| Though neither fertilizer nor labor is required in cultivation, it is known as a kind of farm product whose cultivation is difficult because it can only be cultivated in a place where abundant fresh water is available. |
肥料等は必要なく生育の手間も殆ど要らないが、大量のきれいな水のある場所に生育が限定されるため、栽培の難しい農作物としても知られる。 |