218 results about "Soil nitrogen" patented technology

The invention discloses a landscaping fine management device based on cloud computing, comprising a control device, a soil nitrogen-phosphorus-potassium detector, a GPS (Global Positioning System) positioning device, a soil humidity sensor, a soil compactness measurer, a vibrating device, a water pipe flow valve, a nitrogen fertilizer bin, a phosphorus fertilizer bin, a potassium fertilizer bin and a cloud computing server; the landscaping fine management device based on cloud computing is provided with the soil nitrogen-phosphorus-potassium detector, so that some elements can be specifically and quantitatively added into soil; hard soil can be loosened under the action of the vibrating device via the soil compactness measurer and the vibrating device; the device realizes fine management, and quantitatively supplies elements to the soil, so that plants are grown in the most appropriate soil; and the vibrating device is used for loosening soil via electrical energy generated by branches swinging in air, so that the device is energy-saving and environment-friendly.

The invention discloses a preparation for inhibiting soil nitrogen loss as well as a preparation method and an application thereof. The preparation is prepared from the following raw materials in percentage by mass: 1-40% of 2-chloro-6-trichloromethylpyridine, 0-5% of hydroquinone, 5-20% of accessory ingredient and 35-90% of solvent. The preparation disclosed by the invention can be evenly dispersed in an aqueous phase, and the preparation and a nitrogenous fertilizer are evenly applied into soil so as to effectively alleviate speed of urea to be hydrolyzed into ammonia under the urease action and also effectively inhibit the process of oxidizing NH<4+> into NO<3->; NO<2-> and NO<3-> leaching loss is reduced, and NOX and N2 can be further prevented from escaping because of denitrification; and the utilization rate of the nitrogen fertilizer is improved so as to improve the quality and the yield of the crops and lighten pollution to environment by the nitrogen fertilizer.

The invention discloses a method for restoring and improving uranium tailing residues-contaminated soil, the employed materials comprise Aeschynomene indica, Miscanthus floridulus and Imperatacylindrica, plant ash and cow dropping, the plant ash is made by burning the Miscanthus floridulus and the Imperatacylindrica. The plant ash and the cow dropping is formulated into a mixed fertilizer in accordance with a proportion to be fertilized in a plant ditch that is built in uranium tailing residues-contaminated region, the three plants of the Aeschynomene indica, the Miscanthus floridulus and the Imperatacylindrica are planted in groups in the plant ditch. By using the method, dense vegetation can be constructed in a very short time to prominently increase soil nitrogen, organic matters and pH value, and meanwhile, the soil root density is increased and the content of soil water-soluble uranium is reduced obviously. The method has the advantages of simple operation, low cost, good efficiency of preventing the uranium from transfer and diffusion, and beautifying the environment. The technique can be used in reconstructing vegetation in a degraded ecosystem of mines and greening expressways.

The invention provides a non-point source pollution calculation method based on a remotely sensed image element. The method comprises the following steps of: 1, constructing a land utilization database and a vegetation coverage database; 2, constructing a soil type database, a soil nitrogen and phosphorus attribute database and a gradient and slope length geographic space database; 3, constructing a farmland nitrogen and phosphorus balance amount space database; 4, calculating dissolved state non-point source loads and adsorption type non-point source loads of non-point source pollutants under different pollution types according to database information in the steps from 1 to 3 and the pollution types; and 5, calculating a total amount of non-point source pollutants in a river according to the dissolved state non-point source loads and the adsorption type non-point source loads. By the method, under the condition that a data condition is limited, a non-point source pollution space distribution feature and a source intensity feature can be quickly obtained based on remotely sensed data; effective pollution monitoring measures can be supplied to a pollution prevention, treatment and management department; and important technology support can be supplied to flow domain pollution management.

