Transparent soil, test equipment and method for testing pulling strength of plant root system

Abstract

The invention relates to the technical field of plant solid effect testing, and discloses transparent soil, test equipment and a method for testing the pulling strength of a plant root system, and the test method comprises the following steps: placing a plant to be tested in a transparent test box, and preparing the transparent soil for testing the pulling strength of the plant root system in the transparent test box, when the transparent soil for testing the pulling strength of the plant root system is solidified, burying the root system of the plant to be tested into the transparent soil for testing the pulling strength of the plant root system; the to-be-tested plant is pulled upwards, a root system image of the to-be-tested plant is collected through the camera, and the pulling force of the air cylinder on the to-be-tested plant is monitored through the tension sensor. Transparent soil is adopted to simulate fastening and friction effects of real soil on a plant root system, meanwhile, a transparent test box is adopted, and compared with the prior art, the fracture process of the plant root system in the soil can be observed in the plant drawing process, so that the corresponding drawing force when the plant is fractured is obtained, and the pulling strength of the plant root system is effectively evaluated.

Description

Technical Field

[0001] This invention relates to the field of plant solids effect testing technology, and in particular to a transparent soil, testing equipment, and method for testing the pull-out strength of plant roots. Background Technology

[0002] Planting vegetation to stabilize soil and protect slopes is an important method of implementing ecological slope protection. After plants are planted in the soil, their roots and soil together form a root-soil complex, which can reinforce and anchor the soil. To verify the soil stabilization effect of different plants, it is necessary to test the pull-out strength of the plant roots.

[0003] Currently, plant root pull-out strength testing is mainly conducted through experiments. For example, patent CN104729925A discloses a test device for testing plant root pull-out strength in the field, which measures the pull-out strength of plants by pulling them up in situ. However, this device can only test the pull-out strength of the roots and stems above the ground. For the roots inside the soil, it is impossible to observe whether they break during the pull-out process, nor can it record the pull-out force corresponding to root breakage.

[0004] Therefore, how to test the pull-out strength of plant roots inside the soil is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a transparent soil, testing equipment, and method for testing the pull-out strength of plant roots, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a transparent soil for testing the uplift resistance of plant roots, comprising:

[0007] Silica particles account for 55%–75% of the total volume;

[0008] The refractive liquid is composed of a mixture of phenyl silicone oil and brominated naphthalene, with a volume ratio of phenyl silicone oil to brominated naphthalene of 3:7–7:3, and the refractive liquid accounts for 20%–35% of the total volume.

[0009] A transparent elastic gel three-dimensional network, made by reacting dimethylsiloxane prepolymer with a crosslinking agent, accounts for 3%-10% of the total volume. The transparent elastic gel three-dimensional network binds silica particles and refractive liquid.

[0010] Furthermore, the dimethylsiloxane prepolymer is vinyl-terminated polydimethylsiloxane, and the crosslinking agent is methyl hydrogen silicone oil.

[0011] Furthermore, the transparent elastic gel three-dimensional network has a mesh cross-sectional width of 50-500 nm, a refractive index of 1.405-1.408, a refractive index difference of ≤0.048 with that of the refractive liquid, and a visible light transmittance of ≥85%.

[0012] The present invention also provides a test apparatus for testing the uplift resistance of plant roots, comprising:

[0013] A transparent test chamber is filled with transparent soil for testing the pull-out strength of plant roots. The roots of the plant to be tested are buried in the transparent soil for testing the pull-out strength of plant roots.

[0014] A pulling mechanism is installed above the transparent test chamber and connected to the rootstock of the plant to be tested. The pulling mechanism is capable of pulling the plant to be tested upward.

[0015] The camera, positioned at the front of the transparent test chamber, captures images of the plant's root system as the pulling mechanism pulls the plant upwards.

