Soil remediation and microbiological detection system for agriculture

Abstract

The invention discloses a soil remediation and microbiological detection system for agriculture, and relates to the technical field of soil remediation, the system comprises the following components: a straw treatment and microbiological proliferation module, which is used for crushing straws obtained after crops are harvested to 5-10cm and mixing the crushed straws into a position with the depth of 10-20cm on the surface layer of soil; calculating and adding a proper amount of low-temperature cellulose degrading bacteria according to soil and straw conditions, and supplementing nutrient substances to proliferate in the soil; by accurately controlling straw in-situ field returning and microorganism adding, the soil fertility is effectively improved, the soil structure is improved, the content of organic matter and inorganic salt in the soil is increased by means of close combination of low-temperature cellulose degrading bacteria and straw, and by regulating nitrogenous fertilizer operation and applying a decomposition agent in a matched mode, the soil quality is improved. According to the method, the number of soil microorganisms and the population structure are optimized, the soil remediation effect and efficiency are remarkably improved, the problems that soil fertility is reduced and the structure is damaged are solved, and sustainable development of the agricultural ecological environment is further promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and particularly to a soil remediation and microorganism detection system for agriculture. Background Art

[0002] In agricultural production, soil quality plays a decisive role in the growth and yield of crops. As the basis for crop growth, the fertility, structure, and microbial ecological status of the soil directly affect the root development, nutrient absorption, and overall growth performance of crops. With the increasing intensification of agriculture, the problem of soil degradation has become increasingly serious, including the decline of soil fertility and the destruction of structure. These problems have greatly restricted the sustainable development of agriculture. Therefore, soil remediation and microbial ecological management have become important directions in modern agricultural research.

[0003] Traditional soil remediation technologies, such as straw in-situ returning technology, although can increase the content of soil organic matter and improve soil fertility to a certain extent, still have many deficiencies. In the traditional straw returning process, due to the lack of precise microbial addition and regulation measures, the proliferation effect of low-temperature cellulose-degrading bacteria is limited, and the improvement of soil organic matter and inorganic salt content is not obvious. In addition, different straw returning methods have significant differences in the impact on the rice-wheat rotation farmland ecosystem, but the existing regulation means lack scientific basis, resulting in the difficulty of accurately monitoring the changes in the number, population structure, and carbon source utilization ability of soil microorganisms. In terms of microorganism detection, traditional technologies have problems such as incomplete detection, inaccurate detection, and inability to monitor in real time, which are difficult to meet the in-depth requirements of modern agriculture for soil remediation and microbial ecological research. The existing detection methods usually only focus on a single microbial index or soil parameter, lacking a systematic detection scheme that comprehensively considers multiple indexes, resulting in insufficient understanding of the soil microbial ecology and affecting the formulation and implementation effect of soil remediation measures.

[0004] In view of the above problems, it is necessary to optimize the existing soil remediation and microorganism detection system. By precisely controlling straw in-situ returning and microbial addition, effective soil remediation can be achieved. At the same time, by comprehensively applying a variety of scientific methods, comprehensive and accurate detection and real-time monitoring of soil microorganisms can be carried out. Therefore, it is of great significance to develop a soil remediation and microorganism detection system for agriculture that can comprehensively achieve the above characteristics. Summary of the Invention

[0005] The purpose of the present invention is to make up for the deficiencies of the prior art and provide a soil remediation and microbial detection system for agriculture. It can achieve precise soil remediation by accurately controlling the in-situ return of straw to the field and the addition of microorganisms, effectively improving soil fertility and improving soil structure. At the same time, the system comprehensively uses a variety of scientific methods to conduct comprehensive and accurate detection and real-time monitoring of soil microorganisms, comprehensively considers multiple indicators, and can deeply understand the changes in soil microbial ecology. By analyzing and processing the detection data, a detailed soil microbial ecology report is generated, which provides a more scientific and comprehensive basis for the adjustment of soil remediation measures. In addition, the present invention can also optimize the return method according to different crop growth stages and soil fertility conditions, realize the rational use of resources, reduce the use of chemical fertilizers, reduce agricultural production costs, and reduce pollution to the environment. The present invention helps to achieve the sustainable development of the agricultural ecological environment, improve the yield and quality of crops, and ensure food security.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a soil remediation and microbial detection system for agriculture, the system comprising the following components:

[0007] Straw treatment and microbial proliferation module: crush the harvested crop straw into 5-10 cm and mix it into the soil surface 10-20 cm deep. According to the soil and straw conditions, calculate and add appropriate amount of low-temperature cellulose degrading bacteria, and supplement nutrients to make it proliferate in the soil;

