"Office fields" (zhitian 職田, also called caitian 菜田, lutian 祿田, zhigongtian 職公田 or zhifentian 職分田) were fields from whose revenue the salary (in grain) of state officials was to be covered. This custom was prevalent between the Jin 晉 (265-420) and the early Ming 明 (1368-1644) period, before the introduction of monetary salaries. The Sui 隋 (581-618) and Tang 唐 (618-907) administration made also use of fields whose revenue was to cover administrative expenses (gongxietian 公廨田).
The size of the land depended on the rank of the office (pinji 品級) and thus constituted part of the official's salary (fenglu 俸祿). Quite surprising from the viewpoint of modern bureaucracies is that part of the running cost of an office had to be paid by the salary of the office holder. When the office holder was transferred to another place or promoted to a higher post somewhere, the income from the field remained and was to serve the expenditure of his successor.
The origins of office fields go back to the very late Eastern Han period 東漢 (25-220 CE), when Emperor Xian 漢獻帝 (r. 189-220) tied fields around the capital to concrete offices. This saved the central government bureaucratic work and relieved the capital granaries somewhat. The first regular implementation of office fields was promulgated in 291. The officials of the central government were divided into three classes, according to which their offices were endowed with the yield of fields (caitian) with the size of 10, 8, and 6 qing 頃 (see weights and measures) respectively. According to the regulation, the yields of the whole year served as salary, if the official was appointed before the beginning of summer (lixia 立夏, early May, see calendar); and if appointed after that date, the full harvest was reaped by the predecessor, while the current, new official was given the salary for the current year in other ways.
During the Eastern Jin period 東晉 (317-420), the system of office fields was extended to regions beyond the capital. The size was as follows: a commander-in-chief (dudu 都督) was nourished by 20 qing of land, a regional inspector (cishi 刺史) by 10, the governor of a commandery (junshou 郡守) by 5, and a district magistrate (xianling 縣令) by 3. During the Southern Dynasties period 南朝 (420-589), the size of salary fields (lutian) was raised, and the end of period for change in office changed to the day of the solar term mangzhong 芒種 (beginning of June, see calendar). During the Yuanjia reign-period 元嘉 (424-453), the regulation was changed to a more detailed procedure, according to which the number of months a person served in office was taken into consideration.
The Northern Wei 北魏 (386-534) adopted the system in 481.
The Sui dynasty drastically reduced the size of fields: Officials of the first rank were given 5 qing, and those of ranks 2-5 no more than 3 qing, those of rank 6-8, 50 mu 畝 (?, rather 1 qing), and those of rank 9, one qing (rather 0.5 qing = 50 mu). The Tang dynasty decided to equip with office lands only such offices in which real work was done. Auxiliary officials waiting for a position (neigongfeng 內供奉) and "accompanying officials" (guoxingguan 裹行官?) were not endowed with land. Offices of the latter two types were paid out their salaries in grain (in that case called dizi 地子) by the Capital Granary (taicang 太倉). Supernumerary officials (yuanwaiguan 員外官) were not given any salary by means of land allotment, nor paid out dizi grain.
The office fields were managed by the director for agro-colonies (tuntian langzhong 屯田郎中) in the Ministry of Works (gongbu 工部) who corresponded with officials in the respective institutions and localities. Each year the administration of prefectures and districts had to present the Imperial Secretariat (shangshusheng 尚書省) a register (jizhang 籍帳) of the office fields. The registers were more or less identical to normal households registers (huji 戶籍) and included detailed description on the size, location (sizhi 四至 "the adjacent surroundings"), rent, and yields. The basic register was called "white booklet" (baibu 白簿). In the tenth lunar month (December) the rent was to be paid out to the office. Every third year, "yellow registers" (huangji 黃籍) were compiled which served for long-time archiving.
This system was not always implemented correctly because many local officials seized private land and thus critically disturbed the equal-field system (juntianzhi 均田制) according to which land was distributed to peasant households depending on the number of household members. In 637 and 722 therefore, the system of office fields was stopped, and officials were directly paid out their salary grain from the local granaries, with a conversion rate of 2 dou 斗 of rice per nominal mu of land. After the mid-8th century the phenomenon of large estates became rampant. Local state officials also illegally confiscated land owned by farmers.
The Sui had also invented a system of public land for administrative expenses (gongxietian). It was in 589 introduced for officials of the central government, and in 594 for the provinces. The size reached from respectable 26 qing for the highest institutions down to 2 qing for smaller bureaus of the central government, and from 40 qing down to 1 qing in the local administration. The management of the "expenditure fields" was similar to that of the office fields. They were cultivated by tenant farmers who were to pay a certain rent to the government. The rent was paid in kind, in later years also in money. Expenditure fields were also registered in white and yellow booklets. After the downfall of the Tang dynasty, the system of "expenditure fields" was abolished.
