In-situ rapid measurement device and method for soil exchange-state nutrients

Abstract

The invention relates to the technical field of soil nutrient detection, in particular to a soil exchange state nutrient in-situ rapid detection device and method, which comprises a multi-frequency sensor, a soil temperature sensor and a cloud end, the multi-frequency sensor and the soil temperature sensor transmit data to the cloud end through a wireless terminal DTU, the device further comprises a terminal, and the terminal is connected with the cloud end through access. And the multi-frequency sensor and the soil temperature sensor are also connected with a power supply device. According to the in-situ rapid detection device for the soil exchange state nutrients, the purpose of in-situ soil exchange state nutrients is achieved by adopting the in-situ rapid detection device for the soil exchange state nutrients and setting a calculation model at a cloud end.

Description

Technical Field

[0001] The present invention relates to the technical field of soil nutrient detection, and particularly to an in-situ rapid detection device and method for soil exchangeable nutrients. Background Art

[0002] Soil nutrients include water-soluble nutrients and exchangeable nutrients. In the process of studying soil, the measurement of soil exchangeable nutrients is often involved, including multiple indicators such as nitrate nitrogen, ammonium nitrogen, and cation exchange capacity. Exchangeable nutrients are the nutrient forms adsorbed by the double electric layer in soil clay particles. Their content has an important impact on crop growth and yield. By measuring soil exchangeable nutrients, the soil fertility supply capacity can be mastered, and over-fertilization or under-fertilization can be avoided. When formulating a fertilization plan, the data of exchangeable nutrients also need to be referred to, the ratio of elements such as nitrogen, phosphorus, and potassium is optimized, crop yield is increased, and environmental pollution is reduced.

[0003] Currently, the general method for measuring soil exchangeable nutrients is the chemical extraction method. The chemical extraction method is to collect soil samples in the field and then transfer them to the laboratory for chemical reagent leaching operations. However, the chemical extraction method has problems such as irreversible chemical adsorption; the collection of chemically leached soil samples destroys the original structure of the soil itself, including texture, bulk density, porosity, specific surface area, etc.; the soil-water ratio of the chemical separation method exceeds the highest soil-water ratio in the in-situ state, etc., resulting in a deviation between the measurement result and the actual soil exchangeable nutrients and low measurement efficiency. Summary of the Invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an in-situ rapid detection device and method for soil exchangeable nutrients, which realizes the purpose of in-situ soil exchangeable nutrients by using the in-situ rapid detection device for soil exchangeable nutrients and setting a calculation model in the cloud.

[0005] In order to achieve the above purpose, the main technical solutions adopted by the present invention include: An in-situ rapid detection device for soil exchangeable nutrients, including a multi-frequency sensor, a soil temperature sensor, and a cloud. The multi-frequency sensor and the soil temperature sensor transmit data to the cloud through a wireless terminal DTU. It also includes a terminal, and the terminal is connected to the cloud through access. The multi-frequency sensor and the soil temperature sensor are also connected to a power supply device. The cloud has the following calculation model, FSIC i = ; FSIC i =e -kv·Cxi ; Among them, FSIC is the dielectric function frequency scale index feature; i is the soil exchangeable nutrient label, f 土壤 is the frequency value of the soil, f 纯水 is the frequency value of pure water, f干土 is the frequency value of the soil when the water content is 0%, f 空气 is the frequency value of air, n is the frequency value coefficient; -kv is the sensitive frequency point parameter of the soil index to be measured under multi-spectrum; Cxi is the soil exchangeable nutrient index to be measured, including exchangeable nitrate nitrogen content, exchangeable ammonium nitrogen content, adsorbed phosphorus content, exchangeable potassium content, organic matter content, cation exchange capacity; there is a frequency value coefficient database in the cloud, and the database includes soil texture, soil temperature, soil water content, and frequency value coefficient.

[0006] Further, the soil texture of the database includes sandy soil, loamy soil, and clay soil.

