47 results about "Coated urea" patented technology

The invention discloses a preparation method of an ethyl cellulose and isocyanate cross-linked coated urea slow-release fertilizer, and relates to a preparation method of a urea slow-release fertilizer. The invention aims to solve the problems that the existing nitrogen fertilizer is low in utilization rate and easy to absorb moisture and cake, a polyurethane coating material is non-degradable, and pure ethyl cellulose is insufficient in mechanical strength and limited in water resistance and is not beneficial to being used as a coating matrix of the fertilizer. The method comprises the following steps: 1, preparing an ethyl cellulose cross-linked isocyanate enveloping solution; and 2, preparing the ethyl cellulose and isocyanate cross-linked coated urea slow-release fertilizer. According to the preparation method, etherified derivative ethyl cellulose of cellulose is taken as a raw material, and the defects that a pure ethyl cellulose membrane is insufficient in mechanical strength, limited in water resistance and low in nutrient separation control precision are overcome by utilizing isocyanate crosslinking modification. The prepared slow-release fertilizer has the advantages of being simple in process, low in cost, environmentally friendly, degradable in matrix, capable of effectively preventing urea from absorbing moisture and caking and the like, and is suitable for large-scale preparation and used in agricultural production.

The invention discloses a special organic-inorganic compound fertilizer for improving the yield and quality of rice in a rice field, and belongs to the technical field of agricultural fertilizers. The compound fertilizer comprises a three-layer structure consisting of a porous core layer, a quick release coating layer and a biodegradable film, wherein the porous core layer is prepared from ammonium polyphosphate, potassium humate, nano charcoal modified chicken manure, mineral source potassium fulvate and sodium carboxymethyl cellulose-bentonite composite colloid; the quick-release coating layer is prepared from sulfur-resin double-layer coated urea, amino acid chelated zinc, alginic acid complex boron, silica sol, ammonium molybdate, 5-aminolevulinic acid and nano cerium oxide; the biodegradable film is prepared from a film forming solution and a bioactive microbial agent. Through the design of a three-layer structure and the combination of an organic-inorganic-microorganism synergistic technology, accurate matching of nutrient release and a rice fertilizer requirement rule is achieved, meanwhile, soil health and environmental protection are considered, and an innovative solution is provided for green high-yield rice planting.

The invention relates to the technical field of microbial culture, in particular to a heterotrophic culture method of benthic diatom, which comprises the following steps: S1, adding benthic diatom into an improved SE culture medium, and culturing for 5-7 days until OD540 is 0.8-1.2 to obtain a benthic diatom seed solution; according to the method disclosed by the invention, a nutrition system is constructed by taking waste glycerol as a carbon source and sodium alginate coated urea as a slow-release nitrogen source, and the benthic diatom, nitrogen-fixing bacteria and phosphate solubilizing bacteria are co-cultured on a porous ceramic carrier to be cultured under a dark condition, so that compared with the prior art, the method disclosed by the invention thoroughly gets rid of the dependence on illumination, and the yield is increased. The rapid, high-yield and stable heterotrophic culture of the benthic diatom is realized, meanwhile, the raw material and energy consumption cost is greatly reduced, and the resource recycling rate is improved; the obtained diatom biomass can be used for aquatic bait, biological energy, environmental restoration and development of high-added-value products, and has a wide industrial application prospect.

The application discloses resin-coated urea slow-release fertilizer, a preparation method and application thereof, and first prepares resin-coated urea slow-release fertilizer, adopts polystyrene, polyethylene, talcum powder and starch mixture to be dispersed and heated in tetrachloroethylene to prepare coating liquid, then sprays the coating liquid on the surface of dried urea after pretreatment, and with evaporation of the solvent, a resin layer is formed on the particle, and the resin-coated urea slow-release fertilizer is obtained. The resin-coated urea can simulate atmospheric nitrogen deposition, and can more truly simulate the nitrogen deposition mode.