[0008] Return to field control module: collects data related to farmland soil and crop growth, and formulates initial plans for returning straw to the field, nitrogen fertilizer management, and the application of composting agents based on the data. At the same time, during the crop growth period, the plan is adjusted in real time according to the monitoring results of soil nutrients and microbial indicators;

[0009] Soil microorganism detection module: Use multi-point sampling method to collect soil samples at different depths, and use a variety of scientific detection methods to detect crop yield, CH4 and N2O emissions, soil microbial properties, biomass, quantity and community diversity indicators, and generate soil microbial ecological reports through data analysis and processing;

[0010] Real-time monitoring and feedback control module: Use a variety of sensors and molecular biology technologies to collect real-time data on soil temperature, humidity, pH, nutrient content, and the number, type, and activity of microorganisms. After analysis and judgment by the central control system, feedback is given to abnormal situations based on preset thresholds, and other modules are adjusted to optimize the soil remediation process.

[0011] Furthermore, in the straw treatment and microbial proliferation module, an appropriate amount of low-temperature cellulose degrading bacteria is calculated and added according to the soil and straw conditions, and the calculation formula is: Among them, M is the application amount of the low-temperature cellulose-degrading bacteria, α is the adjustment coefficient determined according to the soil texture and historical data, S is the area of the target farmland, C is the dry weight of the straw per unit area, which is obtained by weighing the straw after harvest and calculating the farmland area, β is the influence coefficient of soil organic matter content on microbial activity, and the higher the soil organic matter content, the larger the value of this coefficient, N s is the content of available nitrogen in the current soil, which is obtained through soil nitrogen detection, N0 is the ideal nitrogen content required for the normal growth of the low-temperature cellulose-degrading bacteria, N m is the effective viable count of the low-temperature cellulose-degrading bacteria per unit mass.

[0012] Furthermore, the returning method regulation module collects data related to farmland soil and crop growth. Specifically, it collects data on the soil texture, fertility level, pH value, and porosity of the target farmland, and analyzes the relevant data and experience of previous straw returning, nitrogen fertilizer operation, and application of decomposing agents in this farmland or similar farmlands according to the growth stage characteristics of the planted crops, including the nutrient demand law and root growth status in different periods. According to the above data and analysis, an initial combination plan for straw returning, nitrogen fertilizer operation, and application of decomposing agents is formulated. During the crop growth period, the soil nutrient content, microbial quantity, and activity indicators are regularly monitored, and based on the monitoring results, the nitrogen fertilizer application amount and the ratio of the decomposing agent are adjusted.

[0013] Furthermore, the returning method regulation module adjusts the nitrogen fertilizer application amount and the ratio of the decomposing agent according to the monitoring results. The adjustment formula for the nitrogen fertilizer application amount is: Among them, ΔN is the adjustment value of the nitrogen fertilizer application amount. If it is a positive value, it means that the nitrogen fertilizer application amount needs to be increased; if it is a negative value, it means that the nitrogen fertilizer application amount needs to be decreased. N l is the theoretical nitrogen demand of the crop at a specific growth stage, N e is the content of nitrogen in the soil that can be absorbed and utilized by the crop, which is obtained through the detection and analysis of the nitrogen form and content in the soil. n is the number of types of straw returned to the field, α i is the nitrogen release coefficient of the i-th type of straw at this growth stage, which is determined according to the type of straw, soil environmental conditions, and the factor of the straw returning time. N si is the amount of nitrogen nutrient provided after the i-th type of straw is returned to the field.

[0014] Furthermore, the N si is the amount of nitrogen nutrient provided after the i-th type of straw is returned to the field, and its calculation formula is: N si =W i ×P i where, W i is the amount of the i-th type of straw returned to the field, and P i is the nitrogen content of the i-th type of straw.

[0015] Further, the tillage method regulation module adjusts the nitrogen fertilizer application rate and the proportion of the decomposer according to the monitoring results. The adjustment formula for the proportion of the decomposer is as follows: where C r is the proportion of the decomposer, γ is the comprehensive adjustment coefficient determined according to the local climate conditions, soil texture, and past practice experience of similar farmlands, S w is the straw returning amount per unit area, H is the current soil humidity, H0 is the ideal soil humidity for promoting straw decomposition determined according to the straw type and decomposition requirements, O s is the existing available organic matter content in the soil, O s0 is the target available organic matter content required for rapid straw decomposition, F a is the effective activity factor of the decomposer.

