Soil total carbon sensing system

Abstract

An in-situ or interfacial soil sensor is provided that includes one or more electrodes. The soil sensor is configured to detect the level of soil total carbon in a soil sample, the sensor comprising: a working electrode coated with a composite sensing coating, where the composite sensing coating comprises: an active sensing component, a sensor includes an organic carbon sensing element functionalized to detect an organic carbon moiety and an inorganic carbon sensing element functionalized to detect an inorganic carbon moiety, and further includes an encapsulant component.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 357,674, filed on July 1, 2022, the contents of which are incorporated herein in their entirety. Background Art

[0003] Soil and water are vital components of Earth's ecosystems and play an important role in maintaining the Earth's ecological balance and sustaining human life. For example, the proper use of resources such as water and fertilizer in agricultural applications has enormous social (e.g., health, economic, etc.) importance as well as environmental importance. Governments, businesses, and nonprofit organizations are working to develop paradigms for protecting, regenerating, and more wisely using soil and water resources for the benefit of both humans and nature. For example, the concept and practices of "regenerative agriculture" have been proposed and implemented to improve soil health, increase crop nutrient levels, increase water use efficiency, and reverse climate change through carbon sequestration.

[0004] For farmers, systematically recording a variety of information about their fields helps them implement high-quality regenerative agricultural systems, with the goal of improving the information farmers rely on for planning and decision-making to increase productivity, land quality and land assets, and reverse losses or inefficiencies on their farms. Optimizing regenerative agriculture is also important at a macro-societal level to protect land for crop production, water availability, quality and security, and reverse negative environmental impacts caused by degraded, inefficient or careless farming practices.

[0005] Traditionally, analytical information on soil health is obtained by manually collecting soil samples from various accessible areas to represent various soil regions. The samples are then transported to a laboratory where they are tested and measured to better understand the various nutrient levels within these soil samples and estimate the overall soil health and water use efficiency across an entire field, farm, or wider region. This traditional measurement system is inefficient, suboptimal, and expensive, limiting practicality and affordability for end-user farmers, thereby limiting the accessibility and motivation needed to implement this “regenerative agriculture” approach on a large scale, among other example shortcomings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] For a more complete understanding of the present disclosure and its features and advantages, reference is made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, and wherein:

[0007] Figure 1 is a simplified block diagram showing an example soil sensor system deployed on a piece of land;

[0008] Figure 2 is a simplified block diagram illustrating an example implementation of a soil carbon sensor device;

[0009] Figure 3 is a diagram illustrating example chemical interactions between components of an example composite sensing coating and carbon molecules in an example soil sample;

[0010] Figure 4 is a graph showing an example relationship between sensor readings and total soil carbon concentration;

[0011] Figure 5 is a simplified block diagram illustrating an example deployment of a soil sensor system including a soil carbon sensor device;

[0012] Figure 6 is a simplified flow chart illustrating a technique for using an example soil sensor.

[0013] The same reference numbers and names in different drawings represent the same elements. DETAILED DESCRIPTION

[0014] Soil is a fundamental core element of the environment in which we live. In addition to being related to other parts of the ecosystem (including water and air), it also directly affects the growth of plants, crops and other vegetation. A better understanding of the nature, composition and health of soil can realize additional solutions to benefit agricultural initiatives, water quality and environmental health. Therefore, it is necessary to reliably collect information related to the physical, chemical and biological components of soil to understand its important association with soil health. In some embodiments, by collecting these parameter groups, observations of soil and chemical profiles related to soil can be used to create a soil health index with high reliability in an in-situ manner. For example, soil chemistry can be derived using field probes that have been adjusted to produce signals significantly related to physical and biological parameters and soil matrix activity. Commercially, soil quality determines crop yields and farmland costs, where, due to the associated changes in the environment and land use changes, comprehensive, reliable, dynamic and in-situ information about soil parameters synchronized in terms of geographic location (space) and period (time) must be obtained. From the perspective of local and global environmental impacts, the implementation of dynamic in-situ soil sensors will be significantly beneficial in characterizing a variety of soil parameters related to soil health.

[0015] Soil health / quality can be defined by the ability of soil to function as a sustainable ecosystem that supports plants, animals, and humans. Generally, soil health can be characterized based on three main types of soil characteristics: biological, physical, and chemical. Although sometimes used interchangeably, in practical terms, soil quality refers to the chemical and physical properties of the soil. For example, soil health assessment depends heavily on the nutrient levels in the soil. Therefore, assessing soil health parameters in a farm setting helps quantify and document the inherent physicochemical and biochemical characteristics of the soil. For example, adequate soil nutrient levels enable sustainable agricultural practices that generally improve the health of agricultural ecosystems and promote crop yields, pasture growth, etc.

[0016] Current attempts to measure soil characteristics include soil sampling and assessment techniques that involve invasive methods of collecting soil samples, through their removal, transportation and subsequent testing in a laboratory setting different from the point of collection. Among these, combustion-based techniques have become one of the most popular techniques for assessing soil anatomy. Even with recent advances in non-destructive methods such as spectroscopy and tomography-based models, obstacles remain in terms of accuracy (especially at soil depths below 5-10 cm), complexity and availability of equipment, and high cost and logistical overhead.

[0017] In addition to the critical need for soil organic matter pools, plant growth requires a large number of primary, secondary and micronutrients. The rate of nutrient release for crop or plant uptake is affected by the availability of various nutrient sources and other soil parameters. There are many electrochemically active species and redox species in soil that exist in a reduced state under ideal conditions (under water), which contributes to electrochemical activity and, in turn, a corresponding effect on soil quality. Some of the soil properties used to assess soil physical properties include bulk density, infiltration parameters, water holding capacity, and soil texture. Soil parameters used for chemical assessments typically include soil pH, plant available nutrients, soil nitrates, active carbon, soil organic matter, and electrical conductivity. Biological properties of soil systems include the diversity and abundance of soil organisms (soil food web), total organic carbon, soil respiration, and soil enzyme activity. The development of improved sensor systems to successfully and dynamically measure each of these individual parameters can be used to develop comprehensive soil health and quality measurements that could have substantial benefits for many aspects of the environment, world food and water supplies, and economic development.