The invention belongs to the field of fertilizer for crops and particularly relates to a special ecological fertilizer for saline-alkali soil and a preparation method thereof. The special ecological fertilizer is characterized by being composed of reed, common cordgrass, sweet potato powder residue, citric acid industrial residue, dry chicken manure, ammonium sulfate, monocalcium phosphate, potassium humate, trace elements, guar gum, esterified starch and a soil conditioner. The special ecological fertilizer is mainly composed of organic fertilizer, is rich in organic matters and humic acid and is added with a small amount of acidic inorganic fertilizer in a compounded way; therefore, the special ecological fertilizer is comprehensive in nutrition and is capable of well meeting the nutrition demands for growth of crops; the soil conditioner in the special ecological fertilizer is capable of improving the soil environment, reducing the pH value of alkali soil, lowering the content of soluble salt and increasing the content of N, P and K in soil and thus the utilization rate of the fertilizer can be improved.

The invention provides a near infrared spectrum technology-based multiband soil nitrogen detection device and a near infrared spectrum technology-based multiband soil nitrogen detection method. A regression equation of near infrared spectrum data and soil sample nitrogen content is established by establishing a soil nitrogen prediction model and using soil spectrum absorbance of seven bands so asto accurately measure the soil nitrogen level. The device and the method have high practical precision, are not affected by weather factors, are suitable for real-time field measurement, provide storage function of a U disk, and are convenient for storing historic records, calling the data and realizing a soil nitrogen distribution graph.

The invention belongs to the technical field of crop growing management and discloses a regulation and control method for rice nitrogen topdressing based on a nitrogen spectral index method. According to the invention, the nitrogen spectral index method is constructed according to nitrogen amount required by target rice yield, apparent utilization rate of spike fertilizer, plant real-time nitrogen accumulation amount estimated based on reflectance spectrum and soil nitrogen supplying amount while nitrogen fertilization based on a nutrient balancing principle. According to the invention, in the aspect of real-time information acquisition, plant canopy group information is utilized, thus the regulation and control method disclosed by the invention has the quicker and lossless characteristics and the like, thereby avoiding the phenomenon of point replacing surface; in the aspect of a nitrogen topdressing regulating and controlling model, the soil nitrogen supplying amount and nitrogen fertilizer utilization rate during the middle-late period are quantified, thereby enhancing the mechanism characteristic and accuracy of nitrogen topdressing amount estimation and improving the quantification level.

The invention relates to a method of determining accurate nitrogen fertilizer applying amount in wheat. In the method, the nitrogen fertilizer applying amount is equal to the difference of the output minus the apparent mineralization amount of soil nitrogen, the nutrient input from environmental nutrients, the amount of nitrogen brought by seeds and the amount of nitrate nitrogen in the 1-meter soil layer before sowing, wherein the output comprises the amount of nitrogen absorbed by crops, the amount of the safety residue of the soil nitrate nitrogen after harvest and the amount of soil nitrogen loss; the amount of the safety residue of the soil nitrate nitrogen after harvest can be obtained through analysis of samples from the 1-meter soil layer of a majority of soil in the sowing land. The invention can determine the nitrogen fertilizer applying amount according to the balance of the nitrogen input and the nitrogen output into the soil-plant system, thereby realizing the accurate application of the nitrogen fertilizer, improving the yield of crops and the absorption and utilization of nitrogen, and reducing the residue of the soil nitrate nitrogen and other negative effects of the nitrogen fertilizer. Therefore, the invention has a high practical value.

The invention discloses a modified charcoal capable of improving the adsorptive property of nitrogen and phosphorus in soil and a preparation method and application thereof. The preparation method comprises the following steps: soaking smashed biomass with a metal salt solution, stirring, standing, drying for dehydration to obtain a mixture, putting the mixture into a porcelain crucible, and putting the porcelain crucible into an atmosphere furnace for carbonization to obtain the modified charcoal, wherein the metal salt solution is a ferric chloride, calcium chloride or magnesium chloride solution. The preparation method of the modified charcoal is simple in steps and low in cost, the prepared modified charcoal has good adsorptive property for nitrogen and phosphorus, after combined application of a fertilizer and the modified charcoal serving as a soil conditioner, the using amount of the fertilizer can be reduced, and the loss of nitrogen and phosphorus is reduced, so that the modified charcoal can be popularized and applied in field experiments.

