152 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 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 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 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 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 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 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 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 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.

The invention provides a method for preventing and controlling nitrogen and phosphorus loss of sandy and dry cultivated land based on EICP root reinforcement and relates to the field of soil ecological protection and agricultural pollution prevention and control. According to the method, a three-dimensional prevention and control system is formed from the two dimensions of surface layer film covering protection and deep root system soil fixation through the synergistic effect of EICP film covering and local plant root system three-dimensional reinforcement, wind erosion and water erosion are effectively resisted, the soil nitrogen and phosphorus loss rate of the large-gradient sandy and dry cultivated land is remarkably reduced, and meanwhile the soil desertification process is slowed down; the EICP film covering layer has good water permeability and moisture retention, nitrogen and phosphorus loss can be prevented, rainfall infiltration and soil moisture conservation can be guaranteed, and the germination rate and the growth speed of crops are increased; according to the method, local crop root system reinforcement is selected, the original planting structure is not disturbed, the economic benefit of cultivated land yield per mu is guaranteed, a harmless means of combining microorganisms, geotechnical engineering and agricultural planting is adopted, external pollution sources are not introduced, original basic characteristics of soil are not damaged, and the requirement for ecological protection of the Yellow River basin is met.

The invention discloses a method and system for rapid detection of field fertility based on soil two-dimensional spectrum data migration learning. Firstly, spectrum data is input into a spectrum data two-dimensionalization module, and bicubic interpolation is performed according to short-time Fourier transform to convert a one-dimensional spectrum into a two-dimensional spectrum graph; the processed two-dimensional spectrum graph is input into an SS-MSC preprocessing module, and two-dimensional standardization processing and two-dimensional multivariate scattering correction processing are performed on the image in sequence; based on an improved Inception-v4 soil nitrogen, phosphorus and potassium content detection network model, pre-training of a neural network is completed according to a pre-training data set; finally, the neural network model is adaptively tuned according to soil nitrogen, phosphorus and potassium content data of a field standard sample point, migration of the neural network model is completed, and rapid detection of field fertility is realized; the problems of too much priori data of a farmland to be tested required for training a prediction model in an existing method and poor universality of the model for different soil types are solved, and the efficiency and accuracy of field fertility detection are improved.

The invention discloses an efficient composite intercropping method for pomegranate, dry rice and broad bean grain, which scientifically combines pomegranate (economic output), dry rice (grain output) and broad bean (partial economic output and biological nitrogen fixation and land cultivation), realizes functional complementation, and breaks through the single target limitation of the traditional intercropping mode. Through effective connection of crops for rotation of'broad bean sowing in winter and upland rice sowing in spring ', full utilization of light and heat resources and land in the orchard from winter to spring, summer and autumn in the next year is realized, and the multiple cropping index is remarkably improved; the pomegranate utilizes the upper-layer three-dimensional space, and the upland rice and the broad beans utilize the middle-lower-layer space, so that an efficient three-dimensional lighting structure and space combination are formed; the nitrogen fixation effect of the rhizobium of the broad beans can directly increase the nitrogen nutrition of the soil, the straw returning can increase the organic matters of the soil, and the built-in fertilizing mechanism of the orchard effectively relieves the consumption of the intercropping system on the soil fertility and ensures the sustainability of the mode.

Disclosed is a method for assessing nitrogen leaching risk based on farmland soil pressure, including the following steps: acquiring soil drilling pressure data from a plurality of soil layers of different depths on soil to be tested using a soil drilling device, to obtain raw soil drilling pressure data; comparing a calibration curve with a raw soil drilling pressure curve; setting an interquartile range (IQR) coefficient based on a first fluctuation factor and a second fluctuation factor, and constructing a box plot of the raw soil drilling pressure data based on the IQR coefficient; and determining a peak soil drilling pressure according to the box plot of the raw soil drilling pressure data, and determining nitrogen leaching risk according to a depth interval of soil layer. The box plot is utilized to filter out abnormal values, ensuring the accuracy of assessing the nitrogen leaching risk in soil.

