稻田湿地系统对面源污染物的消纳性能研究

发布时间：2018-02-01 23:56

本文关键词： 初期径流消纳氮磷素稻田湿地高通量测序　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：富营养化现象的发生与土壤氮、磷养分流失有着密切的关联。地势较低的稻田,可极大的影响地表径流中氮、磷营养物质的迁移转化过程。本研究选择了一个典型种植系统开展了不同时间、不同自然降雨条件下地表径流氮磷输出规律研究,并选取了两种不同的水稻作为稻田湿地作物,采取田间试验的方法,借助核磁共振分析、高通量测序等手段,研究了不同品种水稻对水稻产量、田面水、土壤磷形态、以及土壤微生物的影响,以期为种植业氮磷流失系统阻控提供支持,为高效稻田湿地系统构建提供参考。研究结果如下:(1)通过不同季节4次跟踪调查采样,发现其中3次采样(1月13日、5月15日、9月29日),稻田湿地出口处氮磷浓度均低于入口,表明茶园初期径流在经过稻田后污染物浓度降低,水质得到净化。入口、出口处溶解态氮均是氮素的主要存在形式,分别占各处总氮的48.64%～99.51%和67.72%～98.32%;入口处溶解态磷平均占比58.66%,出口处平均占比43.97%。(2)稻田湿地系统对降雨初期径流氮有消纳作用的是9月29日采样,平均消纳能力为21.58g N/(4h·ha);稻田湿地系统对降雨初期径流磷有消纳作用的是5月15日、9月29日采样,平均消纳能力分别为0.67g P/(4h·ha)、2.97g P/(4h·ha)。其余几次采样均显示稻田输出氮磷。以上结果说明稻田湿地系统消纳氮磷的关键时期是水稻生长中后期。(3)通过比较两个水稻品种(常规:秀水134;浙大研制:渔稻1号),发现渔稻1号比秀水134水稻吸收了更多的碳、氮、磷,并且更多的储存在水稻秸秆中。渔稻1号平均秸秆量为12.62 t ha-1,比秀水134水稻高40.3%,稻谷产量无显著差异。渔稻1号水稻秸秆碳、氮、磷累积量均显著高于秀水134水稻;两种水稻稻谷中碳、氮、磷均无显著性差别。渔稻1号水稻对于缓解农业湿地富营养化、调控高养分投入地区农田土壤氮磷淋溶等方面有积极的意义。田面水分蘖期和灌浆期,秀水134水稻田面水总氮浓度、总磷浓度等均显著大于渔稻1号。(4)秀水134水稻成熟期土壤中残留了更多的碳氮磷素,渔稻1号更易吸收土壤中的碳、氮、磷。高通量测序结果显示,种植一季渔稻1号水稻没有对稻田土壤的主要细菌菌落造成显著的影响。细菌群落多样性的改变主要是SC-I-84_norank等含量较少的菌属的变化引起的。网络分析结果仅显示土壤Total-P、土壤微生物及秸秆生物质之间具有一定的网络关系。土壤pH、Total-C、Total-N以及植株Straw-N、Grain-N、Grain-P的网络关系独立于土壤Total-P网络之外。
[Abstract]:The occurrence of eutrophication is closely related to the loss of soil nitrogen and phosphorus. In this study, a typical planting system was selected to study the nitrogen and phosphorus output of surface runoff at different time and different rainfall conditions. Two different kinds of rice were selected as paddy field wetland crops. By means of nuclear magnetic resonance (NMR) and high-throughput sequencing, the effects of different rice varieties on rice yield and surface water were studied. The forms of soil phosphorus and the influence of soil microbes are expected to provide support for the prevention and control of nitrogen and phosphorus loss system in planting industry. The results of the study are as follows: 1) three samples were collected from four different seasons (January 13th, May 15th, September 29th). The concentration of nitrogen and phosphorus at the exit of the paddy wetland was lower than that at the entrance, indicating that the concentration of pollutants decreased and the water quality was purified after the initial runoff of the tea garden passed through the paddy field. The dissolved nitrogen at the entrance and outlet were the main forms of nitrogen. They accounted for 99.51% and 67.72% of the total nitrogen, respectively, and 98.32% of the total nitrogen. The average proportion of dissolved phosphorus at the entrance is 58.66 and the average proportion at the exit is 43.97. The paddy field wetland system has the effect of absorbing nitrogen from the runoff in the early stage of rainfall by sampling in September 29th. The average absorbability was 21.58 g N / L 4 h 路hage; The paddy field wetland system had the absorption effect on runoff phosphorus in May 15th and September 29th, and the average absorption capacity was 0.67 g P / m 4 h 路ha. respectively. 2. 97g P / m 4 h 路ha.All the other samples showed that N and P were exported from rice field. The above results indicated that the key period of nitrogen and phosphorus uptake in paddy field wetland system was rice in the middle and late stage of rice growth. Two rice varieties were compared (routine: Xiushui 134; Development of Zhejiang University: Yuedao No. 1 found that Yudao No. 1 absorbed more carbon, nitrogen and phosphorus than Xiushui 134 rice. And more stored in rice straw. The average straw amount of Yudao 1 was 12.62 t ha-1, which was 40.3% higher than Xiushui 134 rice. There was no significant difference in rice yield. The accumulation of carbon, nitrogen and phosphorus in rice straw was significantly higher than that in Xiushui 134 rice. There was no significant difference in carbon, nitrogen and phosphorus between the two rice varieties. The regulation of nitrogen and phosphorus leaching in farmland in high nutrient input area has positive significance. At tillering stage and filling stage, total nitrogen concentration in surface water of Xiushui 134 paddy field. Total phosphorus concentrations were significantly higher than those of Yudao No. 1. 4) more carbon, nitrogen and phosphorus remained in the soil of Xiushui 134 at maturity stage, and Yudao 1 was easier to absorb carbon, nitrogen, phosphorus and high throughput sequencing results. No significant effect was found on the main bacterial colonies in paddy soil. The change of bacterial community diversity was mainly caused by the change of SC-I-84_norank and other minor bacterial genera. Network analysis results show only soil Total-P. There is a certain network relationship between soil microorganism and straw biomass. The pH value of soil pH is Total-CTtal-N and the plant Straw-Ne Grain-N. The network relationship of Grain-P is independent of soil Total-P network.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52;X712

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