The invention discloses a functional liquid bioorganic fertilizer and a preparation method thereof. The preparation method comprises the following steps of: fermenting livestock manures to form the mixture of biogas slurry and biogas residues, separating the biogas residues to obtain clear liquid, decomposing the clear liquid, adding photosynthetic bacteria into the clear liquid for intermediate culture, and mixing the cultured clear liquid, chitosan, a synergist, and trace elements required by plants in proportion to prepare the functional liquid bioorganic fertilizer. The functional liquid bioorganic fertilizer has a plurality of functions of promoting the transformation of soil substances, improving soil structure, improving the fertility of soil, promoting the growth of crops, fixing nitrogen, improving the nitrogen level of the soil, promoting the multiplication of beneficial microorganisms of the soil, participating jointly in the circulation of substances of soil ecosystem, improving the cold resistance, drought resistance and disease resistance of the crops, and the like, has the characteristics of small using amount, quick response and high effect persistence so as to reduce the using amounts of chemical fertilizers and pesticides, reduce agricultural pollution and save agricultural cost, can be mainly used for foliage dressing and as a base fertilizer as well as a root fertilizer, plays a very important role in recycling finite resources and protecting the agroecological environment, is particularly applied to the production of organic green pollution-free agricultural products so as to improve the quality and yield of the organic agricultural products, and is of great significance for the realization of ecocycle economy in China.

The invention relates to a spring peanut-summer corn relay intercropping planting method, and belongs to the technical field of crop planting. The planting method comprises the following steps: ridging and mulching plastic film on the ridges to plant the peanut, planting two rows of peanut for each ridge, interplanting two rows of corn for every two ridges of peanut, wherein the ridge bottom width is 84-86 cm; the ridge face width is 54-56 cm; the ridge height is 9-11 cm; the peanut line space on the same ridge is 34-36 cm; the space between the corn and the peanut is 59- 61 cm; the row space of the peanut is 14 cm; the row space of the corn plants is 13-14 cm; the peanut is sown when the ground temperature at 5 cm is 15-18 DEG C; the corn is sown on the fortieth to fiftieth day after the peanut is sown. With adoption of the planting method disclosed by the invention, two crops a year can be yielded, time and space as well as photo-thermal resource are fully utilized, and the land utilization rate is effectively improved; the peanut yield per mu is increased by 112%, and the total revenue is increased by 72%; the soil fertility and the soil nitrogen content are improved; the soil physical properties and the soil looseness can be improved; the problems that when the wheat-corn planting mode is carried out for continuous years, the soil is hardened and the soil fertility is decreased are effectively solved, and soil cultivation and land use are combined.

The invention provides a method for measuring a contribution rate of a plant root system to nitrification and denitrification of soil. The method comprises the following steps: selecting a 20m*20m sample area in a forest or in a field, selecting five 2m*2m small units in the sample area according to an S-shaped point sampling method, digging ditches with widths of 0.3m and depths which exceed the root depth by 0.2m around the small units, inserting fiber glass into the ditches to stop roots from growing inwards, and filling back the dug soil into the ditches; then sampling by adopting a cutting ring, measuring nitrification and denitrification rates of the soil in the 2m*2m small units by utilizing a BaPS soil nitrogen cycle monitoring system, simultaneously measuring nitrification and denitrification rates in adjacent 2m*2m small units, and calculating the contribution rate of the plant root system to the nitrification and denitrification process of the soil according to a formula. The method is used for guiding to measure how the root system influences the forest soil ecological system and regulates carbon-nitrogen balance, and has an important effect of knowing about participation of a root system layer of the integral forest in geobiochemical nitrogen cycle.