[0016] Furthermore, the soil microorganism detection module comprehensively uses a variety of scientific detection methods to detect crop yields, CH4 and N2O emissions, soil microorganism properties, biomass, quantity, and community diversity indicators. For crop yield detection, at the jointing stage, heading stage, and maturity stage of rice, 10 plants are randomly selected respectively, the above-ground parts are cut, washed, and dried, and then their biomass is measured. When the rice is mature, 50 panicles of rice are randomly harvested, threshed, cleaned, and dried, and then weighed to obtain the yield per unit area. For CH4 and N2O emissions, the static chamber-gas chromatography method is used. At 9:00 - 10:00 am every day, gas samples are collected using a static chamber made of stainless steel. Each time, 3 samples are collected at intervals of 20 minutes. The collected gas is injected into a gas storage cylinder, and a gas chromatograph is used to analyze the concentrations of CH4 and N2O. For soil microorganism property detection, soil urease activity is determined by the indophenol blue colorimetric method. A quantitative soil sample is incubated with a urea solution at 37°C for 24 hours for reaction, and the ammonia nitrogen content in the reaction product is measured by colorimetry to calculate the soil urease activity. Soil invertase activity is determined by the 3,5-dinitrosalicylic acid colorimetric method. After the soil sample reacts with a sucrose solution under specific conditions, it is colored with 3,5-dinitrosalicylic acid reagent, and the reducing sugar content is measured by colorimetry to obtain the soil invertase activity. For soil microorganism biomass detection, the chloroform fumigation extraction method is used. Two soil samples of the same mass are taken, one is fumigated with chloroform and the other is not treated. After fumigation, the soil is extracted with a 0.5 mol / L K2SO4 solution, and the carbon and nitrogen contents in the extract are measured. The difference between the fumigated and non-fumigated soil samples is calculated, and the soil microorganism biomass carbon and nitrogen contents are obtained by combining with the coefficient. For microorganism quantity detection, soil DNA is extracted using a kit method, PCR amplification is carried out with specific primers for the target microorganism, the amplified product is cut and recovered by gel electrophoresis, an enzyme-linked reaction is carried out, competent cells are prepared, the enzyme-linked product is introduced, the plasmid is extracted and its concentration is measured, and the gene copy number is calculated according to the formula to determine the microorganism quantity. For microorganism community diversity detection: the soil sample is made into a suspension of appropriate concentration and inoculated into the micro-wells of a Biolog-ECO plate, and cultured at 28°C for about 120 hours. The absorbance value of the micro-wells at a wavelength of 590 nm is measured every 24 hours. By processing and calculating the data, the AWCD value, Shannon index, Simpson index, and McIntosh index are obtained to evaluate the microorganism community diversity.

[0017] Furthermore, in the soil microorganism detection module, for soil microorganism biomass detection, the carbon and nitrogen contents in the extract are measured, the difference between the fumigated and non-fumigated soil samples is calculated, and the soil microorganism biomass carbon and nitrogen contents are obtained by combining with the coefficient. For the carbon content, its calculation formula is: Among them, SMBC is the soil microorganism biomass carbon content, indicating the total amount of organic carbon contained in microorganisms in the soil, k cis the conversion coefficient, which is used to convert the difference in organic carbon between fumigated and non - fumigated soil samples into microbial biomass carbon, E c is the content of organic carbon in the chloroform - fumigated soil extract, which is obtained by measuring the carbon content of the soil extract after fumigation. E0 is the content of organic carbon in the non - fumigated soil extract, which is obtained by measuring the carbon content of the non - fumigated soil extract. R is the actual metabolic rate of microorganisms in the current soil, which is obtained through the monitoring and analysis of soil microbial respiration indicators and reflects the activity intensity of microorganisms in the current soil environment. R0 is the basic metabolic rate of microorganisms under standard conditions, which is determined according to the types and characteristics of microorganisms and ideal soil environmental conditions. Similarly, the nitrogen content can be calculated.

[0018] Furthermore, in the soil microorganism detection module, for the detection of microbial community diversity, by processing and calculating data, the AWCD value, Shannon index, Simpson index, and McIntosh index are obtained. The AWCD value is: where A i is the relative absorbance of the i - th well, and A Al is the relative absorbance of the Al well. For the Shannon index, its formula is: H′ = -∑P i ·ln(P i ), where P i is the ratio of the relative absorbance value of the i - th well to the total relative absorbance value of the entire plate. For the Simpson index, its calculation formula is: D = 1 - ∑(P j ), 2 where P j is the ratio of the relative absorbance value of the j - th well to the total relative absorbance value of the entire plate. For the McIntosh index, its calculation formula is: where n i is the relative absorbance value of the i - th well.

[0019] Compared with the prior art, the soil remediation and microorganism detection system for agriculture has the following

[0020] beneficial effects:

[0021] First, by precisely controlling straw in - situ return and microorganism addition, the present invention effectively improves soil fertility, improves soil structure, uses the tight combination of low - temperature cellulose - degrading bacteria and straw to increase soil organic matter and inorganic salt content, and optimizes the quantity and population structure of soil microorganisms by regulating nitrogen fertilizer operation and applying decomposing agents, significantly enhancing the effect and efficiency of soil remediation. It not only solves the problems of soil fertility decline and structure damage but also promotes the sustainable development of the agricultural ecological environment.

