Compound microbial organic fertilizer and preparation method thereof

Abstract

The invention discloses a compound microbial organic fertilizer and a preparation method thereof, and belongs to the technical field of compound organic fertilizers, the compound microbial organic fertilizer comprises livestock and poultry manure, leaf mold, lignite, seaweed residues, synechococcus, a compound fermentation inoculant, diatom ooze, turf, porous pelelith powder, modified charcoal and living adult earthworms. By means of secondary fermentation and curing treatment, the number of thalli of the finished fertilizer is increased, flora in earthworms is utilized, nutrient activity and soil air permeability are improved, vesuvianite powder, modified charcoal and graphene are adopted, the air permeability, water retention and fertilizer retention effects of soil after fertilization are improved, pesticide residues are effectively adsorbed, slow degradation is achieved, and tea seed cakes and lignite are adopted, so that the effect of improving the fertilizer efficiency is achieved. The soil pH is effectively adjusted, soil-borne diseases are inhibited, and the soil aggregate structure is improved in cooperation with seaweed residues and synechococcus.

Description

Technical Field

[0001] The present invention specifically relates to a compound microbial organic fertilizer and a preparation method thereof, belonging to the technical field of compound organic fertilizers. Background Art

[0002] A compound microbial organic fertilizer is a kind of fertilizer composed of specific microorganisms and nutrients. These microorganisms usually include beneficial strains such as nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria, actinomycetes, and bacillus. They are combined with nutrients such as organic matter and inorganic nutrients to form a living microbial product that can provide, maintain or improve plant nutrition, increase the yield or quality of agricultural products, and is widely used in modern agriculture. When modern compound microbial organic fertilizers are used, most of them use different substrates for mixed fermentation and then undergo ripening treatment before use.

[0003] For example, a compound microbial organic fertilizer and a preparation method thereof disclosed in the Chinese authorized invention patent with the publication number: CN113277895B include microbial cultivation, mixing materials, compost fermentation, turning the pile and adding liquid, and drying and storage; due to the proliferation of harmful microorganisms in the organic fertilizer itself, it restricts the reproduction of the added microbial inoculant, making it difficult to master the time when the compost enters the fermentation state, and then weakening the efficacy of the compound microbial organic fertilizer; therefore, in the present invention, expanded perlite is arranged in the inorganic fertilizer to form a water bath layer at the bottom of the tray, balancing the heating effect of the tray on the bottom area of the organic fertilizer, and also using the water storage performance of expanded perlite to intercept the water evaporated from the bottom during the heating of the tray, maintaining the water content of the organic fertilizer, avoiding dehydration of the organic fertilizer caused by the heating and temperature rise of the tray, and maintaining the metabolic activity of microorganisms in the organic fertilizer, thereby improving the application effect of the compound microbial organic fertilizer.

[0004] Another example is a high-efficiency microbial organic fertilizer and a preparation method and application thereof disclosed in the Chinese authorized invention patent with the publication number: CN107365206B, belonging to the field of fertilizers. The raw materials of the above high-efficiency microbial organic fertilizer include livestock manure, cake meal, straw, feather meal, fish meal, bone meal, blood meal, waste tobacco leaves, rooting agent, sugar, compound microbial flora, magnesium sulfate, trace elements, calcium magnesium phosphate, silicon potassium ore powder, and shale. The raw materials of this high-efficiency microbial organic fertilizer are rich and the ratio is scientific, with comprehensive nutrition and high fertilizer efficiency, and can meet the nutritional requirements of plants at each growth stage. Its preparation method is: mixing livestock manure and straw according to the ratio, then mixing with the remaining raw materials, and then fermenting and granulating. This method is simple, and the organic materials can be fermented at a fixed time and temperature through the microbial flora, which can ensure the content of effective nutrients in the finished product. The production process is advanced and can achieve industrial production. Applying the above fertilizer to crop planting can effectively improve the disease resistance of crops and achieve the effect of increasing production and income.

[0005] During preparation, the obtained fertilizer has a low nutrient content. When in use, there are deficiencies in the number of bacteria and the exertion of fertilizer efficiency, resulting in poor yield increase effect on crops and easily causing a decrease in soil air permeability and soil compaction. Summary of the Invention

[0006] The purpose of the present invention is to provide a compound microbial organic fertilizer and its preparation method in view of the deficiencies of the prior art, so as to achieve the purpose of sufficient nutrients, improving the water retention, fertilizer retention and air permeability of the soil, adsorbing pesticide residues and enhancing soil fertility.

