Development Of A New Type Of Soilless Cultivation Facility And Its Root Zone Temperature Control System

Soilless cultivation as a way to overcome the obstacles of continuous cropping,secondary salinization and other issues, is widely used in greenhouses. Afterwards,soilless cultivation device also begins to development. However, the conventional soilless cultivation of vegetables leads to the weak buffering capacity of root microenvironment buffering and is extremely sensitive to changes in the environment,so root zone temperature control is difficult. When the outside light is sufficient and the temperature is enough high, the matrix can not achieve insulation and cooling,which will lead to crop root zone temperature too high, the emergence of rotten rot and disability to grow normally; If external light is insufficient, the temperature is too low and the matrix insulation temperature is hard to maintain and lift, crop root zone temperature will be extremely low, and root activity will be reduced, or even can not grow normally. Thus, this paper, aiming at the above problems, has designed new soilless cultivation facilities, and has tested on the temperature control performance.The main research work and conclusions are as follows:1. Analysis of existing domestic and foreign research status and existing problems. Soilless cultivation definition, types and characteristics and understanding of the development situation for soilless cultivation facilities are introduced. Through the domestic and foreign research of current status for soilless cultivation analysis, I identify the main problem at this stage, and put forward the main research direction, a clear technology roadmap this study.2. Design of new soilless cultivation facilities. This essay describes the overall design and its various components of soilless these facilities, which include soilless cultivation tank, pipelines up and down, planting support and temperature control systems. We discussed in detail about the main components of soilless cultivation tank,according to the functional requirements of each component, and determine the structure and size of this. The base of design, size and role for soilless cultivation facilities bracket and each component are also included. There are a brief overview ofthe upper and lower water pipeline design and the determination the pipe size in accordance with the requirements of assembling and functions. Finally, complete the mechanical parts of the new soilless cultivation facilities according to the assembly principles of each component3. The design of temperature control system of new facilities soilless cultivation.This thesis introduces details of the overall structure, working principle and the hardware selection of temperature control system, focuses on the main design of the temperature control system, circulating cooling water control program and fluent water discharge and supply regulation method.4. New soilless cultivation experiments and data processing facilities. It is designed to test the flowing water temperature performance, cultivation tank substrate temperature control performance and crop root zone temperature control of lettuce growth. By testing circulating water temperature control, I verify the new soilless cultivation facilities designed in this paper can effectively and accurately control the temperature of the circulating water; Testing the performance of cultivation tank temperature control to verify the new soilless cultivation facilities can accurately and efficiently control cultivation tank substrate temperature; The divided experiments of lettuce growth effects under crop root zone temperature control confirm that the temperature of crop root area influence the growth of crops directly; Finally, these validate the practicability and rationality of the new soilless cultivation facility on root crops zone temperature control.