[0022] II. The present invention comprehensively and accurately detects and real - time monitors soil microorganisms by applying a variety of scientific methods. It comprehensively considers multiple indicators such as crop yield, greenhouse gas emissions, soil microbial properties, biomass, quantity, and community diversity. By real - time monitoring soil environmental parameters and the dynamic changes of microorganisms, and generating a detailed soil microbial ecological report, it provides a scientific basis for the adjustment of soil remediation measures, helps to deeply understand the changes in soil microbial ecology, optimize soil remediation measures, realize the rational use of resources, reduce the amount of chemical fertilizers used, lower agricultural production costs, and at the same time reduce environmental pollution.

[0023] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of a soil remediation and microorganism detection system for agriculture;

[0026] Figure 2 It is a flowchart of a soil remediation and microorganism detection system for agriculture. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention objective, the following will, in combination with the accompanying drawings and preferred embodiments, detail the specific embodiments, structures, features, and their effects of the present invention as follows.

[0028] Embodiment 1

[0029] Using the grid sampling method, 30 sampling points were selected in the farmland, and soil samples at depths of 0-20 cm and 20-40 cm were collected. After testing and analysis, the soil pH value was 4.8, showing strong acidity, the organic matter content was 1.0%, far lower than that of high-quality paddy soil (generally between 2.5% and 3.5%), the total nitrogen content was 0.10%, the available phosphorus content was 8 mg / kg, and the available potassium content was 60 mg / kg, all at relatively low levels. The soil porosity was 32%, with poor air permeability and water permeability, seriously affecting the absorption of nutrients and oxygen by rice roots. The main rice variety planted in the local area of crop cultivation was in the initial tillering stage after transplantation. Through field measurement and observation, the average plant height of the rice was 10 cm, significantly shorter than the normal plant height (about 15 cm), and the average number of tillers per plant was only 1, while under normal circumstances, each plant should have 3-4 tillers. Some plant leaves were yellow, showing symptoms of nutrient deficiency. Microbial detection was carried out on the collected soil samples, and the real-time fluorescence quantitative PCR technology was used to detect the numbers of bacteria, fungi, and actinomycetes in the soil. It was found that the number of bacteria was 1.0×10 8 CFU / g of soil, the number of fungi was 5.0×10 5 CFU / g of soil, and the number of actinomycetes was 2.0×10 6 CFU / g of soil, all lower than the microbial quantity levels of local healthy paddy soil. The Biolog-ECO plate was used to analyze the metabolic functional characteristics of the soil microbial community. The calculated average well color development (AWCD) value was 0.3, the Shannon index was 2.0, the Simpson index was 0.6, and the McIntosh index was 1.5, indicating a relatively low diversity of the soil microbial community. In addition, the chloroform fumigation extraction method was used to determine that the soil microbial biomass carbon content was 80 mg / kg and the biomass nitrogen content was 10 mg / kg, both at relatively low levels. In the past, most of the crop straw in this farmland was burned or discarded randomly, without being fully returned to the field for utilization. Moreover, the amount of nitrogen fertilizer applied was large and the fertilization period was unreasonable, resulting in low nitrogen fertilizer utilization rate and causing certain pollution to the surrounding water bodies. Referring to the research results and practical experience of the local agricultural scientific research department, this rice variety has an urgent need for nutrients such as nitrogen and phosphorus at the initial tillering stage, and the suitable soil pH value is between 6.0 and 7.0. The activity of soil microorganisms is crucial for nutrient transformation and rice growth.

[0030] To improve soil fertility and structure, it was decided to completely crush and return the straw of the previous season's rice to the field, with an estimated return amount of 2.5 tons per mu. By increasing the amount of straw returned to the field, the soil organic matter was supplemented, the soil porosity was increased, and the soil air permeability and water permeability were improved, creating a good environment for the growth of rice roots.

[0031] Based on the nitrogen demand characteristics of rice at the initial tillering stage and the existing nitrogen content in the soil, using the formula where N tBased on the nitrogen requirement model of this rice variety at the early tillering stage and the target yield, it is determined that the nitrogen requirement is 10 kg / mu, N e After testing, the existing nitrogen content in the soil that can be absorbed and utilized by crops is 2 kg / mu, n = 1 (the type of returned straw is rice straw), and α1 is determined to be 0.3 according to previous experiments and experience (the nitrogen release coefficient of rice straw at this stage). W1 is the amount of straw returned to the field at 2500 kg / mu, and P1 is the nitrogen content of rice straw detected to be 0.6%. Then Therefore, ΔN = 10 - 2 - 4.5 = 3.5 kg / mu. The original plan was to apply 35 kg of urea (nitrogen content 46%) per mu, and the nitrogen content was 35×46% = 16.1 kg. Now, according to the calculation, the nitrogen application rate per mu is adjusted to about 3.5 kg, which is converted to about 3.5÷46%≈7.6 kg of urea. Considering the actual situation, it is adjusted to 18 kg per mu. The ratio of basal fertilizer to top dressing is adjusted to 7:3. The basal fertilizer is applied before transplanting, and the top dressing is carried out at the early tillering stage. At the same time, to adjust the soil pH, 50 kg of lime is applied per mu.

