The present invention discloses a system for cultivating surface- growing floating aquatic plants, in particular, duckweeks or lemnoideae species, on a non horizontally positioned sheet-like substrate. The aforementioned system comprises (a) a predetermined volume of growth media flowing through sheet-like substrate provided with a predetermined inoculum of said aquatic plants； (b) at least one sheet-like substrate； (c) an irrigation mechanism configured to a top down irrigation flow in said sheet-like substrate； and (d) a regulation mechanism configured to control said irrigation flow. The present invention further discloses methods for cultivating the aforementioned aquatic plants.
