Combined mesh bag device for evaluating decomposition function of different types of soil food webs

Abstract

The invention provides a combined mesh bag device for evaluating the decomposition function of different types of soil food webs. The combined mesh bag device comprises a first mesh bag, a second mesh bag, a third mesh bag and a fourth mesh bag, the mesh holes are 0.02 mm, 0.75 mm, 3mm and 5mm respectively, the first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag are arranged into a square combined mesh bag, and the first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag in the square combined mesh bag are fixedly connected through buffer strips among the mesh bags. The square combined mesh bag provides microorganisms for researching different types of soil food webs, 0.02 mm, fungi and bacteria; the thickness is 0.75 mm, and soil nematode food webs and microorganisms are added; 3 mm, a soil micro arthropod food web, a soil nematode food web and microorganisms; the method is a novel method for driving litter decomposition through a soil large-scale'nutrient whale 'food web, a soil micro arthropod food web, a soil nematode food web and microorganisms, quantitative evaluation of the decomposition function of the soil food web is achieved, and the method is efficient and practical.

Description

Technical Field

[0001] The invention belongs to the technical field of soil ecology, and in particular relates to a combined net bag device for evaluating the decomposition function of food webs of different types of soils. Background Art

[0002] Litter decomposition is a key biogeochemical process in ecosystems and the initial step in soil nutrient turnover. This process is regulated by organisms at multiple trophic levels within the soil food web. Soil organisms of varying sizes, including large, medium, and small invertebrates and microorganisms, work synergistically to influence litter decomposition and nutrient cycling. Based on organism size characteristics and trophic relationships, the soil food web can be divided into four major categories: large soil "trophic whale" food webs represented by earthworms, ants, etc.; a soil microarthropod food web dominated by springtails and mites; Soil nematode food web dominated by nematodes and protozoa; A microbial community composed of fungi, bacteria, etc.

[0003] These different types of soil food webs play different roles in litter decomposition through differentiated decomposition mechanisms.

[0004] However, the single-pore mesh bag method used in traditional litter decomposition research, such as the 0.02 mm mesh bag, has significant limitations: on the one hand, it can only reflect the decomposition effect of soil organisms of a specific size; on the other hand, it is difficult to quantitatively evaluate the functional contributions of different types of soil food webs.

[0005] Based on this, the present invention proposes a combined net bag device for evaluating the decomposition function of different types of soil food webs, and quantitatively evaluates the contribution of different types of soil food webs to litter decomposition through the gradient elimination method. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a combined net bag device for evaluating the decomposition function of different types of soil food webs, so as to solve the problems raised in the above-mentioned background technology.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a combined net bag device for evaluating the decomposition function of different types of soil food webs, comprising a first net bag, a second net bag, a third net bag and a fourth net bag; The mesh aperture of the first mesh bag is 0.02 mm, the mesh aperture of the second mesh bag is 0.75 mm, the mesh aperture of the third mesh bag is 3 mm, and the mesh aperture of the fourth mesh bag is 5 mm. The first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag are arranged into a square combination mesh bag, and the first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag are fixedly connected by a buffer belt between the mesh bags in the square combination mesh bag.

[0008] As a further illustration of the present invention, the square combination mesh bag is provided with sealing zippers on the outside of the first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag, and the first mesh bag, the second mesh bag, the third mesh bag and the fourth mesh bag can be opened or closed by the sealing zippers.

[0009] As a further illustration of the present invention, the size of the square combined mesh bag is 25 cm*21 cm, and the width of the buffer zone between the mesh bags is 1 cm.

[0010] As a further illustration of the present invention, rivets are provided at the four end corners and the middle of the square combination mesh bag, and the square combination mesh bag can be fixed to the surface of the soil under test through the rivets.

[0011] As a further illustration of the present invention, a pressing sheet is sleeved on the rivet, and the pressing sheet is made of a hard PVC sheet.

