Hotspots and hot moments of amino acid N in soil: Real-time insights using continuous microdialysis sampling
Hotspots and hot moments of amino acid N in soil: Real-time insights using continuous microdialysis sampling
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DOI：
10.1016/j.soilbio.2018.12.026
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发表时间：
2019-04
影响因子：
9.7
通讯作者：
E. J. Hill;Davey L. Jones;E. Paterson;P. Hill
中科院分区：
文献类型：
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作者：
E. J. Hill;Davey L. Jones;E. Paterson;P. Hill
土壤中的蛋白质热点，例如与腐烂的土壤动物或植物凋落物相关的蛋白质热点，可能会产生不成比例的高土壤养分的短暂斑块。这些热点可能发生在靠近植物根部的宏观和微观尺度上，然而，在这些热点中产生的可溶性产物的可能浓度仍然知之甚少。为了解决这个问题，我们埋在土壤中的两个对比生物质残留物，即蚯蚓（蚯蚓）和三叶草（白三叶）。他们转化为氨基酸，NH4+和NO3−连续6天使用微透析监测。所有处理显示出更大的可溶性氮（N）浓度相比，未经修改的控制。最高浓度的两种氨基酸（12.9 mM后12小时）和NH4+（45.3 mM后6小时）在附近的分解酶产生。相比之下，干燥的三叶草残留物在6小时产生2.7 mM的氨基酸。12 h后，干三叶草和鲜三叶草处理的氨基酸和NH4+浓度均急剧下降，接近背景水平（<20 μM）。通过使用微透析，我们能够表明，土壤养分热点可能会提供附近的根与浓度的氨基酸和NH4+几个数量级高于发现在散装土壤溶液。
Protein hotspots in soil, such as those associated with decaying soil fauna or plant litter, may produce ephemeral patches of disproportionately high soil nutrients. These hotspots may occur at the macro- and microscale in close proximity to plant roots, however, the likely concentration of soluble products produced in these hotspots remains poorly understood. To address this, we buried two contrasting biomass residues in soil, namely earthworm (Lumbricus terrestris) and clover (Trifolium repens). Their transformation to amino acids, NH4+and NO3−were monitored continually over 6 days using microdialysis. All treatments showed greater soluble nitrogen (N) concentrations compared to the unamended controls. The highest concentrations of both amino acids (12.9 mM after 12 h) and NH4+(45.3 mM after 6 h) were generated in the vicinity of decomposing earthworm. In comparison, dried clover residues yielded 2.7 mM of amino acids at 6 h. After 12 h, amino acid and NH4+concentrations in both earthworm and dried clover treatments showed a steep decline, returning close to background levels (<20 μM). Through the use of microdialysis we are able to show that soil nutrient hotspots may provide nearby roots with concentrations of amino acids and NH4+several orders of magnitude higher than found in the bulk soil solution.