220 results about "Soil nitrogen" patented technology

The invention discloses a karst underground river system multi-source pollution comprehensive quantitative traceability method, which comprises the following steps: S1, multi-dimensional sample collection and new pollutant screening: carrying out multi-period sampling on a water body, measuring conventional water quality indexes and nitrogen and oxygen isotopes, screening new pollutants, and carrying out targeted quantification on characteristic new pollutants; s2, principal component analysis dimension reduction and pollution factor identification: carrying out principal component analysis on conventional indexes and new pollutant data, extracting principal components of which the cumulative contribution rate exceeds 85%, identifying composite pollution factors, and eliminating secondary interference factors; s3, nitrogen and oxygen isotope auxiliary verification and denitrification elimination: eliminating denitrification interference by utilizing the ratio of delta 15N-NO3 <-> to delta 18O-NO3 <-> in combination with underground water burial depth and runoff velocity, and distinguishing the nitrate source as a chemical fertilizer, soil nitrogen or sewage and wastewater; and S4, PMF model optimization and pollution source quantification: inputting the conventional indexes and the new pollutant concentration matrix into a PMF model, and analyzing the contribution rate of each pollution source.

The invention belongs to the technical field of data processing, and particularly relates to a rice field soil emission reduction potential estimation method and system based on carbon-nitrogen coupling and a medium, and the method comprises the steps: collecting rice field nitrogen application information in a target area through literature statistics, dividing rice fields with similar nitrogen application into the same type, and selecting a plurality of typical areas from each type; carrying out soil sampling at fixed intervals in the typical rice field area, analyzing the nitrogen concentration level of the soil, and obtaining representative samples; performing soil column experimental simulation by using the representative sample, and estimating the average emission of specific gas; and determining significant influence factors, setting different carbon-nitrogen coupling situations to carry out an orthogonal simulation experiment, quantifying factor importance, carrying out weighted accumulation to obtain a comprehensive emission estimation value, and evaluating the carbon-nitrogen coupling-based biochar rice field emission reduction capability. The method can effectively estimate the rice field soil emission reduction potential.

According to the rice field methane emission prediction method based on the CH4MN model, the influence of the rice field methane emission microorganism process and soil nitrogen is considered, the uncertainty of simulation is reduced, and rice field methane emission is accurately predicted. Comprising the following steps: S1, acquiring rice field agricultural production input, water management measures, meteorological data, observed rice field soil environment information, rice information and microorganism information as input data of a CH4MN model; s2, based on a CH4MN model algorithm, calculating a substrate source and a soil environment required by methane generation, and the influence of soil nitrogen on organic matter decomposition; s3, calculating the influence of soil oxidation reduction potential, microorganisms and rice plants on methane generation and oxidation based on a CH4MN model algorithm; s4, calculating a methane generation rate and an emission rate based on a CH4MN model algorithm by using the methane generation and oxidation influence factors calculated in the step S1-3; and S5, verifying the CH4MN model precision based on point observation information.

Disclosed are a maize on-demand fertilization control system and a soil nitrogen soft measurement method. Sensors transmit real-time data to a control unit, which calculates soil nitrogen content using an optimized BP neural network model. Based on maize's nitrogen demand, the system adjusts fertilization amounts using solenoid valves, achieving precise, cost-effective fertilization.

The invention relates to the technical field of intelligent water and fertilizer analysis, in particular to an intelligent water and fertilizer analysis method and system based on farmland regional crop yield increase. The method comprises the following steps: acquiring structure data of a farmland area and extracting the flow direction of irrigation water, deploying a sensor to monitor the farmland state, and generating farmland state data of an irrigation basin; crop form images are collected through electronic monitoring equipment and water flow direction data, the leaf yellowing and curling degree is evaluated, and the soil volume moisture saturation is extracted. According to the soil moisture data, nutrient element content change is extracted, the nutrient leaching loss gradient is quantified, and soil nitrogen circulation abnormity is further simulated; and finally, performing intelligent water and fertilizer dosage controlled release analysis on the leaf yellowing and curling degree based on the nitrogen circulation abnormal data, and sending a result to a terminal to improve the per unit area yield of crops. The water and fertilizer intelligent analysis technology is optimized, so that the water and fertilizer intelligent analysis technology is more perfect.