[0032] Taking into account the amount of straw returned to the field, soil humidity (the soil humidity at that time was 48%, slightly dry), soil organic matter content, and the effective activity factor of the decomposer 0.8, according to the formula where γ is determined to be 1.0 according to the local climate and soil texture, S w is the amount of straw returned to the field per unit area at 2.5 tons / mu, H is the current soil humidity at 48%, H0 is the ideal soil humidity for promoting straw decomposition at 60%, O s is the existing available organic matter content in the soil at 1.0%, O s0 is the target available organic matter content required to meet the rapid decomposition of straw at 2.0%, F a is the effective activity factor of the decomposer at 0.8. The calculation shows that It is determined that the ratio of the decomposer is 2.8 kg of decomposer added per 1 ton of straw per treatment. At the same time, the irrigation amount is appropriately increased to promote the rapid decomposition of straw.

[0033] Use professional straw crushing equipment to crush the straw to a length of 5-10 cm, evenly spread it in the field, turn the straw into the soil through deep plowing, accurately apply urea according to the adjusted nitrogen fertilizer application rate and ratio, and evenly spread lime before transplanting. Thoroughly mix the decomposer with the straw, and evenly spread low-temperature cellulose-degrading bacteria. During the growth process of rice, collect soil samples every 10 days to monitor soil nutrient content, microbial quantity and population structure, soil enzyme activity and other indicators, and at the same time observe the growth status of rice. In terms of microbial detection, real-time fluorescence quantitative PCR technology monitoring shows that the numbers of bacteria, fungi and actinomycetes in the soil begin to increase 15 days after straw returning to the field, and the numbers of beneficial bacteria such as Bacillus subtilis increase significantly. Biolog-ECO plate analysis shows that the AWCD value gradually rises, and the Shannon index, Simpson index and McIntosh index also increase, and the diversity of the soil microbial community increases. The soil microbial biomass carbon content and biomass nitrogen content measured by the chloroform fumigation extraction method gradually increase. At the same time, the activities of soil urease and sucrase increase, the tiller number of rice increases, reaching 3 per plant on average, and the plant height growth accelerates.

[0034] During the booting stage of rice, it is monitored that the available potassium content in the soil drops to 40 mg / kg, which affects the differentiation of young panicles. At the same time, microbial detection shows that the growth of some beneficial microorganisms slows down.

[0035] Immediately adjust the plan, top-dress 12 kg of potassium sulfate per mu, and at the same time supplement 1 kg of low-temperature cellulose-degrading bacteria again. Continuously monitor in the follow-up. The rice grows normally, and the final yield increases by 20% compared with the previous year. The soil pH value rises to 5.8, the organic matter content increases to 1.5%, the soil porosity increases to 38%, the soil microbial activity is significantly enhanced, and the number of beneficial microorganisms increases significantly.

[0036] Example 2

[0037] There is a 60-acre wheat planting field in a plain area in the north. The soil is neutral sandy loam. Due to continuous wheat cropping for many years and over-reliance on chemical fertilizers, the soil microbial community structure is single, the number of beneficial microorganisms decreases, the wheat root system develops poorly, and diseases such as root rot and sheath blight are prone to occur, and the wheat yield is seriously affected. In the past, the average wheat yield per mu of this farmland was about 380 kg, and the yield reduction due to diseases was about 15%.

[0038] Through the grid distribution method, 40 sampling points were set up in the farmland, and soil samples at a depth of 0-20 cm and 20-40 cm were collected. The test results showed that the soil pH value was 7.0, which was neutral, the organic matter content was 2.0%, which was at a medium level, the total nitrogen content was 0.14%, the effective phosphorus content was 18 mg / kg, the quick-acting potassium content was 110 mg / kg, the soil porosity was 46%, and the air permeability was good, but the water and fertilizer retention capacity was weak. In addition, the content of trace elements such as zinc and boron in the soil was low. The crops planted were local high-yield winter wheat varieties, which were in the jointing stage. Field observations and measurements found that some wheat plants had thin stems, with an average plant height of 28 cm, which was lower than the normal plant height (about 35 cm), and an average of 2 tillers per plant, which was less than the normal 3-4. The leaves were light green, and some plants showed mild root rot symptoms at the roots.

