Soil health evaluation method based on biological crust

Abstract

The invention relates to the technical field of ecological environment monitoring and evaluation, in particular to a soil health evaluation method based on biological crust, which comprises the following steps: collecting a plurality of primary environment biological crust samples for expanded culture, and planting the samples to soil with different grading health degrees for apparent state monitoring and microscopic index detection; characteristic indexes are screened out, and a soil health evaluation model is established; and planting the cultured biological crust on to-be-evaluated soil for monitoring, and performing soil health evaluation according to the constructed model. The biological crust of the primary environment is used for indicating the soil health, the cost is low, and the convenience is high; a soil health evaluation method suitable for a target environment can be developed in a targeted manner according to local conditions; the evaluation result is divided into rapid evaluation based on the apparent index and comprehensive evaluation based on the combination of the apparent index and the microscopic index, the evaluation method is more flexible, and the soil health evaluation result can be systematically reflected in multiple dimensions.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological environment monitoring and evaluation, and in particular to a soil health evaluation method based on biological crust. Background Art

[0002] In the field of soil health assessment, the traditional approach is to analyze soil physical, chemical, and biological indicators based on a large number of soil survey samples, combined with survey / investigation data such as crop productivity, ecological health, and runoff pollution risk in the corresponding sample area, and use a bottom-up or top-down approach to screen soil health assessment indicators and build a soil health assessment system to conduct soil health assessment.

[0003] However, the establishment of this soil health assessment method requires a large amount of soil field sampling and analysis work and paired crop, plant, soil animal and microorganism, runoff sampling and analysis work. The workload is huge, the sampling test is expensive, time-consuming and difficult, and the currently established soil health assessment methods often focus on farmland soil health assessment. The index system construction process focuses on incorporating fertility indicators related to crop productivity, which often fails to reflect the full picture of fertility attributes, ecological attributes and sustainable attributes involved in soil health. The high difficulty of establishing this soil health assessment system also makes it difficult to design targeted soil health assessment methods according to local conditions. Only by considering the use of other media that are easier to monitor and analyze (such as biological crusts) that can indicate soil health, and by combining a small amount of field sampling with indoor culture experiments to establish a method for soil health assessment with these media, can the goal of soil environmental and ecological health assessment be achieved at a low cost, in a targeted, more comprehensive and more convenient manner. Summary of the invention

[0004] In order to overcome the problems existing in the prior art, the present invention aims to provide a soil health assessment method based on biological crust.

[0005] To achieve the above object, the present invention provides the following technical solution: a soil health assessment method based on biological crust, comprising the following steps:

[0006] S1: In the target environment, collect several samples of native environmental biological crusts, expand and culture them, and then plant them on soils with different health levels. Monitor the surface state and detect microscopic indicators of the biological crusts on the soils with different health levels.

[0007] S2: Screen out characteristic indicators and establish a soil health evaluation model;

[0008] S3: Planting the cultivated biological crust on the soil to be evaluated, monitoring and analyzing characteristic indicators, and conducting soil health evaluation according to the soil health evaluation model.

[0009] The present invention is further configured as follows: Step S1 specifically comprises the following steps:

[0010] Based on the needs of soil health assessment, soil samples with different health levels are configured, and the soil physical, chemical, and biological indicators of soil samples with different health levels are measured in advance; the biological crusts obtained by expanded culture are colonized on soil samples with different health levels for cultivation tests; during the cultivation tests, the apparent state of the biological crusts is monitored and microscopic indicators are detected according to the needs of soil health assessment.

[0011] The present invention is further configured as follows: the duration of the culture test is 1-2 weeks.

[0012] The present invention is further configured as follows: the apparent state monitoring specifically includes observing whether the planted biological crusts show differences in apparent indicators on soils of different health levels after 3 days of the cultivation test, and recording the corresponding quantitative and qualitative data as a rapid evaluation indicator of soil health;

[0013] The appearance indicators include color, shape, area, roughness, etc.

[0014] The present invention is further configured as follows: the microscopic index detection is specifically to take samples of biological crusts on soils of different health levels after 1-2 weeks of the cultivation test, clean the attached soil, and then measure the microscopic indexes of the biological crusts according to the evaluation requirements;

[0015] The microscopic indicators include basic physical and chemical indicators, nutrient element content indicators, pollutant content indicators, enzymatic indicators and microbiological indicators.

[0016] The present invention is further configured as follows: the basic physical and chemical indicators include weight, humidity, salt content and pH value of the biological crust;

[0017] The nutrient element content indicators include carbon, nitrogen, phosphorus, sulfur content, etc.;

[0018] The pollutant content indicators include heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, plasticizers and perfluorinated pollutants;

[0019] The enzymatic indicators include catalase, phosphatase, amylase and cellulase, etc.;

[0020] The microbiological indicators include bacteria, fungi, archaea and viruses, etc.