The invention discloses a strain of bacillus acidophilus CNBG-PGPR-17 and an application of the bacillus acidophilus CNBG-PGPR-17. The invention further discloses a preparation method of the bacillus acidophilus CNBG-PGPR-17. The strain is preserved in the China General Microbiological Culture Collection Center (CGMCC) on October 28, 2021, the preservation number is CGMCC No.23673, and the strain is classified and named as bacillus acidogenes (Bacillus acidogenes). The strain is high in growth speed, good in stability and easy to amplify and culture; the inorganic phosphorus dissolving capacity is high, and the inorganic phosphorus dissolving amount can reach 277.8 mg / kg 7 days after inoculation; small molecular organic acids such as lactic acid and succinic acid can be secreted, and the pH of the solution is reduced; the contents of soil organic matters, soil total nitrogen, available phosphorus and quick-acting potassium can be increased, and the pH value of the soil is reduced; the growth of blueberry seedlings is promoted, and the blueberry quality is improved.

The invention provides a tobacco area nitrogen management and efficiency evaluation system, which comprises a data acquisition module for acquiring meteorological data, soil nitrogen data, crop growth data and historical fertilization data in real time; the data preprocessing module is used for carrying out noise filtering, space-time alignment and multi-source data fusion; the dynamic nitrogen prediction module is coupled with the soil nitrogen migration and crop absorption model to generate a prediction value; the optimization decision module is used for generating an application strategy based on a dynamic programming algorithm and calculating the optimal application amount and the fertilization time; the efficiency evaluation module is used for calculating nitrogen utilization efficiency (NUE) and environmental benefit index (EBI) by combining the application amount, the environmental loss amount and the crop yield; the self-adaptive feedback module is used for dynamically correcting prediction model parameters according to the deviation degree of the NUE and the EBI; and the visual output module is used for generating a multi-dimensional evaluation report and a fertilization decision map. The nitrogen utilization efficiency and the environmental benefit index can be improved, the environmental risk is reduced, and the tobacco yield and quality are improved.

The invention discloses a soil nitrogen leaching capacity monitoring method based on a frequency domain reflectometry, and relates to the technical field of soil water environment monitoring, in particular to a nitrogen leaching online monitoring method based on the frequency domain reflectometry (FDR), the Darcy law and a Van Genuchten (VG) model. And a monitoring method with high precision and sensitivity, multi-parameter synchronous detection and low cost is provided for the soil nitrogen leaching capacity. Comprising the following steps: 1, collecting and pretreating a soil sample; 2, placing the treated soil sample in a soil experiment cylinder; 3, inserting the multi-parameter sensors into the soil experiment cylinder in a layered manner; 4, 1000 ml of water is injected, and data acquisition is carried out; and 5, realizing soil nitrogen leaching capacity monitoring in combination with a Darcy law and a VG model.

The invention provides a regional soil quality improvement method based on a crop rotation mode, and relates to the technical field of soil quality optimization, and the method comprises the following steps: S1, establishment of the crop rotation mode: establishing a crop rotation system with leguminous forage grass and gramineous crops as cores in a target area, the leguminous forage grass being medicago sativa, the gramineous crops being corn, and the gramineous crops being corn; a carousel or intercropping mode is adopted, the carousel mode is a period of 2-3 years, alfalfa is planted in the first year to the second year, and corn is planted in the third year; according to the intercropping mode, the corn and the alfalfa are planted according to the row ratio of 2: 1-3: 1, the row spacing of the corn ranges from 60 cm to 70 cm, and the row spacing of the alfalfa ranges from 30 cm to 35 cm. According to the method, alternate sowing and intercropping of the medicago sativa and the corn are combined, symbiotic nitrogen fixation of rhizobium of the medicago sativa and absorption of deep potassium by deep root systems are utilized, surface nutrients are utilized in cooperation with shallow root systems of the corn, a layered nutrient utilization mechanism of shallow nitrogen fixation and deep potassium release is formed, and compared with a traditional single cropping mode, the soil improvement quality is improved; the problems of regional surface soil nitrogen loss and low deep nutrient utilization rate are solved.