The invention discloses a special compound fertilizer for food crops as well as a preparation method and application thereof, and belongs to the technical field of organic and microbial fertilizers. The compound fertilizer comprises a basic fertilizer and an organic biological fertilizer source, wherein the basic fertilizer is prepared from sulfur coated urea, urea, calcium superphosphate, potassium chloride, sodium metasilicate and oyster shell powder; the organic biological fertilizer source is composed of a vinasse fermentation product, a microbial activity protective agent and lignosulfonate. The vinasse fermented product is prepared by carrying out three-stage solid state fermentation on vinasse by adopting a compound bacterium suspension consisting of mycobacillus halophilus and ocean sediment vesicular bacillus. Through synergistic fermentation of functional strains, compounding of a microbial active protective agent and introduction of a slow-release nitrogen source and stress-resistant components, synergistic interaction of efficient release of nutrients, soil improvement and improvement of crop stress resistance is realized. The compound fertilizer is suitable for grain crops such as wheat and rice, can remarkably improve root activity, yield and stress resistance, and has a wide application prospect.

Disclosed is a fertilizer granule comprising a core comprising at least 90 wt% urea and a shell comprising a urea calcium sulfate (UCS) adduct, wherein the shell covers at least a portion of the outer surface of the core, and blends of the fertilizer granule with other fertilizers. Also disclosed are methods of making and using the fertilizer granule and blends.

The invention provides a micromolecular organic carbon water-soluble fertilizer for promoting lignification of eucalyptus, and a preparation method and application thereof, and belongs to the technical crossing field of microorganisms, forestry and organic water-soluble fertilizers. The micromolecular organic carbon water-soluble fertilizer for promoting eucalyptus lignification comprises the following components in parts by weight: 3-5 parts of a biological agent, 10-20 parts of food industry leftovers, 20-30 parts of an organic solid fertilizer, 5-15 parts of sodium silicate, 10-20 parts of monocalcium phosphate, 5-15 parts of potassium chloride, 5-15 parts of magnesium nitrate, 5-15 parts of sulfur coated urea, 0.1-0.5 part of a rooting agent, 0.5-1 part of a trace element composite nutrient solution, 5-50 parts of deionized water and 1-3 parts of a pH regulator. The biological agent is prepared by fermenting a new bacillus tequilensis strain, namely, bacillus tequilensis XD63Y, and the collection number of the bacillus tequilensis XD63Y is GDMCC No: 62521. The organic solid fertilizer is prepared by crushing plant straws and then performing composting or fermentation treatment. The micromolecular organic carbon water-soluble fertilizer provided by the invention can promote the growth and lignification process of the eucalyptus, shorten the growth cycle of the eucalyptus, increase the yield of the eucalyptus and enhance the disease and pest resistance of the eucalyptus.

The application discloses a starch-based coated slow-release urea and a preparation method thereof. The slow-release urea is composed of a core and a composite coating layer. The core is urea particles. The composite coating layer comprises a paraffin layer as an inner layer and a starch-based material layer as an outer layer. The mass of the paraffin layer accounts for 0.5-2% of the total mass of the slow-release urea. The total mass of the composite coating layer accounts for 4-10% of the total mass of the slow-release urea. The starch-based material layer is formed by cross-linking reaction of starch and / or modified starch and glutaraldehyde. The method is continuous, simple and low in cost. The coating material is biodegradable. The obtained product has good slow-release performance and moisture-proof stability. In addition, the outer layer film formed by chemical cross-linking has good mechanical strength and is combined firmly with the inner paraffin layer, so that the structural integrity of the coated urea during storage, transportation and application is ensured.

The invention belongs to the technical field of fertilizers, and particularly relates to PBAT-based environment-friendly slow-release coated urea and a preparation method thereof. The PBAT-based environment-friendly slow-release coated urea provided by the invention comprises urea particles and a coating layer coating the urea particles, and the coating layer comprises the following raw materials: PBAT, an organic matter modifier and an inorganic matter modifier; the organic matter modifier comprises at least one of methyl cellulose or polyvinyl ether, and the inorganic matter modifier comprises at least one of bentonite or hydrotalcite. The coating material used in the PBAT-based environment-friendly slow-release coated urea has good biodegradability, degradation products have little harm to soil, the time required for the nitrogen nutrient release amount of the PBAT-based environment-friendly slow-release coated urea to reach 90% is 80-120 days, and the PBAT-based environment-friendly slow-release coated urea is suitable for growth of crops such as corn, soybeans and rice.

