The development of technologies for continuous measurement of nitrogen forms in the soil is essential for optimizing the application of fertilizers in agriculture and preventing water-resource pollution. However, there is no effective commercial technology available for continuous monitoring of ammonium species in soil pore water. This work investigates an approach for real-time measurement of ammonium in soil water using near-infrared transmission spectroscopy and partial least squares regression (PLSR) for spectral analysis. The PLSR model was trained using soil pore water collected from various soils spiked with ammonium to achieve a wide concentration range. The monitoring approach was then validated through transport experiments in a soil column. The results demonstrated capabilities for real-time tracking of the temporal variation in soil ammonium concentration and potential utilization in agronomical or environmental sensing.

开发连续测量土壤中氮形态的技术对于优化农业肥料应用和防止水资源污染至关重要。然而，没有有效的商业技术可用于连续监测土壤孔隙水中的铵种类。这项工作研究了一种使用近红外透射光谱和偏最小二乘回归 (PLSR) 进行光谱分析的实时测量土壤水中铵的方法。PLSR 模型使用从各种土壤中收集的土壤孔隙水进行训练，这些土壤中掺入了铵，以实现较宽的浓度范围。然后通过土柱中的传输实验验证了监测方法。