[0021] It should be noted that the apparent indicators and micro indicators can be screened and supplemented according to the actual conditions of the native environment and the evaluation objectives, and are not limited to the contents listed in the present invention.

[0022] The present invention is further configured as follows: Step S2 specifically includes screening characteristic indicators among apparent indicators and micro indicators based on sensitivity, representativeness, interpretability, and operability; weighting the screened characteristic indicators using one or more indicator weighting methods to establish a soil health evaluation model based on biological crust.

[0023] Sensitivity refers to an indicator that can sensitively reflect the changes and intensity of land use, human disturbance processes and soil erosion processes. Representativeness refers to an indicator that the data in the biological crust has a good correlation with the corresponding soil data. Interpretability refers to an indicator whose indication effect on soil health is easy to clarify the cause and effect relationship; operability refers to an indicator whose measurement process is easy to operate and has low economic, time and labor costs.

[0024] Screen the sensitivity indicators and representative indicators among the apparent indicators and micro indicators, take the intersection of the sensitivity indicators and the representative indicators to continue screening the interpretability indicators and operability indicators; assign points to the screened operability indicators and interpretability indicators, and those with scores higher than the preset values ​​are used as the final characteristic indicators.

[0025] The present invention is further configured as follows: the index weighting method includes hierarchical analysis method, principal component analysis method and Delphi method, etc.

[0026] The present invention is further configured as follows: Step S3 specifically comprises: 2 Small pieces of the biocrust are planted on the soil to be evaluated. The cultivation period is 1-2 weeks. During the cultivation period, the apparent indicators of the biocrust are recorded every day and compared with the rapid evaluation indicators of soil health.

[0027] After the cultivation is completed, the biological crust samples are collected, the attached soil is cleaned, the characteristic indicators are analyzed, and a comprehensive soil health evaluation is performed based on the soil health evaluation model.

[0028] In summary, the beneficial effects of the above technical solution of the present invention are as follows:

[0029] 1. The present invention uses biological crust to indicate soil health, avoiding the cumbersome procedure of pre-treatment of soil samples and greatly reducing the sampling and testing costs of comprehensive soil health evaluation; and the method is simple and easy to implement.

[0030] 2. The present invention utilizes the biological crusts extracted and proliferated from the native environment to develop a soil health assessment method suitable for different targets and environments, which can solve the problem that traditional soil health assessment methods are difficult to conduct targeted assessments based on local conditions and needs.

[0031] 3. The soil health evaluation based on biological crust established in the present invention is divided into two parts: rapid evaluation of apparent indicators observation and comprehensive evaluation of microscopic indicators detection, which can reflect the results of soil health evaluation in a multi-dimensional and systematic manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0033] Figure 1 Flowchart of the soil health assessment method based on biological crust.

[0034] Figure 2 This is a technical roadmap for the soil health assessment method based on biological crust described in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention, taking the soil health evaluation of a typical facility farmland as an example. Based on the embodiments of the present invention, other similar embodiments such as farmland, woodland, grassland or contaminated sites obtained by ordinary technicians in this field without making any creative work should all fall within the scope of protection of the present invention.

[0036] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments.

[0037] Example:

[0038] like Figure 1-Figure 2 As shown in the figure, a preferred embodiment of the present invention is a soil health assessment method based on biological crust, which is characterized by comprising the following steps:

[0039] S1: In the target environment, collect several samples of native biological crusts, expand the biological crusts culture, and then plant them on soils with different health levels. Monitor the surface state and detect microscopic indicators of the biological crusts on the soils with different health levels.

[0040] S11: After removing debris and dust from several biocrust samples collected from a typical vegetable planting base, 1 cm 2 The small pieces of biological crusts are proliferated on several specific culture substrates. After the specific culture substrate suitable for the proliferation is determined, the substrate is used to expand the biological crusts in an incubator;

[0041] S12: Based on the needs of soil health assessment, four soil samples with different health levels of excellent, good, medium and poor are prepared, the soil physical, chemical and biological indicators of soil samples with different health levels are measured in advance, and the soil samples with different health levels are placed in beakers for later use;

[0042] S13: Cut the biological crust cultured in step S11 into 2 cm pieces 2 Small pieces of about 100 μm in diameter were planted on soil samples of different health levels and cultured in an incubator (25° C., 60% humidity); the culture test lasted for 1-2 weeks;

[0043] S14: During the incubation test, the apparent state of soil crust and microscopic index detection are carried out according to the needs of soil health assessment, and the apparent index and microscopic index detection standards are determined.

