Azemame - Azemame

Japanese: あぜ豆 - あぜまめ

…In rice paddies, the purpose is to allow water to be flooded, but they are also used as paths (ridges) for agricultural work and as boundaries between property. The grass that grows on the ridges has long been used as fertilizer or livestock feed, and beans (ridge beans) were often grown on them. They are usually earthen structures that must be strong enough to allow people and work equipment to pass through them.

From soybeans

...The sales method is increasingly being done by agricultural cooperatives in these major production areas. Traditionally, soybeans were grown for self-consumption by farmers, as typified by "azemame" (soybeans grown on the ridges of rice fields), and the remainder was often sold through local producers. Even today, the proportion of local producers is high.

*Some of the terminology that mentions "Azemame" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…水田では湛水（たんすい）を可能にする目的をもつが，農作業を行う場合の通り道(あぜ道)として利用されるとともに，所有地の境界の役割もはたす。また，あぜに生育する草は古くから肥料あるいは家畜の飼料として利用され，マメ類(あぜ豆)などが栽培されることも多かった。通常は土の構造物であり，人間や作業機の通行を可能にする強度をもっていなければならない。…