[0007] Further, the soil temperature range of the database is 0~50°C, and it is statistically analyzed in segments of every 5°C.

[0008] Further, the soil water content range of the database is from 0% to the saturated state, and it is statistically analyzed in segments of every 5% volume water content.

[0009] Further, the soil water content range of the database is from 0% to the saturated state, and the soil water content range according to soil texture is 0%~30% for sandy soil, 0%~45% for loamy soil, and 0%~50% for clay soil.

[0010] Further, the frequency value coefficient n of the database is obtained by using the physical separation method for the soil to be measured, testing the soil frequency data within the corresponding soil texture, soil temperature, and soil water content ranges, and then obtaining the ratio of the tested soil frequency data to the soil frequency data under the standard state. After repeating several times and taking the average, the frequency value coefficient n is obtained.

[0011] The in-situ rapid measurement method for soil exchangeable nutrients using the said device includes the following steps: Step 1: Install the outer tube of the multi-frequency sensor in-situ into the soil, install the soil temperature sensor into the soil, make the installation depth of the soil temperature sensor the same as the installation depth of the outer tube of the multi-frequency sensor, and connect the multi-frequency sensor and the soil temperature sensor to the wireless terminal DTU and the solar power supply device; Step 2: During the test, insert the test end of the multi-frequency sensor into the outer tube, collect the frequency value of the soil, and upload the frequency value of the soil and the soil temperature data measured by the soil temperature sensor to the cloud through the wireless terminal DTU; Step 3: The cloud obtains the soil exchangeable nutrient index to be measured according to the frequency value of the soil and the soil temperature data, based on the frequency value coefficient database and the calculation model; Step 4: The terminal obtains the soil exchangeable nutrient index to be measured in the cloud through access and displays it.

[0012] Further, in the said Step 1, the outer tube of the multi-frequency sensor is processed by the vertical ring knife method.

[0013] Furthermore, the installation range of the soil temperature sensor is centered on the outer tube of the multi-frequency sensor and installed within a radius range of 40 - 50 cm.

[0014] The beneficial effects of the present invention are as follows: By adopting the in-situ rapid measurement device for soil exchangeable nutrients, a frequency value coefficient database and a calculation model are set in the cloud. Based on the physical separation method, the soil exchangeable nutrient indexes to be measured are obtained according to the soil type, soil temperature, soil water content, and frequency value coefficient. The present invention can realize the in-situ soil exchangeable nutrient indexes, improve the accuracy of the test results, and improve the test efficiency. Specific Embodiments

[0015] For better explaining the present invention for easy understanding, the present invention will be described in detail through specific embodiments.

[0016] The present invention provides an in-situ rapid measurement device and method for soil exchangeable nutrients. The in-situ rapid measurement device for soil exchangeable nutrients includes a multi-frequency sensor, a soil temperature sensor, and a cloud. The multi-frequency sensor and the soil temperature sensor transmit data to the cloud through a wireless terminal DTU. It further includes a terminal that is connected to the cloud through access. The multi-frequency sensor and the soil temperature sensor are also connected to a power supply device, specifically a solar power supply device. The cloud has the following calculation models. FSIC i = ; FSIC i =e -kv·Cxi ; Among them, FSIC is the dielectric function frequency scale index feature; i is the soil exchangeable nutrient marker, f 土壤 is the frequency value of the soil, f 纯水 is the frequency value of pure water, f 干土 is the frequency value of the soil when the water content is 0%, f 空气 is the frequency value of air, n is the frequency value coefficient; -kv is the sensitive frequency point parameter of the soil index to be measured under the multi-spectrum; Cxi is the soil exchangeable nutrient index to be measured, including exchangeable nitrate nitrogen content, exchangeable ammonium nitrogen content, adsorbed phosphorus content, exchangeable potassium content, organic matter content, cation exchange capacity; the cloud has a frequency value coefficient database, and the database includes soil type, soil temperature, soil water content, and frequency value coefficient. The method for determining the sensitive frequency point parameter of the soil index to be measured under the multi-spectrum is a prior art and can be determined according to the method described in Chinese Patent Application 201611209179.7, an in-situ nutrient rapid measurement method for soil based on dielectric spectroscopy.

