Kit and method for measuring organic carbon in soil

Abstract

The present invention provides a low-cost kit and method for measuring organic carbon in soil, which provides results in a short time period and is based on the oxidation of a sample of the soil.

Description

[0001] KIT AND METHOD FOR MEASURING ORGANIC CARBON IN SOIL

[0002] FIELD OF INVENTION

[0003] The present invention relates in general to a kit and a method for measuring organic carbon in soil based on the oxidation of a soil sample.

[0004] BACKGROUND OF THE INVENTION

[0005] Soil organic carbon (SOC) is the carbon that remains in the soil after the partial decomposition of any material produced by living organisms. It is a key element of the global carbon cycle through the atmosphere, vegetation, soil, rivers, and ocean. SOC is the main component of soil organic matter (SOM) and, as such, constitutes the fuel of any soil. SOM contributes to key soil functions, as it is fundamental for stabilizing soil structure, retaining and releasing plant nutrients, and enabling water infiltration and storage in the soil. Therefore, it is essential for ensuring soil health, fertility, and food production. The loss of SOC negatively affects not only soil health and food production but also exacerbates climate change, hence the importance of its measurement.

[0006] There are several methods for determining soil organic carbon (SOC). On the one hand, SOC can be obtained from soil profile data derived from soil maps, and on the other hand, it can be measured using various chemical methods.

[0007] In relation to the above, for example, US Patent Application No. US20230125138 describes a method for estimating soil organic carbon content or changes in soil organic carbon content over time using loss on ignition (LOI), in which a first soil sample is taken from a selected location and heated by forcing heated oxygen-containing gas through the soil sample, controlling the sample temperature by using at least one temperature-sensing means within the soil sample and varying the gas supply to the sample according to the sample temperature detected by the sensing means to remove organic materials, including organic carbon, from the soil sample by burning or oxidizing the organic materials,and the apparatus for estimating the soil organic carbon content or changes in soil organic carbon content over time using loss on ignition (LOI), the apparatus comprising: a housing defining a vertical elongated chamber; a gas-permeable means for supporting at least one soil sample within the chamber; at least one temperature-sensing means located within the soil sample; means for forcing a flow of heated, oxygen-containing gas downwards through the chamber and the at least one soil sample; and means for controlling the gas flow according to the temperature detected by the temperature-sensing means.

[0008] U.S. Patent No. 11,882,784 B2 describes implementations for predicting soil organic carbon (SOC) content in agricultural fields detected in digital images. The method comprises: obtaining a plurality of digital images representing a field over multiple growing seasons; applying the plurality of digital images as input to one or more machine learning models to generate a first output indicative of two or more inferred agricultural management practices implemented in the field over the multiple growing seasons, where the two or more inferred agricultural management practices include: an inferred tillage practice employed in the field during the multiple growing seasons; a crop rotation employed in the field during the multiple growing seasons; or a cover crop grown in the field during the multiple growing seasons;and applying indicative data from the two or more inferred agricultural management practices as input to one or more additional machine learning models to generate a second result, wherein the second result represents a predicted measure of the soil organic carbon (SOC) of the field.;

[0009] Chinese patent application No. 114705832 A discloses a portable detector of soil organic carbon content, comprising a main structural body, the main structural body comprising a portable detection box, the portable detection box is provided internally with a first partition plate and a second partition plate, the first partition plate and the second partition plate divide the portable detection box into a storage cavity, a control cavity and a detection cavity which are longitudinally distributed; a storage battery, a lifting motor and a control base plate are arranged in the control cavity, a lifting rod is arranged at the lower end of the lifting motor, and an organic carbon detector is arranged at the lower end of the lifting rod;A sample placement disc is placed in the detection cavity, and the organic carbon detector is placed on top of the sample placement disc; by arranging the portable detection box, in situ soil detection is achieved, and the convenience of in situ soil detection is improved; in the portable detection box, a storage cavity, a control cavity, and a detection cavity are formed; the soil collected in situ is placed in the detection cavity to be detected, and a detection result is shown through a viewing window on a control panel.