[0039] The collected soil samples were tested for microorganisms, and the real-time fluorescence quantitative PCR technology showed that the number of bacteria in the soil was 1.2×10 8 / g soil, the number of fungi is 6.0×10 5 / gram of soil, the number of actinomycetes is 2.5×10 6 The number of beneficial microorganisms symbiotic with plant roots was relatively small. The AWCD value was 0.35, the Shannon index was 2.2, the Simpson index was 0.65, and the McIntosh index was 1.8 using the Biolog-ECO plate analysis, indicating that the diversity of soil microbial communities needs to be improved. The soil microbial biomass carbon content was 100 mg / kg and the biomass nitrogen content was 12 mg / kg determined by the chloroform fumigation extraction method, both of which were at a medium to low level. In the past, the amount of straw returned to the farmland was very small, the amount of nitrogen fertilizer applied was large and lacked scientific planning. Referring to the experience and related research of the local agricultural technology extension station, this variety of wheat has a large demand for nutrients such as nitrogen, phosphorus, and potassium during the jointing stage, and sufficient trace elements are essential to improving wheat stress resistance and yield quality. At the same time, rich soil microbial communities help inhibit the occurrence of diseases.

[0040] After the wheat was harvested last season, all the straw was crushed and returned to the fields. It is estimated that the amount returned per mu will reach 1.8 tons to increase soil organic matter and improve soil water and fertilizer retention capacity. The amount of nitrogen fertilizer applied is adjusted according to the nitrogen requirement of wheat during the jointing period and the existing nitrogen content in the soil. The original plan was to apply 28 kg of urea (nitrogen content 46%) per mu, but it is now adjusted to 22 kg per mu. The ratio of base fertilizer and topdressing is adjusted to 4:6. Base fertilizer is applied before sowing, and topdressing is applied twice at the beginning of jointing. Combined with the amount of straw returned to the field, soil moisture (the soil moisture was 50% at the time, which was suitable), soil organic matter content and the effective activity factor of the composting agent of 0.85, the composting agent ratio was determined to be 2.2 kg of composting agent for every ton of straw treated.

[0041] Use straw crushing machinery to crush straw to 5 - 10 cm, evenly spread it in the field and deeply plow the field. Apply urea accurately according to the adjusted nitrogen fertilizer application rate and ratio, and at the same time apply trace elements in the base fertilizer. Thoroughly mix the composting agent with the straw and evenly spread low-temperature cellulose-degrading bacteria.

[0042] During the wheat growth period, collect soil samples for testing every 10 days, and at the same time closely observe the wheat growth status. Microbial detection shows that the real-time fluorescence quantitative PCR technology monitors that the numbers of bacteria, fungi and actinomycetes in the soil gradually increase, especially the numbers of beneficial microorganisms such as rhizobia and Trichoderma increase significantly. The Biolog-ECO plate analysis shows that the AWCD value gradually rises, and the Shannon index, Simpson index and McIntosh index increase, and the soil microbial community diversity increases. The soil microbial biomass carbon content and biomass nitrogen content measured by the chloroform fumigation extraction method increase, and the activities of soil urease and sucrase increase. The wheat stalks become thicker, the leaf color becomes darker, the tiller number increases to an average of 3 per plant, the plant height grows to the normal level, and the incidence of diseases such as root rot significantly decreases.

[0043] During the wheat filling period, it is monitored that the available phosphorus content in the soil drops to 12 mg / kg, which affects the grain filling. At the same time, microbial detection finds that the activities of some beneficial microorganisms decline. The plan is adjusted in time, 6 kg of potassium dihydrogen phosphate is top-dressed per mu, and 1 kg of microbial activator is supplemented at the same time. Continuous monitoring is carried out subsequently. The wheat fills grains normally, and the final yield increases by 16% compared with the previous year, reaching 441 kg per mu. The soil organic matter content increases to 2.4%, the soil microbial community structure is more abundant, the number of beneficial microorganisms increases significantly, and the soil water and fertilizer retention capacity is further improved.