[0017] Among them, the soil types in the database include sandy soil, loamy soil, and clay soil. The soil temperature range in the database is 0~50°C, which is statistically segmented every 5°C. The soil water content range in the database is from 0% to saturation state, which is statistically segmented every 5% by volume water content. Specifically, the soil water content ranges for different soil types are: 0%~30% for sandy soil, 0%~45% for loamy soil, and 0%~50% for clay soil.

[0018] The frequency value coefficient n of the database is obtained by using a physical separation method for the soil to be tested. The physical separation method is an existing technology, such as the physical separation method mentioned in Chinese Patent CN119086221B. In the corresponding soil type, soil temperature, and soil water content range, the soil frequency data is tested, and then the ratio of the tested soil frequency data to the soil frequency data under standard conditions is obtained. After repeating several times and taking the average value, the frequency value coefficient n is obtained. The soil frequency data under the standard conditions is specifically the soil frequency data obtained under the conditions recorded in Chinese Patent CN119086221B. Specifically, after repeating three times and taking the average value, the frequency value coefficient n is obtained.

[0019] More specifically, the frequency value coefficient database is obtained by the following method: Step 1): Make soil columns: The air-dried soil is respectively tamped in the in-situ sampling calibrator to obtain soil columns, which are divided into 3 groups according to sandy soil, loamy soil, and clay soil for standby.

[0020] Step 2): Add soil water content to each soil type. Slowly add water to the soil column with a syringe. After each addition, let it stand for 0.5~1 hour to allow the water to fully migrate in the soil column, and obtain soil columns within the set soil water content range. The soil water content is added and sampled according to the following soil types, gradient ranges: Sandy soil: 0%~5%, 5%~10%, 10%~15%, 15%~20%, 20%~25%, 25%~30%; Loamy soil: 0%~5%, 5%~10%, 10%~15%, 15%~20%, 20%~25%, 25%~30%, 30%~35%, 35%~40%, 40%~45%; Clay soil: 0%~5%, 5%~10%, 10%~15%, 15%~20%, 20%~25%, 25%~30%, 30%~35%, 35%~40%, 40%~45%, 45%~50%.

[0021] In the above soil water content range, the soil water content range of "0%~5%" includes 0% and 5%. In the remaining soil water content ranges, the data after "~" is an inclusive relationship, and the data before "~" is an exclusive relationship.

[0022] Step 3): Place the soil column obtained in Step 2) within the set soil water content range into an oven. Adjust the oven temperature to the set soil temperature range. Each time the oven preheats to the set temperature for 0.5 hours before placing the soil column. Place a thermometer inside the soil column. When the temperature of the soil column rises to the set temperature range, take out the soil column and measure the soil frequency of the soil column.

[0023] The set soil temperature ranges are as follows: 0°C to 5°C, 5°C to 10°C, 10°C to 15°C, 15°C to 20°C, 20°C to 25°C, 25°C to 30°C, 30°C to 35°C, 35°C to 40°C, 40°C to 45°C, 45°C to 50°C. In the above soil temperature ranges, for the "0°C to 5°C" soil temperature range, 0°C and 5°C are included. In the remaining soil temperature ranges, the data after "~" is an inclusive relationship, and the data before "~" is an exclusive relationship.

[0024] Step 4): Divide the measured soil frequency by the soil frequency obtained under standard conditions to obtain the frequency value coefficient. Here, "under standard conditions" refers to the conditions described in Chinese Patent CN119086221B.

[0025] Step 5): For each soil type, each soil water content range, and each soil temperature range, repeat Steps 1) to 4) three times, take the average value, and obtain the final frequency value coefficient.

