Eldeeb Mohammed A, Dhamu Vikram Narayanan, Paul Anirban, Alam Firas Maqsood, Burgos E Natalie, Muthukumar Sriram, Prasad Shalini
Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75080, United States.
EnLiSense LLC, Allen, Texas 75013, United States.
ACS Omega. 2024 Jul 25;9(31):33928-33934. doi: 10.1021/acsomega.4c04181. eCollection 2024 Aug 6.
The world is facing a food shortage predicament largely fueled by inefficient, outdated farming conventions that are passed down from generation to generation. Overfertilization is one of the major byproducts of inadequate farming techniques. This leads to an imbalance in the soil ecosystem, affecting carbon sequestration, plant-available nutrients, and microorganisms. Sustainable agriculture, on the other hand, efficiently uses the soil with minimal fertilizer and crop rotation to prevent soil erosion. This method requires real-time information on the soil's health. An electrochemical ion-selective electrode (ISE) is presented to measure soil ammonium in situ. The sensor utilized electrochemical impedance spectroscopy for direct, continuous soil ammonium measurement without any soil pretreatment. The ISE is applied by drop-casting onto the working electrode. The sensor response was calibrated against the three main different soil textures (clay, sandy loam, and loamy clay) to cover the entirety of the soil texture triangle. The linear regression models showed an ammonium-dependent response with Pearson > 0.991 for the various soil textures in the range of 2-32 ppm. The sensor response was validated against the gold standard spectrophotometric method after KCl extraction showed a less than 20% error rate between the measured ammonium and reference ammonium. A 16 day in situ soil study showed the capability of the sensor to measure soil ammonium in a temporally dynamic manner with a coefficient of variance of 11%, showing robust stability for in situ monitoring.
世界正面临着粮食短缺的困境，这在很大程度上是由代代相传的低效、过时的耕作传统所导致的。过度施肥是不当耕作技术的主要副产品之一。这会导致土壤生态系统失衡，影响碳固存、植物可利用养分和微生物。另一方面，可持续农业通过最少的肥料使用和作物轮作来高效利用土壤，以防止土壤侵蚀。这种方法需要有关土壤健康状况的实时信息。本文提出了一种电化学离子选择性电极（ISE）来原位测量土壤铵含量。该传感器利用电化学阻抗谱直接、连续地测量土壤铵含量，无需对土壤进行任何预处理。ISE通过滴铸法应用于工作电极上。针对三种主要不同的土壤质地（黏土、砂壤土和壤质黏土）对传感器响应进行了校准，以覆盖整个土壤质地三角形。线性回归模型表明，在2 - 32 ppm范围内，不同土壤质地的铵依赖响应的皮尔逊相关系数大于0.991。在氯化钾提取后，将传感器响应与金标准分光光度法进行验证，结果表明测量的铵含量与参考铵含量之间的误差率小于20%。一项为期16天的原位土壤研究表明，该传感器能够以时间动态方式测量土壤铵含量，变异系数为11%，显示出用于原位监测的强大稳定性。