[0007] A compound microbial organic fertilizer, which includes 10-20 parts of livestock and poultry manure, 20-35 parts of leaf mold, 5-10 parts of lignite, 5-15 parts of seaweed residue, 4-15 parts of tea seed cake, 8-15 parts of Synechococcus, 10-15 parts of compound fermentation bacteria agent, 15-30 parts of diatomite, 1-5 parts of peat, 3-10 parts of porous volcanic stone powder, 10-20 parts of modified biochar by weight ratio, and adds living adult earthworms at 8-18 per kilogram.

[0008] When in use, livestock and poultry manure and leaf mold are used as the main matrix, and lignite and tea seed cake are used to effectively adjust the soil pH and inhibit soil-borne diseases. Combined with seaweed residue and Synechococcus, the soil aggregate structure is improved. Among them, the lignite is the residue after traditional Chinese medicine extraction (such as astragalus, licorice, isatis root residue), retaining plant saponins and flavonoids, and having both disease-resistant and growth-promoting functions in the finished fertilizer. The tea seed cake is the tea seed cake discarded by urban coffee shops or the tea beverage industry, containing organic acids and polyphenols, adjusting the soil pH and inhibiting soil-borne pathogens. And the seaweed residue and Synechococcus are rich in seaweed polysaccharides, natural auxins (such as alginic acid, betaine) and trace elements (iodine, zinc, boron), which can enhance plant stress resistance. Through living adult earthworms, the co-fermentation of earthworm intestinal microorganisms and organic materials is utilized, containing highly active enzymes (protease, lipase), accelerating nutrient release and improving soil fertility.

[0009] Further, the compound fermentation bacteria agent is prepared by mixing nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria and EM bacteria.

[0010] Further, the modified biochar is biochar generated by pyrolysis of agricultural crop by-products, and graphene oxide is loaded by chemical vapor deposition, and the concentration of graphene is less than 0.01%. Utilizing the porous structure of graphene, the water retention and fertilizer retention capacity is improved, and pesticide residues (such as organophosphorus) are effectively adsorbed and slowly degraded to reduce soil drug pollution.

[0011] A preparation method of a compound microbial organic fertilizer. When in preparation, the method includes the following steps: Step 1: First Stirring and Mixing. Mix the raw materials to form mixture A, and the state of the mixture is that it can be formed into a ball by hand and will disperse when released.

[0012] Step 2: Inoculation and Fermentation. Add a compound fermentation agent to mixture A and conduct moisture-preserving fermentation.

[0013] Step 3: Ripening. Spread out the fermented mixture A for ripening.

[0014] Step 4: Second Mixing. Add the remaining raw materials to the ripened mixture A and mix thoroughly to form mixture B.

[0015] Step 5: Shaded Stacking. Use live adult earthworms for biological treatment.

[0016] Step 6: Crushing, Fermentation and Second Ripening. Inoculate the remaining compound fermentation agent and repeat Step 2 and Step 3 for second ripening.

[0017] Step 7: Drying Treatment. Conduct drying and crushing treatment on the second-ripened mixture B.

[0018] Step 8: Post-processing. Granulate and package the dried mixture B to complete the preparation.

[0019] Furthermore, in Step 1, when conducting the first stirring and mixing, stir and mix livestock manure, leaf mold, lignite, seaweed residue and Synechococcus. When mixing, add an appropriate amount of water according to the humidity to form a state that can be formed into a ball by hand and will disperse when released, thus forming mixture A. When using livestock manure, first dry it in the sun for 7 - 14 days and then use it.

[0020] Furthermore, in Step 2, when conducting inoculation and fermentation, add two-thirds of the amount of the compound fermentation agent to mixture A, and during fermentation, conduct shading and moisture preservation, and control the fermentation time within 30 - 60 days. In Step 3, when conducting ripening, control the ripening cycle within 7 - 14 days, and during the ripening process, turn the materials 2 - 3 times.

[0021] Furthermore, in Step 4, when conducting the second mixing, add diatomite, peat, porous volcanic stone powder and modified biochar to the ripened mixture A. After mixing, add live adult earthworms according to the weight of the mixed substrate, and then proceed to Step 5. In Step 5, stack it in a long strip shape, sprinkle water, keep the humidity at 60% - 80%, and control the stacking time within 10 - 20 days.