The invention discloses a method for enhancing the biological nitrogen fixation capacity of soil based on micro-plastics, which comprises the following steps: adding poly (adipic acid-butylene terephthalate) micro-plastics into target soil, and the addition amount is 0.2-2% of the mass of the soil. The activity of dehydrogenase and urease of rhizosphere microorganisms is activated through the degradation process of the poly (butylene adipate-co-terephthalate) micro-plastic in soil, and microorganism groups with a nitrogen fixation function are specifically enriched, so that the expression of nitrogen fixation genes is up-regulated, the biological nitrogen fixation capacity of the soil is enhanced, and the nitrogen condition of the soil is improved.

The invention discloses a small watershed nitrogen and phosphorus load accounting method based on key process parameter calibration, and the method comprises the steps: obtaining the basic geographic hydrological data of a target small watershed, the data comprising the areas of different land utilization types in the watershed, the flow length of a water collection region river channel, and the average flow velocity; based on the hydrology and water quality monitoring data of the long-time sequence of the catchment area, adopting a Bayesian inversion model to quantitatively identify the nitrogen and phosphorus output coefficient of each land utilization type; calculating a soil nitrogen and phosphorus output load in the catchment area, determining a natural reduction coefficient of a nitrogen and phosphorus first-order river, and calculating transport time of nitrogen and phosphorus from a starting point of a river channel of the catchment area to a water outlet and transport time of soil output nitrogen and phosphorus from a tributary estuary to the water outlet of the catchment area; and calculating the water collection area outlet nitrogen and phosphorus load. According to the method, the overestimation error caused by the fact that a production and pollution discharge coefficient method is adopted in a traditional method is remarkably reduced through fusion of'pollution source nitrogen and phosphorus entering the river-remaining soil output-along-the-way natural reduction 'ternary accounting, the accuracy of load accounting is improved, the feasibility and advantages of the technical scheme are verified, and the method is particularly suitable for small watersheds with deficient basic data.

The invention relates to the field of agricultural fertilizers, and discloses a method for determining the nitrogen fertilizer application amount of rice. The method comprises the steps that the soil nitrogen supply amount is determined according to the soil texture, the soil CEC content and the soil organic matter content OM of a target rice field; calculating the nitrogen application amount of the target rice field according to the following formula: nitrogen application amount = total nitrogen demand of rice-nitrogen supply amount of soil; wherein the CEC content of the soil is calculated according to the following formula: the CEC content of the soil is equal to C1 / A1 + C2 / A2 + C3 / A3 + SEA. By means of the method, the application amount of the nitrogen fertilizer can be accurately calculated under different soil conditions, it is guaranteed that the rice can obtain enough nitrogen elements, the optimal growth and yield are achieved, meanwhile, excessive application of the nitrogen fertilizer is avoided, and nitrogen emission is reduced.

The invention discloses a self-repairing coated controlled-release fertilizer of a block nitrogen signal substance and a preparation method of the self-repairing coated controlled-release fertilizer, and belongs to the technical field of controlled-release fertilizer production. The self-repairing coating material of the block nitrogen signal substance comprises an inner coating material and an outer coating material, the inner coating material is prepared from a signal substance, a water-soluble coating liquid matrix and a binder according to a weight ratio of (0.3-0.6): (6-12): (3-6); the outer coating material is prepared from a self-repairing prepolymer, a catalyst and a binder in a weight ratio of (8-10): (0.01-0.2): (3-6). The coated controlled-release fertilizer disclosed by the invention has excellent self-repairing performance and an effect of adjusting nitrogen circulation of root system soil, not only solves the problems of unstable and inaccurate nutrient release caused by membrane shell damage in the popularization and application of the existing bio-based coated controlled-release fertilizer, but also promotes the enrichment of beneficial microbial communities for rhizosphere nitrogen circulation, so that the yield of the fertilizer is improved. The nitrogen utilization rate of crops is improved.

The application discloses an agricultural water quality and water quantity dual risk and cascade transmission evaluation method, belongs to the technical field of water resource management, and aims at solving the problem that traditional methods only stay in water quantity depletion caused water resource pressure accounting and ignore the risk caused by substandard water quality; the application comprises the following steps: based on a farmland soil nitrogen budget and hydrodynamics coupling model, quantifying the pollution emission list of subdivided sources in the growth process of specific crops, simulating agricultural pollution dilution water consumption; using a crop water requirement model to calculate the irrigation water consumption of specific crops in the whole growth period; using a source and sink corrected physical flow trade model to analyze the virtual water transfer path hidden in each agricultural product trade link; integrating the production end and the consumption end results to realize high-precision grid agricultural water resource supply and demand imbalance risk evaluation and cascade effect analysis; and the cascade transmission effect of the application in evaluating the water resource risk provides strong support for reasonable allocation of agricultural water resources and improvement of nitrogen fertilizer utilization efficiency.

