Optimization Experiment of Environmental Parameters for Closing Stereoscopic Rice Seedling Nursery

In order to solve problem that traditional rice seedlings easily affected by climate，led to poor quality of seedlings，rice seedlings climate box and seedling platform based on plant factory were optimized designed with seedlings cultivation environment parameters as target.Environmental parameters with significant influence on seedling indexes were optimized with uniform test and stepwise regression method by using rice seedling climate box，optimal environment parameter combination of rice seedling was chosen，and scale production verification test were carried out by using rice seedling platform based on plant factory technology.Experimental results showed that leaf area coefficient was significantly affected by light intensity in full spectrum（P＜0.05）.In blue light，root number and root length were significantly affected by soil moisture content（P＜0.05），SPAD and leaf area coefficient were significantly affected by light intensity（P＜0.05），stem base width was significantly affected by light intensity and illumination time（P＜0.05）.In red light and blue light ratios were 3∶1，stem base width was significantly affected by light intensity and illumination time（P＜0.05），stem length was significantly affected by light intensity，temperature and soil moisture content（P＜0.05），SPAD was significantly affected by light intensity（P＜0.05），leaf area coefficient was significantly affected by soil moisture content（P＜0.05）.Optimal environment parameter combination of rice seedling was blue light，soil moisture content was 60%（irrigate when lamina wrap and maximum moisture content was 60% after irrigation），light intensity was 1.1×104 lx（measured value at surface of light source，distance between surface of light source and surface of seedling tray was 20 cm），illumination time was 9 h，temperature was 28 ℃/24 ℃（photoperiodic/non-photoperiodic）and humidity was 60%.Morphological indexes and mechanical properties of rice seedlings cultivated by rice seedling platform based on plant factory technology could meet mechanical transplanting standard.Experimental results could provide theoretical reference for large area closing stereoscopic rice seedling and sustainable development of agriculture.