虾稻共作田虾沟溶解氧和pH值对小龙虾产量的影响

Water Quality of Shrimp Ditch and its Effects on Crayfish Yield in Shrimp and Rice Co-cropping Fields

为探究虾稻共作中虾沟中溶解氧和pH值的变化规律及其对小龙虾产量的影响,在湖北荆州市丫角村开展了虾稻共作田的虾沟水质监测与虾产量试验。试验以2019年和2020年虾稻共生期7-9月为主要观测期,对9块虾稻田进行了虾沟中溶解氧含量、pH值的监测。通过试验得出结论:虾稻共作田溶解氧的含量和虾沟中水生植物、降雨、人工处理措施有关。虾沟中浮萍过多、长历时暴雨会降低虾沟中溶解氧的含量。小龙虾的产量与溶解氧含量整体呈正相关关系,当溶解氧低于2 mg/L时,小龙虾产量下降明显。虾沟中pH值总体在7.3~8.4之间变化,2020年虾沟的平均pH值低于2019年。通过与产量进行对比,当pH在7.7左右波动时,小龙虾平均产量处于较高水平。

In order to explore the changes of dissolved oxygen and pH value in shrimp ditches and its effect on crayfish production in shrimprice co-cropping,a shrimp-rice co-cropping field is carried out in the shrimp-rice co-cropping field in Yajiao Village,Hubei Province.The experiment took the shrimp-rice symbiosis period from July to September in 2019 and 2020 as the main observation period,and monitored the dissolved oxygen content and pH value of the shrimp ditch in 9 shrimp paddy fields. Through the experiment,it is concluded that the dissolved oxygen contents in the shrimp-rice co-cropping field is related to the aquatic plants in the shrimp ditch,rainfall,and artificial treatment measures. Excessive duckweed in shrimp ditches and long-lasting heavy rain will reduce the dissolved oxygen contents in shrimp ditches. The production of crayfish is positively correlated with the contents of dissolved oxygen as a whole. When the dissolved oxygen is lower than 2 mg/L,the production of crayfish will decrease significantly. The pH value in the shrimp ditch generally varies between 7.3~8.4,and the average pH value of the shrimp ditch in 2020 is lower than in 2019. By comparing the yields,when the pH fluctuates around 7.7,the average yield of crayfish is at a relatively high level.