The invention relates to the technical field of soil improvement, and particularly discloses a soil nitrogen stable conditioner as well as a preparation method and application thereof, and the soil nitrogen stable conditioner is prepared from the following components in parts by weight: 30-50 parts of pyroligneous acidified biochar, 35-45 parts of organic fertilizer, 10-15 parts of humic acid, 1-5 parts of microelement fertilizer and 1-2 parts of sulfur powder. The wood vinegar acidified charcoal-based soil nitrogen stable conditioner provided by the invention achieves the function of improving the utilization efficiency of a nitrogen fertilizer by inhibiting the activity of soil urease and reducing the decomposition speed of the nitrogen fertilizer and the mineralization and nitration speed of soil nitrogen.

The invention relates to the field of soil nitrogen fixation, in particular to nitrogen fixation biochar particles and a preparation method and application thereof. The preparation method of the nitrogen-fixing biochar particles provided by the invention comprises the following steps: pyrolyzing a biomass raw material to obtain pyrolytic carbon; mixing the pyrolytic carbon with a strong alkali solution, and reacting to obtain nitrogen-fixing biochar particles; the strong base in the strong base solution is alkali metal hydroxide. The number of oxygen-containing functional groups on the surfaces of the nitrogen-fixing biochar particles is increased by adopting strong base modification, and meanwhile, the specific surface area and the porosity of the nitrogen-fixing biochar particles are increased; the method reduces migration of dissolved nitrogen, facilitates fixation of nitrogen in the soil, effectively relieves nitrogen runoff and leaching loss caused by application of nitrogen fertilizer in the soil, improves the utilization rate of the nitrogen fertilizer, and relieves the pollution problem of lake water around a farmland.

The application discloses an adaptive method for relieving double risks of water quality and water quantity of agriculture, and belongs to the technical field of water resource management.The method is based on a farmland soil nitrogen balance and hydrodynamics coupling model, quantifies a pollution emission list of subdivided sources in the growth process of specific crops, and simulates agricultural pollution dilution water quantity; a crop water requirement model is used to calculate irrigation water consumption of the specific crops in the whole growth period; a water resource loss evaluation module is established to evaluate potential agricultural yield reduction and economic loss caused by water resource shortage; a scenario library of water and fertilizer coordination strategies is constructed to compare the relieving effects of different adaptive strategies on water quantity depletion type and water quality pollution type water resource risks.The application solves the technical problem that it is difficult to simultaneously cope with water quantity risks and water quality risks to develop targeted adaptive strategies, can effectively relieve water resource pressure, improve the sustainability of agricultural production, realize optimal allocation of water resources, and further guarantee the health of an ecological system.

The invention discloses bacillus NJAU-N6 with nitrogen fixation, low temperature resistance and drought resistance and application of the bacillus NJAU-N6, the strain is classified and named as Paenibacillus illinoisis, the strain is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.35728. The bacillus NJAU-N6 has the advantages that the bacillus NJAU-N6 can be applied to nitrogen fixation, low temperature resistance and drought resistance; the invention discloses the capability of the compound in soil nitrogen fixation and soybean growth promotion. The invention also discloses a microbial inoculum prepared from the strain and application of the microbial inoculum in soil nitrogen fixation and soybean growth promotion. The strain disclosed by the invention has a relatively wide temperature adaptation range and relatively strong drought resistance, can stably play a nitrogen fixation role and a function of promoting soybean growth in a low-temperature and drought-resistant soil environment, and is particularly suitable for planting scenes of crops such as soybeans in semi-arid windy desert areas in northeast China; the method has good popularization and application values in soil fertility improvement and crop yield increase in the region.

The present application belongs to the technical field of straw decomposition and soil improvement, and particularly relates to a method for promoting decomposition of straw returned to field. The present application forms a biological community of diazotrophs by applying artificial cultivation of nitrogen-fixing blue-green algae to a rice field, uses the diazotrophs to increase soil nitrogen by biological nitrogen fixation, and reduces the amount of nitrogen fertilizer applied. Meanwhile, the diazotrophs can also improve the activity of soil decomposing bacteria by secreting active substances such as extracellular enzymes, accelerate the conversion of straw source carbon to soil microbial source carbon, regulate the carbon-nitrogen balance of soil, and reduce the adverse effects on crops. On the other hand, the present application can reduce greenhouse gas emissions, and achieve rapid accumulation of soil organic matter and improvement of soil fertility.

