Development of vegetable cultivation system aims to eutrophic lake water purification on lakeside paddy field.

尝试在千叶县特加湖滨湖休闲水田开发利用富营养化水体的蔬菜生产新系统。在上一个项目湖滨生产系统的基础上，于2002年开发了新的生产系统。引入铁路系统，提高收获劳动效率。研制出了一种能收获较高作物的新型收割机。同时对供水系统的优化进行了考察，系统上部的通菜产量高于下部，但系统内水的EC值和NO3-N含量上、下部无差异。由于该系统上部特加湖水体中悬浮物的积累量大于下部，悬浮物可能会影响该系统内植物的生长。根据2004年的试验结果，我们确定了通菜的适宜生产制度。1、系统最大长度为20m2，最小供水量为36株/d。结果表明，SS的养分含量对植物生长有影响，SS可以作为一种堆肥。为确定该系统生产的农作物的安全性，于2002年对产品中的重金属含量进行了分析，并于2004年对产品表面的大肠杆菌进行了检测。该系统产品的安全性得到了确认。

Try to develop the new vegetable production system using eutrophic water on lakeside fallow paddy fields of Tega-lake in Chiba Prefecture.New production system based on lakeside production system of the last project was developed on 2002. Introduce the rail system for increasing harvest labor efficiency. New type of harvester was developed which can harvest higher crops. Optimization of water supplying system was examined at the same time.Yield of Ipomoea aquatica at upper part of the system was higher than lower part, though EC value or the NO3-N content of the water inside the system didn't different between upper and lower part. Because accumulation amount of suspended solid (ss) in the Tega-lake water at the upper part of the system was bigger than lower part, ss might affect the plant growth in this system.From the result of the experiment on 2004, we decided the suitable production system for Ipomoea aquatica.The suitable condition is as follows ;1,Maximum length of the system is 20m2,Minimum amount of water supply is 36 litter per day per plant.The result indicates nutrient contents of SS effect on plant growth and ss can be used as a kind of compost.To confirm safety of the crops producted by the system, heavy metal contents of the products were analyzed on 2002 and colon bacillus stained on surface of the products were checked on 2004. Safeties of the products from the system were confirmed.