调控稻田人工生物圈及其新耕作体系研究Ⅲ.外源喷水系统的增氧效果研究
Studies on Artificial Controlling Biosphere in Paddy Field and Its New Cropping System Ⅲ.The Eftect of External Water-sprikling System on Dissolves Oxygen
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摘要: 实验证明淡水白鲳、尼罗罗非鱼、鲤鱼、革胡子鲶正常生长的水体溶氧重应高于3mg/l.稻田人工生物圈中水体的溶氧量的日变化规律与池塘相似都为昼高夜低,但人工生物圈水体的溶氧量低于池塘,而且鱼坑中的溶氧量又低于田面,在养殖的后期人工生物圈中水体夜间的溶氧量表现为缺乏。用外源喷水的方式进行增氧,结果表明,在夜间喷水45min,喷水量225m3/hm3,可以满足产量为4377.2kg/hm2的稻田人工生物圈中鱼类对溶氧的要求。而且,外源喷水系统的增氧效果与水体中鱼类的密度成反比。在相同鱼种及放养比例的条件下,有喷水的人工生物圈的鱼产量是不喷水的高密度养鱼的2倍,且成活率高、个体较大。Abstract: Experitmental results indicated that water dissolved oxygen(DO)need to be more than 3mg/l to meet the healthy growth of Clossoma brachypomum,Tilapia,Cyprinus carpio and Clarias fuscus.The variance of daily DO of artificial biosphere in paddy field(ABPF)is similar to that of the pond,which was high in daytime and low in night tirne,but DO of ABPF is lower than that of the pond,and the DO in pit of ABPF is lower than that on surface.The DO of ABPF frequently deficient during night time of the late stage of fish culture.The experitmental results also showed that,225m3/hm2 sprikling volum for 45min.from external watersprikling(EWS)system during night time could meet the DO requirements of fishes with the yield of 4377.2kg/hm2 in ABPF.The effect of EWS systern is negatively related to the fish density in ABPF,With the same fish mixted rate,the fish yield of ABPF is double to high-density fish culture which without EWS system.