The invention relates to a complete-element bio-organic fertilizer suitable for loess plateau rain-fed agriculture. The complete-element bio-organic fertilizer is prepared from a composted material, a composite plant growth-promoting microbial agent, coated urea, potassium sulfate, boron and zinc trace elements, an anionic polyacrylamide-bentonite compound water-retaining agent and ammonium humate. The rotten material is prepared by fermenting and rotting sheep manure, shiitake mushroom residues, modified mushroom residue biochar and phosphate fertilizer through a composite high-temperature degradation bacterial agent; the compound plant growth promoting bacterial agent is prepared from bacillus subtilis LDB01, bacillus mucilaginosus and trichoderma harzianum Trichoderma harzianum T-22, and the compound plant growth promoting bacterial agent is prepared from bacillus subtilis LDB01, bacillus mucilaginosus and trichoderma harzianum T-22, and the compound plant growth promoting bacterial agent is prepared from bacillus subtilis LDB01, bacillus mucilaginosus and trichoderma harzianum T-22. Meanwhile, the invention further discloses a preparation method of the complete-element bio-organic fertilizer. The complete-element bio-organic fertilizer is comprehensive and balanced in nutrition, the survival rate of bacteria can be increased, and drought stress is avoided.

The invention belongs to the field of fertilizer and rice planting, and discloses a slow mixed fertilizer for improving the quality of rice in saline-alkali soil, which is prepared from the following components in parts by mass: 10-12 parts of urea, 21-25 parts of sulfur coated urea, 39-47 parts of 90-day resin coated urea, 14-22 parts of resin coated diammonium phosphate and 10 parts of resin coated potassium chloride. The slow-mixing fertilizer is applied at one time during paddy field soil preparation, and the nitrogen application amount is 65-80% of the local conventional nitrogen application amount. By optimizing the proportion of nitrogen, phosphorus and potassium and combination of slow-release materials, nutrient release is dynamically matched with fertilizer requirement in the key growth period of rice, nitrogen loss is remarkably reduced, the fertilizer utilization rate is increased, and the yield is stably increased; meanwhile, the processing quality, the appearance quality and the taste quality of the rice are improved; the nitrogen application amount is reduced to 65-80% of the conventional nitrogen application amount, the non-point source pollution risk is remarkably reduced, and both high-quality production and ecological protection are considered.

The invention discloses a slow-mixing fertilizer suitable for increasing yield and reducing emission of machine-transplanted early rice in a low-latitude region. The slow-mixing fertilizer is prepared from the following components in parts by mass: 4-6 parts of sulfur-coated urea and 4-6 parts of 2-month resin-coated urea. The invention further discloses application of the slow-mixing fertilizer in early rice production, fertilization and rice transplanting are synchronously carried out, and the slow-mixing fertilizer is directly applied to the position 5 cm away from the rhizosphere side of seedlings and the position 3-5 cm deep in soil. The slow-mixing fertilizer provided by the invention can improve yield and nitrogen fertilizer utilization efficiency and reduce greenhouse gas emission. Compared with the conventional high-yield fractional fertilization, the slow-mixing fertilizer disclosed by the invention has the advantages that by applying the slow-mixing fertilizer disclosed by the invention, the yield of rice is increased by 7.5%-7.8%, the nitrogen fertilizer utilization efficiency is increased by 30.5%-44.5%, meanwhile, the global temperature increasing potential is reduced by 12.8%-27.5%, and the greenhouse gas emission intensity is reduced by 19.3%-32.7%.