[0018] In accordance with the above, an improved sensor can be provided that utilizes soil electrochemistry to correlate soil health with an understandable electrochemical signal. Such a sensor can be implemented as an integrated and miniaturized platform, as well as having reliable data output. For example, the sensor device can be implemented as an on-chip in-situ (e.g., deployed in the field, within the soil and measuring soil characteristics at the location of the soil sample itself) diagnostic platform for continuously monitoring active parameters within a dynamic soil ecosystem. Using such a sensor, data sets can be collected and processed to determine correlations between electrochemical activity and the presence of active substances that contribute to soil nutrient cycling. In fact, such an improved in-situ soil sensor can allow soil health to be assessed and monitored at the interface level using a probe system. Therefore, the resulting data can be used to characterize the soil matrix in order to provide information about various physicochemical phenomena occurring at the electrode interface. Subsequently, this information can be used to correlate it with useful data that helps understand soil fertility and nutrient bioavailability by plants and other vegetation at the field level, as well as other example insights.

[0019] Go to Figure 1 , a simplified block diagram 100 is shown illustrating an example soil sensing system implemented using one or a group of computing and / or sensor devices. In one example system, a set of sensors (e.g., 105, 105a-d), as discussed in the example below, can be deployed in an agricultural plot 150 to test various locations within the plot 150 and / or various volumes or samples of soil (e.g., 110) in various electrochemical forms, thereby visualizing a composite soil chemical profile of the plot through point measurements from different characterization perspectives. The collection of these different perspectives can utilize a sensor collection (e.g., 105, 105a-d) that includes sensors in various areas of a dispersed plot and / or different types of sensors (e.g., measuring the same or different portions of a plot), as well as collecting measurements from sensors on an undulating or continuous substrate, in order to investigate the development of health attributes of the soil over time. Therefore, because the sensor device captures the dynamic behavior of the soil through sensor readings in a range of temporal and spatial settings, improved data and results insights can be derived in such field or in-situ applications. The system can utilize the integration of these measurements from a distribution of points in time and space to calculate the overall soil profile for the corresponding area, among other example applications and potential benefits.

[0020] In some embodiments, a supplemental or collaborative computing system may be provided to communicate with and use data generated by a sensor collection (e.g., 105, 105a-d). In one example, a gateway device or other I / O device (e.g., 115) may be used to collect signals and other data generated by the sensor devices (e.g., 105, 105a-d) and collect, aggregate, filter, and / or classify the data for use by other computing systems and logic. For example, a computing system (e.g., 125) may be provided with computing logic to determine a correlation between readings of sensors (e.g., 105, 105a-d) and corresponding soil properties that the sensors are configured to measure. For example, a sensor (e.g., 105) may include one or more electrodes (e.g., 140) that contact the soil (e.g., 110) and measure the electrochemical properties of the soil. In some embodiments, the electrode 140 may be coated with a specialized coating to enable the electrode 140 to properly operate within the sensor 105, thereby enabling the sensor to detect total soil carbon within a given soil sample (e.g., 110). For example, sensor 105 may generate a signal based on these measured electrochemical properties. The signal itself may not directly indicate the level of certain soil health attributes, but through analysis by correlation engine 155 (e.g., implemented in software and / or hardware of computing system (e.g., 125)), correlations between certain electrochemical property measurements and the levels of corresponding one or more soil health attributes may be determined. Figure 1 It is shown that the correlation engine 155 can be executed by the processor 145 and stored in the memory 150 of the computing system remote from the sensor (e.g., 105, 105a-d), but in some embodiments, the hardware and logic of the system 125 can be integrated on the sensor itself to allow such conversion between electrochemical readings and various soil health attribute measurements to be determined locally. In some embodiments, the soil health attribute results determined by the correlation engine 155 can be shared with other computing systems for further storage and / or processing, such as a cloud-based soil health analysis system (e.g., 130), as well as other example embodiments.

[0021] Carbon sequestration refers to different practices that contribute to the uptake and storage of carbon in soils. While the impact of carbon sequestration is primarily from organic sources, the impact of soil inorganic carbon (IC) accumulation is not insignificant, especially in arid and semi-arid regions where the share of IC in sequestration is also significant. Effective carbon sequestration has the potential to improve soil health, thereby increasing agricultural productivity and food security value, enhance climate resilience (e.g., potentially addressing climate change impacts), and reduce fertilizer use, which can reduce farmers' economic burden and agricultural expenses. In order to achieve these strategic management practices that contribute to carbon sequestration and regenerative agriculture, it is critical to understand, detect, and track these different sources of soil carbon as an integrated, holistic measure. Recently, the scientific community, environmental agencies, and community users at large have recognized that tracking only soil organic carbon (SOC) and soil inorganic carbon (SIC), while useful, is not entirely sufficient, and that total soil carbon (TSC) needs to be used as an objective surrogate measure to more generally keep a close eye on carbon sequestration.

[0022] In the improved system, the sensor device can be equipped with electrodes functionalized to detect soil carbon concentration in a given field soil sample in situ or point-of-use (PoU) manner. Providing real-time field sensors is a major advancement compared to state-of-the-art systems, which rely on collecting samples from the field and transporting these samples to a laboratory for testing. Currently, traditional soil testing to monitor and verify carbon removal and addition through soil carbon sequestration in the environment is difficult and expensive. Currently, traditional soil carbon monitoring is based on bulk soil sampling for laboratory analysis or the use of proximal sensing techniques, which are less accurate. The improved sensing platform presented in this article allows for easy and efficient detection of total soil carbon (TSC) and enables real-time monitoring and data analysis of soil plots where such sensing platforms are deployed, such as Figure 1 and environments shown in examples elsewhere.

[0023] In some embodiments, the improved sensor device can utilize electrodes to capture chemical reactions occurring at the soil sample interface, and the resulting electrical energy or signals derived from these chemical reactions. The corresponding electrical signals are captured and converted by the sensing device and can be provided to processing logic (e.g., implemented in hardware logic circuits and / or software / firmware) for interpretation. In some embodiments, the sensor device can generate and share with another device the electrical signals generated by the chemical reactions. In other embodiments, the sensor device can also be equipped with interpretation logic (e.g., based on a trained data analysis model), and can instead of or in addition share interpretation results with a supporting system (e.g., interpretation results identifying TSC levels determined by the sensor device), which are based on potential electrical signals directly generated from chemical reactions captured from sensor electrodes, as well as other example embodiments.

[0024] As described above, soil carbon can include carbon from both organic and inorganic sources. Organic carbon sources can include the movement and sequestration of atmospheric carbon dioxide (CO2) into plant biomass or other organic matter present in the soil, followed by the conversion of the biomass into stable soil organic carbon (SOC) by the formation of an organo-mineral complex. Inorganic carbon can include atmospheric CO2 entering soil resources through photosynthesis and root respiration, followed by the formation of bicarbonate in the soil, for example, in the form of bicarbonate in the solution phase of groundwater sources, or precipitated as CaCO3 primarily in the soil phase, among other example forms. While the above processes constitute meaningful processes in the global carbon cycle, the two processes are interrelated and contribute to the overall increase in carbon in the soil, for example, based on an increase or decrease in microbial activity, which is a function of SOC levels due to enhanced water retention capacity, which may be critical to the production and storage of soil carbonates. Therefore, measurements of total soil carbon can be very useful for assessing the current characteristics and trends of soils in a given plot, as well as other example advantages and considerations.