[0044] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A soil remediation and microbial detection system for agriculture, characterized in that: The system consists of the following components: Straw treatment and microbial proliferation module: crush the harvested crop straw into 5-10 cm and mix it into the soil surface 10-20 cm deep. According to the soil and straw conditions, calculate and add appropriate amount of low-temperature cellulose degrading bacteria, and supplement nutrients to make it proliferate in the soil; Return to field control module: collects data related to farmland soil and crop growth, and formulates initial plans for returning straw to the field, nitrogen fertilizer management, and the application of composting agents based on the data. At the same time, during the crop growth period, the plan is adjusted in real time according to the monitoring results of soil nutrients and microbial indicators; Soil microorganism detection module: Use multi-point sampling method to collect soil samples at different depths, and use a variety of scientific detection methods to detect crop yield, CH4 and N2O emissions, soil microbial properties, biomass, quantity and community diversity indicators, and generate soil microbial ecological reports through data analysis and processing; Real-time monitoring and feedback control module: Use a variety of sensors and molecular biology technologies to collect real-time data on soil temperature, humidity, pH, nutrient content, and the number, type, and activity of microorganisms. After analysis and judgment by the central control system, feedback is given to abnormal situations based on preset thresholds, and other modules are adjusted to optimize the soil remediation process.

2. The soil remediation and microbial detection system for agriculture according to claim 1, characterized in that: In the straw treatment and microbial proliferation module, an appropriate amount of low-temperature cellulose degrading bacteria is calculated and added according to the soil and straw conditions, and the calculation formula is: Where M is the amount of low-temperature cellulose-degrading bacteria released, α is the adjustment coefficient determined based on soil texture and historical data, S is the area of ​​the target farmland, C is the dry weight of straw per unit area, which is calculated by weighing the harvested straw and the area of ​​farmland, β is the influence coefficient of soil organic matter content on microbial activity. The higher the soil organic matter content, the larger the value of this coefficient. N s It is the content of available nitrogen in the soil, obtained through soil nitrogen detection. N0 is the ideal nitrogen content required for the normal growth of low-temperature cellulose-degrading bacteria. m It is the effective number of viable bacteria per unit mass of low-temperature cellulose-degrading bacteria.

3. The soil remediation and microbial detection system for agriculture according to claim 1, characterized in that: The returning to field mode control module collects data related to farmland soil and crop growth. Specifically, it collects soil texture, fertility level, pH and porosity data of the target farmland. According to the growth stage characteristics of the crops planted, including the nutrient demand patterns and root growth conditions in different periods, the module analyzes the relevant data and experience of the previous straw returning, nitrogen fertilizer management and application of composting agents of the farmland or similar farmlands. Based on the above data and analysis, an initial combination plan of straw returning, nitrogen fertilizer management and application of composting agents is formulated. During the growth period of crops, the soil nutrient content, microbial quantity and activity indicators are regularly monitored. According to the monitoring results, the amount of nitrogen fertilizer and the ratio of composting agents are adjusted.

4. The soil remediation and microbial detection system for agriculture according to claim 3, characterized in that: The field return mode control module adjusts the nitrogen fertilizer dosage and the composting agent ratio according to the monitoring results, and the nitrogen fertilizer dosage adjustment formula is: Among them, ΔN is the adjustment value of nitrogen fertilizer application. If it is a positive value, it means that the nitrogen fertilizer application needs to be increased, and if it is a negative value, it means that the nitrogen fertilizer application needs to be reduced. l is the theoretical nitrogen requirement of crops at a specific growth stage, N e is the existing nitrogen content in the soil that can be absorbed and utilized by crops, which is obtained by detecting and analyzing the form and content of soil nitrogen. n is the number of types of straw returned to the field, and α i is the nitrogen release coefficient of the i-th straw at this growth stage, which is determined according to the type of straw, soil environmental conditions and the time of returning to the field. si is the nitrogen nutrition that can be provided after the i-th type of straw is returned to the field.

5. The soil remediation and microbial detection system for agriculture according to claim 4, characterized in that: The N si is the nitrogen nutrition that can be provided after the i-th type of straw is returned to the field, and its calculation formula is: Among them, W i is the amount of straw returned to the field of the i-th type, P i is the nitrogen content of the i-th type of straw.

6. The soil remediation and microbial detection system for agriculture according to claim 3, characterized in that: The field return mode control module adjusts the nitrogen fertilizer dosage and the composting agent ratio according to the monitoring results, and the adjustment formula of the composting agent ratio is: Among them, C r is the ratio of the composting agent, γ is the comprehensive adjustment coefficient, which is determined according to the local climate conditions, soil texture and past practical experience of similar farmlands, and S w is the amount of straw returned per unit area, H is the current soil moisture, H0 is the ideal soil moisture for promoting straw decomposition, which is determined according to the type of straw and the requirements for decomposition, and O s is the available organic matter content in the soil, O s0 The target available organic matter content required for rapid straw decomposition is F a It is the effective active factor of the composting agent.

