The optimization of environmental control parameter in greenhouse for eucalyptus seedlings production

Taking the eucalyptus seedling (D-2) as an example, this thesis discusses the optimization control of eucalyptus seedlings´ environmental parameter in greenhouse. It includes two levels. Firstly, in search of the theoretical optimal solution which is best for seedlings growth (apparent photosynthetic rate maximum), the thesis figures out the maximum of target function, that is, Y_max = 36.89μmol.CO₂/(m²s) Correspondingly, the temperature is 27.1 °C, light intensity is 487.9340μmol/(m²s), and carbon dioxide concentration is 700 ppm. The second part is to find out the suboptimal of environmental parameter by considering different seasons and weather conditions and economic factors. From the view of economy, the conclusion is that the theoretical optimal solution is not always the best solution. Some suboptimal environmental factors are determined by the best rate of input output concerning the different climate, costs regulation of environmental factors and output ratio.