Increasing longevity of the nitrogen content of soil through improved liquid delivery formulations of urease inhibitors and / or nitrification inhibitors designed to apply to fertilizers, especially urea and manure based fertilizers These delivery formulations provide an environmentally sound and inherently safe solvating system that improves the storage stability of the urease inhibitors by utilizing aprotic solvents, maintain the urease inhibitors and / or nitrification inhibitors in solution to storage temperatures of at least 10° C. and provides improved application to fertilizer of urease and / or nitrification inhibitors. These delivery formulations enable safe storage, transport and subsequent application or blending with urea based or manure based fertilizers that can be applied to soil in either a liquid or granular form to provide improved nitrogen retention in the soil for uptake for plant life.

The invention relates to a canonical correspondence analysis-based soil nitrogen reserve estimation method, and belongs to a pedometrics and spatial analysis-oriented soil nitrogen reserve estimation method. The calculation of soil nitrogen density of a one-meter soil body and the simulation of spatial variation characteristics of the soil nitrogen density under different landscape characteristics are involved; an independent variable can be subjected to effective information preprocessing through multiple dimension reduction technologies; a comprehensive influence variable of nitrogen reserves of different depths is analyzed by using canonical correspondence analysis; and especially in the aspect of analyzing attribute influence factors of soil with different properties and different depths, a comprehensive fitting relationship between multiple soil attributes and typical characteristics of environment variables is established.

The invention relates to a water and fertility retaining agent and a preparation method thereof. The water and fertility retaining agent consists of a gamma-polyglutamic acid biological water retaining agent and one or more adsorbents selected from humic acid raw powder, zeolite powder, bentonite or attapulgite. The gamma-polyglutamic acid type water and fertility retaining agent provided by the invention can promote the absorption of nitrogen, phosphorus and potassium of green Chinese cabbage, and the yield increase rate of the green Chinese cabbage reaches 9.96%-15.61%; and simultaneously, the water and fertility retaining agent also plays a positive role in retaining nitrogen, phosphorus and potassium nutrients in soil, increasing organic matter contents in the soil, and retaining soil moisture. The gamma-polyglutamic acid type water and fertility retaining agent provided by the invention can improve the wheat yield on sandy ground and the kernels per spike and thousand kernel weight of component factors, and simultaneously when the gamma-polyglutamic acid type water and fertility retaining agent provided by the invention is applied, the soil organic matter, available nitrogen, available phosphorus, available potassium and moisture content in wheat paddocks are higher than contrast, thus showing good water and fertility retaining effects.

A method of reducing gaseous state loss of nitrogen in limestone soil by utilization of charcoal is disclosed. The method includes following steps of: 1) naturally withering corn straw, smashing until the size is 2-5 cm, adding the smashed corn straw into a carbonization device, and performing pyrolysis under anaerobic or anoxic conditions to obtain charcoal; 2) grinding the charcoal, and sieving; 3) modifying the charcoal, and adjusting the pH value of the charcoal; and 4) fully mixing the charcoal with agriculture limestone soil in subtropical zones according to a ratio of 20-50 t / ha, and fertilizing with the fertilizing depth being 20 cm from the surface layer of soil. The method is simple in operation, low in cost, prone to industrial production, convenient in popularization and easily accepted by farmers, is capable of effectively reducing the gaseous state loss of soil nitrogen, improving soil quality and playing a role of nitrogen fixation and fertilizer efficiency increasing, can be widely popularized and applied in the rural areas and has a good market prospect.

The invention provides a biological organic fertilizer and a preparation method thereof. A biological aerobic composting technology is adopted, a carbon nitrogen ratio, moisture, particle size and other material parameters are adjusted, an organic material decomposition agent is added, and oxygen is supplied in a forced mode, so that the organic materials are fully decomposed, and easily absorbed total nutrition is provided for crops. After functional microbes are added, the utilization rate of the chemical fertilizer is greatly improved, the amount of the chemical fertilizer is reduced by 50 percent, and output reduction is avoided. The content of organic matters of the soil can be improved due to continuous utilization, and the water and fertilizer retaining capacity is improved. The biological organic fertilizer is greatly popularized, the amount of the chemical fertilizer can be greatly reduced, the content of nitrogen, phosphorus and potassium in the soil is increased, and the amount of the chemical fertilizer flowing into the water body is reduced, so that the problem that nitrate in underground water exceeds standard is fundamentally solved. According to the biological organic fertilizer, the problems such as soil hardening and reduction of fertility utilization can be solved, the problem of water and soil pollution caused by application of the chemical fertilizers in a large scale is relieved, and the quality of agricultural products can be improved due to large-area application.

