Aims

Plant residues decomposing within the soil matrix are known to serve as hotspots of N₂O production. However, the lack of technical tools for microscale in-situ N₂O measurements limits understanding of hotspot functioning. Our aim was to assess performance of microsensor technology for evaluating the temporal patterns of N₂O production in immediate vicinity to decomposing plant residues.

Methods

We incorporated intact switchgrass leaves and roots into soil matrix and monitored O₂ depletion and N₂O production using electrochemical microsensors along with N₂O emission from the soil. We also measured residue’s water absorption and b-glucosidase activity on the surface of the residue - the characteristics related to microenvironmental conditions and biological activity near the residue.

Results

N₂O production in the vicinity of switchgrass residues began within 0–12 h after the wetting, reached peak at ~0.6 day and decreased by day 2. N₂O was higher near leaf than near root residues due to greater leaf N contents and water absorption by the leaves. However, N₂O production near the roots started sooner than near the leaves, in part due to high initial enzyme levels on root surfaces.

Conclusion

Electrochemical microsensor is a useful tool for in-situ micro-scale N₂O monitoring in immediate vicinity of soil incorporated plant residues. Monitoring provided valuable information on N₂O production near leaves and roots, its temporal dynamic, and the factors affecting it. The N₂O production from residues measured by microsensors was consistent with the N₂O emission from the whole soil, demonstrating the validity of the microsensors for N₂O hotspot studies.

中文翻译：

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植物残体附近N 2 O的动力学：微传感器方法

目的

已知在土壤基质中分解的植物残渣可作为N ₂ O产生的热点。但是，缺乏用于微型原位N ₂ O测量的技术工具限制了对热点功能的理解。我们的目标是评估微传感器技术的性能，以评估植物残体分解附近N ₂ O产生的时间模式。

方法

我们将完整的柳枝叶和根部整合到土壤基质中，并使用电化学微传感器以及土壤中的N ₂ O排放来监测O _2的消耗和N ₂ O的产生。我们还测量了残留物表面上的残留物吸水率和b-葡萄糖苷酶活性-与微环境条件和残留物附近的生物活性有关的特征。

结果

柳枝switch残渣附近的N ₂ O产生在润湿后的0–12小时内开始，在〜0.6天达到峰值，并在第2天下降。由于叶中N含量更高，叶片附近的N ₂ O高于根部残留。叶片吸收水分。但是，根附近的N ₂ O产生比叶附近的N ₂ O产生更快，部分原因是根表面的初始酶水平很高。

结论

电化学微传感器是用于在土壤中掺入植物残体的附近进行原位微型N ₂ O监测的有用工具。监测提供了有关叶和根附近N ₂ O产生，其时间动态以及影响其的因素的有价值的信息。的N个₂从由微传感器测量的残留物0产量为与N一致₂从整个土壤O排放，展示出微传感器的有效性对于N ₂ ö热点研究。