Rice yield parameters in different treatments.

Rice fish co-culture synergistically boosts food production, resulting in numerous advantages across the environmental, social, and financial domains. A study was conducted to investigate the effects of three different rice spacing densities, rice high density (RHD) 9inch×12inch, rice medium density (RMD) 12inch × 12inch, rice low density (RLD) 15inch×12inchon both rice and fish. Various parameters were assessed to evaluate the performance of the co-culture system, including water quality, growth parameters, muscle quality, soil characteristics, rice stem characteristics, and rice yield parameters. When comparing the species, it was observed that GMT (Genetically Male Tilapia) demonstrated superior weight gain (303.13g vs 296.41g) and specific growth rate (1.16 vs 1.15). Regarding the proximate composition, results showed that RMD had the highest crude protein and fat content compared to RLD and RHD. GMT also exhibited greater crude protein and fat content than Cyprinus carpio, with RMD showing the highest values. Treatment groups significantly influenced the amino acid profile of experimental species, with RMD exhibiting the highest values. GMT showed significantly higher levels of essential, non-essential, half-essential, and umami amino acids compared to Cyprinus carpio. The interaction between RMD and GMT further demonstrated significant differences in various amino acid categories with RMD. A non-significant difference was observed among the treatments regarding soil biochemical characteristics. Regarding the rice stem characters, the height of the plant, panicle length, and stem length of rice were found to be comparable in the RMD and RLD groups however, significantly higher in RHD. Regarding rice yield parameters, no significant differences were observed among the other treatment groups, except for yield per hectare (yield/ha), which was significantly higher in the RHD group compared to RMD and RLD. Additionally, 1000-grain weight and panicle number (ears per hill) were significantly higher in the RLD treatment than in the other treatments. In conclusion, our findings indicate that the RMD treatment consistently yielded superior results compared to RLD and RHD. Furthermore, within the rice-fish co-culture system, GMT proved to be a more competent species compared to Cyprinus carpio. The study provides data to understand the interactions between rice spacing density, fish growth and overall productivity can guide the development of sustainable and profitable rice-fish co-culture systems.

稻鱼综合种养可协同提升粮食产量，在环境、社会与经济领域展现出多重优势。本研究旨在探究三种不同水稻种植密度对水稻与鱼类的影响，其中水稻高密度（RHD, Rice High Density）组为9英寸×12英寸，水稻中密度（RMD, Rice Medium Density）组为12英寸×12英寸，水稻低密度（RLD, Rice Low Density）组为15英寸×12英寸。研究通过多项指标评估该综合种养系统的表现，涵盖水质、生长参数、肌肉品质、土壤特性、稻株茎秆特性及水稻产量相关参数。对受试物种进行对比后发现，基因雄性尼罗罗非鱼（GMT, Genetically Male Tilapia）的增重效果更优（303.13g vs 296.41g），特定生长率也更高（1.16 vs 1.15）。就常规营养组成而言，结果显示RMD组的粗蛋白与粗脂肪含量均高于RLD组与RHD组。GMT的粗蛋白与粗脂肪含量也高于鲤（Cyprinus carpio），且RMD组的上述指标数值最高。不同处理组对受试物种的氨基酸谱存在显著影响，其中RMD组的各项氨基酸数值均为最高。相较于鲤，GMT的必需氨基酸、非必需氨基酸、半必需氨基酸及鲜味氨基酸含量均显著更高。RMD与GMT的组合进一步在各类氨基酸分类中展现出显著差异。不同处理组间的土壤生化特性未呈现显著差异。关于稻株茎秆性状，RMD组与RLD组的水稻株高、穗长及茎秆长度均无显著差异，但三者均显著低于RHD组。在水稻产量相关参数方面，除公顷产量（yield/ha）外，其余参数在各处理组间均无显著差异；其中RHD组的公顷产量显著高于RMD组与RLD组。此外，RLD组的千粒重与每穴穗数均显著高于其余两组。综上，本研究结果表明，RMD处理组的综合表现始终优于RLD组与RHD组。此外，在稻渔综合种养系统中，GMT相较于鲤展现出更优异的养殖性能。本研究提供的相关数据有助于明晰水稻种植密度与鱼类生长及整体生产性能之间的相互作用，可为可持续且具备经济效益的稻渔综合种养系统的发展提供指导。