The invention discloses an agricultural non-point source pollution conditioning agent and a preparation method thereof, and belongs to the field of an agricultural fertilizer. The method is characterized in that the agricultural non-point source pollution conditioning agent is obtained by using rice stalk biomass charcoal, dry sheep manure and polyacrylamide as major materials and using calcium carbonate, zeolite powder and EDTA-chelate iron as regulating agents through mixed fermentation and drying. The adsorption effect of charcoal and the zeolite powder on soil nitrogen, phosphorus, heavy metal ions and the like is fully utilized; through the PAM bridging effect, the charcoal and sheep manure particle bonding and large-pore structure is manufactured; the specific surface area of the charcoal micropore structure is enhanced; through chelate iron and calcium carbonate, the surface functional group of the charcoal is enriched, so that the adsorption effect is further reinforced; meanwhile, the product contains higher nutrient substances; a slow release effect is achieved; the soil nutrient substance loss cannot be caused. The product can be used for preventing, controlling and conditioning the loss of farmland elements such as nitrogen and phosphorus, can be used for heavy metal polluted soil restoration and can also be used as a compound organic fertilizer.

The invention relates to the technical field of control of soil nitrogen pollution, in particular to shewanella and application thereof to control of soil nitrogen pollution in a vegetable field. Theshewanella has the collection number of CGMCC No. 16843 and is collected on November 30, 2018. The invention further discloses molecular biological characteristics and a culture method of the strain.The shewanella is verified to have the characteristic of promoting crop growth, and is further used as a soil conditioner for controlling the soil nitrogen pollution in the vegetable field.

The invention relates to a nitrogen fertilizer synergist for vegetable planting and an application method of the synergist. The nitrogen fertilizer synergist is prepared by screening a high-efficiency urease inhibitor (quinhydrone), a nitrification inhibitor (dicyandiamide) and sepiolite with appropriate prices and good effects in a ratio of 1:10:100, 15 to 20kg of synergist is applied per mu in a single season, the synergist serving as a base fertilizer is applied to soil after being fully mixed with other conventionally applied base fertilizers uniformly, and the total amount of a nitrogen fertilizer in the base fertilizer is reduced by 20 to 30 percent compared with the local conventional using amount. The synergist is easy to operate, the yield and quality of vegetables can be improved on the basis that the cost of the nitrogen fertilizer is saved by 20 to 30 percent, the pollution of the nitrogen fertilizer can be relieved to a certain extent, the nitrogen fertilizer is efficiently managed and utilized, and win-win economic benefits and ecological benefits are achieved; and the synergist has a good application prospect in vegetable production, particularly in a vegetable production base with serious soil nitrogen enrichment.

The invention discloses a coast salinized soil improvement method improving plough layer soil nitrogen immobilization capability; the method comprises the following steps: laying subsurface pipes, washing, ploughing soil, pre-applying soil composition conditioning agent, applying organic-inorganic composite fertilizer, supplementing bacterium source, and dry spreading a soil amendment in a fallow period. The coast salinized soil is large in salt content, high in soil hardening level, and severe in nitrogen nutrient loss in leaching; the novel method considers these problems, organically couples soil improving physical, chemical and biological means, thus developing the coast salinized soil improvement technology and application method thereof that improves salinized soil nitrogen immobilization capability and salinized soil physical and chemical properties; subsurface pipe drainage and organic-inorganic composite fertilizer are combined; soil composition conditioning agent and soil amendment are respectively applied before cultivation and in the fallow period; microbe inocula is supplemented after base fertilizer and additional fertilizer, thus greatly improving plough layer salinized soil nitrogen immobilization capability, and improving salinized soil physical and chemical properties.