A machine-transplanted rice milk seedling transplanting technology belongs to the technical field of rice cultivation, and is characterized in that the leaf age of transplanted milk seedlings is 1.5-2.1 leaves, the plant height is 7-10cm, the dry seeding rate per square meter is 1200-1800g, the packing is good and suitable for machine-transplanted rice seedlings, compared with the traditional machine-transplanted rice seedlings, the seedling raising area is reduced by 50%, the seedling raising time is shortened by 40%, 20% of nutrients still remain in endosperm after transplanting, and the seedling recovery is overweight. 8 roots of the third extending leaf and the incomplete leaf node extending simultaneously are formed; coated urea with the release period of 30 days (transplanting with nitrogen fertilizer) is spread before transplanting to continue nitrogen nutrition supply in the weaning period, tillering of the first leaf position and the second leaf position extending together with the fourth leaf and the fifth leaf is promoted, the growth period is shortened by 20 days compared with that of transplanted seedlings with 3.1-3.5 leaves, plant protection measures such as disease prevention, rooting and acid regulation in the weaning period are omitted, pesticide is reduced, the environment is protected, cost is saved, consumption is reduced, and the yield increasing potential is achieved.

The invention discloses a preparation method of large-particle urea surface treatment liquid and application of the large-particle urea surface treatment liquid in polyurethane coating, and belongs to the technical field of chemical fertilizer industry. The large-particle urea surface treatment liquid is prepared from nano powder, a dispersing agent, a film-forming high polymer, a wetting agent, a defoaming agent and water. The large-particle urea for surface treatment is coated with polyurethane, so that the large-particle urea with high smoothness can be obtained under the conditions of high efficiency and low energy consumption. Tests show that the nitrogen nutrition accumulative release rate in 24 hours is 0.10-0.33%, the nitrogen nutrition accumulative release rate in 7 days is 3.59-5.02%, the nitrogen nutrition accumulative release rate in 28 days is 14.95-16.37%, the nitrogen nutrition accumulative release rate in 60 days is 30.46-32.09%, and the polyurethane coated urea is excellent in controlled release rate.

The application provides a coated urea production system, which comprises a coating liquid conveying system and a urea conveying system; the coating liquid conveying system comprises a coating liquid storage tank, a conveying pipeline and a spraying assembly arranged on the conveying pipeline which are sequentially connected; a coating power pump and a pressure adjusting system for controlling the spraying amount of the coating liquid are arranged on the conveying pipeline, the pressure adjusting system comprises the following control parameters: power air pressure 0.35-0.6 Mpa, pump outlet pressure 0.25-0.5 Mpa; the urea conveying system comprises a conveying belt and a stirring device arranged on the conveying belt, the modified urea has a core-shell structure, the inner core is urea particles, the intermediate coating layer is modified attapulgite and polyvinyl alcohol, and the outer shell is starch-acrylonitrile graft copolymer; the obtained urea has good coating effect, and the coating stability and the urea stability are both excellent, and the strength and the slow-release effect of the urea product are improved.

The invention discloses a resin-coated urea slow-release fertilizer and a preparation method and application thereof.The resin-coated urea slow-release fertilizer is prepared firstly, specifically, a mixture of polystyrene, polyethylene, talcum powder and starch is dispersed and heated in tetrachloroethylene to prepare coating liquid, then the surface of dried urea is pretreated and then sprayed with the coating liquid, and the resin-coated urea slow-release fertilizer is obtained; along with evaporation of the solvent, a resin layer is formed on the particles, and the resin coated urea slow-release fertilizer is obtained. The resin-coated urea is adopted to simulate atmospheric nitrogen sedimentation, so that a nitrogen sedimentation mode can be simulated more truly.

The invention relates to the technical field of agricultural organic fertilizers, and discloses a soil improvement efficient slow-release bio-organic fertilizer and a preparation method thereof.The soil improvement efficient slow-release bio-organic fertilizer is prepared from, by mass, 30%-38% of a slow-release matrix, 6%-8% of a biological functional fungicide, 18%-25% of a soil improvement auxiliary, 30% of a modified carrier framework and 6%-8% of a keep-alive and forming auxiliary, the slow-release matrix is formed by compounding calcium alginate microspheres and humic acid coated urea according to the mass ratio of (12-18): (18-20), the particle size of the calcium alginate microspheres is 100-150 microns, the crosslinking degree is 85%, and the embedding rate of nitrogen, phosphorus and potassium nutrients is larger than or equal to 90%; the nitrogen content of the humic acid coated urea is 46%, the slow release period is 90 days, and the coating thickness is 50 microns. The humic acid activated straw powder-peanut shell carbon composite carrier is adopted, the porosity is high, a survival microenvironment is provided for microorganisms, and soil salt and heavy metal can be adsorbed; and a keep-alive system of vitamin C and maltodextrin is matched, so that the attenuation rate of microorganisms stored for 120 days is reduced.