[0025] The improved sensor devices can be specifically configured for in situ sensing with probe integration to measure TSC levels within soil samples in ground plots. The readings generated by these sensor devices can be used to correlate carbon sequestration with soil quality for agricultural and environmental planning and enhancement, among other example uses. In one example embodiment, the improved sensor device can implement a sensor stack based on an improved three-electrode system that functions to selectively determine organic and inorganic carbon functional groups in a soil sample matrix. For example, the sensor can use a functionalized sensor electrode that has a nanomaterial layer or a specialized chemical layer and is modified to measure the total amount of total soil carbon.

[0026] Go to Figure 2 , a simplified block diagram 200 is shown, which shows an example sensor device 105. In this example, the sensor device 105 includes two or more electrodes. For example, in this example, a three-electrode configuration including a counter electrode 270, a working electrode 265, and a reference electrode 260 is utilized. Figure 2A detailed cross-sectional perspective view 205 is shown showing a close-up view of one of the example electrodes of the sensor device 105. More specifically, the cross-sectional view 205 shows the composition of an example composite film coated on a working electrode 265 to functionalize the working electrode 265 (and the sensor device 105) to detect total soil carbon in a soil sample in contact with or in proximity to the electrode of the sensor device 105. In one example, the film 250 can include an active sensing element 210, an encapsulant 215, and a sealant 220. One or more of the active sensing element 210, the encapsulant 215, and the sealant 220 can be implemented as corresponding layers within the film.

[0027] In one exemplary embodiment, the functionalized composite sensing membrane is coated on the working electrode 265 of the sensor device 105 to utilize the interaction between the working electrode 265 and the soil analyte, in comparison with the uncoated reference electrode 260. In another example, the working electrode 265 is functionalized by applying only the active sensing element 210 and the encapsulant 215 to the working electrode 265, the sealant layer 220 is applied to coat each of the working electrode 265, the reference electrode 260, and the counter electrode 270, and serves as a supporting electrolyte for electrochemical transduction, and the composite sensing membrane configured to detect soil carbon is used in other exemplary embodiments.

[0028] The example composite sensing membrane can be functionalized to include materials or sensing elements corresponding to the detection of organic carbon and inorganic carbon. More specifically, the active sensor element can be selected based on the specific interaction between the modified electrode and the organic carbon and inorganic carbon content in the soil, which can be determined by applying an experimentally determined input bias and process, specifically corresponding to the OC and IC parts. In some embodiments, the components or coatings used to form the composite sensing membrane 250 selectively interact and functionalize the detection of the organic portion of soil carbon, which is triggered by an input signal that drives a chemical reaction by perturbing the electrode-soil double layer interface and captures the charge movement and modulation as a function of organic carbon in the soil system. These corresponding electrochemical kinetics-driven signal changes are used to quantify and monitor changes in unstable and refractory organic carbon (OC). This combination of membrane components can also be used to detect different carbonate and bicarbonate ion entities in the soil, which can be explained by operating a sensor system with a specific input bias (e.g., determined experimentally) to interact and capture a complete profile of inorganic-derived carbon-based minerals (IC) in the soil sample.

[0029] In one example embodiment, a first active sensing element layer can be deposited or otherwise applied to the outer surface of the electrode layer 225. The active sensing element can be composed of nanomaterial structures, ion-related liquids, covalent capture frameworks integrated with organic compounds, such as pyridine or calixarene-based compounds (for ion capture) that promote binding / interaction using electrochemical mode capture to track soil carbon analogs, and other examples. The active sensing element can be used as the main sensing element of the system. For the example encapsulant layer, in one example embodiment, diatomaceous earth, activated carbon powder can be used to maintain the active element of the sensing structure while promoting nutrient interaction and retention properties in the soil, thereby facilitating the capture of soil mineral groups. More generally, the encapsulant layer or material 215 can include an amorphous carbon-based or derived material that can be mixed with the active sensing element material (210) into a cement or putty-like substance and coated on the sensor electrode. This putty-like structure acts as a precursor to serve as the main interaction site / layer between the electrode and the soil analyte medium. In some embodiments, the materials of the active element layer 210 and the encapsulant layer 215 can be uniformly mixed into the composite precursor (e.g., by mixing with a stirrer and a pipette). Such a composite precursor can serve as a functional component of the membrane and represent where sensing and interaction sites exist to interpret soil carbon in a given sample using physicochemical reactions between the sensor and the soil analyte. In one example, the sealant layer 220 can be composed of a polymer entity (e.g., polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polyaniline, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), etc.). The sealant layer material can be added to the composite coating precursor to act as a membrane sealant that fixes the composite material to the electrode layer in a functionalized manner, thereby acting as a supporting electrolyte layer in such a modified electrochemical sensor structure. In one example embodiment, the composite materials of the composite sensing membrane (e.g., collectively referred to as layers 1, 2, and 3) can be mixed by pipetting to form a gel-like physical structure, followed by sonication (e.g., 15 minutes) and vortexing (e.g., 5 minutes). This gel-like composite ink can then be applied to the sensor by drop casting or spin coating to form a functionalized layer on the working electrode of the 3-layer electrode system.

[0030] Although some examples discuss the components of the composite sensing film 250 as "layers", it should be understood that these layers represent the components of the composite sensing film 250 and may not be physically arranged on the electrode as a layer. For example, in some embodiments, the active sensing element 210 and the encapsulant 215 can be mixed together to form a precursor composite material (e.g., a putty-like substance) and applied as a mixture to the sensor electrode to create an interaction layer. The interaction layer can be enhanced by a secondary film network of a sealant layer 220 added on top of the precursor composite material. This forms a layer-by-layer stack with 210 and 215 as the base stack and the sealant film 220 as the second layer stack. In another example implant, the precursor composite material (formed by a mixture of the active sensing element 210 and the encapsulant 215) can be mixed with the sealant material 220 to form a composite mixed blend coated on the sensor, forming a single-layer network composed of different sub-layer elements (e.g., 210, 215 and 220), as well as other example embodiments of the composite sensing film 250.

