种植水稻对池塘沉积物中养分和氨氧化古菌的影响
RICE PLANTING ON NUTRIENTS AND AMMONIA-OXIDIZING ARCHAEA IN POND SEDIMENTS
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摘要: 为科学管理和利用池塘长期养殖产生的沉积物, 实行池塘养殖和种植适度轮换是利用底泥养分和改善池塘底质的重要途径。将基本情况完全相同的9个池塘停止养鱼, 进行种植水稻改良底质试验, 以空置为对照(CK)、设种稻不晒田(T1)和晒田(T2)两个处理, 检测试验过程沉积物的主要化学性质和氨氧化古菌(Ammonia-oxidizing archaea, AOA)的丰度及水稻收获后AOA的群落多样性和结构差异。结果表明, 与CK相比, T1(或T2)处理下沉积物中TN、TP和OM显著减少, 分别降低了26.58%(31.04%)、58.84%(58.38%)和11.17%(16.11%); T2与T1相比, 显示种稻过程中晒田可以加速沉积物中TP和OM的去除; 沉积物硝化强度和AOA丰度整体上呈现先增后减的趋势, 其中, 与CK相比, T1、T2的沉积物硝化强度在水稻分蘖期和拔节孕穗期显著提高, AOA丰度在分蘖期显著增加; 种植水稻可以显著提升沉积物AOA的α多样性和OTU数量, 增加许多新的AOA种群, T1主要增加了Candidatus nitrosocosmicus cluster(占总序列的3.84%), T2主要增加了Candidatus nitrosotenuis cluster(占总序列的3.24%)。以上结果表明, 种植水稻可以有效缓解池塘沉积物养分富集危害, 可作为池塘可持续生产的配套措施。Abstract: Scientific management and properly utilization of sediment is of significance for healthy aquaculture and resource utilization in long-term culture ponds. Rotation of pond culture and cultivation appropriately is an effective way, which can reuse the nutrients in sediments and improve the sediment environment. Nine ponds with the same basic conditions were suspended aquaculture activities and used for the experiment of rice substrate improvement. Empty pond was used as the control (CK), two treatments were set: planting rice without field drying (T1) and planting rice with field drying group (T2). The main chemical properties and abundance of ammoxidation archaea in the sediments during rice growth were determined, and the community diversity and structure difference of AOA in rice after harvest were determined. The results showed that, compared with CK, the TN, TP and OM in sediments of T1 (or T2) decreased significantly by 26.58% (31.04%), 58.84% (58.38%) and 11.17% (16.11%) respectively. Compared with T1 and T2, it was concluded that the degradation of TP and OM in sediment was accelerated by solarization. The nitrification intensity and the abundance of AOA in the sediments increased at first and then decreased. Compared with CK, the nitrification intensity of T1 and T2 was significantly increased at tillering stage and jointing stage, while the abundance of AOA was significantly increased at tillering stage. Diversity index and OUT number of AOA in sediments were increased and a large amount of new AOA populations generated by rice cultiviton. The increased species in T1 was Candidatus nitrosocosmicus cluster (3.84% of the total sequence), and which in T2 was Candidatus nitrosotenuis cluster (3.24% of the total sequence). It indicated that rice planting can effectively alleviate the nutrient enrichment in pond sediments, which can be used as a supporting measure for sustainable pond aquaculture.