[0016] Furthermore, the pulling mechanism includes:

[0017] Secure the clamp to the rootstock of the plant to be tested;

[0018] A cylinder is positioned above the fastening fixture, and the output end of the cylinder is connected to the fastening fixture. A tension sensor is installed at the connection point.

[0019] Furthermore, the fastening clamp includes:

[0020] The top plate, the tension sensor is disposed on the upper surface of the top plate, and the output end of the cylinder is connected to the tension sensor;

[0021] Two side panels are attached to the lower surface of the top panel and close to the left and right ends of the top panel;

[0022] The clamping plate is fixed to the inner surface of a side plate by a connecting rod;

[0023] The movable clamping plate has a screw hole on its other side plate. A screw is installed in the screw hole from the outside to the inside. The screw is threaded to the screw hole. One end of the screw is connected to the movable clamping plate, and the other end is provided with an operating rod. When the screw rotates, the movable clamping plate moves closer to or further away from the fixed clamping plate, and the rootstock of the plant to be tested can be clamped between the movable clamping plate and the fixed clamping plate.

[0024] Furthermore, the cylinder is fixed on a bracket, which is mounted on the ground.

[0025] This invention also provides a test method for testing the uplift resistance of plant roots, using test equipment for testing the uplift resistance of plant roots, including the following steps:

[0026] S1: Remove the plant to be tested from the soil without damage and place it in a moisturizing bag;

[0027] S2: Remove the plant to be tested from the moisturizing bag and place it in the transparent test chamber. Prepare transparent soil for testing the pull-out strength of the plant roots in the transparent test chamber. When the transparent soil for testing the pull-out strength of the plant roots solidifies, the roots of the plant to be tested are buried in the transparent soil for testing the pull-out strength of the plant roots.

[0028] S3: The rootstock of the plant to be tested is clamped between the movable clamp and the fixed clamp. The cylinder is activated and the plant to be tested is pulled upward. The root system image of the plant to be tested is captured by the camera, and the pulling force of the cylinder on the plant to be tested is monitored by the tension sensor. Both the camera and the tension sensor are equipped with a time recording module. The time point of root breakage of the plant is obtained by the root system image of the plant to be tested captured by the camera, and the corresponding tension at the time of breakage is obtained based on the time point of root breakage.

[0029] Furthermore, step S2 includes:

[0030] S201: Dry the silica particles at 110℃ to constant weight;

[0031] S202: Mix phenyl silicone oil with naphthalene bromide and degas under vacuum for 30 minutes to obtain a refractive liquid;

[0032] S203: After cooling the refracting liquid to 10°C, add silica particles, maintain the temperature at 10°C and stir continuously;

[0033] S204: Dimethylsiloxane prepolymer is mixed with crosslinking agent, 0.1% platinum catalyst is added, and after vacuum degassing, it is uniformly injected into the mixture obtained by S203 in the form of spray. At the same time, the temperature is raised to 25°C, and it is allowed to stand for 30 min for degassing and homogenization to obtain a flowing slurry.

[0034] S205: Clamp the rootstock of the plant to be tested between the movable clamp and the fixed clamp, vertically position the plant to be tested above the transparent test chamber and place its root system inside the transparent test chamber, inject the flowing slurry to submerge the root system of the plant to be tested, and maintain a vacuum of -0.08MPa for two hours to eliminate air bubbles.

[0035] S206: Maintain a static temperature of 25℃ for 12-24 hours to complete cross-linking and obtain transparent soil for testing the pull-out strength of plant roots. Under vacuum of -0.08MPa, add refracting liquid to the transparent soil for testing the pull-out strength of plant roots to fill the pores until no air bubbles escape.

[0036] Furthermore, in step S206, the volume of the added refractive liquid is no more than 5% of the total volume of the transparent soil used to test the uplift strength of the plant roots.

