不同中华绒螯蟹放养密度对寒区稻蟹综合种养生产性能及环境因子的影响

Effects of different crab stocking density on production performance and environmental factors under integrated cultivation of rice crab in the cold areas

为探明寒区稻蟹综合种养过程中扣蟹的适宜放养密度,本实验以水稻单作为对照,采用生态学方法,研究了不同中华绒螯蟹(Eriocheir sinensis)放养密度(200、350、500、650和800只/667m^(2))对寒区稻蟹综合种养过程中河蟹和水稻的生长性能及稻田水质和底质的影响。结果显示:随着放养密度的增加,中华绒螯蟹的终末体重、增重率、特定生长率整体均出现显著下降的趋势。350只/667m^(2)处理组水稻的结实率和产量均显著高于水稻单作组和其他处理组。随着中华绒螯蟹放养密度的增加,各处理组土壤的总磷含量均呈逐渐上升趋势。800只/667m^(2)处理组土壤总氮和总磷含量均显著高于350只/667m^(2)和500只/667m^(2)处理组,与其它组差异均不显著。整个实验过程中,稻田水体的平均温度(T)、溶解氧(DO)、pH、总氮(TN)、总无机氮(TIN)、总氨氮(TAN)、非离子氨(NH_(3)-N)、亚硝酸态氮(NO_(2)-N)、硝酸态氮(NO_(3)-N)、总磷(TP)及化学需氧量(COD)在各组之间均无显著差异。综合各参数分析结果表明,寒区稻蟹综合种养过程中扣蟹的最佳放养密度为350只/667m^(2),该密度条件下,稻田水质环境较好,中华绒螯蟹及水稻的生长性能均能达到较高水平。

This study aimed to explore the optimum stocking density of young crab in the integrated cultivation of rice crab in the cold region.In this experiment,rice single cropping was used as the control group.The treatment groups were set according to the stocking density of Eriocheir sinensis(200,350,500,650 and 800 inds/667m^(2))to study the effect on growth performance of Eriocheir sinensis and rice.Meanwhile,water quality and soil quality under integrated cultivation of rice crab in the cold areas were revealed.The results showed that the final body weight,weight gain rate and specific growth rate of crabs showed a significant decrease with the increase of stocking density.The seed setting rate and yield in 350 inds/667m^(2) treatment groups were significantly higher than that in the rice single cropping and other treatment groups.The total phosphorus contents of paddy soil in treatment groups showed a gradually increasing trend.The total nitrogen content of 800 inds/667m^(2) treatment group was significantly higher than that of 350 inds/667m^(2) and 500 inds/667m^(2) treatment groups,and there was no significant difference between the other groups.During the whole experiment period,there were no significant differences in average temperature(T),dissolved oxygen(DO),pH,total nitrogen(TN),total inorganic nitrogen(TIN),total ammonia nitrogen(TAN),nitrite nitrogen(NO_(2)-N),nitrate nitrogen(NO_(3)-N),nonionic ammonia(NH_(3)-N),total phosphorus(TP)and chemical oxygen demand(COD)among all groups.Based on the analysis of various parameters,the optimum stocking density of crab in integrated cultivation of rice crab in the cold areas was 350 inds/667m^(2).The water quality environment in paddy was better,and the growth performance of crab and rice could reach a higher level at the condition of the density.