[0022] Further, in step six, the mixture with live adult earthworms is crushed to kill the live adult earthworms, and the remaining one-third of the compound fermentation inoculant is inoculated, and then mixed to form mixture B. After mixing, steps two and three are repeated.

[0023] Further, in step seven, when drying, a fluidized bed dryer is used for drying. After drying, it is crushed, and after crushing, the post-processing of step eight is carried out to complete the preparation.

[0024] Beneficial effects: By adopting secondary fermentation and ripening treatment, the number of bacteria in the finished fertilizer is increased, and the bacteria in the live earthworms are used to enrich the fertilizer, improve the nutrient activity and soil aeration. In the finished product, there are earthworm corpse fermentates and earthworm feces, which effectively improve the nutrient situation of the soil.

[0025] By adopting volcanic stone powder, modified biochar and graphene, the air permeability, water retention and fertilizer retention effects of the soil after fertilization are improved, the pesticide residues are effectively adsorbed and slowly degraded, which is helpful for the growth of crops.

[0026] By using tea seed cake and lignite, the soil pH can be effectively adjusted, soil-borne diseases can be inhibited, and the soil aggregate structure can be improved in cooperation with seaweed residues and Synechococcus. Brief Description of the Drawings

[0027] Figure 1 It is the ingredient ratio diagram of the present invention; Figure 2 It is the flow chart when the present invention is prepared; Figure 3 It is the test and fertilization experiment result diagram of the present invention. Detailed Embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0029] Please refer to Figures 1 - 3As shown, a compound microbial organic fertilizer and its preparation method. The compound microbial organic fertilizer includes, by weight ratio, 10 parts of livestock and poultry manure, 20 parts of leaf mold soil, 5 parts of lignite, 5 parts of seaweed residue, 4 parts of tea seed cake, 8 parts of Synechococcus, 10 - 15 parts of compound fermentation bacteria agent, 15 parts of diatomite, 1 part of peat, 3 parts of porous volcanic stone powder, 10 parts of modified biochar, and 8 live adult earthworms are added per kilogram. The compound fermentation bacteria agent is made by mixing nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, potassium-solubilizing bacteria and EM bacteria.

[0030] When in use, livestock and poultry manure and leaf mold soil are used as the main matrix, and lignite and tea seed cake are used to effectively adjust the soil pH and inhibit soil-borne diseases. Combined with seaweed residue and Synechococcus, the soil aggregate structure is improved. Among them, the lignite is the residue after traditional Chinese medicine extraction (such as astragalus, licorice, isatis root residue), retaining plant saponins and flavonoids, which have both disease-resistant and growth-promoting functions in the finished fertilizer. The tea seed cake is from the waste tea seed cake of urban coffee shops or tea beverage industries, containing organic acids and polyphenols, which can adjust the soil pH and inhibit soil-borne pathogenic bacteria. Moreover, seaweed residue and Synechococcus are rich in seaweed polysaccharides, natural auxins (such as alginic acid, betaine) and trace elements (iodine, zinc, boron), which can enhance the stress resistance of plants. And through live adult earthworms, the co-fermentation of earthworm intestinal microorganisms and organic materials is utilized, containing highly active enzymes (protease, lipase), accelerating nutrient release and improving soil fertility.

[0031] The modified biochar is biochar generated by pyrolysis of agricultural crop by-products, and graphene oxide is loaded by chemical vapor deposition, with the concentration of graphene lower than 0.01%. Utilizing the porous structure of graphene, the water and fertilizer retention capacity is improved, and pesticide residues (such as organophosphorus) are effectively adsorbed and slowly degraded to reduce soil drug pollution.

[0032] A preparation method of a compound microbial organic fertilizer. When preparing, the method includes the following steps: Step 1: First stirring and mixing, mixing the raw materials to form mixture A, and the state of the mixture is that it can be formed into a ball when held in the hand and will disperse when released.

[0033] Step 2: Inoculating and fermenting, adding the compound fermentation bacteria agent to mixture A and carrying out moisture-preserving fermentation.

[0034] Step 3: Ripening, spreading out the fermented mixture A for ripening.