[0012] Compared with the prior art, the present invention has the following advantages: The present invention combines four mesh bags with pore sizes of 0.02 mm, 0.75 mm, 3 mm, and 5 mm to form a square combination mesh bag with a length of 25 cm and a width of 21 cm. This provides a new method for studying different types of soil food webs: 0.02 mm, microorganisms composed of fungi and bacteria; 0.75 mm, soil nematode food web + microorganisms; 3 mm, soil micro-arthropod food web + soil nematode food web + microorganisms; 5 mm, soil large "nutritional whale" food web + soil micro-arthropod food web + soil nematode food web + microorganisms driving litter decomposition, realizing the quantitative evaluation of the decomposition function of the soil food web, which is efficient and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a top view of the overall structure of the present invention; Figure 2 This is a graph showing the effect of the amount of organic fertilizer applied on the contribution of the soil "trophic whale" animal food web and the soil microarthropod food web to driving straw decomposition in Experimental Example 1 of the present invention; No organic fertilizer was applied, and the amount of organic fertilizer applied was 0 tons / hectare; 30 tons / hectare, the amount of organic fertilizer applied is 30 tons / hectare; 45 tons / hectare, the amount of organic fertilizer applied is 45 tons / hectare; Description of reference numerals: 1-first mesh bag; 2-second mesh bag; 3-third mesh bag; 4-fourth mesh bag; 5-rivet; 6-pressing sheet; 7-buffer strip between mesh bags; 8-sealing zipper. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] like Figure 1 As shown, the present invention provides a technical solution: a combined net bag device for evaluating the decomposition function of different types of soil food webs, comprising a first net bag 1, a second net bag 2, a third net bag 3 and a fourth net bag 4; The mesh size of the first mesh bag 1 is 0.02 mm, which only allows microorganisms composed of fungi and bacteria to enter the mesh bag and participate in the decomposition of litter.

[0016] The mesh size of the second mesh bag 2 is 0.75 mm. In addition to the mesh bag 1, the second mesh bag 2 allows nematodes and protozoa in the soil nematode food web to enter the mesh bag and participate in the decomposition of litter.

[0017] The mesh size of the third mesh bag 3 is 3 mm. In addition to the mesh bag 2, it allows springtails, mites, etc. in the soil micro-arthropod net to enter the mesh bag and participate in the decomposition of litter.

[0018] The mesh size of the fourth mesh bag 4 is 5 mm. In addition to the mesh bag 3, it allows earthworms, ants and the like in the soil's large "nutrient whale" food web to enter the mesh bag and participate in the decomposition of litter.

[0019] The first mesh bag 1 , the second mesh bag 2 , the third mesh bag 3 and the fourth mesh bag 4 are arranged into a square combined mesh bag, and the size of the square combined mesh bag is 25 cm*21 cm.

[0020] In the square combined mesh bag, the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4 are fixedly connected by a buffer belt 7 between the mesh bags. The width of the buffer belt 7 between the mesh bags is 1 cm.

[0021] The square combination mesh bag is provided with a sealing zipper 8 on the outside of the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4, and the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4 can be opened or closed through the sealing zipper 8.

[0022] Rivets 5 are provided at the four corners and the middle of the square combination mesh bag, and the square combination mesh bag can be fixed to the soil to be evaluated through the rivets 5. In order to improve the stability of the installation of the directional combination mesh bag, a pressing sheet 6 is sleeved on the rivet 5, and the pressing sheet 6 is made of a hard PVC sheet.

[0023] During specific use, first fix the square combination mesh bag in the corresponding site to be evaluated, then open the sealing zippers 8 on the outside of the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4 respectively, and put 10 g of litter dried to a constant weight into the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4 respectively, and then close the sealing zippers 8 on the outside of the first mesh bag 1, the second mesh bag 2, the third mesh bag 3 and the fourth mesh bag 4 respectively.

[0024] After the preset decomposition time t, the square combination net bag is taken back, and the remaining litter in the first net bag 1, the second net bag 2, the third net bag 3 and the fourth net bag 4 in the square combination net bag is washed with distilled water and dried at 65℃ to constant weight. The litter decomposition rate k (year -1 ): M0: initial mass of litter, g; Mt: residual mass of litter, g; t: decomposition time, year.