The invention discloses an autotrophic nitrogen fixation Klebsiella strain with antimony oxidation and growth promoting capabilities and application thereof. The strain is different from traditional heterotrophic nitrogen-fixing bacteria depending on an organic carbon source, nitrogen fixation can be carried out by taking carbon dioxide as a main carbon source under an oligotrophic condition, Sb (III) oxidation is taken as a main energy acquisition way, autotrophic metabolism is realized, and plant growth can also be promoted. Through identification, Sb (III) can be oxidized into Sb (V) in three days in a high-antimony environment, and the oxidation rate reaches 89.11 (mu mol / L / day); the activity of nitrogenase is greater than or equal to 167.4 (nmolC2H2 / (g.h)). The strain has unique advantages in the field of in-situ remediation of antimony-polluted tailings and other oligotrophic matrixes, and can synchronously realize multiple effects of antimony pollution treatment, soil nitrogen supply and quality improvement. The strain is safe to human and livestock, has no environmental pollution problem, is simple in culture condition and easy to preserve, and has good development and application prospects.

The invention relates to the technical field of tobacco production, and discloses a tobacco nitrogen fertilizer application method based on ion sensing, and the method comprises the following steps: soil foundation determination; applying a base fertilizer; transplanting and fertilizing; field topdressing; fertilizing in a vigorous growth period; management after fertilization: the nitrogen content of the soil is measured again 7-10 days after each time of topdressing, the fertilization frequency and dosage are adjusted according to monitoring data, stable nitrogen supply of the tobacco is ensured, and tobacco reviving or nitrogen fertilizer waste caused by excessive fertilization is avoided. By monitoring nitrogen ions in soil in real time, application of the nitrogen fertilizer is accurately regulated and controlled, the utilization efficiency of the fertilizer is improved, and tobacco growth is optimized. The precise fertilization method based on the ion selective electrode technology aims at solving the problems that in traditional fertilization, the nitrogen fertilizer dosage is difficult to precisely control, waste is caused, and tobacco leaves turn green. By monitoring the soil nitrogen ion concentration in real time and adjusting the fertilization amount according to the growth stage, the nitrogen fertilizer utilization efficiency is improved, the environmental pollution is reduced, the tobacco growth environment is optimized, and the tobacco yield and quality are improved.

The invention relates to a method for improving soil fertility and enzyme activity of a rice field by using a nitrogen-fixing cyanobacteria biological membrane, which comprises the following steps: step 1, expanding propagation of nitrogen-fixing cyanobacteria: selecting anabaena globifera as a rice field application algae species, and performing expanding culture on the algae species to obtain a nitrogen-fixing cyanobacteria secondary algae species; step 2, applying nitrogen-fixing cyanobacteria: applying the nitrogen-fixing cyanobacteria in a rice base fertilizer period and a tillering period, and replacing part of chemical fertilizer with the nitrogen-fixing cyanobacteria to reduce the application amount of the chemical fertilizer; secondly, the nitrogen-fixing cyanobacteria returns to the rice field through biological nitrogen fixation and rotting decomposition of dead algae, the content of nitrogen and carbon in the soil is increased, the soil fertility is improved, and the nitrogen-fixing cyanobacteria can provide nutrient substances for microorganisms in the soil, improve the enzyme activity of the soil and improve the quality of the soil when applied to the rice field.

The invention provides a microorganism synergistic nitrogen fixation fertilizer based on flavone induction and a preparation method thereof, and belongs to the technical field of agricultural fertilizers. The fertilizer induces the formation of an azotobacter biofilm through a flavonoid compound, promotes the colonization and nitrogen fixation of rhizosphere azotobacter, improves the nitrogen supply capability of soil, and reduces the dependence on chemical nitrogen fertilizer. The fertilizer comprises the following components: 5-15% of a flavone extract, 3-8% of an azotobacter, 20-30% of an organic carrier, 30-40% of an inorganic nutrient medium and 5-15% of a filler. The preparation method comprises the following steps: mixing the organic carrier and the inorganic nutrient substrate, adding the filling agent, granulating, adding the nitrogen-fixing bacterial agent and the flavone extract to form a composite liquid, spraying the composite liquid, drying and packaging. Compared with the prior art, the fertilizer disclosed by the invention has the advantages of remarkably improving the nitrogen fixation efficiency, reducing the use of chemical nitrogen fertilizer, enhancing the slow release performance, improving the fertilizer utilization rate, improving the soil ecological environment and promoting the healthy growth of plants. The method is simple, efficient and suitable for large-scale production and application.