[0031] As another example of a composite coating, the composite coating can be deposited on a working electrode of an example sensor device to functionalize the sensor device for detecting or measuring TSC concentrations, and the coating composition can utilize a composite base system to evaluate the organic and inorganic carbon groups present in a soil sample in contact with the electrode of the sensor device. In one example, a mixture of an inorganic carbon sensing element and an organic carbon sensing element can be brought together (e.g., mixed) and distributed in a buffer suspension. In one example, the organic carbon sensing element can be implemented using a room temperature ionic liquid (RTIL) formulated to interact with an organic carbon portion (e.g., active organic matter (AOM) and humus (HS)). For the inorganic carbon sensing element, in one example embodiment, the interaction of a calixarene-based compound with a carbonate (CO3) group can be applied. The organic carbon sensing compound and the inorganic carbon sensing compound can be provided in a solution at different concentrations and ratios. For example, in one example embodiment, the composite coating can be based on a ratio of 1:4, i.e., one part (e.g., by weight) of an organic carbon sensing element to four parts of an inorganic carbon sensing element. These amounts of organic and inorganic carbon sensing elements can be dispensed in a suspension (eg, chloroform) to form a composite substrate.

[0032] In one example, the sensing element composite substrate can be combined with a solution providing a polymer film network, and the active sensing layer can be arranged on the polymer film network, allowing the soil to penetrate the sensing layer and interact with the organic and inorganic carbon sensing elements in the composite. In one example, a chitosan solution can be used to implement the polymer film network. In one instance, 5uL of a high molecular weight chitosan solution can be added to 20uL of an organic-inorganic-composite solution to form (e.g., 25uL) a composite coating for sensing TSC. In some embodiments, the composite coating can form an "ink" composition that can be deposited on a working electrode of a TSC sensor device by screen printing, drop casting, or otherwise, and functionalize the working electrode for TSC detection. Table 1 below shows the properties of an example coating. For example, an organic carbon sensing element can be implemented as an RTIL, such as [EMIM TF2N], as well as other examples:

[0033] RTIL Conductivity Electrochemical Window Physical properties EMIM TF2N 6.63mS / cm 4.7V Aromatic, weakly coordinating anion, hydrophobic, viscosity 40 cP

[0034] Table 1: Examples of selected components used for TSC sensor coating and measurement

[0035] As discussed in the above examples, electrochemical reactions can be observed using example sensor devices. For example, a two-pronged combined approach can be used to simultaneously detect electrochemical properties associated with the presence of organic carbon and inorganic carbon in a sample. From these two methods, a full picture of the total carbon composition of the sample can be determined. For example, in a first electrochemical impedance spectroscopy-based approach, impedance bilayer analysis and modeling can be used to study the interaction of the sensing membrane-soil carbon (OC and IC) interface and associate modulation for the total soil carbon level (e.g., using electrochemical impedance spectroscopy (EIS) analysis). For example, impedance-based detection techniques can be used to detect the interface formed between the soil system (analyte) and the functionalized sensor, where the presence of different levels of soil carbon is associated with corresponding changes / modulations in the impedance signal generated at the sensor device. For example, in one example, the EIS technique can be used to map different chemical reactions and interactions occurring at the sensor-soil interface by applying a small AC input bias and scanning the impedance spectrum across frequency. For example, a voltage can be applied and scanned between the working electrode and the reference electrode of the sensor device, and the resulting current formed at the working electrode is measured as an output. In such an example, at a specific frequency (e.g., which can be experimentally obtained by scanning over a larger frequency range), the chemical interaction caused between the functionalized sensor layer and the soil analyte causes impedance modulation. In one example, a 10mVAC voltage input is swept from 100MHx to 1Hz. Therefore, the measurement at this selected specific frequency represents the area of ​​interest, and the impedance signal at this frequency is extracted as an output corresponding to the different soil carbon levels that cause output impedance modulation. This specific frequency of interest also corresponds to whether the physicochemical reaction measured between the sensor and the soil causes more resistance modulation, which requires a frequency of interest in a higher range, or whether the interaction causes capacitance / diffusion based changes that appear at the lower end of the frequency range. Therefore, the frequency characteristics used for output impedance extraction as a function of soil carbon changes can be experimentally obtained.

[0036] A second cyclic voltammetry method can be used to apply a pulsed direct current (DC) signal (e.g., with an AC auxiliary input) to the sensor device (e.g., between a working electrode and a reference electrode of the sensor device) to perturb the sensing membrane and capture the polarization interaction layer formed between the electrode layer and the soil carbon groups, which corresponds to a method of mapping the signal amplitude to the TSC concentration (e.g., using differential pulse voltammetry (DPV) and linear sweep voltammetry). For example, the interface formed between the soil analyte and the functionalized sensor can be excited by applying a pulsed voltage signal as an input. For example, in other examples, a scan of -1V to +1V can be applied at a rate of 100mV / second. Next, the observed peak currents are recorded, which are formed due to the induced activity of the soil carbon entities at the same interface (e.g., due to the excitation voltage). Based on the concentration of soil carbon molecules present in the soil sample, the activity level will be adjusted, and thus the peak current level will change. This peak current can be extracted and correlated with the soil carbon level to determine the input-output conversion between the signal generated by the sensor response and the corresponding TSC level in the soil sample. In some embodiments, a combination of cyclic voltammetry and electrochemical impedance-based methods can be used to derive a multivariate relationship for TSC concentration in a sample, among other examples. Thus, the impedance and / or current generated by a TSC-functionalized sensor device can be read and used to derive a corresponding TSC level. In other cases, among other examples, either the impedance or the current generated by the sensor device can be relied upon and mapped to a corresponding TSC level.

[0037] Figure 3300 is a schematic diagram showing an example interaction between an RTIL-based organic carbon sensing element 305 (e.g., [EMIM TF2N]) and a calixarene-based inorganic carbon sensing element 310 with various carbon chemical moieties that may be present in a soil sample in contact with a functionalized electrode for detecting TSC levels. For example, in this example, a complex formulation of organic and inorganic soil components (e.g., 315, 320, 325, 330, 335, etc.) may interact with the sensing elements 305, 310. For example, soil carbon components may interact with cations of the RTIL-based organic carbon sensing element 305, anions of the RTIL-based organic carbon sensing element 305 may interact with the calixarene-based inorganic carbon sensing element 310, which further interacts with fulvic acid-based components (e.g., 330) and carbonate entities (e.g., 335) to form a carbon complex overall that may represent the total soil carbon in the sample. In this example, the carbon complex includes eight hydrogen bonds. The corresponding thermodynamic energies can correspond to the spontaneity and ease with which the TSC compounds interact with the functionalized TSC sensor coating or layer. For example, the high negative free energy of interaction and bonding with TSC compounds in soil indicates a large number of hydrogen bonding interactions and higher spontaneity.