[0025] The contribution of soil macrotrophic whales, soil microarthropods, and soil nematodes to litter decomposition was calculated using the following formula: Contribution 土壤大型"营养鲸”食物网= (1- k 3mm / k 5mm ) × 100% Contribution 土壤微型节肢动物食物网= (1-k0.75mm / k 3mm ) × 100% Contribution 土壤线虫食物网 = (1- k 0.02mm / k 0.75mm ) × 100% Among them, k 5mm 、k 3mm、k 0.75mm 、k 0.02mm Corresponding to the decomposition rates of litter in mesh bags with pore sizes of 5 mm, 3 mm, 0.75 mm, and 0.02 mm, respectively.

[0026] This will enable quantitative assessment of the contribution of different food web types to litter decomposition, using a gradient in mesh bag aperture to quantitatively calculate their contribution. This will advance research on the mechanisms of the relationship between soil biodiversity and ecosystem function, parameter optimization of nutrient cycling models under the context of global change, and the development of ecological restoration technologies based on the regulation of key functional groups.

[0027] Experimental Example 1: Based on a long-term fertilization location experiment in the dryland area of ​​the Loess Plateau, a combination of mesh bags with pore sizes of 0.02 mm, 3 mm, and 5 mm were used to explore how different organic fertilizer application rates (no organic fertilizer, 30 tons / hectare, and 45 tons / hectare) affect the contribution of different types of soil food webs to straw decomposition. The results are as follows: Figure 2 As shown; The results showed that under high organic fertilizer application, the contribution of the soil large "nutrient whale" food web to straw decomposition was significantly lower than 76% and 40% of the control group and 30 tons / hectare application rate; however, the contribution of the soil micro-arthropod food web to straw decomposition was not significant under different organic fertilizer application rates.

[0028] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0029] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A combined mesh bag device for evaluating the decomposition function of different types of soil food webs, characterized by: It comprises a first mesh bag (1), a second mesh bag (2), a third mesh bag (3) and a fourth mesh bag (4); The mesh aperture of the first mesh bag (1) is 0.02 mm, the mesh aperture of the second mesh bag (2) is 0.75 mm, the mesh aperture of the third mesh bag (3) is 3 mm, and the mesh aperture of the fourth mesh bag (4) is 5 mm. The first mesh bag (1), the second mesh bag (2), the third mesh bag (3) and the fourth mesh bag (4) are arranged to form a square combined mesh bag. Inside the square combined mesh bag, the first mesh bag (1), the second mesh bag (2), the third mesh bag (3) and the fourth mesh bag (4) are fixedly connected via a buffer zone (7) between mesh bags.

2. A combined net bag device for evaluating the decomposition function of different types of soil food webs according to claim 1, characterized in that: The square combined mesh bag is provided with sealing zippers (8) on the outer sides of the first mesh bag (1), the second mesh bag (2), the third mesh bag (3) and the fourth mesh bag (4), and the first mesh bag (1), the second mesh bag (2), the third mesh bag (3) and the fourth mesh bag (4) can be opened or closed by the sealing zippers (8).

3. The combined net bag device for evaluating the decomposition function of different types of soil food webs according to claim 1, characterized in that: The size of the square combined mesh bag is 25 cm*21 cm, and the width of the buffer zone (7) between the mesh bags is 1 cm.

4. The combined net bag device for evaluating the decomposition function of different types of soil food webs according to claim 1, characterized in that: Rivets (5) are provided at the four end corners and the middle of the square combined mesh bag, and the square combined mesh bag can be fixed to the surface layer of the test soil via the rivets (5).

5. The combined net bag device for evaluating the decomposition function of different types of soil food webs according to claim 4, characterized in that: A pressing sheet (6) is sleeved on the rivet (5), and the pressing sheet (6) is made of a hard PVC sheet.

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