Kanno is a general term in the history of Japan for the overall acts by which the rulers typically promoted and encouraged agriculture. Originally, kanno was a shortened term for "kankanoso" written in the Chinese classics and in Japan that was first regarded as the duty of kokushi in the ritsuryo system of governance (a constitutional form of governance). Sometimes it was called "shuno" in fall and "kanno" in spring.
Kanno is a term covering very wide-ranging concepts, it included the maintenance of irrigation facilities, lend-lease and benefit of seeds and agriculture fees ("suikyo," land lease at interest was also included), the allocation of farm lands, the organization of the agricultural labor, the development of denuded lands, the up-down adjustment of the tax rate, and so on. These were originally intended to promote and enhance production of farmers, and also ensued tax collection for the rulers. The cultivation plan for a million-cho rice field under the ritsuryo government in 722 is a kind of kanno and the government tried to increase and ensure financial revenues by promoting agricultural production. Under the ritsuryo system, kanno was defined as the duty of kokushi and the measures and policies of kanno were implemented by kokushi.
Kanno in shoen (manor) system
Around the middle of the Heian period, the ritsuryo governmental system collapsed, a system whereby shoen and kokuga region were governing units was established and the contents of kanno gradually changed. Especially in shoen, nengu (render) collection was sometimes referred to as kanno. Kanno in the medieval shoen was roughly divided into two. One was the kanno by shoen owners and the other was by local landlords.
Shoen owners appointed the local leading farmers (such as tato who managed the rice fields in shoen or kokuga domain) as myoshu (the class entrusted to manage myoden, rice field as a basic unit for tax levying), sent the direct subordinate azukari dokoro (appointed local shoen manager) to the local region as well as stabilized the local management of shoen and they did their best to strengthen and maintain the governance of shoen. Meanwhile, the kanno by shoen owners was expected by farmers or myoshu, for example, the exemption of nengu or benefits for laborers and so on. Sometimes, shoen owners ordered myoshu or azukari dokoro to implement the kanno.
During the middle and late of the Heian period, the local landlords accumulated fortunes by the management of myoden, amassed neighboring or cultivated rice fields, and aimed to govern ordinary farmers in these rice fields. For this reason, they developed an irrigation plan and strengthened the governance over the local regions through the kanno acts which made ordinary farmers cultivate their own private rice fields and so on. Such a move became more prominent during the Kamakura period and lawsuits over the right of kanno between shoen owners and local landlords occurred frequently during the middle of the Kamakura period. At this stage, the right of kanno meant the practical governance over local regions. That is, jito during the Kamakura period insisted on their effective authority by practicing the kanno as local landlords and in this way the jito's invasion of the shoens was completed.
The kanno during the Edo period
During the Edo period the society was stabilized, bushis as a ruling class aimed to moderate governance according to the spirit of Confucius, that is, governance by humanity and justice. Meanwhile, the ruling class not only exploited farmers by nengu, but also implemented several measures of kanno to cultivate farmers. Especially around 1643, the mighty famine encouraged the landlord class such as daimyo (leading bushi who governed the local regions) or hatamoto (direct retainer of the shogun) to implement the kanno to develop new rice fields and so on to ensure production revenue. Cultivated areas dramatically increased with these measures, from about one million six hundred thousand choho in the early seventeenth century to about three million choho in the early eighteenth century.
During the middle of the Edo period life in farming villages was exhausting, but during the late eighteenth century to the early nineteenth century (from Kansei era to Bunkabunsei era) the Edo bakufu began to drastically revive the farming villages, maintained irrigation facilities and developed denuded lands as well as made loans for them, appointed competent men as daikan (managing post instead of the landlord) and made him perform the same duties for a long time. These daikans actively performed several kannos and were honored as excellent daikans by the local people in various regions and the shrines which enshrine their honorable monuments or the daikans themselves have been carefully preserved until now.