The invention relates to the technical field of soil fertilization, in particular to a method for interplanting leguminous green manure crops in wheat field to culture a soil nitrogen pool. The methodcomprises the six specific steps of interplanting of the leguminous green manure crops, irrigation, spring wheat harvesting, irrigation, harvesting of the leguminous green manure crops and sowing ofspring wheat in the next year. The method has the advantages that a fertilizer is saved by 20-30%; labor and time are saved during sowing; mutualistic symbiosis between the interplanting crops is achieved; the organic matter of soil is improved by 7-12%, total nitrogen is improved by 2.54-3.56%, nitrate nitrogen is reduced by 7.01-38.51%, ammonium nitrogen is improved by 0.94-19.28%, microbial nitrogen is improved by 10.22-24.67%, and organic nitrogen is improved by 12.43-23.65%; dissolved organic nitrogen is improved by 10.56-15.43%; particulate organic nitrogen is improved by 10.12-21.76%.

The invention discloses cloud computing based intelligent garden management equipment. The equipment comprises a control device, a soil nitrogen phosphorus and potassium detector, a GPS positioning device, a soil humidity sensor, a soil compactness measurement device, a vibration device, a water pipe flow valve, a nitrogen fertilizer bin, a phosphorus fertilizer bin, a potassium fertilizer bin, a cloud computing server and a thin film solar cell. The cloud computing based intelligent garden management equipment can be used for quantitatively adding certain elements into soil correspondingly by virtue of the soil nitrogen phosphorus and potassium detector; the soil compactness measurement device and the vibration device are provided, so that compact soil can be loosened due to action of the vibration device; soil is quantitatively fed due to delicacy management of the equipment; and the soil compactness can meet requirement due to vibration of the vibration device, and water and fertilizer can be easily absorbed by plants; the vibration device can generate electric energy by branches swinging in wind to loosen soil; and a solar generation device is energy-saving, environment-friendly and pollution-free.

The invention discloses a soil nitrogen detection pretreatment method based on a portable near-infrared spectroscopy. The soil nitrogen detection pretreatment method comprises step 1 of soil sample pretreatment: drying a soil sample under 60 to 70 DEG C for at least 12 hours, grinding the soil sample to the particle diameter smaller than or equal to 160mu m after a temperature of the soil sample is cooled to a room temperature and pressing to a cuboid sample; step 2 of utilizing a near-infrared spectrum to detect the cuboid sample to obtain spectral information; step 3 of inputting the spectrum information into a spectral signal and soil nitrogen content relation model to obtain a soil nitrogen content. According to the soil nitrogen detection pretreatment method disclosed by the invention, the soil sample and a urea solution are treated by a series of strict pretreatment operation of fully mixing, drying, grinding, sieving, tabletting and the like; then a near-infrared spectrum is collected to establish the spectral signal and soil nitrogen content relation model, and the nitrogen content in the soil can be obtained according to the relation model; thus, detection accuracy is improved, and a foundation is laid for following agriculture and scientific researches.

The present invention provides a food product comprising at least 1.5%, 5%, 10%, 20%, 30%, or more, by weight total ingredients of a low bitter chicory plant material or flour. The present invention also provides a method for obtaining a chicory product with reduced bitterness, comprising blanching chicory roots or root chips, drying the blanched chicory root chips, and optionally grinding the dried chicory root chips and incorporating it into flour, dough, or other food products. Also provided is a method for obtaining a chicory taproot with reduced bitterness, comprising cultivating a chicory plant at a soil nitrogen level of 150 lbs per acre or less in the upper 3 feet of the soil.