[0010] International patent application No. W02024020629A1 describes a soil carbon sensor comprising: a probe body configured for operative placement in the soil; a first detector supported by the probe body and configured to transmit a frequency-modulated signal in said soil, the first detector including a first electrode configured to respond to moisture content and bulk density of said soil; a second detector supported by the probe body and configured to transmit an amplitude-modulated signal in said soil, the second detector including a second electrode configured to respond to soil organic carbon (SOC) content of said soil; and a processor arranged in signal communication with the first and second detectors, said processor configured to: i. generate and control the transmission of the frequency- and amplitude-modulated signals;iii. control the first electrode to capture an impedance measurement indicative of moisture content and bulk density; and iii. control the second electrode to capture a current measurement indicative of soil organic carbon (SOC) content; wherein such captured impedance and current measurements can be used to calculate the soil carbon content.This document also describes the method for detecting carbon in the soil, which comprises the steps of: transmitting a frequency-modulated signal to the soil through a first detector having a first electrode configured to respond to the moisture content and bulk density of said soil; transmitting an amplitude-modulated signal to said soil through a second detector having a second electrode configured to respond to soil organic carbon (SOC); monitoring, by means of a processor arranged in signal communication with said first and second detectors, of the first electrode to capture an impedance measurement indicative of moisture content and bulk density, and of the second electrode to capture a current measurement indicative of soil organic carbon (SOC); and calculating a soil carbon content according to said captured impedance and current measurements.

[0011] Chinese patent application No. 114462579 A relates to a method for estimating soil organic carbon content based on ground and remote sensing data, wherein the method comprises the following steps: collecting the soil sample to obtain the first sampling point data, performing data processing on the first sampling point data to obtain the first Landsat5 remote sensing data and the first DEM data that meet the pre-established requirement; building the initial neural network model, introducing the Landsat5 remote sensing data and the DEM data that meet the pre-established requirement into the initial neural network model for training, obtaining the predicted value of the organic carbon content of the soil sample;According to the predicted value of the organic carbon content of the soil sample and the preset loss function, calculate to obtain the loss value, according to the loss value, perform the reverse propagation to the initial neural network model to update the network parameter of the initial neural network model and iterate the training times, when the training times reach the preset times, obtain the trained initial neural network model;Collect the soil sensing product to obtain the second sampling point data, perform data processing on the second sampling point data to obtain the second Landsat remote sensing data and the second DEM data that meet the pre-established requirement, introduce the second Landsat remote sensing data and the second DEM data into the trained initial neural network model, estimate to obtain the organic carbon content value of the soil sensing product.

[0012] Chinese patent application No. 109991389 A describes a method for determining the organic carbon content of soils. The method involves placing a silver beaker on a balance, zeroing the balance, removing the silver beaker, placing a soil sample into the silver beaker, placing the beaker and soil sample on a balance, and recording the weight of the soil sample. Hydrochloric acid (6 mol / L) is added to the silver beaker containing the soil sample, allowed to react for 0.5–1 hour, and then heated to 50–55°C for 0.5 hours. The silver beaker containing the soil sample is then removed with flat tongs, packed into a regular block, and placed in an organic matter analyzer to determine the carbon and nitrogen content.

[0013] Chinese patent application No. 103940980 A discloses a device for measuring soil organic carbon content. The device comprises a vacuum pump connected to a liquid nitrogen cold trap via a corrugated tube, and two high-vacuum three-way junctions. One high-vacuum three-way junction is connected to the liquid nitrogen cold trap and a CO2 collection tube, while the other is connected to a compression tube and a water collection trap. A helical valve is arranged in the compression tube. The water collection trap is connected to the CO2 collection tube via a CO2 cold trap. Two helical valves are arranged at the top of the CO2 cold trap. The device forms a vacuum system. This document also describes a method for measuring soil organic carbon content using the device.

[0014] Chinese patent application No. 116380817 A discloses a method and device for the rapid measurement of soil organic carbon content. The method comprises the following steps: treating an organic matter solution from a soil sample using a spectrophotometric method, calculating the concentration of organic matter in the organic matter solution, and calculating the initial organic carbon content of the soil sample based on the organic matter concentration; and correcting the initial organic carbon content of the soil sample using a correction model to obtain the actual organic carbon content of the corrected soil sample.According to the described method, the concentration of organic matter in the organic matter solution of the soil sample can be easily and conveniently obtained by adopting the spectrophotometric method. Then, the first organic carbon content of the soil sample can be directly obtained, the first organic carbon content is corrected by adopting the correction model, and the more accurate organic carbon content of the actual soil sample can be obtained.