The invention relates to a strawberry greenhouse digital twinning system based on YOLOv10 and a decision tree algorithm and a management method, and belongs to the technical field of automatic cultivation. The environment detection system comprises an air temperature and humidity sensor, a soil temperature and humidity sensor, a soil nitrogen, phosphorus and potassium content detection sensor and a camera which are arranged in a greenhouse, the camera is used for detecting the growth condition of crops, the environment detection system communicates with the switch through an RS485 bus for data transmission, and the control system comprises a PC terminal. A production control algorithm based on YOLOv10 and a decision-making tree algorithm is arranged in the PC terminal, and the decision-making tree evaluates the health state and demand of strawberry growth in real time according to multi-dimensional data such as soil temperature and humidity, air temperature and humidity, illumination intensity and the like in combination with the characteristics of the strawberry growth stage, so as to determine whether watering and fertilization are needed or not; when the fertilizer needs to be watered, the watering and fertilizing time is calculated by utilizing a designed linear weighted sum formula, so that the effect of accurate watering and fertilizing is realized.

The invention discloses a soil-vegetation collaborative ecological restoration method aiming at a shrub invaded wetland, which comprises the following steps of: performing targeted restoration on key factors of soil by designing a fish-scale pit and a composite water-retaining matrix and a layered pH regulation method, controlling the water content and the pH of the soil at a certain level, and performing vegetation reconstruction. High-leaf-area (LA) type plants, high-specific-leaf-area (SLA) type plants and deep-root-system plants are planted in a matched mode, leaf dry matter accumulation is reduced through the canopy complementary effect, and the soil nitrogen conversion efficiency is improved through rhizosphere collaborative design; and finally, the intelligent control system performs long-term monitoring and feedback regulation on the soil condition, so that the maintenance energy consumption is reduced. According to the method, long-acting recovery of the degraded wetland is realized through a closed-loop system of soil matrix improvement, vegetation function configuration and feedback maintenance.

The present invention discloses a method for assessing nitrogen emissions from farmland soil at a regional scale based on transfer learning, the method comprising: obtaining existing farmland soil nitrogen, nitric oxide and nitrous oxide data, and constructing an emission database; establishing a coupled domain adaptive and random forest regression model based on the data in the emission database; adjusting the parameters of the random forest model using farmland soil nitrogen emission observation data, and optimizing the random forest model; using the optimized model to perform global farmland emission prediction on farmland soil nitrogen data, and obtaining a regional scale farmland soil nitrogen emission assessment result. The present invention uses field measured data of nitrous oxide and nitric oxide, which have the same production pathway as nitrogen, to construct a random forest model, and based on transfer learning technology and ideas, uses limited nitrogen field observation data to calibrate the constructed model to meet the needs of large-scale assessment of farmland soil nitrogen emissions, thereby achieving farmland soil nitrogen emission assessment.

The invention provides a method and system for calculating the utilization rate of soil nitrogen under the action of arbuscular mycorrhiza, and relates to the technical field of calculation of the utilization rate of soil nitrogen under the action of arbuscular mycorrhiza. Soil nitrogen absorption amount data of an experimental group and a control group are collected, meanwhile, the total amount of externally input nitrogen is recorded, and related photosynthetic parameters of plants are measured; in addition, through an in-vitro mycelium culture experiment, mycelium nitrogen absorption rates under different nitrogen concentrations are measured, and a semi-saturation constant and a nitrogen effectiveness index are calculated, so that a carbon-nitrogen coupling factor is calculated, morphological parameters of mycelia are collected, and a relation equation of a pipe diameter and a transport rate is established; calculating the total flux of the hypha network, calculating the original nitrogen utilization rate in combination with the nitrogen absorption amount difference value of the experimental group and the control group and externally input nitrogen data, and introducing a transportation continuity coefficient for dynamic correction to finally obtain the soil nitrogen utilization rate of the target area.

