Analytical Sciences

Abstract − Analytical Sciences, 35(5), 595 (2019).

Construction of an Automatic Nutrient Solution Management System for Hydroponics—Adjustment of the K+-Concentration and Volume of Water—
Kebin XU, Yuki KITAZUMI, Kenji KANO, and Osamu SHIRAI
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan
An automatic management system for nutrient solutions was constructed using a programmable logic controller (PLC) and a K+-ion selective electrode (K+-ISE). The concentration of K+ was monitored by the K+-ISE. When the concentration of K+ fell to the threshold limit, an appropriate amount of a concentrated K+ solution was added to the hydroponic solution. The volume was also maintained at a constant level by addition of water. This system can be constructed simply and inexpensively without any computers and pumps.