[0015] U.S. Patent Application No. 9,945,764 B2 describes a method for determining the organic carbon content of a soil sample using heated air / gas and the variations / changes in carbon content, wherein said method consists of taking a soil sample and forcing heated gas through the soil sample to remove carbon from the soil sample. The organic carbon content in the soil sample is determined from a change in the weight of the soil sample.

[0016] Chinese patent No. 103969397 B describes a method for detecting organic carbon in plants and soil, and the heating device for the method. The method comprises the following steps: pretreating a plant or soil sample, mixing the pretreated plant or soil sample, potassium dichromate solution, and concentrated sulfuric acid solution in a triangular flask, heating to carry out the oxidation reaction, adding distilled water after the reaction is complete, cooling, adding phenanthroline solution as an indicator, titrating the residual potassium dichromate from the oxidation reaction using ferrous sulfate solution, and calculating the organic carbon content.

[0017] Finally, the Mexican Official Standard NOM-021-RECNAT-2000, entitled “SPECIFICATIONS FOR SOIL FERTILITY, SALINITY, AND CLASSIFICATION. STUDIES, SAMPLING, AND ANALYSIS,” establishes the specifications for soil fertility, salinity, and classification, as well as the studies, sampling, and analysis procedures applicable in Mexico. This Mexican Official Standard describes the method for determining soil organic matter using the AS-07 method of Walkley and Black, which is based on the oxidation of soil organic carbon by means of a potassium dichromate solution and the heat of reaction generated when it is mixed with concentrated sulfuric acid. After a certain waiting period, the mixture is diluted, phosphoric acid is added to avoid interference from Fe3+, and the residual potassium dichromate is titrated with ferrous sulfate.This procedure detects between 70 and 84% of the total organic carbon, so it is necessary to introduce a correction factor, which can vary from soil to soil. In Mexican soils, it is recommended to use a factor of 1.298 (1 / 0.77).

[0018] Although there are many methods for measuring soil organic carbon, they are expensive and time-consuming. Therefore, there is a need for a method that can be performed quickly and at a low cost.

[0019] BRIEF DESCRIPTION OF THE INVENTION

[0020] In one aspect, the present invention provides a kit and method for measuring organic carbon in the soil that is low-cost and provides results in a short period of time.

[0021] In a second aspect, the present invention provides a kit and a method for measuring organic carbon in the soil based on the oxidation of a sample of said soil.

[0022] The invention will be better understood after reviewing the detailed description set forth below, taken together with the figures in the accompanying drawings, which are briefly described below.

[0023] BRIEF DESCRIPTION OF THE FIGURES

[0024] Figure 1 is a schematic representation of the method of the present invention.

[0025] Figure 2 is a comparison of nine soil organic carbon measurements using the method and kit of the invention and those obtained using a method used in the art.

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] The inventors of the present invention found that it is possible to measure the organic carbon in the soil by oxidizing a sample of it.

[0028] Therefore, in a first embodiment, the method developed by the inventors for measuring soil organic carbon comprises the steps: 1) weighing a soil sample; 2) oxidizing a soil sample in a suitable medium; 3) collecting the organic carbon released as a gas in a basic medium; 4) determining the amount of sodium carbonate that is formed; and 5) measuring the organic carbon present in the soil sample.

[0029] In a second preferred modality, the method for measuring soil organic carbon comprises the following steps:

[0030] 1) weigh a soil sample, homogenize it, and optionally sieve it;

[0031] 2) place a specified quantity of the sample in a suitable container, called the sample container, add a specified quantity of a catalyst and optionally an antifoaming agent;

[0032] 3) In a second suitable container, called the white container, add a specific quantity of the catalyst;

[0033] 4) Cover both the sample container and the blank container;

[0034] 5) In two suitable containers, called trap containers, add a specified quantity of a basic solution to each, and cover them;

[0035] 6) Connect both the sample container and the blank container to each of the trap containers;

[0036] 7) Add an oxidizing agent to the sample container as well as to the blank container in order to oxidize the soil sample;

[0037] 8) collect the generated carbon dioxide in the trap containers;

[0038] 9) determine, by titration with a suitable acid solution, the amount of sodium carbonate that is formed; and

[0039] 10) Calculate the amount of organic carbon in the sample.