The invention belongs to the technical field of soil improvement, and particularly relates to a soil activation method. The soil activation method comprises the step of applying a Govff soil antidote into soil, wherein the Govff soil antidote comprises Govff soil antidote granules, Govff soil antidote powder and a Govff soil antidote aqueous solution. The invention solves the problems of reduced physical and chemical properties of soil, reduced grape quality and the like caused by the input and retention of major elements of nitrogen, phosphorus and potassium in the soil in the current Xichang Clenon grape cultivation process, and can improve the resistance of grape vines, promote the germination, flowering and fruit setting of grapes, enhance the root growth, enhance the root activity, increase the thickness and flexibility of leaves and improve the yield of the grapes. Meanwhile, the proportion of beneficial bacteria in soil is increased, soil micro-ecological balance is restored, the yield of grapes is increased, grape fruit cracking is reduced, the influence of grapes on resisting diseases, drought and other adverse environments is increased, and guarantee is provided for yield increase.

The invention relates to the technical field of microorganisms and particularly discloses paenibacillus mucilaginosus as well as a microbial agent and application thereof. The preservation number of the paenibacillus mucilaginosus N-002 is CGMCC (China General Microbiological Culture Collection Center) No.32752, and the preservation number of the paenibacillus mucilaginosus N-002 is CGMCC No.32752. The paenibacillus mucilaginosus N-002 provided by the invention can produce a urease inhibitor and indoleacetic acid at high yield and has no denitrification effect, the urease inhibitor produced by the paenibacillus mucilaginosus N-002 can reduce the urease activity of soil, significantly reduce the ammonia emission and nitrous oxide emission of the soil, especially after a nitrogen fertilizer is applied, is beneficial to soil nitrogen element maintenance, improves the fertilizer efficiency of the nitrogen fertilizer, and has a good application prospect. Meanwhile, the influence of emission of ammonia and nitrous oxide on the environment is reduced; the strain has no denitrification effect, and can increase the proportion of non-denitrifying bacteria in soil and reduce the denitrification effect of the soil after being applied to the soil, so that the emission of nitrous oxide in the soil is reduced, and environmental protection is facilitated.

The invention relates to the technical field of microorganisms, and discloses a pseudomonas putida strain and a preparation method and application thereof.The strain is pseudomonas putida which is separated from soil and has the capacity of dissimilatory reduction of nitrate into ammonium and is classified into a new pseudomonas putida strain based on GTDB-TK. A dissimilatory NOreductive gene cluster, namely an nirBD gene cluster, exists on a genome of the gene, nirK / nirS genes are deleted, and NOs can be reduced into NH under the anaerobic culture condition. According to the application of the pseudomonas putida strain in improvement of soil nitrogen management, the pseudomonas putida strain can be mixed with organic fertilizer for use so as to enhance the effective utilization and conversion capacity of nitrogen in soil. By means of the pseudomonas putida strain, NON can be reduced into NHH under the anaerobic condition, the culture method is simple, the growth speed is high, variation is not prone to occurring, and a brand new microbial resource is provided for soil nitrogen cycle research.

The invention belongs to the technical field of fertilization, and particularly relates to a method for promoting corn growth through root-leaf complementary nitrogen application under the salt stress condition and application. The invention provides a method for promoting corn growth by root-leaf complementary nitrogen application under a salt stress condition, corn is planted in saline soil, soil nitrogen application and leaf surface nitrogen application are performed, the soil nitrogen application amount is a soil nitrogen application amount threshold value, and the leaf surface nitrogen application amount is a leaf surface nitrogen application amount threshold value. As nutrient absorption of corn roots is blocked under the salt stress condition, nitrogen fertilizer is applied through soil and leaf surface complementation, and the nitrogen fertilizer is applied through leaf surfaces to supplement insufficient nitrogen fertilizer absorption of the corn roots, so that nitrogen absorption of the corn can be improved, stress resistance of the corn is improved, and growth of the corn is promoted.

The invention provides a soil ammonium nitrogen content hyperspectral prediction method based on an improved extreme learning machine, and relates to the technical field of hyperspectral prediction. The method comprises the following steps: firstly, collecting and treating a soil sample for soil spectral measurement and NH4 < + >-N content determination; measuring soil spectral reflectivity data; preprocessing the soil spectral reflectivity data to form a spectral reflectivity data set; then carrying out characteristic wave band selection by adopting a sequential forward selection algorithm; an improved butterfly optimization algorithm IBOA is adopted to optimize model parameters of an extreme learning machine ELM, and then a hyperspectral prediction model used for predicting the NH4 < + >-N content of the soil is constructed; and finally, the ELM model after parameter optimization is selected to construct a hyperspectral prediction model to predict the NH4 < + >-N content. The method not only provides theoretical and technical support for soil ammonium nitrogen content monitoring, but also provides important reference and guidance for soil nitrogen cycle research and soil management.