[0037] The present invention discloses the following technical effects:

[0038] 1. This invention uses transparent soil to simulate the binding and friction effect of real soil on plant roots. At the same time, it uses a transparent test chamber. Compared with the existing technology, it can clearly observe the breaking process of plant roots in the soil during the pulling process, and thus obtain the pulling force corresponding to the plant breakage, and effectively evaluate the pull-out strength of plant roots.

[0039] 2. After the plants are removed from the soil, they are placed in a transparent test chamber. Transparent soil is prepared inside the transparent test chamber. After the transparent soil solidifies, it can be formed as one with the plant roots. Therefore, it is not necessary to rebury the plants in the transparent soil. On the one hand, this can avoid damage to the plant roots and affect the test results. On the other hand, the transparent soil can naturally wrap the plant roots during the forming process, which can better simulate the effect of real soil on the plant roots and the friction, thus improving the accuracy of the test. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the fastening fixture structure;

[0043] The components include: 1. Transparent test chamber; 2. Tensile sensor; 3. Cylinder; 4. Top plate; 5. Side plate; 6. Fixed clamp; 7. Moving clamp; 8. Screw; 9. Operating rod; 10. Bracket; 11. Root system. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] like Figures 1 to 2As shown, this embodiment of the invention provides a transparent soil for testing the uplift resistance of plant roots, comprising:

[0047] Silica particles account for 55%–75% of the total volume;

[0048] The refractive liquid is composed of a mixture of phenyl silicone oil and brominated naphthalene, with a volume ratio of phenyl silicone oil to brominated naphthalene of 3:7–7:3, and the refractive liquid accounts for 20%–35% of the total volume.

[0049] The transparent elastic gel three-dimensional network, made by reacting dimethylsiloxane prepolymer with a crosslinking agent, accounts for 3%–10% of the total volume. The transparent elastic gel three-dimensional network binds silica particles and refractive liquid.

[0050] In this embodiment, the dimethylsiloxane prepolymer is vinyl-terminated polydimethylsiloxane, and the crosslinking agent is methyl hydrogen silicone oil.

[0051] In this embodiment, the mesh cross-sectional width of the transparent elastic gel three-dimensional network is 50-500nm, the refractive index is 1.405-1.408, the difference in refractive index between the network and the refractive liquid is ≤0.048, and the visible light transmittance is ≥85%.

[0052] like Figure 1 As shown, the present invention also provides a test apparatus for testing the pull-out resistance of plant roots, comprising:

[0053] Transparent test chamber 1, filled with transparent soil for testing the pull-out strength of plant roots, with the roots 11 of the plant to be tested buried in the transparent soil for testing the pull-out strength of plant roots;

[0054] A pulling mechanism is set above the transparent test chamber 1 and connected to the rootstock of the plant to be tested. The pulling mechanism can pull the plant to be tested upward.

[0055] A camera is positioned at the front of the transparent test chamber 1. During the process of the pulling mechanism pulling the plant to be tested upward, the camera acquires images of the root system 11 of the plant to be tested.

[0056] In this embodiment, the pulling mechanism includes:

[0057] Secure the clamp to the rootstock of the plant to be tested;

[0058] Cylinder 3 is positioned above the fastening fixture. The output end of cylinder 3 is connected to the fastening fixture, and a tension sensor 2 is installed at the connection point. The upper and lower surfaces of the tension sensor 2 can be connected to cylinder 3 and the fastening fixture respectively by bonding, or can be replaced with other existing fixed or detachable connection methods, which will not be elaborated here.

[0059] In other embodiments, cylinder 3 can be replaced with a more precise servo motor-screw structure, or it can be a continuously variable cylinder 3 controlled by a proportional valve or servo valve. Regardless of the drive structure used, the goal is to pull the plant under test at a uniform speed and stably.