[0038] Go to Figure 4 , a graph 400 is shown showing a relationship between a TSC concentration response and a current value measured, in one example, between electrodes on a sensor device that is functionalized to have its working electrode interact with both inorganic and organic carbon moieties. In this example, a composite active layer deposited on the working electrode enables a chemical interaction that results in a correlation 405 (e.g., a linear correlation) between the current generated at the sensor device (e.g., 410) and the concentration of TSC within the sample (e.g., 415). The soil sensing system can utilize this correlation to derive TSC levels from signals generated by TSC sensor devices deployed in various soil samples within a plot.

[0039] Go to Figure 5, a simplified block diagram 500 is shown, which illustrates an example soil sensor system. For example, an enhanced soil sensor system configured to detect TSC levels, as discussed in the above examples, may include a sensor device 105 having one or more functionalized sensor electrodes as discussed in the above examples, which are inserted or deployed into soil 110 to detect soil carbon entities in a soil sample, including a total soil total carbon level 505 consisting of an organic carbon level 310 and an inorganic carbon level 515, for example, using a composite coating applied to a working electrode (e.g., only a working electrode) of the sensor device 105. In some embodiments, the soil sensor device can be hard-wired or wirelessly connected (e.g., via an integrated wireless communication module) to supporting hardware (e.g., 520) that is capable of recording or performing analysis on data generated by and received from the sensor device. In some embodiments, such a system may be deployed locally. In other embodiments, such a system may include a cloud-based computing system (e.g., the sensor device may communicate with it via a local gateway device). In other embodiments, data storage and analysis / interpretation logic may be included on the sensor device, as well as in other example embodiments. As an example, the sensor device can be connected to a potentiostat system (e.g., a portable or battery-powered system) that is capable of performing calculations on measurements obtained from the sensor device (as discussed in the first and second methods above) and recording and analyzing the output data.

[0040] While the above examples illustrate implementations of example soil sensors, it should be understood that these are presented as illustrative examples only, and that a variety of other additional interface soil sensors may be implemented based on and applied to the principles described herein, including sensors having different form factors and substrates, sensors having different active, encapsulant and / or sealant layers or coatings applied, and sensors capable of measuring other attributes of soil health (e.g., other soil organic compounds). In addition, multiple sensor designs may be implemented and integrated into a single sensor device to enable the device to simultaneously measure multiple different soil health attributes of a corresponding soil sample matrix and perform multivariate analysis of the tested soil. Indeed, a range of soil health attributes may be advantageously measured using a soil sensor system as described herein to develop a measure of the overall health of a piece of land (e.g., a crop field, pasture, orchard, vineyard, etc.).

[0041] Figure 6600 is a simplified flowchart illustrating an example technique involving the use of an example in-situ soil sensor. The sensor may be deployed in a specific soil sample (either isolated in a container or representing a portion of a large area of ​​land or soil). The electrodes of the soil sensor may be in long-term and direct contact with the soil and may be configured to react, measure or detect the chemical properties of the soil based on an electrochemical reaction measured at the sensor electrodes. The sensor may generate a signal based on a composite sensing coating applied to the sensor electrodes through the electrodes. The coating may include an active sensing element composed of a composite of an inorganic sensing element and an organic carbon sensing element. In addition, the coating may also include an encapsulant and a sealant element. A sensor having an electrode with the coating (e.g., a working electrode thereof) may generate a signal corresponding to the carbon composite concentration (inorganic and organic carbon levels) of the soil (step 605). The signal may be sent to a collaborative computing device (step 610), which includes computer processing hardware and logic to determine the correlation between the generated signal and the organic and inorganic carbon levels of the soil sample (step 615). In some embodiments, the collaborative computing device may be different from the sensor device and away from the sensor device. In other embodiments, the computing device and its hardware may be integrated with the sensor device and deployed together in the field. Measurement data may be generated based on the determined correlation to indicate a measurement of the total soil carbon level at the soil sample (step 620). This information may be further used, stored, shared, or tracked to assess the total soil carbon level and carbon sequestration of this portion of soil on an ongoing basis, and to assess the overall soil carbon properties of a piece of land and its soil by deploying multiple such sensors in multiple nearby soil samples, as well as other example applications and benefits.

[0042] Note that in this document, references to various features (e.g., elements, structures, modules, components, steps, operations, characteristics, etc.) included in "one embodiment," "example embodiment," "embodiment," "another embodiment," "some embodiments," "various embodiments," "other embodiments," "alternative embodiments," etc.) are intended to mean that any such features are included in one or more embodiments of the present disclosure, but may or may not be combined in the same embodiment. In addition, the words "optimize," "optimize," and related terms refer to technical terms for improvements in speed and / or efficiency of a particular result, and are not intended to indicate that a process for achieving a particular result has achieved or is capable of achieving an "optimal" or very fast / very efficient state.

[0043] In general, a computing system connected to a biosensor via a wired or wireless communication channel may include electronic computing devices that can be used to receive, transmit, process, store, or manage data and information related to the biosensor and other subsystems of the computing system. As used in this document, each of the terms "computer," "processor," "processor device," "microcontroller," or "processing device" is intended to cover any suitable data processing device. For example, while in some examples, a microcontroller may be implemented as a single device within a computing system, in other embodiments, the processing functions of the system may be implemented using multiple computing devices and processors, such as a fog computing system, a server pool, a cloud computing system, or other distributed computing systems including multiple computers. In addition, any, all, or some computing devices may be suitable for executing any operating system, including Linux, UNIX, Microsoft Windows, Apple OS, Apple iOS, Google Android, Windows Server, etc., as well as virtual machines suitable for virtualizing the execution of specific operating systems, including customized and proprietary operating systems.

[0044] In some embodiments, all or part of the computing platform can be used as a wearable device, an independent biosensor device, or other sensor device. The sensor device can be connected to other computing devices and communicate with other computing devices via a wired or wireless network connection. For example, the wireless network connection can utilize a wireless local area network (WLAN), such as a wireless local area network standardized under the IEEE802.11 family of standards; a home local area network, such as a home local area network standardized under the Zigbee Alliance; a personal local area network, such as a personal local area network standardized by the Bluetooth Special Interest Group; a cellular data network, such as a cellular data network standardized by the Third Generation Partnership Project (3GPP); and other types of networks with wireless or wired connections. For example, the endpoint device can also achieve connection to the security domain through a bus interface, such as a universal serial bus (USB) type connection, a high-definition multimedia interface (HDMI), etc.