The invention provides a combined nitrogen and phosphorus loss prevention and control method for corn-winter green manure rotation planting. Comprising the following steps: step 1, preparing soil in mid-to-late September, sowing winter green manure crops in drill, and applying a yeast substrate along with the seeds; step 2, crushing the upper part of the green manure ground in April of the next year, scattering the treated sesbania straw, and turning and pressing by a rotary cultivator; step 3, sowing the corn, and applying a nitrification inhibitor along with the seeds; step 4, applying slow-release urea while intertilling the corn in a large horn mouth period of the corn; and 5, repeating the operations from the step 1 to the step 4 every year. According to the invention, the fertilizer is saved by more than 50%, the nutrient volatilization and leaching loss is reduced by 50-85%, the fertilizer utilization rate is improved by more than 30%, the cost is saved by 100-200 yuan per mu, the soil fertility is obviously improved, the soil nitrogen and phosphorus accumulation is obviously reduced, the non-point source pollution risk is obviously reduced, the biological coverage in winter and spring is obviously increased, and the beautiful tourism scene is provided.

The invention provides a saline-alkali soil conditioner as well as a preparation method and application thereof, and belongs to the technical field of soil improvement. The saline-alkali soil conditioner is prepared from the following raw material components in parts by mass: 80 to 90 parts of edible fungus residues, 10 to 20 parts of humic acid and 0.1 to 0.3 part of a microbial agent. The saline-alkali soil conditioner provided by the invention can obviously reduce the pH and total salt content of the surface layer of soil, obviously improve the content of nitrogen nutrients in the soil, optimize the distribution structure of the nitrogen nutrients and reduce the risk of nitrogen leaching loss. Meanwhile, the water and fertilizer retention capacity of soil can be improved, soil nutrients can be supplemented, the soil fertility can be improved, the harm of soil salinity to crops can be reduced, and the stress resistance and the yield of the crops can be improved. The soil conditioner for the saline-alkali land can solve the problems that at present, soil of salinized farmland in Hetao irrigation districts is prone to hardening, the soil fertility is low, the soil water and fertilizer utilization rate is low, and the crop biomass is low.

The invention belongs to the field of crop growth monitoring integrated devices, and particularly relates to a crop growth monitoring integrated system which is designed to acquire related information of a crop planting area in real time by using a soil hydrothermal salt sensor, a soil nitrogen element sensor, meteorological monitoring equipment, a ground infrared camera and an imaging spectrometer carried by an unmanned aerial vehicle. According to the technical scheme of the utility model, data information required by decisions such as watering, fertilization and pest control can be efficiently and comprehensively acquired in a large range, reasonable decisions such as watering, fertilization and pest control can be timely made, crops can be rescued, and the situation that the growth of the crops is seriously influenced can be avoided.

The invention relates to the technical field of data evaluation processing, in particular to a data evaluation method, electronic equipment, a storage medium and a program product, and the method comprises the steps: obtaining a field remote sensing image corresponding to a current moment, and recognizing a region remote sensing image corresponding to a to-be-improved region from the field remote sensing image; spectral data in the area remote sensing image are recognized, improvement parameters corresponding to the area to be improved are determined based on the spectral data, and the improvement parameters comprise the soil salt content, the soil alkalization degree and the soil nitrogen content; determining a corresponding improvement period standard parameter based on the current moment and preset improvement measure information, and evaluating the improvement parameters based on the improvement period standard parameter to obtain a parameter evaluation value of each improvement parameter; and determining a total evaluation value corresponding to the current moment according to each parameter evaluation value, and when the total evaluation value is lower than a preset evaluation standard value, generating abnormal warning information based on each parameter evaluation value. The method is convenient for improving the accuracy of the data evaluation result.