The invention provides a special compound fertilizer for rice planting and a preparation method thereof, and belongs to the technical field of fertilizers. The compound fertilizer is prepared from the following raw materials: animal waste, plant straw, sawdust, quick lime, sulfur coated urea, diammonium phosphate, potassium sulfate, compound zymophyte, cellulase, calcium hydrophosphate, zinc sulfate, borax, bentonite and a compound microbial agent. The animal waste is firstly fermented and then mixed with the inorganic components for granulation, finally, the complex microbial inoculant is sprayed at normal temperature, meanwhile, the variety and content of the inorganic components are adjusted, and only a small amount of inorganic fertilizer is added into the prepared compound fertilizer, so that the compound fertilizer can be suitable for rice planting, and the yield of rice is increased.

The invention relates to the technical field of fertilizers, in particular to a solid blended fertilizer containing vegetable oil coated slow-release urea and a preparation method of the solid blended fertilizer. A solid bulk blending fertilizer containing vegetable oil coated slow-release urea is prepared from, by mass, 40-50 parts of coated urea particles, 20-30 parts of diammonium phosphate particles, 15-20 parts of potassium chloride particles, 2-3 parts of a synergist and 1-2 parts of auxiliary materials, and the coated urea particles are prepared by spraying composite vegetable oil on the surfaces of preheated urea particles and cooling the urea particles to the room temperature. Through systematic innovation of a coating technology, synergist design and process optimization, synchronization of nutrient release and crop requirements is realized, and the bottleneck of the utilization rate of a traditional fertilizer is broken through; ecological protection is compatible with high yield and high efficiency, and green and sustainable development of agriculture is promoted; low cost and high adaptability are combined, and the requirements of large-scale planting and precision agriculture are met.

The application discloses a biodegradable coated urea added with zirconium-based MOF nanocrystals with phosphatase activity and a preparation method and application thereof, and belongs to the technical field of fertilizers. The zirconium-based MOF nanocrystals with phosphatase activity are prepared, a solution of the zirconium-based MOF nanocrystals is mixed with urea and dried, polypropylene carbonate is used as a coating material, and then the biodegradable coated urea added with the zirconium-based MOF nanocrystals with phosphatase activity is prepared through a fluidized bed solvent method. The coated urea prepared in the application can realize nitrogen control release, hydrolyze soil organic phosphorus through the phosphatase activity of the Zr-MOF nanocrystals, realize the dual functions of continuous supply of nitrogen and in-situ activation of soil phosphorus, simultaneously meet the demand of crops for two core nutrient elements of nitrogen and phosphorus, significantly relieve the low-phosphorus stress of crops, promote the growth of the root system and the aboveground part of crops, and improve the biomass of crops.

The utility model relates to the field of coated urea, in particular to a urea particle mixing and polishing device. The urea particle mixing and polishing device comprises a machine body, a paddle, a telescopic pipe and a limiting mechanism, a coating pan is installed on one side of the machine body, baffles are fixedly connected to the interior of the coating pan at equal intervals, the paddle is rotationally connected to the middle of the coating pan, a cover plate is installed on one side of the machine body, and the interior of the cover plate and the paddle are installed in a matched mode; a telescopic pipe is installed at the top end of the machine body, and one end of the telescopic pipe is fixedly connected with the middle of the cover plate. According to the utility model, after the paddle stirrer is introduced, the rotation of the stirrer can generate a stronger mixing effect, and the mixing uniformity of urea particles in the coating process is obviously improved under the combined action of the stirrer and the baffle plate in the coating pan. Therefore, the coating effect of the urea particles is facilitated, and the uniformity and consistency of the coating layer are also ensured.