[0045] It is also important to note that the operations and steps described with reference to the preceding figures illustrate only some of the possible scenarios that may be performed by or within the system. Where appropriate, some of these operations may be deleted or removed, or the steps may be modified or altered, without departing from the scope of the concepts discussed. In addition, the timing of these operations may be significantly changed and still achieve the results taught in the present disclosure. The foregoing operational flows are provided for purposes of example and discussion. The system provides considerable flexibility in that any suitable arrangement, chronological order, configuration, and timing mechanism may be provided without departing from the teachings of the concepts discussed.

[0046] The following examples relate to embodiments according to the present specification. Example 1 is a device comprising: a sensor for detecting the total soil carbon level in a soil sample, the sensor comprising: a working electrode coated with a composite sensing film, and another electrode; wherein the composite sensing film comprises: an active sensing component functionalized to simultaneously detect an organic carbon portion and an inorganic carbon portion; an encapsulant component; and a sealant component.

[0047] Example 2 includes the subject matter of Example 1, wherein the encapsulant component comprises a material that facilitates capture of mineral groups from the soil sample.

[0048] Example 3 includes the subject matter of any of Examples 1-2, wherein the sealant component serves as a supporting electrolyte for electrochemical transduction.

[0049] Example 4 includes the subject matter of any of Examples 1-2, wherein the other electrode comprises a reference electrode.

[0050] Example 5 includes the subject matter of Example 4, wherein the sensor further includes a counter electrode.

[0051] Example 6 includes the subject matter of Example 5, wherein the composite sensing membrane is layered over the working electrode and the reference electrode, and a sealant layer including a sealant component is coated on the counter electrode.

[0052] Example 7 includes the subject matter of Example 6, wherein a composite layer including a mixture of an active sensing component and an encapsulant component is deposited on the working electrode and the reference electrode, and an encapsulant layer is also deposited on the composite layer to form a composite sensing membrane.

[0053] Example 8 includes the subject matter of Example 5, wherein the composite sensing film is layered over each of the working electrode, the reference electrode, and the counter electrode.

[0054] Example 9 includes the subject matter of any of Examples 1-8, further comprising a circuit for: applying a voltage at the sensor; and detecting an impedance at the sensor based on the presence of organic or inorganic soil carbon in the soil sample.

[0055] Example 10 includes the subject matter of Example 9, wherein the voltage comprises a pulsed voltage signal applied to the working electrode and the reference electrode.

[0056] Example 11 includes the subject matter of Example 10, wherein the pulsed voltage signal is applied according to a specific frequency associated with detection of different levels of soil carbon.

[0057] Example 12 includes the subject matter of Example 9, further comprising a communication module for sending a signal to another computing device to communicate the detected impedance.

[0058] Example 13 includes the subject matter of any of Examples 1-12, wherein the sensor comprises an in-situ soil sensor.

[0059] Example 14 is a method comprising: applying a voltage to a working electrode and a reference electrode of an in-situ soil sensor deployed in a soil sample, wherein the working electrode is coated with a composite sensing membrane, the composite sensing membrane comprising an active sensing component, an encapsulant component, and a sealant component; and generating an impedance signal at the in-situ soil sensor, wherein the impedance signal is generated based on the concentrations of inorganic soil carbon and organic soil carbon in the soil sample, wherein the active sensing component is configured to detect the organic carbon portion and the inorganic carbon portion.

[0060] Example 15 includes the subject matter of Example 14, further comprising determining a concentration of total soil carbon within the soil sample from the impedance signal.

[0061] Example 16 includes the subject matter of Example 15, further comprising sending a signal to another computing device to identify an impedance signal to the other computing device, wherein the other computing device determines a concentration of total soil carbon in the soil sample.

[0062] Example 17 is a system comprising an apparatus for performing the method of any of Examples 14-16.

[0063] Example 18 is a system, comprising: a sensor device, comprising: a plurality of electrodes, wherein the plurality of electrodes comprises a working electrode coated with a composite sensing film, wherein the composite sensing film comprises an active sensing component functionalized to detect an organic carbon portion and an inorganic carbon portion, an encapsulant component, and a sealant component; and a circuit for generating an impedance based on a concentration of total soil carbon in a soil sample when in contact with the plurality of electrodes, wherein the total soil carbon comprises organic soil carbon and inorganic soil carbon. The system also comprises an analysis system, comprising: a processor; and analysis logic executable by the processor to determine a concentration value of total soil carbon in the soil sample from the impedance.

[0064] Example 19 includes the subject matter of Example 18, further comprising a plurality of sensor devices deployed in a plurality of soil samples within an environment.

[0065] Example 20 includes the subject matter of Example 18, wherein the sensor device comprises an in-situ soil sensor.

[0066] Example 21 includes the subject matter of Example 18, wherein the sensor device comprises the apparatus of any of Examples 1-13.

[0067] Example 42 is a device comprising: a sensor for detecting the total soil carbon level in a soil sample, the sensor comprising: a working electrode coated with a composite sensing coating, and another electrode; wherein the composite sensing coating comprises: an active sensing component comprising an organic carbon sensing element functionalized to detect an organic carbon portion and an inorganic carbon sensing element functionalized to detect an inorganic carbon portion; and an encapsulant component.

[0068] Example 43 includes the subject matter of Example 42, wherein the organic carbon sensing element comprises a room temperature ionic liquid (RTIL).

[0069] Example 44 includes the subject matter of Example 43, wherein the RTIL comprises [EMIMTF2N].

[0070] Example 45 includes the subject matter of any of Examples 42-44, wherein the inorganic carbon sensing element comprises calixarene.

[0071] Example 46 includes the subject matter of any of Examples 42-45, wherein the composite sensing coating further includes a sealant component.

[0072] Example 47 includes the subject matter of any of Examples 42-46, wherein the encapsulant component comprises a material that facilitates capture of mineral groups from the soil sample.

[0073] Example 48 includes the subject matter of Example 47, wherein the encapsulant component comprises a polymer film network.

[0074] Example 49 includes the subject matter of any of Examples 42-48, wherein the composite sensing coating further includes a sealant component.

[0075] Example 50 includes the subject matter of Example 49, wherein the sealant component serves as a supporting electrolyte for electrochemical transduction.

[0076] Example 51 includes the subject matter of any of Examples 42-50, wherein the other electrode comprises a reference electrode.

[0077] Example 52 includes the subject matter of Example 51, wherein the sensor further includes a counter electrode.

