CN105758995B - The root case and its application method with Rhizosphere DGT tests are cultivated for submerged plant - Google Patents

Abstract

The invention provides a root box for submerged plant cultivation and rhizosphere micro-region DGT testing and its use method. The root box uses two filter screens to separate the inner cavity of the box into lower layers arranged sequentially from bottom to top chamber, the middle chamber and the upper chamber, and the roots of the submerged plants are cultivated in the middle chamber, effectively distinguishing the deposits of the rhizosphere micro-regions from the rootless deposits, and the root box of the present invention The side wall of the middle chamber of the device is provided with detection ports for DGT and sediment samplers to pass through, which realizes the in-situ and accurate measurement of phosphorus and other elements by DGT during the migration process of the plant rhizosphere/sediment interface. Complete plant root characteristics can be obtained, and the root box of the present invention has the advantages of simple structure, high plant survival rate and can be used for evaluating the bioavailability of elements such as phosphorus. The method for using the root box of the present invention can simultaneously realize the cultivation of submerged plants and the in-situ test of rhizosphere micro-zone DGT, and the operation is simple and easy to be popularized on a large scale.

Description

Root box for submerged plant cultivation and rhizosphere microplot DGT testing and method of use thereof

technical field

The invention relates to the technical field of water environment ecological restoration, in particular to a root box device for submerged plant cultivation and DGT in-situ testing of phosphorus and other elements in plant rhizosphere micro-regions and a use method thereof.

Background technique

At present, more than 80% of the lakes in our country have been polluted, and the eutrophication of the water body is becoming more and more serious, which has become a major environmental problem that needs to be solved urgently. Therefore, water body treatment and water environment ecological restoration technologies have emerged as the times require. According to the different principles of water body treatment and restoration, the technology can be divided into three categories: physical method, chemical method and biological-ecological method. It has developed into the main technical means of water environment pollution control. In bio-ecological restoration technology, as competitors of planktonic algae in terms of nutrients and water energy utilization, submerged plants can effectively inhibit the growth of planktonic algae, and at the same time absorb nutrients such as nitrogen and phosphorus in the water body, playing a role Therefore, the aquatic phytoremediation technology based on submerged plants is a hot research direction in this field.

In the prior art, the methods for planting submerged plants mainly include (1) fork planting method: use a forked bamboo pole to fork the neck of the submerged plant and fork it into the water; Throw submerged plants into the water in still water; (3) Gradual sinking planting method: plant submerged plants on the carrier, and the carrier controls the sinking depth of the submerged plants in the water through the matching lifting adjustment device . Regarding the above planting methods, due to the poor visibility of the polluted water body, when people are on a moving boat, neither the fork planting method nor the seed throwing method can accurately control the planting density of submerged plants, and the flowing water will also affect the seed throwing. The position of the plants planted by the traditional method will cause the plants to tilt or even fall flat on the bottom after sinking into the water, thus affecting the survival of the submerged plants; and the gradual sinking planting method is because the submerged plants are usually cultivated on the culture medium at the bottom of the planting device Above all, the barrier of the culture medium reduces the dissolved oxygen in the water near the river bed and in the sediment, leading to the reproduction of anaerobic microorganisms, which seriously affects the restoration effect of the water body, and the existing planting devices generally need to add mixed Bacteria form biofilms to repair water bodies, but the purification of biofilms is weak and the effect on pollutants is poor. The introduction of foreign bacteria is not conducive to water restoration, and the structure of the planting device is complicated. , the cost is high, and it is difficult to popularize and apply, so there is an urgent need to improve the structure of the existing sinking planting device.

In addition, since the rhizosphere is an important area for the exchange of nutrients and energy between the root system of the crop and the soil, it is the most active place for soil microorganisms, and it is a specific area that is affected by the growth of the root system of the crop and at the same time affects the absorption and transport of crop nutrients. Therefore, the rhizosphere Microzones have always been the focus of multidisciplinary research in soil science, plant nutrition, and agronomy at home and abroad. Revealing phosphorus migration and phosphorus bioavailability in submerged plant rhizosphere microzones is a key science that must be solved in the restoration and reconstruction of submerged vegetation. However, research in this area is still relatively weak. Although thin-film diffusion gradient technique (DGT) can be used for the kinetics of phosphorus uptake by plant roots in soil, the migration and transformation characteristics of phosphorus between plant rhizosphere/pore water/sediment, and the prediction of phosphorus bioavailability in plant root zone and plant However, so far, DGT has never been tested on the rhizosphere micro-area of submerged plants, nor has it been used to study the uptake mechanism of phosphorus and other elements in the rhizosphere area and the biological availability.