Office fields were cultivated by serfs (zouzu 騶卒), civilian or military sub-officials (wen-wu li 文武吏) and sometimes even underage serfs (tong 僮). Even if their work was called corvée (yaoyi 徭役), it was during the Jin and Southern Dynasties periods practically that of slaves. Moreover, the status of serf was hereditary during that time, and they remained for generations in the service of the successive holders of the same state office. This situation was ameliorated by the Tang, and the official nourished and paid by the revenue from the office field had to "cultivate fields by himself" (zi tian 自佃). Office fields were managed by a petty official who hired the farmers working the office fields. Normally, the authorities ordered peasants from the village in the neighbourhood to care for the office field. These forced cultivators were rewarded with the harvest, from which they theoretically had to pay a rent of between 2 and 6 dou per mu, yet in practice, the authorities requested a higher payment as well as various services related to the office field and its produce. Of course, peasants were reluctant to deliver such services, and with the introduction of the twice-taxation method (liangshuifa 兩稅法) in the late 8th century, revenue formerly reaped from the office fields was attached to the new tax. This custom gave the authorities the possibility to raise additional taxes as a substitute for service on office land.
The Song dynasty 宋 (960-1279) nevertheless took over the system, but only endowed officials outside the central government with office fields. Officials received land according to their rank and position, with an amount of 40 qing for prefects of large jurisdictions (da fan fu 大藩府), down to 7 qing for magistrates of small districts. Transport commissioners (zhuanyunshi 轉運使) received 10 qing of land. These amounts, determined in 999, were considerably downsized in 1043. The old regulation of the date of change in office was refreshed in the following way: if an official was appointed earlier than the third month (in case of dry rice fields, lutian 陸田), the fourth month (irrigated rice fields, shuitian 水田) or the ninth month (wheat, maitian 麥田), the full harvest of the year was his annual salary.
Around 1080, the whole amount of office fields run up to 2.348 million mu. The number of tenant households was restricted to 3 households per qing of land, and it was forbidden to rent out any tracts of land to other farmers. In some regions, the authorities requested a certain quota of the harvest as rent (fenchengzu 分成租), on others, a fix quota as rent (ding'ezu 定額租). With the increasing monetization of the economy during the Northern Song 北宋 (960-1126), the authorities went over to a payment of the rent in cash (xianqian 現錢) instead of in grain. Yet the phenomenon of illegal seizure of land by state officials continued under the Song.
The Jin dynasty 金 (1115-1234) also adopted this system and distributed office land according to rank, ranging from 30 qing for an official of rank 3A to 2-3 qing for someone of rank 9B. Apart from the rank, the concrete size of office land also depended on the nature of the office. Members of the Jurchen's native household system meng'an mouke 猛安謀克, and supervisors of official pastures (urgu, wulugu 烏魯古), were not endowed with land. The rent was 3 dou of grain per mu of land, as well as a bunch of hay for horses. After 1150, the harvest was to be brought to the official granaries, and not to the office directly, and officials were consequently paid out their monthly salary from the granary.
Under the Yuan dynasty 元 (1279-1368), only a restricted number of officials were endowed with office fields, namely those of circuits, prefectures, districts, local administration offices (lushisi 錄事司), the surveillance commission (anchasi 按察司 or suzheng lianfang si 肅政廉訪司) and transport commissions (zhuanyunsi 轉運司). The size reached, according to the regulations from 1337, from 16 qing to 2 qing. The necessary field was taken from wasteland or abolished households (hujue di 戶絕地), and tenants were hired who cultivated the fields, while the rent was paid by the whole village. Yet as early as 1309 a different mode of salary was tested by paying out the officials their salary in grain directly, at a rate of between 100 shi 石 for a rank-3 official down to 40 shi for rank 7. This had been custom during the Han period. Yet two years later, the experiment was aborted. The rule of date of appointment was in 1312 given up in favour to monthly salary. Tenant farmers had to deliver a fix rent, either in kind or in paper money (chao 鈔), regardless the real size of the harvest. In the course of time the rent requested by the local authorities increased boundlessly, and was as high as 3 dan per mu for the surveillance commission in Fujian.
The Ming dynasty also introduced the office field system in 1377, under the name "public field" (gongtian 公田). When exactly the government went over to a salary payment in money and abolished the office fields is not clear.