social History of the Orient, 54/2, 2011, 239–269