[0035] Step 4: Second mixing, adding the remaining raw materials to the ripened mixture A and mixing thoroughly to form mixture B.

[0036] Step 5: Shading and stacking, using live adult earthworms for biological treatment.

[0037] Step 6: Crushing, fermenting, and performing secondary ripening. Inoculate the remaining compound fermentation inoculant and repeat Steps 2 and 3 for secondary ripening.

[0038] Step 7: Drying treatment. Perform drying and crushing on the mixture B after secondary ripening.

[0039] Step 8: Post-processing. Granulate and package the dried mixture B to complete the preparation.

[0040] In Step 1, during the first stirring and mixing, stir and mix livestock manure, humus soil, lignite, seaweed residue, and Synechococcus. When mixing, add an appropriate amount of water according to the humidity to form a state where it can be formed into a ball by hand and dispersed when loosened, forming mixture A. When using livestock manure, first sun-dry the livestock manure in the sun for 7 days and then use it.

[0041] In Step 2, during inoculation and fermentation, add two-thirds of the compound fermentation inoculant to mixture A, and during fermentation, carry out light-shielding and humidity preservation. The fermentation time is controlled within 30 days. In Step 3, during ripening, the ripening cycle is controlled within 7 days, and during the ripening process, turn the materials 2 times.

[0042] In Step 4, during secondary mixing, add diatomite, peat, porous volcanic stone powder, and modified biochar to the ripened mixture A. After mixing, add live adult earthworms according to the weight of the mixed substrate, and then proceed to Step 5. In Step 5, stack it into a long strip, sprinkle water, keep the humidity at 60%, and control the stacking time within 10 days.

[0043] In Step 6, crush the mixture with live adult earthworms to kill the live adult earthworms, inoculate the remaining one-third of the compound fermentation inoculant, and then mix to form mixture B. After mixing, repeat Steps 2 and 3.

[0044] In Step 7, during drying, use a fluidized bed dryer for drying. After drying, perform crushing, and after crushing, carry out the post-processing in Step 8 to complete the preparation. Example

[0045] Please refer to Figures 1 - 3As shown, the difference between this embodiment and the first embodiment is as follows: by weight ratio, it includes 12 parts of livestock and poultry manure, 22 parts of leaf mold, 7 parts of lignite, 8 parts of seaweed residue, 6 parts of tea seed cake, 10 parts of Synechococcus, 11 parts of compound fermentation bacteria agent, 17 parts of diatom mud, 2 parts of peat, 5 parts of porous volcanic stone powder, 12 parts of modified biochar, and 10 live adult earthworms are added per kilogram. And the preparation steps are the same as those in the first embodiment. The differences from the first embodiment in each step are as follows: in Step 1, the livestock and poultry manure is sun-dried for 9 days and then used.

[0046] In Step 2, the fermentation time is controlled within 40 days.

[0047] In Step 3, when aging, the aging cycle is controlled within 9 days, and during the aging process, the materials are turned over 2 times.

[0048] In Step 5, the humidity is maintained at 65%, and when stacking, the time is controlled within 13 days. Embodiment

[0049] Please refer to Figures 1 - 3 As shown, the difference between this embodiment and the first embodiment is as follows: by weight ratio, it includes 15 parts of livestock and poultry manure, 25 parts of leaf mold, 8 parts of lignite, 10 parts of seaweed residue, 10 parts of tea seed cake, 12 parts of Synechococcus, 13 parts of compound fermentation bacteria agent, 25 parts of diatom mud, 3 parts of peat, 8 parts of porous volcanic stone powder, 15 parts of modified biochar, and 15 live adult earthworms are added per kilogram. And the preparation steps are the same as those in the first embodiment. The differences from the first embodiment in each step are as follows: in Step 1, the livestock and poultry manure is sun-dried for 10 days and then used.

[0050] In Step 2, the fermentation time is controlled within 40 days.

[0051] In Step 3, when aging, the aging cycle is controlled within 10 days, and during the aging process, the materials are turned over 3 times.