In view of this, how to combine the DGT test of the submerged plant rhizosphere micro-zone with its root box planting device to realize the DGT in situ test of the submerged plant rhizosphere micro-zone directly in the root box, so as to obtain a more realistic situation. The migration characteristics of phosphorus and other elements in the rhizosphere interface, the DGT parameters of the root absorption mechanism, and the concentration of phosphorus and other elements in various phases such as plants, sediments, pore water, and DGT are the key to truly mastering the root zone of submerged plants. The key to the mechanism of element absorption and water ecological restoration is also a technical problem that has not been solved by those skilled in the art.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defects of the existing submerged plant planting devices, such as complex structure, poor water body repair effect, and inability to perform DGT in-situ testing, and to provide a simple structure, good water body repair effect and A root box for submerged plant cultivation and rhizosphere micro-zone DGT testing for DGT in situ testing and methods of use thereof.

For this reason, the technical scheme that the present invention realizes the above-mentioned purpose is:

A root box for submerged plant cultivation and rhizosphere microzone DGT testing, comprising:

A box body, a first filter screen and a second filter screen are arranged in the box body, the first filter screen is located above the second filter screen, the first filter screen and the second filter screen will The inner cavity of the box body is divided into a lower chamber, a middle chamber and an upper chamber arranged sequentially from bottom to top; wherein,

The top opening of the upper chamber is provided with a plurality of through holes for the stems of submerged plants to pass through on the first screen;

The middle chamber is used to cultivate the roots of the submerged plants, and the side wall of the middle chamber is provided with detection ports for DGT and sediment samplers to pass through;

A third filter screen is installed at the bottom of the lower chamber.

The height ratio of the middle chamber to the lower chamber is 1:1˜2:1.

The apertures of the first filter screen and the third filter screen are all smaller than the particle size of the sediment used to cultivate the submerged plants; the first filter screen, the second filter screen and the third filter screen are all made of glass Made of fiber.

It also includes a DGT placement device, the DGT placement device includes a delivery rod, clamps and buttons are respectively arranged at both ends of the delivery rod, and a spring mechanical device connecting the clamps and buttons is arranged along the length direction of the delivery rod.

Also included is a sediment sampler, which is a plastic syringe without a needle for taking samples of rhizosphere sediment;

Probes for detecting the pH value, Eh value and temperature of the rhizosphere microzone are arranged in the through hole located in the middle part of the first filter screen.

A longitudinal scale is arranged along the height direction outside the side wall of the box body; a scale is arranged on the conveying rod along the length direction of the conveying rod.

It also includes a pair of lifting lugs, and the pair of lifting lugs are fixedly arranged on the opposite side walls of the top of the box;

A sealing cover is also included, and the sealing cover is arranged on the outside of the detection port.

The using method of above-mentioned root box comprises the following steps:

(1) Add sediment to the lower chamber and the middle chamber, plant the roots of the submerged plants in the middle chamber, and make the stems of the submerged plants pass through the The through hole extends into the upper chamber;

(2) Fix the root box on a floating platform built in the water area under study, so that the top of the root box is 0.5-1m away from the water surface;

(3) After the submerged plants are cultivated in the floating platform for a period of time, the rhizosphere micro-regions of the submerged plants are tested, and the steps of the test include:

S1. Take out the root box from the floating platform;

S2. Clamp the circular DGT with thin wires on the fixture of the DGT placement device, send the circular DGT into the rhizosphere deposits in the middle chamber through the detection port, and press the the button to place the circular DGT in the rhizosphere deposit, remove the DGT placement device, and place the end of the thin wire outside the detection port;

S3, then fix the root box with the circular DGT in the floating platform, so that the circular DGT is tested in situ in the rhizosphere micro-region of the submerged plant, and the in situ test is to be performed Once complete, the circular DGT is removed by pulling on the thin wire.

