培养基投放对池塘表层底泥磷形态及底栖 饵料生物培育效果的影响

目的]探究培养基投放对池塘表层底泥磷形态及底栖饵料生物培育效果的影响,为新型培养基在池塘生态健康养殖中的推广应用提供参考依据.方法]在池塘中按不同比例4.50×103(处理1)、1.35×104(处理2)、6.75×104(处理3)kg/ha]投放培养基,以不投放培养基为对照,每处理设2个平衡.分别于春、夏、秋三季,每季度采集池塘表层底泥两次,测定不同磷形态含量;每月采集底栖饵料生物一次,统计其生物量.结果]投放培养基后,池塘底栖水蚯蚓的数量密度随培养基投放比例的增加而增加,而摇蚊幼虫的生物量表现为:处理2(12.82 g/m2)>处理1(10.77 g/m2)>处理3(10.02 g/m2)>对照(8.19 g/m2),其中处理1、2、3分别比对照高20.85%、43.90%和12.50%.池塘表层底泥中总磷(TP)、无机磷(IP)、钙结合态磷(Ca-P)、铝吸附态磷和(Al-P)及弱吸附态磷(Labile-P)含量均表现为:处理3>处理2>处理1>对照,即与培养基投放量呈正相关;各培养基投放处理组Labile-P含量的季节变化表现为:秋季>春季>夏季,Fe-P、Al-P和Ca-P含量的季节变化表现为:春季>夏季>秋季.Labile-P与Fe-P的平均含量分别高出对照27.00%和31.00%左右.结论]在池塘中投放培养基可有效提高底栖饵料生物的生物量,其对池塘表层底泥不同磷形态的贡献主要表现为增加Labile-P和Fe-P的含量,尤其是Fe-P的增加有利于摇蚊幼虫培育,更好地为虾蟹类池塘养殖提供天然饵料.

Influences of media provisioning on phosphorus forms in surface sediments and benthos baits cultivation effects

Objective]Influences of media provisioning on phosphorus forms in surface sediments and benthos baits cultivation effects were studied to provide reference for application of new media in ecological pond culture. Method]In the experiment,different amounts of culture media were buried in ponds,which were 4.5×103 (treatment 1)、1.35×104(treat-ment 2)、6.75×104(treatment 3)kg/ha,control group did not deliver culture medium, and each group set two repeats. In spring, summer and autumn, surface sediment was collected twice each quarter for measuring phosphorus of different forms. At the end of each month, benthos baits were collected to measure the biomass.Result]Density of Tubificidae increased with the increase of culture medium amount in four experimental treatments, the order of biomass of Chironomid larvae was:treatment 2(12.82 g/m2)>treatment 1(10.77 g/m2)>treatment 3(10.02 g/m2)>control(8.91 g/m2). Biomass in treatment 1, 2 and 3 were 43.90%, 20.85%, and 12.50%higher than that in control respectively. The contents of total phosphorus(TP), inorganic phosphorus (IP), calcium-bound phosphorus (Ca-P), aluminum-bound phosphorus (Al-P), and loosely sorbed phosphorus(Labile-P) were all represented as follows: treatment 3>treatment 2>treatment 1>control, which meant these indexes were positively correlated with media amount. The seasonal variation of Labile-P content in four treatments was:autumn>spring>summer, and the seasonal variations of Fe-P, Al-P and Ca-P was spring>summer>autumn. The average contents of Labile-P and Fe-P were 27.00%and 31.00%higher than those in control respectively. Conclusion]Media pro-visioning in aquaculture ponds can effectively improve the biomass of benthos baits and increase Labile-P and Fe-P con-tents of phosphorus of different forms in surface sediment. Rising Fe-P content is benefical for culture of Chironomid lar-vae, then can provide natural baits for pond culture for shrimp and crab.