ISHS Acta Horticulturae 588: II International Symposium on Cucurbits
FEEDBACK CONTROL OF NUTRIENT SOLUTION SUPPLY BASED ON FLOW RATE OF DRAINAGE IN MIST CULTURE OF CUCUMBER |
| Authors: | T. Higashide, H. Hamamoto, H. Shimaji |
| Keywords: | hydroponics, automatic, electric balance, computer, nutrient uptake, water uptake |
| Abstract:
We tested a system that uses feedback based on drainage flow rate to match the supply of nutrient solution to demand by plants. The experiment used cucumber (Cucumis sativus) in mist culture without substrate. Without substrate, it is easier to alter nutrient concentrations and water supply than with substrate, which retains large amounts of nutrients and water. Nutrients and water that plants don’t absorb are discharged. We have developed a method based on an electric balance for measuring flow rates as low as 10 mg/10 seconds of water. The volume of nutrient solution and interval of supply were controlled to maintain a set drainage flow rate. During the daytime, the volume of nutrient solution supply was changed in proportion to solar radiation. The volume also increased automatically in proportion to growth of plants. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