[0044] The apparent state monitoring specifically involves observing whether the colonized biological crusts show differences in apparent indicators such as color, area (proliferation size), roughness, etc. on soils of different health levels 3, 7, and 12 days after the incubation test, and recording the corresponding quantitative and qualitative data as a rapid evaluation indicator of soil health.

[0045] In this embodiment, at 3 days after planting, the differences of various apparent indicators in soils of different health grades were small. At 7 days after planting, the color of the biological crust planted in the excellent health soil was green, the area was slightly increased, and the roughness was not significantly different from the previous period; the color of the biological crust planted in the good health soil was dark green, the area was slightly increased, and the roughness was not significantly different from the previous period; the color of the biological crust planted in the medium health soil was dark green with a slightly purple-red color, and the area and roughness were not significantly different from the previous period; the color of the biological crust planted in the poor health soil was dark green with a slightly purple-red color, the area was slightly reduced, and the surface was rougher. After 12 days of planting, the biological crusts planted in the excellent health soil were green in color, with an increased area, and no significant difference in roughness compared with the previous period; the biological crusts planted in the good health soil were dark green with a slightly yellowish color, with a slightly increased area, and no significant difference in roughness compared with the previous period; the biological crusts planted in the medium health soil were dark green with a purple-red color, with no significant change in area, and a rougher surface; the biological crusts planted in the poor health soil were purple-red mixed with dark green in color, with a reduced area, and a rougher surface.

[0046] According to the observation results of the rapid evaluation indicators, in this embodiment, the color and proliferation area of ​​the biological crust are more suitable for rapid evaluation. The greener the color of the biological crust, the healthier the soil; the more purple or yellow the color, the lower the soil health. The larger the final proliferation area of ​​the biological crust, the higher the soil health.

[0047] The microscopic index detection is specifically as follows: after 1-2 weeks of cultivation, samples of biological crusts on soils of different health levels are taken, and after cleaning the attached soil, the basic physical and chemical indicators such as weight, humidity, salt content, pH value, etc. of the biological crusts are measured according to the evaluation requirements; the content indicators of nutrient elements such as carbon, nitrogen, phosphorus and sulfur; the content indicators of pollutants such as heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, plasticizers, perfluorinated compounds, etc.; the content of enzymatic indicators such as catalase, phosphatase, amylase, cellulase, etc.; and microbiological indicators such as bacteria, fungi, archaea, viruses, etc. are measured.

[0048] This example analyzes five basic physical and chemical indicators, including weight, humidity, chlorophyll, salt, and pH, of biological crusts; six nutrient element indicators, including total carbon, total nitrogen, total phosphorus, total sulfur, iron, and manganese; the total amount and effective state of 20 metal and metalloid indicators, including cadmium, chromium, copper, zinc, nickel, lead, mercury, arsenic, and selenium; pollutant indicators, including 14 polycyclic aromatic hydrocarbons, 7 polychlorinated biphenyls, 11 organochlorine pesticides, and 49 antibiotics; eight enzymatic indicators, including catalase, phosphatase, amylase, and cellulase; and microbial community diversity indicators, including bacteria, fungi, and archaea.

[0049] S2: Screen out characteristic indicators and establish a soil health evaluation model;

[0050] Based on sensitivity, representativeness, interpretability and operability, characteristic indicators among apparent indicators and micro-indicators were screened; one or more indicator weighting methods were used to weight the screened characteristic indicators, and a soil health assessment model based on biological crust was established.

[0051] Sensitivity refers to the ability of characteristic indicators to sensitively reflect the changes and intensities of land use, human disturbance processes and soil erosion processes. In this embodiment, a single-factor ANOVA comparative analysis was used to analyze the inter-group differences of the above indicators in different soil health classifications, and the indicators with significant differences were the sensitivity indicators.

[0052] Representativeness means that the data of the characteristic index in the biological crust has a good correlation with the corresponding soil data. In this embodiment, the Pearson correlation index is used to perform a correlation analysis between the measured values ​​of a certain index in the biological crust and the measured values ​​in soils of different health levels. The index with significant correlation (p<0.05) is the representative index.

[0053] The intersection of sensitivity indicators and representative indicators is taken to obtain the screened indicators for further screening of interpretability indicators and operability indicators.

[0054] Interpretability means that the indicative effect of the characteristic indicator on soil health is easy to clarify the cause and effect relationship. Operability means that the characteristic indicator measurement process is easy to operate, and the economic, time and labor costs of the measurement are low. In this embodiment, based on the questionnaire scores of 20 experts in related fields (0-100 points), the interpretability and operability of the initial screening indicators are scored, and the final scoring items with a single score of 75 points or more and an average score of 80 points or more are used as the final characteristic indicators. There are 6 characteristic indicators screened in this embodiment for constructing a soil health model based on biological crust, namely: weight, salt, total carbon, total phosphorus, available copper and catalase.

