稻田种养模式生态效益研究

Studies on the ecological effect of plantingbreeding models in the rice field

1991年在湖北潜江进行了一个包括 5个处理、3个重复的随机区组试验 :处理 A,普通稻田 ,不养鱼 ( CK) ;B,垄稻沟鱼 ,宽、深各 3 3 cm的小沟中养鱼 ;C,B+横沟或围沟 ,深 50 cm,宽 3 3 cm,或加一小坑 ,宽 1～ 2 m,深 1 m,长度以占小区 8%的面积为准 ,养鱼 ;D,B+大围沟 ,宽 2 m,深 2～ 2 .5m,占小区面积的 1 5%,养鱼 ;E,D+鸭。结果表明 ,在酷暑 7、8月份 ,宽而深的大沟的水温比窄而浅的更适于养鱼 ;水溶氧量、浮游生物和底栖动物量都以宽而深的沟为高 ,特别是加了鸭的。本课题组提出的“回”字型大沟鱼、鸭兼养模式还能大幅度提高土壤氮、磷、钾、有机质含量 ,且具防治稻田杂草、病、虫的作用。其对稻。

A random block experiment consisted of five treatments was conducted.Treatment A was an ordinary paddy field with no fish.B was rice planted on the ridge and fish reared in the little ditch,with the width and depth of ridges or ditches of 33cm;C was the same as B except the ridges and ditches are larger in width and depth;D was same as B except the large surrounding ditch of 2m in width and 2.0～2.5m in depth,occupying 15% area ;E,D+ducks.\;The results indicated that in July and August,the temperature in the wide and deep ditches was more suitable to fish growth than that in narrow and shallow ones.The water soluble oxygen was highter in wide ditches than that in narrow ones,specially with ducks.The phytoplankton,zooplankton and benthic animals were richer in wide ditches,too.The fishes and ducks could eat weeds,rice insects and control the rice diseases,and increase nutrients and organic matter content in the soil.The more wider and deeper ditches,the more yield of rice and fishes were gained.Ducks were the most active factors in this system.