[0078] Example 53 includes the subject matter of any of Examples 51-52, wherein the composite sensing coating is layered overlying only the working electrode.

[0079] Example 54 includes the subject matter of Example 53, wherein a composite layer comprising a mixture of an active sensing component and an encapsulant component is deposited on the working electrode, and an encapsulant layer is deposited on the composite layer to form a composite sensing coating.

[0080] Example 55 includes the subject matter of any of Examples 42-54, further comprising a circuit for: applying an alternating current (AC) voltage; and detecting impedance at the sensor based on the presence of carbon complexes including organic carbon and inorganic carbon in the soil sample.

[0081] Example 56 includes the subject matter of Example 55, wherein a voltage is applied to the working electrode and the other electrode.

[0082] Example 57 includes the subject matter of Example 56, wherein the voltage is applied according to a specific frequency associated with the detection of different levels of soil carbon.

[0083] Example 58 includes the subject matter of any of Examples 56-57, further comprising a circuit for: applying a DC voltage; and detecting a current at the sensor based on the presence of carbon complexes including organic carbon and inorganic carbon in the soil sample.

[0084] Example 59 includes the subject matter of any of Examples 56-58, further comprising a communication module for sending a signal to another computing device to communicate the detected impedance or current.

[0085] Example 60 includes the subject matter of any of Examples 42-59, wherein the sensor comprises an in-situ soil sensor.

[0086] Example 61 is a method comprising: applying a voltage to a working electrode and a reference electrode of an in-situ soil sensor deployed in a soil sample, wherein the working electrode is coated with a composite sensing coating, the composite sensing coating comprising an active sensing component, an encapsulant component, and a sealant component; and generating an impedance signal at the in-situ soil sensor, wherein the impedance signal is generated based on the concentration of inorganic soil carbon and organic soil carbon in the soil sample, wherein the active sensing component is configured to detect the concentration of a carbon complex in the soil sample, and the carbon complex comprises an organic carbon portion and an inorganic carbon portion.

[0087] Example 62 includes the subject matter of Example 61, further comprising determining the concentration of total soil carbon in the soil sample from the impedance signal.

[0088] Example 63 includes the subject matter of Example 62, further comprising sending a signal to another computing device to identify an impedance signal to the other computing device, wherein the other computing device determines a concentration of total soil carbon in the soil sample.

[0089] Example 64 includes the subject matter of any of Examples 61-63, wherein the active sensing component comprises an organic carbon sensing element functionalized to detect an organic carbon portion and an inorganic carbon sensing element functionalized to detect an inorganic carbon portion.

[0090] Example 65 includes the subject matter of Example 64, wherein the organic carbon sensing element comprises a room temperature ionic liquid (RTIL).

[0091] Example 66 includes the subject matter of Example 65, wherein the RTIL includes [EMIMTF2N].

[0092] Example 67 includes the subject matter of any of Examples 64-66, wherein the inorganic carbon sensing element comprises calixarene.

[0093] Example 68 includes the subject matter of any of Examples 64-67, wherein the active sensing component comprises a polymer membrane network.

[0094] Example 69 is a system comprising an apparatus for performing the method of any of Examples 61-68.

[0095] Example 70 is a composite coating that interacts with a carbon composite including inorganic carbon and organic carbon, wherein the composite coating includes: an organic carbon sensing element functionalized to detect an organic carbon portion; an inorganic carbon sensing element functionalized to detect an inorganic carbon portion; and a polymer film network.

[0096] Example 71 includes the subject matter of Example 70, wherein the organic carbon sensing element comprises a room temperature ionic liquid (RTIL).

[0097] Example 72 includes the subject matter of Example 71, wherein the RTIL includes [EMIMTF2N].

[0098] Example 73 includes the subject matter of any of Examples 70-72, wherein the inorganic carbon sensing element comprises calixarene.

[0099] Example 74 includes the subject matter of any of Examples 70-73, including a mixture of an organic carbon sensing element, an inorganic carbon sensing element, and a polymer membrane network.

[0100] Example 75 includes the subject matter of any of Examples 70-74, wherein the composite coating is adapted to be screen printed or drop cast onto a surface of the sensor electrode.

[0101] Example 76 includes the subject matter of any of Examples 70-75, further comprising a sealant layer.

[0102] Example 77 is a system comprising: a sensor device and an analysis system, the sensor device comprising: a plurality of electrodes, wherein the plurality of electrodes comprise a working electrode coated with a composite sensing coating, wherein the composite sensing coating comprises an active sensing component functionalized to detect an organic carbon portion and an inorganic carbon portion, an encapsulant component and a sealant component; and a circuit for generating a signal based on the concentration of total soil carbon in a soil sample when in contact with the plurality of electrodes to identify impedance or current, wherein the total soil carbon comprises organic soil carbon and inorganic soil carbon; and the analysis system comprising: a processor; and analysis logic executable by the processor to determine a value of the total soil carbon concentration in the soil sample from the impedance.

[0103] Example 78 includes the subject matter of Example 77, further comprising a plurality of sensor devices deployed in a plurality of soil samples within an environment.

[0104] Example 79 includes the subject matter of any of Examples 77-78, wherein the sensor device comprises an in-situ soil sensor.

[0105] Example 80 includes the subject matter of any of Examples 77-79, wherein the analysis system is used to collect a series of readings over time and determine a change in total soil carbon concentration from the series of readings.

[0106] Example 81 includes the subject matter of any of Examples 77-80, wherein the active sensing component comprises a composite of an organic carbon sensing element and an inorganic carbon sensing element, and the organic carbon sensing element comprises a room temperature ionic liquid (RTIL).

[0107] Example 82 includes the subject matter of Example 81, wherein the RTIL includes [EMIMTF2N].

[0108] Example 83 includes the subject matter of any of Examples 81-82, wherein the inorganic carbon sensing element comprises calixarene.

[0109] Example 84 includes the subject matter of any of Examples 77-83, wherein the sealant component comprises a polymer film network.

[0110] Example 85 includes the subject matter of Example 77, wherein the sensor device comprises the apparatus of any of Examples 42-60.

[0111] Although the present disclosure has been described in detail with reference to specific arrangements and configurations, these example configurations and arrangements may be significantly changed without departing from the scope of the present disclosure. Many other changes, substitutions, variations, alterations and modifications may be determined by those skilled in the art, and the present disclosure is intended to include all such changes, substitutions, variations, alterations and modifications that fall within the scope of the appended claims.

