Agricultural greenhouse, plant cultivation method using the same, and heat-ray reflecting film structure

Abstract

The agricultural greenhouse of the invention and the plant cultivation method using the same can cultivate plants economically and efficiently with less energy per crop yield, as it is provided with a CO2 supply means, a heat-ray shielding means, and a dehumidification and cooling means, the heat-ray shielding means is formed of using a heat-ray reflecting film, and plural through holes are formed in the heat-ray shielding means. The heat-ray reflecting film structure can cultivate plants by the agricultural greenhouse utilizing sunlight economically and efficiently as it has a structure that narrow band-shaped tapes obtained by cutting a multi-layer laminated film made by laminating at least two kinds of resin layers with different refractive indices alternately and having an average transmittance at 80% or more for visible light and an average reflectance at 70% or more for heat-ray is woven or knitted as a warp or a weft.

What is claimed is: 
     
         1 . An agricultural greenhouse utilizing sunlight in which skylights provided on a ceiling part are closed in the daytime and the skylights provided on the ceiling part are opened in the night-time, wherein
 at least a CO 2  supply means supplying carbon dioxide, a heat-ray shielding means and a dehumidification and cooling means cooling an inside of the agricultural greenhouse are provided inside the agricultural greenhouse,   the heat-ray shielding means is formed using a heat-ray reflecting film having an average transmittance at 80% or more for light with wavelength of 400-700 nm and an average reflectance at 70% or more for light with wavelength of 800-1200 nm, and   a plurality of through holes are formed in the heat-ray shielding means at a predetermined interval.   
     
     
         2 . The agricultural greenhouse according to  claim 1 , wherein the heat-ray reflecting film is a multi-layer laminated film made by laminating at least two kinds of resin layers with different refractive indices alternately. 
     
     
         3 . The agricultural greenhouse according to  claim 2 , wherein at least one of the two kinds of resin layers of the multi-layer laminated film is a resin layer made of resin having a condensed aromatic ring. 
     
     
         4 . The agricultural greenhouse according to  claim 1 , wherein an aperture ratio of the plurality of through holes to be provided in the heat-ray shielding means is in a range from 0.5% to 10%. 
     
     
         5 . The agricultural greenhouse according to  claim 1 , wherein the heat-ray shielding means has a structure in which through holes are drilled on the heat-ray reflecting film. 
     
     
         6 . The agricultural greenhouse according to  claim 1 , wherein the heat-ray shielding means has a knitted or woven structure using a narrow band-shaped tape obtained by cutting the heat-ray reflecting film into a narrow band shape as a warp and/or a weft, and through holes are formed between the warps and/or the wefts. 
     
     
         7 . The agricultural greenhouse according to  claim 1 , wherein a transmittance of light with wavelength of 350 nm of the heat-ray reflecting film is 10% or less. 
     
     
         8 . The agricultural greenhouse according to  claim 1 , wherein the heat-ray reflecting film has an ultraviolet absorbing layer on at least one side of an outermost layer. 
     
     
         9 . The agricultural greenhouse according to  claim 8 , wherein the ultraviolet absorbing layer contains a binder resin and the binder resin is a fluorine resin. 
     
     
         10 . The agricultural greenhouse according to  claim 1 , wherein the agricultural greenhouse is used for cultivation of fruits and vegetables which perform photosynthesis by sunlight. 
     
     
         11 . A plant cultivation method using the agricultural greenhouse according to  claim 1 , wherein
 the concentration of carbon dioxide is adjusted by closing skylights provided on a ceiling part in the daytime and a temperature is adjusted by opening the skylights provided on the ceiling part in the night-time, and   plants are cultivated by controlling the temperature in the agricultural greenhouse to be 35° C. or lower, the concentration of carbon dioxide to be from 500-1500 ppm and a humidity deficit to be 4 g/m 3  or smaller, at least in the daytime.   
     
     
         12 . The agricultural greenhouse according to  claim 1 , wherein an aperture ratio of the plurality of through holes to be provided in the heat-ray shielding means is in a range from 0.5% to 10%, and the heat-ray shielding means has a structure in which through holes are drilled on the heat-ray reflecting film. 
     
     
         13 . The agricultural greenhouse according to  claim 1 , wherein an aperture ratio of the plurality of through holes to be provided in the heat-ray shielding means is in a range from 0.5% to 10%, and the heat-ray shielding means has a knitted or woven structure using a narrow band-shaped tape obtained by cutting the heat-ray reflecting film into a narrow band shape as a warp and/or a weft, and through holes are formed between the warps and/or the wefts.