[0060] In this embodiment, the fastening clamp includes:

[0061] Top plate 4, tension sensor 2 is set on the upper surface of top plate 4, and the output end of cylinder 3 is connected to tension sensor 2;

[0062] Two side plates 5 are connected to the lower surface of the top plate 4 and are close to the left and right ends of the top plate 4;

[0063] The fixed clamp 6 is fixed to the inner surface of a side plate 5 by a connecting rod;

[0064] The movable clamping plate 7 has a screw hole on its other side plate 5. A screw rod 8 is installed in the screw hole from the outside to the inside. The screw rod 8 is threadedly connected to the screw hole. One end of the screw rod 8 is connected to the movable clamping plate 7, and the other end is provided with an operating lever 9. When the screw rod 8 rotates, the movable clamping plate 7 moves closer to or further away from the fixed clamping plate 6, and the roots and stems of the plant to be tested can be clamped between the movable clamping plate 7 and the fixed clamping plate 6.

[0065] In this embodiment, the cylinder 3 is fixed on the bracket 10, and the bracket 10 is installed on the ground. The specific structure of the bracket 10 can adopt existing technology, as long as it can fix the cylinder 3 and stably arrange it on the ground.

[0066] This invention also provides a test method for testing the uplift resistance of plant roots, using test equipment for testing the uplift resistance of plant roots, including the following steps:

[0067] S1: Remove the plant to be tested from the soil without damage and place it in a moisturizing bag. In specific operation, you can first dig the soil near the soil depth with a shovel, and then remove the soil near the plant roots 11 with a small shovel. The remaining soil has very low adhesion to the plant roots 11, so it can be shaken off manually or carefully brushed off with a brush. The purpose of putting it in a moisturizing bag is to prevent the plant roots 11 from losing moisture, which is conducive to improving the accuracy of the test.

[0068] S2: Take the plant to be tested out of the moisturizing bag and place it in the transparent test chamber 1. Prepare transparent soil for testing the pull-out strength of the plant roots in the transparent test chamber 1. When the transparent soil for testing the pull-out strength of the plant roots solidifies, bury the roots 11 of the plant to be tested in the transparent soil for testing the pull-out strength of the plant roots.

[0069] S3: The rootstock of the plant to be tested is clamped between the movable clamp 7 and the fixed clamp 6. The cylinder 3 is activated and the plant to be tested is pulled upward. The root system 11 of the plant to be tested is captured by the camera. The pulling force of the cylinder 3 on the plant to be tested is monitored by the tension sensor 2. Both the camera and the tension sensor 2 are equipped with a time recording module. The time point of root system 11 breakage is obtained by the root system 11 image captured by the camera. The tension corresponding to the breakage is obtained based on the time point of root system 11 breakage.

[0070] In this embodiment, step S2 includes:

[0071] S201: Dry the silica particles at 110℃ to constant weight;

[0072] S202: Mix phenyl silicone oil with naphthalene bromide and degas under vacuum for 30 minutes to obtain a refractive liquid;

[0073] S203: After cooling the refracting liquid to 10°C, add silica particles, maintain the temperature at 10°C and stir continuously;

[0074] S204: Dimethylsiloxane prepolymer is mixed with crosslinking agent, 0.1% platinum catalyst is added, and after vacuum degassing, it is uniformly injected into the mixture obtained by S203 in the form of spray. At the same time, the temperature is raised to 25°C, and it is allowed to stand for 30 min for degassing and homogenization to obtain a flowing slurry.

[0075] S205: Clamp the rootstock of the plant to be tested between the movable clamp 7 and the fixed clamp 6, vertically position the plant to be tested above the transparent test chamber 1 and place its root system 11 inside the transparent test chamber 1, inject flowing slurry so that the flowing slurry submerges the root system 11 of the plant to be tested, and maintain a vacuum of -0.08MPa for two hours to eliminate air bubbles.

[0076] S206: Maintain a static temperature of 25℃ for 12-24 hours to complete cross-linking and obtain transparent soil for testing the pull-out strength of plant roots. Under vacuum of -0.08MPa, add refracting liquid to the transparent soil for testing the pull-out strength of plant roots to fill the pores until no air bubbles escape.