Claims

1. A device comprising: A sensor for detecting a soil total carbon level in a soil sample, the sensor comprising: A working electrode, wherein the working electrode is coated with a composite sensing coating, wherein the composite sensing coating comprises: an active sensing component comprising an organic carbon sensing element functionalized to detect an organic carbon fraction and an inorganic carbon sensing element functionalized to detect an inorganic carbon fraction; and an encapsulant component; and Another electrode.

2. The device according to claim 1, wherein: The organic carbon sensing element includes a room temperature ionic liquid (RTIL).

3. The device according to claim 2, wherein: The RTIL includes [EMIMTF2N].

4. The device according to any one of claims 1 to 3, wherein: The inorganic carbon sensing element includes calixarene.

5. The device according to any one of claims 1 to 4, wherein: The composite sensing coating also includes a sealant component.

6. The device according to any one of claims 1 to 5, wherein: The encapsulant component includes a material that facilitates capture of mineral groups from the soil sample.

7. The device according to claim 6, wherein: The encapsulant component comprises a polymer film network.

8. The device according to any one of claims 1 to 7, wherein: The composite sensing coating also includes a sealant component.

9. The device according to claim 8, wherein: The sealant component serves as a supporting electrolyte for electrochemical transduction.

10. The device according to any one of claims 1 to 9, wherein: The other electrode comprises a reference electrode.

11. The device according to claim 10, wherein: The sensor also includes a counter electrode.

12. The device according to any one of claims 10-11, wherein: The composite sensing coating is only layered on the working electrode.

13. The device according to claim 12, wherein: A composite layer including a mixture of the active sensing component and the encapsulant component is deposited on the working electrode, and an encapsulant layer is deposited on the composite layer to form the composite sensing coating.

14. The apparatus according to any one of claims 1 to 13, further comprising a circuit for: applying an alternating current (AC) voltage; and Impedance at the sensor is detected based on the presence of carbon complexes including organic carbon and inorganic carbon in the soil sample.

15. The device according to claim 14, wherein: The voltage is applied to the working electrode and the other electrode.

16. The device according to claim 15, wherein: The voltage is applied at specific frequencies associated with different levels of soil carbon detection.

17. The apparatus according to any one of claims 14 to 16, further comprising a circuit for: applying a DC voltage; and An electrical current is detected at the sensor based on the presence of carbon complexes including organic carbon and inorganic carbon in the soil sample.

18. The apparatus of any one of claims 14-17, further comprising a communication module for sending a signal to another computing device to communicate the detected impedance or current.

19. The device according to any one of claims 1 to 18, wherein: The sensor comprises an in-situ soil sensor.

20. A method comprising: applying a voltage across a working electrode and a reference electrode of an in-situ soil sensor deployed in the soil sample, wherein the working electrode is coated with a composite sensing coating comprising an active sensing component, an encapsulant component, and a sealant component; and An impedance signal is generated at the in-situ soil sensor, wherein the impedance signal is generated based on the concentration of inorganic soil carbon and organic soil carbon in the soil sample, wherein the active sensing component is configured to detect the concentration of carbon complexes in the soil sample, and wherein the carbon complexes include an organic carbon portion and an inorganic carbon portion.

21. The method of claim 20, further comprising determining a concentration of total soil carbon within the soil sample from the impedance signal.

22. The method of claim 21, further comprising sending a signal to another computing device to identify an impedance signal to the other computing device, wherein: The other computing device determines a concentration of total soil carbon within the soil sample.

23. The method according to any one of claims 20 to 22, wherein: The active sensing component includes an organic carbon sensing element functionalized to detect an organic carbon fraction and an inorganic carbon sensing element functionalized to detect an inorganic carbon fraction.

24. The method according to claim 23, wherein: The organic carbon sensing element includes a room temperature ionic liquid (RTIL).

25. The method according to claim 24, wherein: The RTIL includes [EMIMTF2N].

26. The method according to any one of claims 23 to 25, wherein: The inorganic carbon sensing element includes calixarene.

27. The method according to any one of claims 23 to 26, wherein: The active sensing component includes a polymer membrane network.

28. A system comprising means for performing the method of any one of claims 20-27.

29. A composite coating interacting with a carbon composite comprising inorganic carbon and organic carbon, wherein: The composite coating comprises: an organic carbon sensing element functionalized to detect an organic carbon moiety; an inorganic carbon sensing element functionalized to detect an inorganic carbon moiety; and Polymer membrane networks.

30. The composite coating according to claim 29, wherein: The organic carbon sensing element includes a room temperature ionic liquid (RTIL).

31. The composite coating according to claim 30, wherein: The RTIL includes [EMIMTF2N].

32. The composite coating according to any one of claims 29 to 31, wherein: The inorganic carbon sensing element includes calixarene.

33. The composite coating of any one of claims 29-32, comprising a mixture of the organic carbon sensing element, the inorganic carbon sensing element and the polymer membrane network.

34. The composite coating according to any one of claims 29 to 33, wherein: The composite coating is suitable for screen printing or drop casting onto the surface of the sensor electrode.

35. The composite coating of any one of claims 29-34, further comprising a sealant layer.

36. A system comprising: A sensor device, the sensor device comprising: a plurality of electrodes, wherein the plurality of electrodes comprises a working electrode coated with a composite sensing coating, wherein the composite sensing coating comprises an active sensing component functionalized to detect an organic carbon portion and an inorganic carbon portion, an encapsulant component, and a sealant component; and an electrical circuit for generating a signal to identify impedance or current based on a concentration of total soil carbon in the soil sample when in contact with the plurality of electrodes, wherein the total soil carbon includes organic soil carbon and inorganic soil carbon; and An analysis system, comprising: processor; Analysis logic, executable by the processor, for determining a concentration value of total soil carbon in the soil sample from the impedance.

37. The system of claim 36, further comprising a plurality of sensor devices deployed in a plurality of soil samples within the environment.

38. The system according to any one of claims 36-37, wherein: The sensor device includes an in-situ soil sensor.

39. The system according to any one of claims 36-38, wherein: The analysis system is used to collect a series of readings over time and determine changes in total soil carbon concentration from the series of readings.

40. The system according to any one of claims 36-39, wherein: The active sensing component includes a composite of an organic carbon sensing element and an inorganic carbon sensing element, and the organic carbon sensing element includes a room temperature ionic liquid (RTIL).

41. The system of claim 40, wherein: The RTIL includes [EMIMTF2N].

42. The system according to any one of claims 40-41, wherein: The inorganic carbon sensing element includes calixarene.

43. The system of any one of claims 36-42, wherein: The sealant component includes a polymer film network.

44. The system of claim 36, wherein: The sensor device comprises the apparatus of any one of claims 1-19.

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