PURPOSE: To provide agricultural materials useful in house cultivation and tunnel cultivation, obtained by compounding a metal powder and an inorg. powder to a thermoplastic resin and forming the compounded thermoplastic resin into a film in such a manner that the transmission ratio of visible rays is regulated above a specific value.

CONSTITUTION: As fillers, a metal powder and an inorg. powder absorbing infrared rays with a wave length of 5W50μ are compounded in a thermoplastic resin and a film with a thickness of 20W200μ is prepared therefrom, wherein aforementioned fillers are compounded so as to regulate the transmission ratio of visible rays to 40% or more. As a metal powder, an aluminum powder is convenient in use, because it has a good reflective property and can be obtained inexpensively and the adding amount thereof is 0.3wt% or less. As an inorg. powder, silicon oxide, aluminum oxide, magnesium oxide,aluminum hydroxide, a silicate compound and a phosphate compound are used and the adding amount thereof is 1W15wt%.