[0077] In this embodiment, the volume of the added refractive liquid is no more than 5% of the total volume of the transparent soil used to test the pull-out strength of the plant roots. The purpose of adding the refractive liquid is to completely fill the microbubbles and shrinkage pores generated during the cross-linking process, making the entire soil "glass-like transparent" again, while adjusting the refractive index to the design value. The added refractive liquid is relatively small compared to the total volume and will not affect the binding and friction effect of the transparent soil on the roots 11 of the plant under test.

[0078] In the above steps, a vacuum environment can be achieved through a sealed enclosure and a vacuum pump, and temperature regulation can be achieved by arranging a temperature control unit such as a heating wire inside the sealed enclosure. Alternatively, the above structure can be replaced with other existing structures, as long as a vacuum environment can be created and the temperature can be regulated; these will not be elaborated upon here.

[0079] During the preparation of transparent soil for testing the pull-out strength of plant roots, the temperature ranged from a maximum of 25℃ to a minimum of 10℃, which is consistent with the general growth environment temperature of plants and will not affect the pull-out strength of plant roots 11.

[0080] The direct shear test showed that the transparent soil prepared in this embodiment for testing the pull-out strength of plant roots had an internal friction angle ≤ ±2° and a cohesion ≤ ±1 kPa difference compared to natural soil. Therefore, the transparent soil for testing the pull-out strength of plant roots can fully simulate the binding and friction effects of real soil on plant roots 11.

[0081] The light transmittance test showed that the transparent soil prepared in this embodiment for testing the root pull-out strength of the plant had a light scattering loss of ≤5%, and the root system of the plant under test could be clearly captured by the camera.

[0082] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0083] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A transparent soil for testing the uplift resistance of plant roots, characterized in that, include: Silica particles account for 55%–75% of the total volume; The refractive liquid is composed of a mixture of phenyl silicone oil and brominated naphthalene, with a volume ratio of phenyl silicone oil to brominated naphthalene of 3:7–7:3, and the refractive liquid accounts for 20%–35% of the total volume. A transparent elastic gel three-dimensional network, made by reacting dimethylsiloxane prepolymer with a crosslinking agent, accounts for 3%-10% of the total volume. The transparent elastic gel three-dimensional network binds silica particles and refractive liquid.

2. The transparent soil for testing the uplift resistance of plant roots according to claim 1, characterized in that, The dimethylsiloxane prepolymer is vinyl-terminated polydimethylsiloxane, and the crosslinking agent is methyl hydrogen silicone oil.

3. The transparent soil for testing the uplift resistance of plant roots according to claim 2, characterized in that, The transparent elastic gel three-dimensional network has a mesh cross-sectional width of 50-500 nm, a refractive index of 1.405-1.408, a refractive index difference of ≤0.048 with that of the refractive liquid, and a visible light transmittance of ≥85%.

4. A testing device for testing the uplift resistance of plant roots, characterized in that, include: A transparent test chamber (1) is filled with transparent soil for testing the pull-out strength of plant roots as described in any one of claims 1-3, and the roots (11) of the plant to be tested are buried in the transparent soil for testing the pull-out strength of plant roots. A pulling mechanism is set above the transparent test chamber (1) and connected to the rootstock of the plant to be tested. The pulling mechanism is capable of pulling the plant to be tested upward. The camera is set at the front end of the transparent test chamber (1) and collects images of the root system (11) of the plant under test during the process of the pulling mechanism pulling the plant upward.

5. The testing equipment for testing the uplift resistance of plant roots according to claim 4, characterized in that, The pulling mechanism includes: Secure the clamp to the rootstock of the plant to be tested; A cylinder (3) is positioned above the fastening fixture. The output end of the cylinder (3) is connected to the fastening fixture, and a tension sensor (2) is provided at the connection point.