[0040] In relation to the method described above, suitable containers for receiving the sample and blank can be glass tubes, glass flasks, etc. Similarly, trap containers can be glass tubes, glass flasks, etc.

[0041] Additionally, the catalyst used is selected from the group comprising manganese oxide. Preferably, the catalyst is manganese oxide. The antifoaming agent can be selected from paraffin.

[0042] The basic solution is selected from the group comprising a sodium hydroxide solution. When using sodium hydroxide solution as the basic solution, it is preferable to use a CO2 precipitating agent such as a barium chloride solution.

[0043] The acid solution is selected from the group comprising a hydrochloric acid solution.

[0044] In a functional modality, the method for measuring soil organic carbon comprises the following steps:

[0045] 1) Weigh a 20-gram sample of soil, homogenize it, and optionally sieve it;

[0046] 2) Add a 2-gram sample of soil to a first container, such as a glass tube (sample tube), and add 1.5 ml of 2% manganese oxide solution and 1 g of paraffin flakes;

[0047] 3) Add to a second container, such as a glass tube (white tube), 1.5 ml of a 2% manganese oxide solution;

[0048] 4) Cover both the sample tube and the blank tube with a rubber stopper;

[0049] 5) In two suitable containers, such as glass tubes, called trap containers, add to each 10 ml of a 0.5 M sodium hydroxide solution and subsequently 2 ml of a 2% bath chloride solution, and cover them;

[0050] 6) Connect, using suitable means such as a rubber hose, the sample tube and the blank tube to each of the trap tubes;

[0051] 7) Using a syringe, add 30 ml of a 30% hydrogen peroxide solution to the sample tube and the blank tube in order to oxidize the soil sample;

[0052] 8) collect the generated carbon dioxide in the trap containers;

[0053] 9) Determine, by titration with a 0.5 M hydrochloric acid solution, the amount of sodium carbonate that is formed; and

[0054] 10) Calculate the amount of organic carbon in the sample using the following formula: mg COS = ([(ml used in BLANK - ml used in SAMPLE)(0.5)(0.106)(1000)(50)] / 2) where:

[0055] (0.5)= Molarity of the titrant solution

[0056] (0.106)= Milliequivalent of sodium carbonate

[0057] (1000)= Expression for mg

[0058] (50)= Dilution factor

[0059] (2)= Grams of sample

[0060] In addition to the above, the present invention also provides a kit for measuring soil organic carbon comprising:

[0061] 1) a first means for containing a soil sample, a specified quantity of a catalyst and optionally, an antifoaming agent;

[0062] 2) a second means of containing a specified quantity of the catalyst;

[0063] 3) means for sealing the first means comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and the second means comprising a determined quantity of the catalyst;

[0064] 4) first and second means to contain a basic solution;

[0065] 5) means for covering the first and second means for containing a basic solution;

[0066] 6) means for connecting the first medium comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined quantity of the catalyst to each of the first and second media containing the basic solution;

[0067] 7) means for adding an oxidizing agent to the first medium comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and to the second medium comprising a determined quantity of the catalyst; and

[0068] 8) means to determine by titration the amount of sodium carbonate that is formed.

[0069] In relation to the kit of the present invention, the first medium, comprising a soil sample, a predetermined quantity of a catalyst, and optionally, an antifoaming agent, and the second medium, comprising a predetermined quantity of the catalyst, are selected from glass tubes or glass flasks. Particularly, it is preferred that the first and second mediums be glass tubes. Likewise, the means for containing the basic solution are selected from glass tubes, glass flasks, etc. Preferably, the means for containing the basic solution are glass tubes. The means for sealing the first medium, comprising a soil sample, a predetermined quantity of a catalyst, and optionally, an antifoaming agent, and the second medium, comprising a predetermined quantity of the catalyst, are selected from rubber stoppers or screw caps. Preferably, the means for sealing the first and second mediums are rubber stoppers.