The deposits were made by the following method:

Collect the lake sediment with a total phosphorus content of 3000mg/Kg and air-dry it;

Collect lake sand from unpolluted waters and air dry;

The sediment is obtained by mixing the air-dried lake bottom mud and lake sand at a mass ratio of 1:14 to 14:1.

The distance between the placement position of the circular DGT and the detection port is equal to the distance between the projection of the detection port on the first filter and the center of the through hole;

The test in step (3) also includes the step of sampling the rhizosphere deposits, specifically: before performing the step S2, inserting the deposit sampler into the middle chamber through the detection port In the rhizosphere deposits, extract the rhizosphere deposits;

It also includes inserting the probes for detecting the pH value, Eh value and temperature of the rhizosphere micro-zone into the rhizosphere deposits in the middle chamber.

The technical scheme of the present invention has the following advantages:

1. The root box used for submerged plant cultivation and rhizosphere micro-zone DGT test provided by the present invention divides its box cavity into lower chamber, middle chamber and upper chamber, and the roots of submerged plants are cultivated in the middle chamber, thereby effectively distinguishing the deposits of the rhizosphere micro-regions from the rootless deposits, and the root box device of the present invention is in the middle chamber The side wall is provided with a detection port for the DGT and sediment sampler to pass through, which is conducive to the in-situ and accurate determination of the DGT on the migration of phosphorus and other elements at the plant rhizosphere/sediment interface, and can also obtain a complete plant. Root characteristics, so that it can more truly reveal the dynamic absorption mechanism of phosphorus and other elements in the roots of submerged plants and the ecological restoration function of trophic lake water.

And, in order to carry out DGT in-situ test conveniently, root box device of the present invention needs to be fixed on the buoyant platform, and in addition for the purpose of the element migration and material exchange of real simulation sediment/water/plant interface, so the present invention is in A lower chamber is arranged below the middle chamber, and deposits are also filled in the lower chamber.

2. The root box provided by the present invention for submerged plant cultivation and rhizosphere micro-zone DGT test is provided with a longitudinal scale along the height direction outside the side wall of its casing, and along the length direction of the delivery bar on the delivery bar. The scale is set to help accurately determine the placement positions of the probe and DGT, so as to more accurately test the rhizosphere micro-zone of submerged plants.

In addition, the root box device of the present invention has the advantages of simple structure, high plant survival rate, good water restoration effect and can be used for evaluating the bioavailability of phosphorus and other elements.

3. The method for using the root box of the present invention, by planting the roots of the submerged plants in the sediment in the middle chamber, and allowing the stems of the submerged plants to pass through the through holes Extending to the upper chamber, and setting the top of the root box at a distance of 0.5-1m from the water surface, on the one hand, it can provide the required light and nutrients for the survival of submerged plants, which is conducive to improving the survival rate of submerged plants. On the other hand, the reduction of dissolved oxygen in the water environment near the root box is avoided, and since the root box of the present invention is used to cultivate submerged plants without adding additional strains, the restoration effect of the submerged plants on the water body can be ensured.

In addition, the method for using the root box of the present invention can simultaneously realize the cultivation of submerged plants and the in-situ test of rhizosphere micro-zone DGT, and has the advantages of simple operation and easy large-scale promotion.

Description of drawings

In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings that need to be used in the description of the specific embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative work.

Fig. 1 is the structural representation of root box device of the present invention;

Fig. 2 is a schematic structural diagram of the DGT placing device in the present invention.

Among them, the reference signs are as follows:

1-box; 2-first filter screen; 3-second filter screen; 4-lower chamber; 5-middle chamber; 6-upper chamber; 7-through hole; 8-detection port; 9-the first Three filter screens; 10-conveying rod; 11-fixture; 12-button; 13-circular DGT; 14-hanging lug; 15-submerged plant.