The invention discloses modified biochar for preventing and controlling soil nitrogen loss and a preparation method thereof, and the preparation method comprises the following steps: 1) adding a FeSO4 solution into biochar; 2) adding dilute sulphuric acid into the mixed solution obtained in the step 1), and uniformly mixing; (3) oscillating and heating the mixed solution treated in the step (2); 4) centrifuging the mixed solution treated in the step 3), and repeatedly washing the precipitate with deionized water; and (5) putting the centrifuged precipitate obtained in the step (4) into an electrothermal blowing drying box, and drying at 105 DEG C until the weight is constant. According to the invention, after the ferrous modified biochar is applied to soil, the pH value, EC value and CEC value of the soil are increased, the volume weight (VW) of the soil is reduced, and the contents of carbon, nitrogen and phosphorus nutrients in the soil are increased. According to the method disclosed by the invention, the leaching loss of nitrate nitrogen and ammonium nitrogen in the soil is remarkably inhibited by adding the modified biochar. The method has the advantages of easily available raw materials, no pollution, low treatment cost, convenient operation, large-scale application, high economy, and suitableness for popularization and application in the industry.

The invention discloses a rapid distinguishing method for predicting a nitrogen source produced by flooded soil through combination of in-situ observation and a model, and relates to the technical field of agro-ecology. Field micro-areas are divided in a target area, an intelligent sensing system is deployed, and soil environment parameters are monitored in real time; the method comprises the following steps: sampling soil in a target area, measuring soil bulk density, root layer depth, total nitrogen content and 15N abundance parameters of a soil sample, and obtaining soil basic data; and calculating the optimal 15N fertilizer abundance according to the recommended nitrogen fertilizer dosage recommended by the target area in combination with the soil nitrogen library content, the fertilizer application amount and the soil background 15N abundance. According to the method, dynamic changes of soil environment parameters are captured through combination of in-situ observation and an intelligent sensing system, the generation rate of nitrogen isotopes is monitored synchronously, the limitation that a traditional method depends on a single parameter is avoided, the distinguishing precision of nitrogen loss sources is remarkably improved, and the contribution rate of the in-situ observation and the intelligent sensing system to nitrogen loss can be rapidly calculated by combining model analysis.

The invention discloses an application method for realizing rice nitrogen fertilizer substitution by utilizing a photocatalytic nitrogen fixation material in the technical field of agricultural production. The application method comprises the following steps: S1, pretreating and proportioning a catalyst; s2, reaction container deployment and illumination optimization; s3, carrying out photocatalytic reaction and ammonium nitrogen generation; s4, synergistically applying base fertilizer and additional fertilizer; s5, monitoring and feeding back nitrogen utilization efficiency; the performance of the photocatalyst is improved by adopting a surface doping and composite modification technology, atmospheric nitrogen can be stably and efficiently converted into ammonium nitrogen which can be directly absorbed by rice under a complex environmental condition, and the nitrogen conversion rate and the nitrogen supply efficiency are improved; the AI algorithm is combined with the chlorophyll meter, the soil nitrogen sensor and the water ammonia nitrogen concentration data to predict and dynamically adjust the nitrogen demand of the rice in real time; a closed loop of nitrogen fixation-conversion-absorption-recovery is formed through a segmented application strategy of base fertilizer and topdressing in combination with physical and chemical synergism and a biochar improvement technology.

The invention relates to the technical field of soil improvement, and particularly discloses a soil conditioner based on microbial community regulation and control and a preparation method thereof, the soil conditioner comprises: (a) a composite functional flora comprising nitrogen-fixing bacteria, phosphate solubilizing bacteria, potassium-dissolving actinomycetes and trichoderma, and the viable count ratio of the nitrogen-fixing bacteria to the phosphate solubilizing bacteria to the potassium-dissolving actinomycetes to the trichoderma is (1.0-1.5): (0.8-1.2): (0.5-1.0): (0.3-0.8); b) modified biochar carrier: the modified biochar carrier is prepared by oxygen-limited thermal cracking of agricultural wastes and is subjected to surface modification by a chitosan solution with a mass fraction of 3-5%; (c) a synergistic component which comprises humic acid particles and an enzymolysis seaweed extract; (d) a flora activator: compounding fructo-oligosaccharide and L-aspartic acid according to a mass ratio of 2: 1; through the synergistic effect of multifunctional composite flora of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing actinomycetes and trichoderma, the biotransformation process of nitrogen, phosphorus and potassium elements in soil is synchronously activated, and the modified charcoal carrier is subjected to multi-stage pyrolysis and chitosan modification to form a graded pore structure.