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从东德引进的细绿萍,又名蕨类满江红(Azolla Filiculoidea),原生长于美洲,后传入东德。我国引进后,除研究扩大养殖与其固氮作用外,在北京地区喂猪和雏鸡,均取得可喜结果。一、细绿萍的生物学特性1.细绿萍引进我国后,它的抗寒性比较强,起繁温度低,固氮率高,在北京早春低温进行春繁比较适宜。在5℃开始生长,10℃生长率比南方萍高8倍,15℃～20℃时生长率高2倍,大面积水面养殖,平均气温20℃时2～3天萍产量可翻一番。细绿萍有3种生态型:即平面浮生、斜
Introduced from East Germany fine green duck, also known as fern Azolla (Filipino) Azolla, originally grew up in the Americas, after the spread to East Germany. After the introduction of China, in addition to studying the role of expanding aquaculture and its nitrogen fixation, pigs and chicks in Beijing have achieved gratifying results. First, the biological characteristics of fine green duckweed 1. After the introduction of fine green duckweed, it is relatively strong cold, the low temperature from the fan, high rate of nitrogen fixation, spring early spring in Beijing more suitable for spring and more. Growth started at 5 ℃. The growth rate at 10 ℃ was 8 times higher than that at the south, and the growth rate was 2 times higher at 15 ℃ ~ 20 ℃. Large-scale aquaculture could be carried out. The average yield could be doubled from 2 to 3 days at 20 ℃. Fine green Ping there are three kinds of ecological type: that is, flat floating, oblique