Papers - KIRIMURA Masaaki
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Studies on NH_4-N Supply Method in Ion Concentration Controlled Hydroponic System of Cucumber Reviewed
KIRIMURA Masaaki, INDEN Haruhisa
Shokubutsu Kojo Gakkaishi 19 ( 3 ) 123 - 131 2007.9
Authorship：Lead author, Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists
A technique for keeping a suitable pH value of nutrient solution without addition of acid and/or alkali examined. Cucumber plants were cultivated with various methods of NH<sub>4</sub>-N supply in ion concentration controlled hydroponic system. <BR>In the first experiment, plants were grown in solution culture for 6 days at 4 levels of initial NH<sub>4</sub>-N concentration. NH<sub>4</sub>-N absorption rate increases drastically and solution pH decreased as the NH<sub>4</sub>-N concentration increased.<BR>In the second experiment, cucumber were cultivated with nutrient solution controlled by the IIAS (Integrated IonAdjuster System) or the PEIS (Popular Edition of Intelligent System) to investigate the effects of NO<sub>3</sub>-N:NH<sub>4</sub>-N ratio, and concentrations of each N source on the growth and solution pH. Solution pH decreased severely under PEIS and IIAS (set value of NH<sub>4</sub>-N concentration 8 mg <I>l</I><sup>-1</sup>), and increased under IIAS (NO<sub>3</sub>-N:NH<sub>4</sub>-N=30:1 or fuzzy) in this experiment. The results showed that pH of the nutrient solution for cucumber culture with IIAS management system could be stabilized by limiting NH<sub>4</sub>-N supply through the ratio basis control in which the ratio of NO<sub>3</sub>-N to NH<sub>4</sub>-N was kept at 30:1. However in the mid stage of cucumber growth with that system, the pH tended to increase gradually until harvesting stage, indicating that the relatively higher ratio of NH<sub>4</sub>-N supply in the mid stage than in other stages might be better to prevent the pH fluctuation.<BR>To maintain pH value of the nutrient solution, the control method through the NO<sub>3</sub>-N:NH<sub>4</sub>N ratio was more feasible than the method through keeping the concentration of NH<sub>4</sub>-N.
DOI： 10.2525/shita.19.123
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KIRIMURA Masaaki, INDEN Haruhisa
Shokubutsu Kojo Gakkaishi 18 ( 4 ) 261 - 270 2006.12
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists
"Integrated IonAdjuster System" (IIA System) integrated an ion concentration control method with an EC control method for controlling nutrient solution in hydroponics was developed. The IIA System adopted the EC control method for real-time control of total ion concentrations, and adopted the ion concentration control system for preparation of the stock solutions which could adjust ion composition of nutrient solutions. Cultivation of cucumber using the IIA System led to laborsavings, sustained good condition of rhizosphere, and increased yields. Moreover saving initial and running cost should be possible in the IIA System, and consequently the IIA System may contribute to promotion of closed hydroponic system.
DOI： 10.2525/shita.18.261
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イオン濃度制御キュウリ養液栽培においてNH4-N濃度設定値が培養液のpH変動に及ぼす影響 Reviewed
霧村雅昭，位田晴久
植物環境工学 17 ( 4 ) 199 - 204 2005.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Optimization of Calculation for the Ion Concentration Control in Hydroponics Reviewed
KIRIMURA Masaaki, INDEN Haruhisa
Shokubutsu Kankyo Kogaku 16 ( 4 ) 198 - 203 2004.12
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：JAPANESE SOCIETY OF AGRICULTURAL, BIOLOGICAL AND ENVIRONMENTAL ENGINEERS AND SCIENTISTS
The software for automatic ion control of nutrient solution for hydroponics, named "IonAdjuster", was invented and inspected practically. The ion unbalance problem in the nutrient solution sometimes occurred due to the uneven distribution of ion error range, in the software. To improve the precision of calculation of nutrient solution, Tolerance method and Least squares method were developed and examined.<br>Least squares method was suggested as the most suitable way in calculating a supply of fertilizer to the nutrient solution for compensation of ion concentrations.