The invention provides bio-based polyurethane coated urea as well as a preparation method and application thereof. The bio-based polyurethane coated urea comprises urea and a coating material coating the surface of the urea, the coating material comprises bio-based polyurethane, and the bio-based polyurethane is prepared from bio-based polyol and an isocyanate compound, the bio-based polyol is a reaction product of a lactic acid prepolymer and epoxidized vegetable oil. The polyurethane coated urea has the advantages of being excellent in nitrogen fertilizer slow release effect, high in bio-based content, capable of being degraded by microorganisms, small in pollution, low in cost and the like.

The utility model discloses a film laminating mechanism, including feeding mechanism, sealing film mechanism and cutting mechanism, feeding mechanism includes the support frame, the belt conveyer that is movably installed in the support frame, the sealing film mechanism, the sealing film mechanism includes two hydraulic cylinder that the slide passes through the support frame top, the U-shaped plate that connects between the two hydraulic cylinder. In the utility model, after a urea bag is laminated by the laminating column, the piston rod of the cylinder extends out to drive the machine sleeve, the motor on the machine sleeve and the rubber plate I to integrally move, so that the rubber plate I is inserted between the laminating column and the laminated urea bag and compresses the movable end of a film, then the motor is started to drive the rubber plate II and the blade to rotate through the plastic arc plate; the second rubber plate stretches the film and presses and attaches the film to subsequent urea bags, when the second rubber plate is turned to be parallel to the plane of the top of the belt conveyor, the blade cuts off the film between every two adjacent urea bags, and therefore the phenomenon that the film floats up is effectively avoided.

The invention relates to a one-time fertilization method for saline-alkali soil rice in a whole growth period. Fertilizer is applied according to the salt content of the soil and the target yield, and when the salt content of the soil is larger than or equal to 0.3% and the target yield is larger than or equal to 400 kg / mu, 12-15 kg / mu of nitrogen fertilizer is applied according to pure N, 5-7 kg / mu of phosphate fertilizer is applied according to P2O5, 4-6 kg / mu of potassium fertilizer is applied according to K2O; when the salt content of the soil is larger than or equal to 0.2% and the target yield is larger than or equal to 600 kg / mu, 15-18 kg / mu of nitrogen fertilizer is applied according to pure N, 7-9 kg / mu of phosphate fertilizer is applied according to P2O5, and 6-8 kg / mu of potassium fertilizer is applied according to K2O. The nitrogen fertilizer contains the following components in parts by mass: 20-30 parts of urea, 30-40 parts of 60-day and 90-day resin coated urea and 30-50 parts of 60-day and 90-day resin coated urea, so that the nutrient release of the nitrogen fertilizer is highly matched with the fertilizer required by the growth of the saline-alkali soil rice, and the yield of the coastal saline-alkali soil rice, the fertilizer utilization rate and the planting benefit are improved.

The application belongs to the technical field of soil improvement, and discloses a sandy ginger black soil low-yield field soil improvement method, which comprises the following steps: adding a soil improvement agent, then deep ploughing the soil, planting wheat, and returning straw to the field at harvest time, wherein the soil improvement agent comprises the following components in parts by weight: dry animal manure 32 parts, soybean meal 21 parts, humic acid 18 parts, edible mushroom residue 14 parts, water-retaining agent 11 parts, compound fertilizer 2 parts, resin-coated urea 1 part and microbial inoculant 1 part. The application improves the soil condition, thereby improving the crop yield.

The invention discloses anti-floating coated urea based on a water-soluble pigment and a preparation method of the anti-floating coated urea, and belongs to the technical field of slow-release fertilizers. Azone, dodecyl glucoside and polyvinyl alcohol are compounded to prepare a composite surfactant, then the composite surfactant is used for preparing the anti-floating coated urea based on the water-soluble pigment, and the anti-floating coated urea is specifically prepared from the following raw materials in parts by mass: 0.05-1 part of food-grade pigment, 0.5-5 parts of the composite surfactant, 900-1100 parts of urea and 5-20 parts of polyhydric alcohol. 5 to 20 parts of isocyanate; 5 to 20 parts of water; compared with the situation that the surfactant is not used or a single surfactant is used, the anti-floating capacity of the anti-floating coated urea is effectively enhanced. The anti-floating coated urea prepared by the invention is good in anti-floating property, controllable in nutrient release, good in environmental protection property and high in appearance identification degree, meets the development requirements of green and environment-friendly agriculture, and improves the market competitiveness of the product.

