Improving greenhouse cladding by the additives of inorganic nano-particles

摘要

Currently, the greenhouse is widely used for the cultivation of various crops. Solar radiation transmits into the greenhouse through the cladding to afford the crops for photosynthesis. However, nearly half of the solar radiation energy is the near-infrared radiation (MR, 780-2500 nm), a direct source of heat. In tropical and subtropical regions, the undesired MR raises the temperature inside the greenhouse. Therefore, developing suitable covering materials to reduce the transmittance of MR into the greenhouse is a critical problem to be solved. The purpose of this study is to improve the plastic greenhouse cladding to reduce the transmittance of MR and keep enough photosynthetically active radiation (PAR, 400-700 nm). The low-density polyethylene (LDPE) was chosen as the matrix Additives made of UV stabilizer and inorganic particles were blended with LDPE to produce the plastic greenhouse covering material. Experimental results showed that under a 35°C ambient condition, the inner temperature of the simulated greenhouse with the new-developed cladding was 2-3°C less than that of the greenhouse with the commercial agricultural polyethylene (PE) film.