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

Example 1

As shown in Figure 1, the root box for submerged plant cultivation and rhizosphere micro-zone DGT test described in the present embodiment includes:

A box body 1, a first filter screen 2 and a second filter screen 3 are arranged in the box body 1, the first filter screen 2 is located above the second filter screen 3, and the first filter screen 2 and the second filter screen 3 divide the inner cavity of the box body 1 into a lower chamber 4, a middle chamber 5 and an upper chamber 6 arranged in sequence from bottom to top; wherein, the top of the upper chamber 6 Opening, three through holes 7 for the stems of submerged plants to pass are arranged on the first filter screen 1; the middle chamber 5 is used to cultivate the roots of the submerged plants, and the The side wall of the middle chamber 5 is provided with a detection port 8 passing through for the DGT and the sediment sampler; the bottom of the lower chamber 4 is equipped with a third filter screen 9; in the present embodiment, the whole root box is made of Opaque PVC plastics is made, and it is that an inner diameter is 26cm, is the cylinder of 50cm high, and the height of described lower chamber 4 and described middle chamber 5 is 15cm, and described first filter screen 2 and described second The apertures of the three filter screens 9 are all 28 μm, less than the particle size of the sediment used to cultivate the submerged plants, the aperture of the second filter screen 3 is 1mm, and the first filter screen 2 in the present embodiment , The second filter screen 3 and the third filter screen 9 are all made of glass fiber.

The root box device in this embodiment can effectively distinguish the soil in the rhizosphere micro-region from the rootless soil by cultivating the roots of submerged plants in the middle chamber, and the root box device of the present invention is in the middle chamber The side wall of the chamber is provided with detection ports for DGT and sediment samplers to pass through, which is conducive to the in-situ and accurate determination of DGT on the migration of phosphorus and other elements at the plant rhizosphere/sediment interface, so that it can be more realistically To reveal the dynamic absorption mechanism of phosphorus and other elements in the roots of submerged plants and the ecological restoration function of trophic lake water. In addition, the root box device of the present invention also has the advantages of simple structure, high plant survival rate and good water restoration effect.

The using method of the root box in the present embodiment comprises the steps:

(1) Collect lake sediment with a total phosphorus content of 3000mg/Kg in the area with a high degree of eutrophication in Erhai Lake, Yunnan, and air-dry; collect unpolluted lake sand in waters with better water quality, and air-dry; air-dry the lake The bottom mud and lake sand were mixed according to the mass ratio of 1:14 to 14:1, and 14 parts of a series of sediments with a concentration gradient of total phosphorus were obtained;

(2) Add the sediment of step (1) in the lower chamber and the middle chamber of the root box, add 1 part of sediment in each of the root boxes, and plant the root of Foxtail algae in the root box In the middle layer chamber, and make the stem portion of P. spicae extend into the upper layer chamber through the through hole;

(3) the root box is fixed on the floating platform built in the Erhaiguan aquatic plant experimental base, so that the top of the root box is 0.5m away from the water surface;

(4) After Crystachys spicaculata is cultivated for a growth period in the floating platform, the rhizosphere micro-region of Picaria spicosa is tested, and the steps of the test include:

S1. Take out the root box from the floating platform;

S2. Clamp the circular DGT with thin wires on the fixture of the DGT placement device, send the circular DGT into the rhizosphere deposits in the middle chamber through the detection port, and press the Press the button to place the circular DGT in the rhizosphere deposit, take out the DGT placement device, and place the end of the thin wire outside the detection port;

S3, then fix the root box with the circular DGT in the floating platform, so that the circular DGT is tested in situ in the rhizosphere micro-region of P. After completion (generally takes 24 hours), the circular DGT can be removed by pulling on the thin wire.

The using method of the root box described in the present embodiment, by planting the root of P. spica in the rhizosphere deposit of described middle chamber, and make the stem of P. spica pass through the passage The hole extends into the upper chamber, and the top of the root box is set at a distance of 0.5m from the water surface. On the one hand, it can provide the required light and nutrients for the survival of the submerged plant P. The survival rate of plants, on the other hand, avoids the reduction of the dissolved oxygen in the water environment near the root box, and because the root box of the present invention does not need to add additional bacterial classification when cultivating P. Restoration effect of Cercoides on water bodies. In addition, the method for using the root box in this embodiment can simultaneously realize the cultivation of P. spicaculata and the in-situ test of DGT in the rhizosphere micro-zone, and has the advantages of simple operation and easy large-scale promotion.

