Abstract:

Rice-fish co-culture system is an agricultural model that utilizes water resources for dual purposes, which is beneficial for stabilizing aquaculture while increasing grain production. The effects of different rice planting coverage rate (0%, 25%, 50%, and 75%) on grain yield and water quality were investigated for high-quality indica rice varieties Yuexiang 430 and Wushansimiao in fish ponds for breeding Australian freshwater lobsters. The aim is to provide scientific basis for optimizing rice-fish co-culture technology, improving production and efficiency of rice and fish. Concurrently, 30 rice varieties (with a planting coverage rate of about 37.1%) were used as experimental materials to screen rice varieties in fish ponds for breeding largemouth black bass. The results indicated that the rice yield of the treatments with 50% and 75% rice planting coverage was significantly higher than that of the treatment with 25% coverage. Specifically, Yuexiang 430 achieved the highest yield at 50% coverage, while Wushansimiao peaked at 75% coverage. The rice-crayfish co-culture led to significantly lower concentrations of NO₃^--N, NH₄⁺-N, NO₂^--N, COD, and BOD of pond water while compared to the 0% coverage. Similarly, the concentration of TOC of pond water exhibited the same trend during the early growth stages of rice, while pH value and dissolved oxygen levels have no significant difference during the rice growth period. Additionally, the rice varieties such as Huahang 48, Shuanghuangzhan, Qingxiangyousimiao, Yuexiang 430, Taifengyou 208, and Wushansimiao demonstrated superior performance with grain yields exceeding 5.50 t/hm² in rice-planting and largemouth bass co-culture system. In summary, a rice planting coverage rate of 50% under the rice-shrimp symbiotic mode has a relatively stable rice yield and a purifying effect on aquaculture water quality, making it more suitable for rice production in fishponds culturing Australian freshwater crayfish.

Key words: rice-fish co-culture system, rice, planting coverage rate, variety screening, yield, fishpond water quality

摘要：

稻渔共生是“一水两用”的生态农业模式,有利于在稳定水产养殖的同时增加粮食产量。以优质籼稻品种粤香430和五山丝苗为试验材料,在养殖澳洲淡水龙虾鱼塘中开展不同水稻种植覆盖率(0%、25%、50%和75%)对水稻产量和鱼塘水质的影响,以为优化稻渔共生技术、提高稻渔产量和效益提供科学依据;同时以30个水稻品种(种植覆盖率约37.1%)为参试材料,在养殖大口黑鲈鱼塘中进行水稻品种筛选试验。结果表明,水稻种植覆盖率50%和75%处理的稻谷产量明显高于覆盖率25%的处理,其中,粤香430以覆盖率50%处理的产量最高,五山丝苗以覆盖率75%处理的产量最高。种稻养虾模式下鱼塘水体的硝态氮(NO₃^--N)、铵态氮(NH₄⁺-N)、亚硝态氮(NO₂^--N)、化学需氧量(COD)和生化需氧量(BOD)浓度均显著低于不种稻处理(覆盖率0%),水体总有机碳(TOC)在水稻生长前期也表现相同趋势,水体酸碱值(pH)和溶解氧含量(DO)在整个水稻生育期内无显著变化。在鱼塘种稻养殖大口黑鲈模式下,华航48号、双黄占、青香优丝苗、粤香430、泰丰优208和五山丝苗的稻谷产量较高,均达到5.50t/hm²以上。综上所述,稻虾共生模式下50%水稻种植覆盖率具有较稳定的水稻产量和净化养殖水质,适合在鱼塘养殖澳洲淡水龙虾模式应用。

关键词: 稻渔共生, 水稻, 种植覆盖率, 品种筛选, 产量, 鱼塘水质