7. The soil remediation and microbial detection system for agriculture according to claim 1, characterized in that: The soil microorganism detection module uses a variety of scientific detection methods to detect crop yield, CH4 and N2O emissions, soil microbial properties, biomass, quantity and community diversity indicators. For crop yield detection, 10 plants are randomly selected at the jointing stage, heading stage and maturity stage of rice, and the aboveground parts are cut off, washed and dried before measuring their biomass. When the rice is mature, 50 ears of rice are randomly harvested, threshed, cleaned and dried before weighing to obtain the yield per unit area. For CH4 and N2O emissions, static dark box-gas chromatography is used. Every morning from 9:00 to 10:00 am, the aboveground parts are cut off, and the aboveground parts are washed and dried before measuring their biomass. When the rice is mature, 50 ears of rice are randomly harvested, threshed, cleaned and dried before weighing to obtain the yield per unit area. For CH4 and N2O emissions, static dark box-gas chromatography is used. , gas samples were collected using a stainless steel static box, 3 times each time with an interval of 20 minutes, the collected gas was injected into the gas cylinder, and the CH4 and N2O concentrations were analyzed using a gas chromatograph. For the detection of soil microbial properties, soil urease activity was determined using the indigo blue colorimetric method. Quantitative soil samples were cultured with urea solution at a constant temperature of 37°C for 24 hours for reaction. The ammonia nitrogen content in the reaction product was measured by colorimetry to calculate the soil urease activity. Soil sucrase activity was determined using the 3,5-dinitrosalicylic acid colorimetric method. After the soil sample reacted with sucrose solution under specific conditions, 3,5-dinitrosalicylic acid was used to measure the activity of soil urease. The acid reagent was used for color development, and the reducing sugar content was measured colorimetrically to obtain the soil sucrase activity. For the detection of soil microbial biomass, the chloroform fumigation extraction method was used. Two soil samples of the same mass were taken, one for chloroform fumigation and the other for non-treatment. After fumigation, the soil was extracted with a 0.5 mol / L K2SO4 solution, and the carbon and nitrogen contents in the extract were measured. The difference between the fumigated and unfumigated soil samples was calculated, and the soil microbial biomass carbon and nitrogen contents were obtained by combining the coefficients. For the detection of microbial quantity, the soil DNA was extracted using the kit method, and PCR amplification was performed for the specific primers of the target microorganisms, and the amplification products were cut and recovered. Perform enzyme-linked reaction, prepare competent cells, introduce enzyme-linked products, extract plasmids and measure concentrations, calculate gene copy numbers according to the formula, and determine the number of microorganisms. For microbial community diversity detection: make soil samples into a suspension of appropriate concentration, inoculate them into the microwells of the Biolog-ECO plate, and culture them at 28°C for about 120 hours. Measure the absorbance of the microwells at a wavelength of 590nm every 24 hours. By processing and calculating the data, obtain the AWCD value, Shannon index, Simpson index and Mcintosh index to evaluate the diversity of the microbial community.

8. The soil remediation and microbial detection system for agriculture according to claim 7, characterized in that: In the soil microbial detection module, for soil microbial biomass detection, the carbon and nitrogen contents in the extract are measured, the difference between fumigated and unfumigated soil samples is calculated, and the soil microbial biomass carbon and nitrogen contents are obtained by combining the coefficients. For the carbon content, the calculation formula is: Among them, SMBC is the soil microbial biomass carbon content, which indicates the total amount of organic carbon contained in the microorganisms in the soil, k c is the conversion factor used to convert the difference in organic carbon between fumigated and unfumigated soil samples into microbial biomass carbon, E c It is the content of organic carbon in the chloroform fumigated soil extract, which is obtained by measuring the carbon content of the soil extract after fumigation. E0 is the content of organic carbon in the unfumigated soil extract, which is obtained by measuring the carbon content of the unfumigated soil extract. R is the actual metabolic rate of microorganisms in the current soil, which is obtained by monitoring and analyzing the soil microbial respiration indicators, reflecting the activity intensity of microorganisms in the current soil environment. R0 is the basal metabolic rate of microorganisms under standard conditions, which is determined according to the type and characteristics of the microorganisms and the ideal soil environmental conditions. The nitrogen content can be calculated in the same way.

9. The soil remediation and microbial detection system for agriculture according to claim 7, characterized in that: In the soil microorganism detection module, for the detection of microbial community diversity, the AWCD value, Shannon index, Simpson index and Mcintosh index are obtained by processing and calculating data. The AWCD value is: Among them A i is the relative absorbance of the ith well, A Al is the relative absorbance of Al pores. For Shannon index, the formula is: H′=-∑P i ·ln(P i ), where P i The ratio of the relative absorbance value of the ith well to the total relative absorbance value of the entire plate. For the Simpson index, the calculation formula is: D = 1-∑(P j ) 2 , where P j is the ratio of the relative absorbance value of the jth well to the total relative absorbance value of the entire plate. For the McIntosh index, the calculation formula is: where n i is the relative absorbance value of the ith well.

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