6. The testing equipment for testing the uplift resistance of plant roots according to claim 5, characterized in that, The fastening clamp includes: Top plate (4), the tension sensor (2) is disposed on the upper surface of the top plate (4), and the output end of the cylinder (3) is connected to the tension sensor (2); Two side plates (5) are connected to the lower surface of the top plate (4) and close to the left and right ends of the top plate (4); The fixed clamp (6) is fixed to the inner surface of a side plate (5) by a connecting rod; The movable clamping plate (7) has a screw hole on the other side plate (5). A screw rod (8) is installed in the screw hole from the outside to the inside. The screw rod (8) is threadedly connected to the screw hole. One end of the screw rod (8) is connected to the movable clamping plate (7), and the other end is provided with an operating rod (9). When the screw rod (8) rotates, the movable clamping plate (7) moves closer to or further away from the fixed clamping plate (6), and the rootstock of the plant to be tested can be clamped between the movable clamping plate (7) and the fixed clamping plate (6).

7. The testing equipment for testing the uplift resistance of plant roots according to claim 6, characterized in that, The cylinder (3) is fixed on the bracket (10), which is installed on the ground.

8. A test method for testing the uplift resistance of plant roots, characterized in that, The test equipment for testing the uplift resistance of plant roots as described in claim 7 includes the following steps: S1: Remove the plant to be tested from the soil without damage and place it in a moisturizing bag; S2: Take the plant to be tested out of the moisturizing bag and place it in the transparent test chamber (1). Prepare transparent soil for testing the pull-out strength of the plant roots in the transparent test chamber (1). When the transparent soil for testing the pull-out strength of the plant roots solidifies, the roots (11) of the plant to be tested are buried in the transparent soil for testing the pull-out strength of the plant roots. S3: The rootstock of the plant to be tested is clamped between the movable clamp (7) and the fixed clamp (6). The cylinder (3) is started and the plant to be tested is pulled upward. The root system (11) image of the plant to be tested is captured by the camera. The pulling force of the cylinder (3) on the plant to be tested is monitored by the tension sensor (2). Both the camera and the tension sensor (2) are equipped with a time recording module. The time point of the plant root system (11) breakage is obtained by the root system (11) image of the plant to be tested captured by the camera. The tension corresponding to the breakage is obtained according to the time point of the plant root system (11) breakage.

9. The test method for testing the uplift resistance of plant roots according to claim 8, characterized in that, Step S2 includes: S201: Dry the silica particles at 110℃ to constant weight; S202: Mix phenyl silicone oil with naphthalene bromide and degas under vacuum for 30 minutes to obtain a refractive liquid; S203: After cooling the refracting liquid to 10°C, add silica particles, maintain the temperature at 10°C and stir continuously; S204: Dimethylsiloxane prepolymer is mixed with crosslinking agent, 0.1% platinum catalyst is added, and after vacuum degassing, it is uniformly injected into the mixture obtained by S203 in the form of spray. At the same time, the temperature is raised to 25°C, and it is allowed to stand for 30 min for degassing and homogenization to obtain a flowing slurry. S205: Clamp the rootstock of the plant to be tested between the movable clamp (7) and the fixed clamp (6), vertically position the plant to be tested above the transparent test chamber (1) and place its root system (11) inside the transparent test chamber (1), inject flowing slurry so that the flowing slurry submerges the root system (11) of the plant to be tested, and maintain a vacuum of -0.08MPa for two hours to eliminate air bubbles; S206: Maintain a static temperature of 25℃ for 12-24 hours to complete cross-linking and obtain transparent soil for testing the pull-out strength of plant roots. Under vacuum of -0.08MPa, add refracting liquid to the transparent soil for testing the pull-out strength of plant roots to fill the pores until no air bubbles escape.

10. The test method for testing the uplift resistance of plant roots according to claim 9, characterized in that, In step S206, the volume of the added refractive liquid is no more than 5% of the total volume of the transparent soil used to test the uplift strength of plant roots.

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