[0070] The means for connecting the first medium, comprising a soil sample, a predetermined quantity of a catalyst, and optionally an antifoaming agent, and the second medium, comprising a predetermined quantity of the catalyst, to each of the first and second media containing the base solution, are selected from a standard drip irrigation hose, glass tubing, and rubber stoppers and donut fittings. Preferably, the means for connecting the first medium and the second medium to each of the first and second media containing the base solution are standard drip irrigation hoses.

[0071] The means for sealing the first and second containers for holding a basic solution are selected from rubber stoppers or threaded plugs. Preferably, the means for sealing the first and second containers for holding a basic solution are threaded plugs.

[0072] The means for adding an oxidizing agent to the first medium, which comprises a soil sample, a predetermined quantity of a catalyst, and optionally an antifoaming agent, and to the second medium, which comprises a predetermined quantity of the catalyst, are selected from a syringe or an ampoule with a needle. An ampoule with a needle is particularly preferred.

[0073] The means for determining by titration the amount of sodium carbonate that is formed are selected from a glass burette, an electronic burette, preferably selected from a glass burette.

[0074] The advantages of the method and kit of the present invention are numerous compared to currently used methods in the art. First, the kit allows measurements to be taken on-site, as it is not necessary to send samples to laboratories with specialized equipment. Second, the method reduces measurement time by at least 60 minutes. Similarly, the costs of performing the measurements can be reduced by up to 1000% since complex equipment is not required.

[0075] EXAMPLES

[0076] Nine soil organic carbon measurements were performed using the method and kit of the invention, and the results were compared with those obtained using the DUMAS method (Leco Truspec carbon-nitrogen analyzer). As shown in Figure 2, the results obtained with the method and kit of the present invention did not differ significantly from the results obtained with the comparison method. However, as noted above, the advantages of the method and kit of the present invention are that the measurement was carried out at the site of interest, the time required to obtain the result was shorter, and the cost of the measurement was lower.

[0077] The invention has been described herein in terms of preferred embodiments and methodologies considered by the inventor to represent the best way of carrying out the invention. Those skilled in the art will understand, however, that a wide range of additions, deletions, and modifications, both subtle and general, may be made to the illustrated and exemplary embodiments of the composite substrate without departing from the spirit and scope of the invention. Those skilled in the art may make these and other revisions without departing from the spirit and scope of the invention, which is restricted only by the following claims.

Claims

CLAIMS 1. A method for measuring soil organic carbon, characterized in that it comprises the following steps: 1) weigh a soil sample, homogenize it, and optionally sieve it; 2) place a specified quantity of the sample in a suitable container, called the sample container, add a specified quantity of a catalyst and optionally an antifoaming agent; 3) In a second suitable container, called the white container, add a specific quantity of the catalyst; 4) Cover both the sample container and the blank container; 5) In two suitable containers, called trap containers, add a specified quantity of a basic solution to each, and cover them; 6) Connect both the sample container and the blank container to each of the trap containers; 7) Add an oxidizing agent to the sample container, as well as to the blank container, in order to oxidize the soil sample; 8) collect the generated carbon dioxide in the trap containers; 9) determine, by titration with a suitable acid solution, the amount of sodium carbonate that is formed; and 10) Calculate the amount of organic carbon in the sample.

2. The method for measuring soil organic carbon according to claim 1, further characterized in that the containers suitable for receiving the sample and blank are selected from glass tubes, glass flasks.

3. The method for measuring soil organic carbon according to claim 2, further characterized in that the containers suitable for receiving the sample and the blank are glass tubes.

4. The method for measuring soil organic carbon according to claim 1, further characterized in that the trap containers are selected from glass tubes, glass flasks.

5. The method for measuring soil organic carbon according to claim 4, further characterized in that the trap containers are glass tubes.

6. The method for measuring soil organic carbon according to claim 1, further characterized in that the catalyst is selected from manganese oxide.

7. The method for measuring soil organic carbon in accordance with the claim 1, further characterized in that the antifoaming agent is paraffin.

8. The method for measuring soil organic carbon according to claim 1, further characterized in that the basic solution is a sodium hydroxide solution.