Example 2

As shown in Figure 1, the root box for submerged plant cultivation and rhizosphere micro-zone DGT test described in the present embodiment includes:

A box body 1, a longitudinal scale is arranged along the height direction outside the side wall of the box body 1, a first filter screen 2 and a second filter screen 3 are arranged in the box body 1, and the first filter screen 2 is located at Above the second filter screen 3, the first filter screen 2 and the second filter screen 3 divide the inner cavity of the box body 1 into a lower chamber 4 and a middle chamber arranged in sequence from bottom to top. 5 and the upper chamber 6; wherein,

The top opening of the upper chamber 6 is provided with 5 through holes 7 for the stems of submerged plants to pass through on the first filter screen 1, and in the middle part of the first filter screen 1 Probes for detecting the pH value, Eh value and temperature of the rhizosphere micro-zone are set in the through hole 7;

The middle chamber 5 is used to cultivate the roots of the submerged plants, and the side wall of the middle chamber 5 is provided with a detection port 8 for DGT and sediment samplers to pass through. There is a sealing cover on the outside;

A third filter screen 9 is installed at the bottom of the lower chamber 4;

The DGT placement device, referring to Fig. 2, comprises a delivery rod 10, on which a scale is arranged along the length direction of the delivery rod 10, and clamps 11 and buttons are respectively arranged at both ends of the delivery rod 10 12. A spring mechanical device connecting the clamp 11 and the button 12 is arranged along the length direction of the delivery rod 10;

A pair of lifting lugs 14, said pair of lifting lugs 14 are fixedly arranged on the opposite side walls of the top of the box body 1 .

In the present embodiment, the whole root box is made of opaque PVC plastic, which is a cylinder with an inner diameter of 26cm and a height of 50cm, and the heights of the lower chamber 4 and the middle chamber 5 are respectively 15cm, 30cm, the aperture of the first filter screen 2 and the third filter screen 9 is 28 μm, which is smaller than the particle size of the sediment used to cultivate the submerged plants, the aperture of the second filter screen 3 is 1mm, and this The first filter screen 2, the second filter screen 3 and the third filter screen 9 in the embodiment are all made of glass fiber. The probes used in this example are 5-Star portable pH/Eh electrode probes (Thermoelectric Orion Corporation, USA) and soil temperature data collector probes (Wuxi Gaocheng Precision Instrument Co., Ltd.).

The using method of the root box in the present embodiment comprises the steps:

(1) Collect lake sediment with a total phosphorus content of 3000mg/Kg in the area with a high degree of eutrophication in Erhai Lake, Yunnan, and air-dry; collect unpolluted lake sand in waters with better water quality, and air-dry; air-dry the lake The bottom mud and lake sand were mixed according to the mass ratio of 14:1 to 1:14, and 14 parts of a series of sediments with a gradient of total phosphorus concentration were obtained;

(2) Add the sediment of step (1) in the lower chamber and the middle chamber of the root box, add 1 part of sediment in each of the root boxes, and plant the root of Foxtail algae in the root box In the middle layer chamber, and make the stem of P. spicae extend to the upper chamber through the through hole; the probe for detecting the pH value, Eh value and temperature of the rhizosphere microzone inserted into the rhizosphere deposits of the middle chamber;

(3) A cable is set on the pair of lifting lugs 14, and the root box is fixed on the floating platform built in the Erhaiguan Aquatic Plant Experimental Base by the cable, so that the top of the root box is 1m away from the water surface ;

(4) After Crystachys spicaculata is cultivated for a growth period in the floating platform, the rhizosphere micro-region of Picaria spicosa is tested, and the steps of the test include:

S1. Take out the root box from the floating platform, and open the sealing cover;

S2. Insert the sediment sample into the rhizosphere deposit in the middle chamber through the detection port, extract the rhizosphere deposit, and obtain a rhizosphere deposit sample;

S3. Clamp the circular DGT with thin wires on the fixture of the DGT placement device, send the circular DGT into the rhizosphere deposits in the middle chamber through the detection port, and press the Press the button to place the circular DGT in the rhizosphere deposit, and ensure that the distance between the placement position of the circular DGT and the detection port is equal to that of the detection port on the first filter The distance between the projection of and the center of the through hole; then take out the DGT placement device, place the end of the thin wire outside the detection port, and close the sealing cover;

