Non-Linear Response of Ammonia Volatilization to Periphyton in Paddy Soils
Non-Linear Response of Ammonia Volatilization to Periphyton in Paddy Soils
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水稻土氨挥发对附生生物的非线性响应
DOI：
10.1029/2020jg005870
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
夏永秋
中科院分区：
文献类型：
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作者：
黄晶;刘雪梅;颜晓元;吴永红;严星;刘宇晴;夏永秋
稻田土壤氨挥发是农业氨排放的主要来源之一，然而普遍存在的附着生物对稻田土壤氨挥发的影响研究较少。考虑到附着生物的组成主要是由自养生物，直接影响氧化还原和pH条件，它是假设的存在下，附着生物可能是一个重要的影响因素NH3排放。在这项研究中，NH3挥发测定下，6个附着生物生物量处理和6个不同的施氮量的处理下，以评估在实验室代表水稻土系统的附着生物NH3挥发的贡献。结果表明，附着生物通过pH值和NH4+浓度对NH3挥发具有平衡效应。当附着生物量大于110 g·m−2时，附着生物对NH3挥发有净抑制作用。当附着生物量小于110 g·m−2时，附着生物对NH3挥发有净促进作用。附着生物对NH3挥发的贡献随着施氮量的增加呈指数增加（即，随着上覆水氮浓度的增加）。在低氮处理（≤20 kg N. ha−1）下，附着生物对NH3挥发无显著影响。相比之下，在高氮浓度（100 kg N·ha−1）下，附着生物对NH3挥发的贡献高达47.4%。本研究为深入了解附着生物对NH3挥发的影响提供了有价值的信息，并提供了附着生物与NH3挥发的定量关系，提高了区域水稻土NH3挥发估算的准确性。
Ammonia (NH3) volatilization from paddy soils is one of the main contributors to agricultural NH3 emissions, however, little attention has been paid to the role of the ubiquitous periphyton in paddy soils on NH3 volatilization. Considering that the composition of periphyton is dominated by autotrophs that directly affect the redox and pH conditions, it is hypothesized that the presence of periphyton may be an important factor affecting NH3 emissions. In this study, NH3 volatilization was determined under six periphyton biomass treatments and under treatments with six different N application rates to evaluate the contribution of periphyton to NH3 volatilization in the laboratory representing the paddy soils system. Results showed that periphyton had trade‐off effects on NH3 volatilization through pH and the NH4+ concentration. Periphyton had net inhibition effects on NH3 volatilization when the periphyton biomass was higher than 110 g·m−2. In contrast, periphyton had net promotion effects on NH3 volatilization when the periphyton biomass was less than 110 g·m−2. The contribution of periphyton to NH3 volatilization increased exponentially with increasing N application rates (i.e., with the increasing nitrogen concentration of the overlying water). In the low‐nitrogen treatments (≤20 kg N·ha−1), periphyton had no significant effect on NH3 volatilization. In contrast, periphyton contributed as much as 47.4% of NH3 volatilization at high nitrogen concentrations (100 kg N·ha−1). This study provides valuable insight into the role of periphyton on NH3 volatilization, offers quantified relationship between periphyton and NH3 volatilization, and improves the accuracy of NH3 volatilization estimation in regional paddy soils.