The land quota system (zhantian zhi 占田制) and the tax quota system (ketian zhi 課田制) were simplified means of taxation used during the Jin period 晉 (265-420). They can be seen as the result of the ancient system of taxation according to the rate of field area per person (mingtian zhi 名田制) of the Qin 秦 (221-206 BCE) and Han 漢 (206 BCE-220 CE) periods.
During that time, each owner of arable or cultivable fields was recorded in a household register (huji 戶籍) and was taxed according to the size of the household, not the field – the ancient tax was thus a poll tax (suanfu 算賦), not an income tax. This led to the situation that owners of estates bought the fields of neighboring peasant, which in turn became tenant farmers. The purchase did not increase the tax burden of the new estate owner, but deprived the government of the tax yielded from individual farmers. Already during the mid-Former Han period 前漢 (206 BCE-8 CE), Dong Zhongshu 董仲舒 (179-104 BCE) was aware of this tendency and recommended the restriction of the size of land owned by private persons (xian min mingtian 限民名田). A century later Shi Dan 師丹 (d. 3 CE) and He Wu 何武 (d. 3 CE) repeated the suggestion of Dong. A similar approach to field ownership was realized in the "royal field system" (wangtian zhi 王田制) during the reign of the usurper Wang Mang 王莽 (r. 8-23 CE).
The intensity of wars during the late Eastern Han period 東漢 (25-220 CE) forced many peasants to flee their homeland and wander around (liuwang 流亡) in search for means of living. On the other hand, many fields were lying fallow. The warlord Cao Cao 曹操 therefore initiated a project of agro-colonies (tuntian 屯田) in which he resettled peasant families to fallow land and ordered them, with promise of non-taxation for several years, to reclaim new land. The project proved successful through the reactivation of the economy during the Cao-Wei period 曹魏 (220-265), and the Jin dynasty thereupon decided to give up the agro-colonies and transform them into private land owned by individual farmers. The size of land owned by private persons was legally restricted, in order to preserve an adequate tax revenue for the government as well as a sufficient supply of corvée (yaoyi 徭役) to be delivered to the authorities by independent farmers. In 280 the Jin dynasty proclaimed an edict on the ownership and taxation of land (zhantian lingtian ling 占田課田令).
Each male person (nanzi 男子) was allowed private, tax-free field (zhantian 占田) with a size of 70 mu 畝 (see weights and measures), each female (nüzi 女子) 30 mu. Adult males (dingnan 丁男) were "furthermore" (qi wai 其外) granted taxed field (ketian 課田) with the size of 50 mu, adult females (dingnü 丁女) of 20 mu, under-age and elderly males (ci dingnan 次丁男) 10 mu. Under-age and elderly females were not taxed. The term ding 丁 or zhengding 正丁 referred to persons older than 16 and younger than 60 sui, the term ciding 次丁 to persons between 13 and 15 and 61 and 65 sui, all others (children and old persons) were called laoxiao 老小 (see Jinshu 晉書, 26 Shihuo zhi 食貨志).
State officials were given land according to their rank (guanpin 官品, pinji 品級), in steps of 5 qing 頃, reaching from 50 qing for a rank-1B official to 10 qing for an official of rank 9. Princes and members of the nobility were allowed fields with the size of between 7 and 15 qing.
Apart from owning a fix amount of land, state officials were granted the freedom to house several "clients" which were not liable for taxation. The number of clients related by kinship (yin qinshu 蔭親屬) reached from nine generations (jiu zu 九族) down to three (san shi 三世), the number of non-relative clients in the household (yin yishi ke 蔭衣食客, yinke 蔭客) reached from 1 to 3 persons, depending on the rank of official, and the number of client farmers (yin dianke 蔭佃客) was fixed at 15 households for officials of rank 1 and 2, with decreasing amounts down one household for officials of ranks 8 and 9.
The quotas of land ownership and of how much land was taxed were fixed by the government, but the authorities did not care about how much land peasants or state officials were really owning, as long as they did not surpass the quota. Unlike in the later equal-field system, the government was not responsible for the individual allotment of land, and was not interested in supporting peasants to obtain the allowed amount of arable fields. The land quota system thus saved the authorities enormous bureaucratic efforts.
The greatest problem of the system was that the height of tax levied and corvée required from each individual farmer was tied to the quota of land owned. The tax amounted to 8 sheng 升 of grain per mu of land, but the tax collectors did not care whether a male peasant did really own 50 mu of taxable land or not, and collected a poll tax of 400 sheng of grain per adult male.
In remote regions, the tax consisted of a "charity" (yimi 義米) donation of 3 hu 斛 of grain per household, sometimes only 5 dou 斗 or a monetary payment (suanqian 算錢) of 28 cash per person – the latter type of tax dated from the Han period.
There was also a further tax in kind to be delivered by each household (see household tax system, hudiao zhi 戶調制), namely 3 bolts of crude silk fabric (juan 絹) and 3 jin 斤 of silk wad (mian 綿) for each adult male, and females and young males half of this amount. The amount of cloth was lower in remote regions, where only payment of 1 zhang 丈 was due, or 1 bolt of "barbarian" cloth (zongbu 賨布).
During the Taikang reign period 太康 (280-289) the economy recovered by this simple measure. The number of registered households amounted in 280 CE to 2.45 million, and the registered population to 16,16 million. Three years later, the census reported 3.77 million registered households. This could mean that under the land quota system more peasants were willing to work as independent farmers. Yet in practice, there was no control over the ownership of land neither over the number of "client farmers" serving a landlord. The state was unable to check whether state officials really kept to the restriction of land ownership nor whether they employed more tenant farmers than allowed. In fact, there were many individual farmers not being able to survive because they could not reach the land quota allowed (and from which a family would be able to survive after taxation).
The system remained in force even after the Jin dynasty had fled to the southeast in 316. The barbarian states ruling over northern China adopted the bureaucratically simple system, and the Northern Wei 北魏 (386-534) did the same. Only in 485 they introduced a new system, the equal-field system (juntian zhi 均田制), in which the government actively distributed land to farmers.
Scholars are still discussing some issues concerning the land quota system. It might be that the amount of land taxed (in case of an adult male, 50 mu) was included in the quota land (70 mu). In the opinion of the supporters of that thesis, the land quota system (zhantian zhi) and the tax quota system (ketian zhi) were two separate issues and cannot be seen as one regulation on the ownership of land of any type. Some scholars are of the opinion that the government did indeed own and distribute the land (shoutian 授田), like in the later equal-field system, while others bring forward the argument that only the taxed land (ketian) belonged to the government, while the rest (zhantian) was seen as private. Concerning the tax, the latter opinion would mean that the tax was a kind of rent for the (enforced) lease government-owned land, and not a proper tax in kind.
As long as these issues are not clearly solved, the land quota system can be seen as a novelty introduced by the Jin dynasty, as a continuation of the agro-colony system of the Cao-Wei dynasty, as an advancement of the Han dynasty restriction of land ownership, or as the result of development in the field ownership and taxation systems of the Qin and Han dynasties.