The invention discloses a high-yield drop irrigation maize soil nutrient diagnosis and nitrogen fertilizer recommendation method which comprises the following steps: detecting the content of soil base mineral nitrogen (Nmin) before maize sowing, performing the fertilization treatment pre-stage test, and recommending the total nitrogen fertilization content of the high-yield drop irrigation maize in the total growth period under high-density cultivation conditions according to the fitted equation of the total nitrogen supply amount and yield; and measuring the soil mineral nitrogen content of the maize at each growth and development stage, and according to the fitted equation of the nitrogen supply amount and yield of maize at each growth and development period, determining the critical level of the nitrogen supply of the soil at each stage, and recommending the optimal topdressing amount at each stage. According to the high-yield drop irrigation maize soil nutrient diagnosis and nitrogen fertilizer recommendation method disclosed by the invention, the soil serves as a test object, the content of the mineral nitrogen (Nmin) in the soil is detected, the soil nitrogen supply condition is judged, the nitrogen supply capacity of the soil can be directly and accurately reflected by virtue of the measurement indexes, and the method has high practicality for guiding the fertilizing management of drop irrigation maize of which the planting density is 105000 plants / hm<2> and the target yield is more than 17000kg / hm<2>.

The invention relates to an intelligent variable rate fertilization adjustment device and a control method. The intelligent variable rate fertilization adjustment device includes a frame traction device, a deep loosening soil preparation device, a variable rate fertilization device and a variable rate fertilization control device. The deep loosening soil preparation device includes a rotary tilling device and a deep loosening device. The variable rate fertilization device includes a single fertilization device, a fertilizer discharge pipe, a fertilizer box and an electrical control box. The variable rate fertilization control device includes an embedded industrial personal computer, a single chip microcomputer, an opening degree adjustment stepped motor driver, a speed adjustment stepper motor driver, an opening degree sensor, a speed sensor and a soil nitrogen content sensor. Variable adjustment in the fertilization process can be realized according to the nitrogen content of soil, and precision fertilization for each position of a plot can be realized. Moreover, the intelligent variable rate fertilization adjustment device has the advantages of simple structure, reasonable designand easy popularization, the problem of fertilizer application in the process of crop fertilization can be fully solved, fertilizers can be effectively utilized, and environmental pollution and wasteof fertilizers can be avoided.

The invention discloses a method for reducing a nitrogen fertilizer in a wheat-corn rotation system, belonging to the technical field of management of soil nitrogen nutrients. The method comprises the following steps: carrying out seed dressing on a Mn-Zn micronutrient fertilizer; adding a nitrification inhibitor and a coated controlled release nitrogen fertilizer when the nitrogen fertilizer is applied, and carrying out foliar topdressing of a boron fertilizer. By adopting the method, once fertilization of the nitrogen fertilizer in a wheat-corn planting system is achieved, the labor force is saved, materials are easily available, the operation process is simple, the fertilization method is simple and convenient, the cost is low, popularization is facilitated, and the application prospect is good. The application rate of the nitrogen fertilizer is obviously reduced, compared with the traditional fertilization in wheat and corn planting, the method has the advantage that the dosage of the nitrogen fertilizer is reduced by over 20%, loss of the nitrogen nutrients is obviously reduced, the pollution to water and an atmospheric environment is relieved, the environment risk is reduced, and the needs of agricultural sustainable development are satisfied.

The invention discloses a method of determining nitrogen fertilizer application in crops, which can determine the nitrogen fertilizer application Nfert of the crops according to the quantitative relation of nitrogen fertilizer, soil nitrogen and nitrogen uptake by the crop at the crop root zone. The method can realize quick, accurate and quantitative nitrogen fertilizer application without testing the soil or plants, so that the cost for determining the nitrogen fertilizer application in the production is greatly saved.

The invention discloses a method for preparing a composite biological agent by double-bacterium co-culture. The method is characterized in that two microbes with different functionalities are co-cultured in a same fermentation apparatus. According to the invention, with life activities between the two microbes, and produced substances or a formed environment, the microbes are interdependent and are mutually benefited. At a same time, a preparation containing products of two microbes is obtained. According to physiological characteristics of strains, two microbes with different growth speeds and different growth periods are adopted, wherein the microbes can perform nutrition complementation, and can live in a same environment. With a co-culturing process, a product containing two functional microbes and metabolite thereof is obtained. Compared with independent culturing, the method provided by the invention is advantaged in improved production efficiency, reduced production cost, and substantially improved application effect. With the product, soil water-soluble phosphorus is increased, and soil nitrogen fixation capacity is improved.