9. The method for measuring soil organic carbon according to claim 9, further characterized in that it additionally comprises employing a CO2 precipitating agent, wherein the precipitant is a barium chloride solution.

10. The method for measuring soil organic carbon according to claim 1, further characterized in that the acid solution is a hydrochloric acid solution.

11. A method for measuring soil organic carbon, characterized in that it comprises the following steps: 1) Weigh a 20-gram sample of soil, homogenize it, and optionally sieve it; 2) Add a 2-gram sample of soil to a first container, such as a glass tube (sample tube) and add 1.5 ml of 2% manganese oxide solution and optionally, 1 g of paraffin flakes; 3) Add to a second container, such as a glass tube (white tube), 1.5 ml of a 2% manganese oxide solution; 4) Cover both the sample tube and the blank tube with a rubber stopper; 5) In two suitable containers, such as glass tubes, called trap containers, add to each 10 ml of a 0.5 M sodium hydroxide solution and subsequently 2 ml of a 2% bath chloride solution, and cover them; 6) Connect, using suitable means such as a rubber hose, the sample tube and the blank tube to each of the trap tubes; 7) Add 30 ml of a 30% hydrogen peroxide solution to the sample tube and the blank tube in order to oxidize the soil sample; 8) collect the generated carbon dioxide in the trap containers; 9) Determine, by titration with a 0.5 M hydrochloric acid solution, the amount of sodium carbonate that is formed; and 10) Calculate the amount of organic carbon in the sample.

12. A kit for measuring soil organic carbon, characterized in that it comprises: 1) a first means of containing a soil sample, an amount determined by a catalyst and, optionally, an antifoaming agent; 2) a second means of containing a specified quantity of the catalyst; 3) means for sealing the first means comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and the second means comprising a determined quantity of the catalyst; 4) first and second means to contain a basic solution; 5) means for covering the first and second means for containing a basic solution; 6) means for connecting the first medium comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined quantity of the catalyst to each of the first and second media containing the basic solution; 7) means for adding an oxidizing agent to the first medium comprising a soil sample, a determined quantity of a catalyst and optionally, an antifoaming agent and to the second medium comprising a determined quantity of the catalyst; and 8) means to determine by titration the amount of sodium carbonate that is formed.

13. The kit for measuring soil organic carbon according to claim 12, further characterized in that the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst are selected from glass tubes, glass flasks.

14. The kit for measuring soil organic carbon according to claim 13, further characterized in that the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst are glass tubes.

15. The kit for measuring soil organic carbon according to claim 12, further characterized in that the means for containing the basic solution are selected from glass tubes, glass flasks.

16. The kit for measuring soil organic carbon according to claim 15, further characterized in that the means for containing the basic solution are glass tubes.

17. The kit for measuring soil organic carbon according to claim 12, further characterized in that the means for sealing the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst are selected from rubber stoppers, threaded stoppers.

18. The kit for measuring soil organic carbon according to claim 17, further characterized in that the means for sealing the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst are rubber stoppers.

19. The kit for measuring soil organic carbon according to claim 12, further characterized in that the means for connecting the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst to each of the first and second media containing the basic solution are selected from a normo dripper-type hose, glass tubes and rubber and donut stoppers.

20. The kit for measuring soil organic carbon according to claim 19, further characterized in that the means for connecting the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and the second medium comprising a determined amount of the catalyst to each of the first and second media containing the basic solution are a normo dripper type hose.

21. The kit for measuring soil organic carbon according to claim 12, further characterized in that the means for adding an oxidizing agent to the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and to the second medium comprising a determined amount of the catalyst are selected from a syringe or an ampoule with a needle.

22. The kit for measuring soil organic carbon according to claim 21, further characterized in that the means for adding an oxidizing agent to the first medium comprising a soil sample, a determined amount of a catalyst and optionally, an antifoaming agent and to the second medium comprising a determined amount of the catalyst in an ampoule with a needle.

23. The kit for measuring soil organic carbon in accordance with the claim 12, further characterized in that the means for determining by titration the amount of sodium carbonate that is formed are selected from a glass burette, an electronic burette.

24. The kit for measuring soil organic carbon according to claim 23, further characterized in that the means for determining by titration the amount of sodium carbonate that is formed is a glass burette.

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