[0026] Step 6): List the relationships among the soil type, soil temperature, soil water content, and the final frequency value coefficient, as shown in Table 1.

[0027] Table 1 is a relationship table of soil type, soil temperature, soil water content, and frequency value coefficient based on the physical separation method: 。

[0028] The present invention also provides an in-situ rapid measurement method for soil exchangeable nutrients. Using the in-situ rapid measurement device for soil exchangeable nutrients described in the present invention, it includes the following steps: Step 1: Install the outer tube of the multi-frequency sensor in-situ into the soil, install the soil temperature sensor into the soil, so that the installation depth of the soil temperature sensor is the same as the installation depth of the outer tube of the multi-frequency sensor. Connect the multi-frequency sensor and the soil temperature sensor to the wireless terminal DTU and the solar power supply device.

[0029] Specifically, in Step 1, the outer tube of the multi-frequency sensor is processed by the vertical ring knife method, and the outer tube of the multi-frequency sensor can be installed in-situ to a soil depth of 40 cm. The installation range of the soil temperature sensor is centered on the outer tube of the multi-frequency sensor and installed within a radius range of 40 - 50 cm.

[0030] Step 2: During testing, insert the test end of the multi-frequency sensor into the outer tube to collect the frequency values of the soil. The frequency values of the soil and the soil temperature data measured by the soil temperature sensor are uploaded to the cloud. Step 3: The cloud obtains the soil exchangeable nutrient indexes to be measured based on the frequency values of the soil and the soil temperature data, according to the frequency value coefficient database and the calculation model. The measurement method of soil volume water content is an existing technology and will not be elaborated here.

[0031] Step 4: The terminal accesses and obtains the soil exchangeable nutrient indexes to be measured from the cloud and displays them.

[0032] Example 1 Select a loamy soil area with corn as the crop. In-situ install the outer tube of the multi-frequency sensor into the soil. Specifically, use the vertical ring knife method to in-situ install the outer tube of the multi-frequency sensor into the soil at a depth of 40 cm, which can collect in-situ data of the soil at 10 cm, 20 cm, 30 cm, and 40 cm. After installing the outer tube, place the multi-frequency sensor. Then install the soil temperature sensor. The installation position of the soil temperature sensor is centered on the outer tube of the multi-frequency sensor and installed at a radius of 43 cm, with the installation depth the same as that of the outer tube of the multi-frequency sensor, i.e., 40 cm. Connect the multi-frequency sensor and the soil temperature sensor to the wireless terminal DTU and the solar power supply device.

[0033] During testing, insert the test end of the multi-frequency sensor into the outer tube to collect the frequency values of the soil. The frequency values of the soil and the soil temperature data measured by the soil temperature sensor are uploaded to the cloud through the wireless terminal DTU. Specifically, the in-situ rapid measurement device for soil exchangeable nutrients can be set to automatically collect data and upload it to the cloud at a frequency of one group per day. The cloud obtains the soil exchangeable nutrient indexes to be measured based on the frequency values of the soil and the soil temperature data, according to the frequency value coefficient database and the calculation model. The terminal accesses and obtains the soil exchangeable nutrient indexes to be measured from the cloud and displays them.

[0034] Taking the indexes of exchangeable ammonium nitrogen content and exchangeable nitrate nitrogen content in the 20-cm soil layer as an example in this embodiment, based on the calculation model and the frequency value coefficient database in the cloud, at a soil depth of 20 cm, the soil temperature is 21°C, the volume water content is 24%, the exchangeable ammonium nitrogen content is 1.15 mg / kg, and the exchangeable nitrate nitrogen content is 9.45 mg / kg.

[0035] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any modifications, alterations, substitutions, and variations made by those of ordinary skill in the art to the above embodiments fall within the scope of the present invention.