The present application belongs to the field of ecology and environmental monitoring technology, and relates to a kind of detection and analysis method for decomposition rate of leguminous sand-fixing shrub litter in field.The present application screens sample area by system grid method, collects and lays out litter bag, synchronously determines initial and current nitrogen content of soil, calculates net increment of soil nitrogen, determines horizontal diffusion boundary of nitrogen, and then obtains soil absorbed nitrogen amount;obtains equivalent dry matter loss amount based on nitrogen balance calibration, and finally determines litter decomposition rate by exponential decay fitting.The method solves the decomposition rate estimation deviation problem caused by nitrogen migration and soil absorption in traditional detection, can more accurately reflect the actual decomposition process in field, improves the reliability of monitoring data, and provides reliable technical support for nutrient cycling research and ecological restoration effect evaluation of desert ecosystem.

The invention provides a soil nitrogen content dynamic estimation method and device, a terminal and a storage medium, and relates to the technical field of soil content analysis. The method comprises the following steps: acquiring a hyperspectral remote sensing image of crops in a to-be-detected area, and calculating spectral characteristic parameters and vegetation indexes according to the hyperspectral remote sensing image; inputting the spectral characteristic parameters and the vegetation indexes into a crop spectrum-nitrogen content inversion model, and outputting the plant nitrogen content in the to-be-detected area; calculating the soil nitrogen variable quantity of the to-be-detected area by utilizing the plant nitrogen content, and dynamically estimating the soil nitrogen content of the to-be-detected area by utilizing the soil nitrogen variable quantity. According to the invention, the efficiency and accuracy of soil nitrogen content estimation can be improved.

The invention discloses an in-situ determination device for the nitrogen and phosphorus conversion rate of soil, and belongs to the technical field of soil nutrient determination, the in-situ determination device comprises at least one sampling pipe, drawer grooves are distributed on the sampling pipe along the vertical direction, sampling boxes are arranged in the drawer grooves in an extractable manner, the side walls of the sampling boxes, which are in contact with soil, are made of PTFE microporous membranes, and the PTFE microporous membranes are made of PTFE microporous membranes. An anti-permeation partition plate is arranged in the sampling box, an inner cavity of the sampling box is divided into a nitrogen collecting cavity and a phosphorus collecting cavity by the anti-permeation partition plate, a pipe opening in the upper end of the sampling pipe located at the uppermost end is covered with a waterproof breathable film, and an air pressure balance valve is arranged on the sampling pipe. The invention also discloses an in-situ determination method for the nitrogen and phosphorus conversion rate of the soil. The method can effectively realize in-situ, synchronous, layered and continuous measurement of the nitrogen and phosphorus mineralization rate of the soil, overcomes many defects in the prior art, and provides strong technical support for related research and application.

This invention discloses a slow-release fertilizer suitable for lateritic soils in Hainan, comprising a fertilizer core and a coating layer; the fertilizer core comprises the following raw materials in parts by weight: 10-20 parts isobutylene diurea, 1-3 parts 3,4-dimethyl-1H-pyrazole dihydrogen phosphate, 1-3 parts dicyandiamide DCD, 20-30 parts humic acid, and 30-50 parts organic fertilizer; the coating layer comprises the following raw materials in parts by weight: 5-10 parts natural nanotube halloysite, 3-5 parts bentonite, 5-10 parts cyclodextrin, 1-3 parts polyglutamic acid, 1-3 parts wood vinegar, and 5-10 parts polyacrylamide. The isobutylene diurea, humic acid, and organic fertilizer of this invention can effectively replenish organic matter and nitrogen in iron-aluminate soil, maintain soil nitrogen levels, and effectively control the conversion of ammonium nitrogen to nitrate nitrogen in lateritic soil, thereby reducing nitrogen loss and achieving a stable supply of nitrogen. In addition, polyglutamic acid and polyacrylamide have strong water retention capacity, and the fertilizer core is coated with a coating layer to achieve slow release and water retention.