[0055] Based on the measured data, the membership degree of the six characteristic indicators was calculated, and then the range was normalized. In this embodiment, the principal component analysis method was combined with the Delphi method to perform weighting, and a soil health model based on biological crust was established.

[0056] The model established is:

[0057] Soil health index indicated by biological crust = weight*13.70+salt*15.65+total carbon*23.40+total phosphorus*12.33+available copper*15.25+catalase*19.67.

[0058] S3: Planting the cultivated biological crust on the soil to be evaluated, monitoring and analyzing characteristic indicators, and conducting soil health evaluation according to the soil health evaluation model.

[0059] The biological crust obtained by cultivation was 2 Small pieces of the biocrust are planted in the soil of the facility farmland to be evaluated. The cultivation period is 1-2 weeks. During the cultivation period, the apparent indicators of the biocrust are recorded every day, including color, area (proliferation size), and roughness. The recorded apparent indicators are compared with the rapid evaluation indicators of soil health to preliminarily determine the soil health status.

[0060] After the cultivation is completed, the biocrust samples are collected, and after cleaning the attached soil, the surface state monitoring indicators and microscopic indicators are analyzed, and a comprehensive soil health evaluation is performed based on the soil health evaluation model.

[0061] In this embodiment, six indicators, namely, weight, salt, total carbon, total phosphorus, available copper and catalase, of the biocrust are analyzed. After calculating the degree of membership, the established model is used to conduct a comprehensive evaluation of soil health.

[0062] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A soil health assessment method based on biological crust, characterized in that: The following steps are involved: S1: In the target environment, collect several samples of native environmental biological crusts, expand and culture them, and then plant them on soils with different health levels. Monitor the surface state and detect microscopic indicators of the biological crusts on the soils with different health levels. S2: Screen out characteristic indicators and establish a soil health evaluation model; S3: Planting the cultivated biological crust on the soil to be evaluated, monitoring and analyzing characteristic indicators, and conducting soil health evaluation according to the soil health evaluation model.

2. The soil health assessment method based on biological crust according to claim 1, characterized in that: In step S1, based on the needs of soil health assessment, soil samples with different health levels are configured, and the soil physical, chemical, and biological indicators of the soil samples with different health levels are measured in advance; the biological crust obtained by expanded culture is colonized on the soil samples with different health levels for cultivation tests; during the cultivation test, the surface state of the biological crust is monitored and the microscopic indicators are detected according to the needs of soil health assessment.

3. The soil health assessment method based on biological crust according to claim 2, characterized in that: The culture test lasts for 1-2 weeks.

4. The soil health assessment method based on biological crust according to claim 3 is characterized in that: The apparent state monitoring specifically includes observing whether the biocrusts planted on soils of different health levels show differences in apparent indicators 3 days after the incubation test, and recording the corresponding quantitative and qualitative data as a rapid evaluation indicator of soil health; The appearance indicators include color, shape, area and roughness.

5. The soil health assessment method based on biological crust according to claim 4, characterized in that: The microscopic index detection is specifically to take samples of biological crusts on soils of different health levels 1-2 weeks after the incubation test, clean the attached soil, and then measure the microscopic indexes of the biological crusts according to the evaluation requirements; The microscopic indicators include basic physical and chemical indicators, nutrient element content indicators, pollutant content indicators, enzymatic indicators and microbiological indicators.

6. The soil health assessment method based on biological crust according to claim 5, characterized in that: The basic physical and chemical indicators include weight, humidity, salt content and pH value of the biological crust; The nutrient element content indicators include carbon, nitrogen, phosphorus and sulfur content; The pollutant content indicators include heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, plasticizers and perfluorinated pollutants; The enzymatic indicators include catalase, phosphatase, amylase and cellulase; The microbiological indicators include bacteria, fungi, archaea and viruses.

7. The soil health assessment method based on biological crust according to claim 5, characterized in that: Step S2 specifically includes screening characteristic indicators among apparent indicators and micro indicators based on sensitivity, representativeness, interpretability and operability; weighting the screened characteristic indicators using one or more indicator weighting methods to establish a soil health assessment model based on biological crust.

8. The soil health assessment method based on biological crust according to claim 7, characterized in that: The index weighting method includes hierarchical analysis method, principal component analysis method and Delphi method.

9. The soil health assessment method based on biological crust according to claim 7, characterized in that: Step S3 specifically includes: 2 Small pieces of the biocrust are planted on the soil to be evaluated. The cultivation period is 1-2 weeks. During the cultivation period, the apparent indicators of the biocrust are recorded every day and compared with the rapid evaluation indicators of soil health. After the cultivation is completed, the biological crust samples are collected, the attached soil is cleaned, the characteristic indicators are analyzed, and a comprehensive soil health evaluation is performed based on the soil health evaluation model.

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