Claims

1. An in-situ rapid measurement device for soil exchangeable nutrients, characterized in that: It includes a multi-frequency sensor, a soil temperature sensor, and the cloud. The multi-frequency sensor and the soil temperature sensor transmit data to the cloud through a wireless terminal DTU. It also includes a terminal that is connected to the cloud through access. The multi-frequency sensor and the soil temperature sensor are also connected to a power supply device. The cloud has the following calculation model. FSIC i = ; FSIC i =e -kv·Cxi ; Among them, FSIC is the dielectric function frequency scale index feature; i is the soil exchangeable nutrient marker, f 土壤 is the frequency value of the soil, f 纯水 is the frequency value of pure water, f 干土 is the frequency value of the soil when the water content is 0%, f 空气 is the frequency value of air, n is the frequency value coefficient; -kv is the sensitive frequency point parameter of the soil index to be measured under multi-spectrum; Cxi is the soil exchangeable nutrient index to be measured, including exchangeable nitrate nitrogen content, exchangeable ammonium nitrogen content, adsorbed phosphorus content, exchangeable potassium content, organic matter content, cation exchange capacity; there is a frequency value coefficient database in the cloud, and the database includes soil texture, soil temperature, soil water content, frequency value coefficient.

2. The in-situ rapid measurement device for soil exchangeable nutrients according to claim 1, characterized in that: The soil types in the database include sandy soil, loamy soil, and clay soil.

3. The in-situ rapid measurement device for soil exchangeable nutrients according to claim 1, characterized in that: The soil temperature range in the database is 0 to 50 °C, and it is statistically segmented every 5 °C.

4. The in-situ rapid measurement device for soil exchangeable nutrients according to claim 1, characterized in that: The soil water content range in the database is from 0% to the saturated state, and it is statistically segmented every 5% volume water content.

5. The in-situ rapid measurement device for soil exchangeable nutrients according to claim 4, wherein: The soil water content range in the database is from 0% to the saturated state. The water content ranges for different soil types are: for sandy soil, it is 0% - 30%; for loamy soil, it is 0% - 45%; for clay soil, it is 0% - 50%.

6. The in-situ rapid measurement device for soil exchangeable nutrients according to claim 1, characterized in that, The frequency value coefficient n of the database is obtained by using a physical separation method for the soil to be measured. In the corresponding soil type, soil temperature, and soil water content range, the soil frequency data is tested. Then, the ratio of the tested soil frequency data to the soil frequency data under the standard state is obtained. After repeating several times and taking the average, the frequency value coefficient n is obtained.

7. The in-situ rapid measurement method for soil exchangeable nutrients using the device according to any one of claims 1-6, characterized in that, It includes the following steps: Step 1: In-situ install the outer tube of the multi-frequency sensor into the soil, and install the soil temperature sensor into the soil so that the installation depth of the soil temperature sensor is the same as that of the outer tube of the multi-frequency sensor. Connect the multi-frequency sensor and the soil temperature sensor to the wireless terminal DTU and the solar power supply device. Step 2: During the test, insert the test end of the multi-frequency sensor into the outer tube to collect the frequency value of the soil. The frequency value of the soil and the soil temperature data measured by the soil temperature sensor are uploaded to the cloud through the wireless terminal DTU. Step 3: The cloud obtains the soil exchangeable nutrient index to be measured based on the frequency value of the soil and the soil temperature data according to the frequency value coefficient database and the calculation model. Step 4: The terminal obtains the soil exchangeable nutrient index to be measured from the cloud through access and displays it.

8. The in-situ rapid measurement method for soil exchangeable nutrients according to claim 7, characterized in that: In Step 1, the outer tube of the multi-frequency sensor is processed by the vertical ring knife method.

9. The in-situ rapid measurement method for soil exchangeable nutrients according to claim 7, characterized in that: The installation range of the soil temperature sensor is within a radius of 40 - 50 cm centered on the outer tube of the multi-frequency sensor.