S4, then fix the root box with the circular DGT on the floating platform, so that the circular DGT can be tested in situ in the rhizosphere microregion of P. After the test is completed, the circular DGT can be removed by pulling the thin wire.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. a method for using the root box of submerged plant cultivation and rhizosphere micro-region DGT test, characterized in that: The root box includes, A box body, a first filter screen and a second filter screen are arranged in the box body, the first filter screen is located above the second filter screen, the first filter screen and the second filter screen will The inner cavity of the box body is divided into a lower chamber, a middle chamber and an upper chamber arranged sequentially from bottom to top; wherein, The top opening of the upper chamber is provided with a plurality of through holes for the stems of submerged plants to pass through on the first screen; The middle chamber is used to cultivate the roots of the submerged plants, and the side wall of the middle chamber is provided with detection ports for DGT and sediment samplers to pass through; A third filter screen is installed at the bottom of the lower chamber; DGT placement device, the DGT placement device includes a delivery rod, clamps and buttons are respectively arranged at both ends of the delivery rod, and a spring mechanical device connecting the clamps and buttons is arranged along the length direction of the delivery rod; The method of use comprises the steps of: (1) Add sediment to the lower chamber and the middle chamber, plant the roots of the submerged plants in the middle chamber, and make the stems of the submerged plants pass through the The through hole extends into the upper chamber; (2) Fix the root box on a floating platform built in the water area under study, so that the top of the root box is 0.5-1m away from the water surface; (3) After the submerged plants are cultivated in the floating platform for a period of time, the rhizosphere micro-regions of the submerged plants are tested, and the steps of the test include: S1. Take out the root box from the floating platform; S2. Clamp the circular DGT with thin wires on the fixture of the DGT placement device, send the circular DGT into the rhizosphere deposits in the middle chamber through the detection port, and press the the button to place the circular DGT in the rhizosphere deposit, remove the DGT placement device, and place the end of the thin wire outside the detection port; S3, then fix the root box with the circular DGT in the floating platform, so that the circular DGT is tested in situ in the rhizosphere micro-region of the submerged plant, and the in situ test is to be performed Once complete, the circular DGT is removed by pulling on the thin wire. 2 . The method for using the root box according to claim 1 , wherein the height ratio of the middle chamber to the lower chamber is 1:1˜2:1. 3. the using method of root box according to claim 1, is characterized in that, the aperture of described first filter screen and described the 3rd filter screen is all less than the granularity of the deposit that is used to cultivate described submerged plant; The first filter screen, the second filter screen and the third filter screen are all made of glass fiber. 4. according to the using method of the root box described in any one of claim 1-3, it is characterized in that, also comprises sediment sampler, and it is the plastic syringe without needle, is used for extracting rhizosphere deposit sample; Probes for detecting the pH value, Eh value and temperature of the rhizosphere microzone are arranged in the through hole located in the middle part of the first filter screen. 5. The using method of the root box according to claim 1, characterized in that, a longitudinal scale is set along the height direction outside the side wall of the box body; There are scales. 6. The method of using the root box according to claim 1, further comprising a pair of lifting lugs, the pair of lifting lugs are fixedly arranged on the opposite side walls of the top of the box; A sealing cover is also included, and the sealing cover is arranged on the outside of the detection port. 7. the using method of root box according to claim 1, is characterized in that, described deposit is made by following method: Collect the lake sediment with a total phosphorus content of 3000mg/Kg and air-dry it; Collect lake sand from unpolluted waters and air dry; The sediment is obtained by mixing the air-dried lake bottom mud and lake sand at a mass ratio of 1:14 to 14:1. 8. The method of using the root box according to claim 1, characterized in that the distance between the placement position of the circular DGT and the detection port is equal to the projection of the detection port on the first filter distance from the center of the via. 9. The using method of root box according to claim 4, is characterized in that, described in step (3) test also comprises the step that rhizosphere deposit is sampled, specifically: before carrying out described step S2 , insert the sediment sampler into the rhizosphere deposit in the middle chamber through the detection port, and extract the rhizosphere deposit. 10. The method for using the root box according to claim 4, further comprising inserting the probe for detecting the pH value, Eh value and temperature of the rhizosphere microregion into the rhizosphere of the middle chamber in the sediment.