The invention discloses a method and system for evaluating the slow release property of coated urea based on a contact angle, and the method comprises the steps: determining a coated urea sample to be evaluated, and measuring the contact angle of a coating material of the coated urea sample to be evaluated; establishing a correlation model of the contact angle and the slow release performance of the coated urea; the measured contact angle is input into the correlation model for calculation, and the nitrogen cumulative release rate of the coated urea sample to be evaluated is obtained; and evaluating the slow release property of the coated urea to be evaluated according to the accumulated nitrogen release rate in combination with a set evaluation standard. By establishing the quantitative relation between the contact angle and the slow release performance of the coated urea, the slow release performance of the coated urea can be rapidly and accurately evaluated, and a scientific basis is provided for research, development, production and quality control of the coated urea.

The application discloses a kind of fertilizer for rice planting and its preparation method, the fertilizer is the particle with the triple structure of core-shell-outer functional layer, including: core layer, by 35±2 parts of polyurethane coated urea is constituted;Intermediate layer, is covered outside the core layer, by 25±2 parts of sulfur-coated urea is constituted;Outer layer, is covered outside the intermediate layer, and total weight is 40±5 parts.The application realizes the programmed release of nutrient by the triple structure design of "core-shell-outer functional layer", and outer layer mineral source humic acid potassium, composite silicon source and the like are rapidly dissolved and released, stimulate seedling root and provide early resistance ability;Intermediate layer sulfur-coated urea is degraded in tillering to early jointing stage, releases nitrogen and sulfur element, accurately interfaces rice first nitrogen uptake peak, and sulfur element activates nitrogen metabolic enzyme, improves nitrogen assimilation efficiency;Core layer polyurethane coated urea continuously releases nitrogen in late jointing to milk stage, effectively prevents late period from losing fertilizer.

The invention belongs to the technical field of feed industrial quality detection and analytical chemistry, and provides a rapid detection method for the urea content of coated urea for feed, which comprises the following steps: dispersing coated urea particles in a water-based solvent (water) or a compound organic solvent, leaching in a constant-temperature water bath at 60-100 DEG C for 5-120 minutes, melting and crushing a coating layer, and carrying out solid-liquid separation to obtain the coated urea for the feed. Carefully sucking the supernate (water phase), filtering, washing residues with pure water, and combining filtrates to obtain a to-be-detected solution; testing the refractive index of the to-be-tested liquid, substituting the refractive index into a pre-generated urea concentration-refractive index standard curve, calculating to obtain the urea concentration of the to-be-tested liquid, and further calculating the urea content of the coated urea. The method can directly aim at complete particles, pretreatment errors are avoided, operation is safe and rapid, the result is accurate and reliable, the detection period is shortened to 1 hour from 3-4 hours, and the problems that an existing method is large in sample pretreatment error, dangerous and tedious in operation, insufficient in result precision and accuracy and the like are solved.

The invention discloses a slow-mixing fertilizer suitable for increasing yield and reducing emission of machine-transplanted late rice. The slow-mixing fertilizer is prepared from the following components in parts by mass: 4-6 parts of sulfur coated urea and 4-6 parts of 3-month resin coated urea. The invention further discloses application of the slow-mixing fertilizer in late rice planting, fertilization and rice transplanting are synchronously carried out, and the slow-mixing fertilizer is directly applied to the position 5 cm away from the rhizosphere side of a seedling and the position 3-5 cm deep in soil. Compared with an existing nitrogen fertilizer management scheme, by applying the slow-mixing fertilizer, the rice yield and the nitrogen fertilizer utilization efficiency are improved by 8.26% and 32.67% respectively, and meanwhile the global warming potential and the greenhouse gas emission intensity are reduced by 10.07% and 16.81% respectively.