Water Culture on Ornamental Crops Using Eutrophic Water in the lake of Kojima

小岛湖富营养化水体中含有农作物生长所需的营养元素，其浓度较低。在以往的研究中，我们明确了培养液中的低浓度营养物质能够正常生长许多观赏作物，如果培养液连续供应到根系中，本研究利用连续流水法的富营养化水栽培系统对园艺作物的最佳水培品种进行了评价。在另一个课题中，我们开发了一套利用太阳能漂浮在湖面上的垫花栽培系统：(1)在筛选评价最佳园艺作物时，有几种作物被评为四个等级：A(生长良好)4种垫花，3种切花和1种蔬菜，B(正常生长)3种垫花，2种切花和2种蔬菜，C(生长偏死)：2种垫花和2种切花；(2)漂浮栽培系统“移动花坛”由种植作物用的聚苯乙烯泡沫板、两个太阳能电池、一个螺杆和移动方向控制装置组成。该系统在富营养化的水体中，在3个月内正常生长垫花。

Eutrophic water in the lake of Kojima contained nutrient elements for the growth of crops, existing its at low concentration. In previous study, we cleared that the low concentration of nutrients in culture solution was able to grow normally many ornamental crops, if the solution supplied continuously to roots system in a water culture.In this study, we evaluated optimum species of horticultural crops for water culture using the eutrophic water by water culture system of continuous water flowing method. In other subject, we developed a floating culture system for bedding flowers getting about on the lake surface by solar energy.(1) In screening test evaluating optimum horticultural crops, several crops were ranked four grades as followed ; A (growing excellently) 4 species of bedding flowers, 3 species of cutting flowers and 1 specie of vegetable ; B (growing normally) 3 species of bedding flowers, 2 species of cutting flowers and 2 species of vegetables ; C (growing partial dead) : 2 species of bedding flowers and 2 species of cutting flowers ; D (not growing) : 7 species of bedding flowers and 5 species of cutting flowers.(2) Floating culture system "Moving flower bed" was consisted of styrene foam plate for planting crops, two solar cells, a screw and control device for moving direction. Bedding flowers were grown normally during three months by the system in the eutrophic water.