[0052] In Step 5, the humidity is maintained at 70%, and when stacking, the time is controlled within 16 days. Embodiment

[0053] Please refer to Figures 1 - 3As shown, the difference between this embodiment and the first embodiment is as follows: by weight ratio, it includes 18 parts of livestock and poultry manure, 30 parts of leaf mold, 9 parts of lignite, 12 parts of seaweed residue, 14 parts of tea seed cake, 13 parts of Synechococcus, 13 parts of compound fermentation bacteria agent, 28 parts of diatom mud, 4 parts of peat, 9 parts of porous volcanic stone powder, 18 parts of modified biochar, and 16 live adult earthworms are added per kilogram. The preparation steps are the same as those in the first embodiment. The differences from the first embodiment in each step are as follows: in step one, the livestock and poultry manure is sun-dried for 12 days and then used.

[0054] In step two, the fermentation time is controlled within 50 days.

[0055] In step three, when ripening, the ripening cycle is controlled within 12 days, and during the ripening process, the materials are turned over 3 times.

[0056] In step five, the humidity is maintained at 75%, and when stacking, the time is controlled within 18 days. Embodiment

[0057] Please refer to Figures 1 - 3 As shown, the difference between this embodiment and the first embodiment is as follows: by weight ratio, it includes 20 parts of livestock and poultry manure, 35 parts of leaf mold, 10 parts of lignite, 15 parts of seaweed residue, 15 parts of tea seed cake, 15 parts of Synechococcus, 15 parts of compound fermentation bacteria agent, 30 parts of diatom mud, 5 parts of peat, 10 parts of porous volcanic stone powder, 20 parts of modified biochar, and 18 live adult earthworms are added per kilogram. The preparation steps are the same as those in the first embodiment. The differences from the first embodiment in each step are as follows: in step one, the livestock and poultry manure is sun-dried for 14 days and then used.

[0058] In step two, the fermentation time is controlled within 60 days.

[0059] In step three, when ripening, the ripening cycle is controlled within 14 days, and during the ripening process, the materials are turned over 3 times.

[0060] In step five, the humidity is maintained at 80%, and when stacking, the time is controlled within 20 days.

[0061] Comparative Example 1 Please refer to Figures 1 - 3 As shown, the difference between this embodiment and the first embodiment is as follows: by weight ratio, it includes 15 parts of livestock and poultry manure, 30 parts of leaf mold, 8 parts of lignite, 10 parts of seaweed residue, 10 parts of tea seed cake, 10 parts of Synechococcus, 12 parts of compound fermentation bacteria agent. When preparing, after step three is completed, directly proceed to step seven without performing the processing of steps four to six. The differences from the first embodiment in the preparation steps are as follows: In Step 1, the livestock and poultry manure is sun-dried for 10 days and then used.

[0062] In Step 2, the fermentation time is controlled within 40 days.

[0063] In Step 3, during the ripening process, the ripening cycle is controlled within 10 days, and during the ripening process, the material is turned twice.

[0064] When the compound microbial organic fertilizers prepared in Examples 1 to 5 and the compound microbial organic fertilizer prepared in the comparative example are tested and applied, the results are as Figure 3 shown, and during application, fertilization is carried out in the wheat field according to the same weight, and the yield results are as Figure 3 shown. According to the test and application results, it can be seen that the nutrient content and yield increase effect of the compound microbial organic fertilizer after secondary treatment are obvious.

[0065] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0066] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A composite microbial organic fertilizer, characterized in that: The composite microbial organic fertilizer comprises, by weight, 10-20 parts of livestock and poultry manure, 20-35 parts of leaf mold, 5-10 parts of lignite, 5-15 parts of seaweed residues, 4-15 parts of tea seed cakes, 8-15 parts of Synechococcus, 10-15 parts of composite fermentation bacteria, 15-30 parts of diatom mud, 1-5 parts of peat, 3-10 parts of porous volcanic stone powder, 10-20 parts of modified biochar, and 8-18 live adult earthworms are added per kilogram.

2. The composite microbial organic fertilizer according to claim 1, characterized in that: The composite fermentation bacterial agent is prepared by mixing nitrogen-fixing bacteria, phosphate-dissolving bacteria, potassium-dissolving bacteria and EM bacteria.

3. The composite microbial organic fertilizer according to claim 1, characterized in that: The modified biochar is biochar generated by pyrolysis of agricultural crop byproducts, and graphene oxide is loaded by chemical vapor deposition, and the concentration of graphene is less than 0.01%.

4. A method for preparing a composite microbial organic fertilizer, characterized in that: When preparing the composite microbial organic fertilizer according to claim 1 to claim 3, the method comprises the following steps: Step 1: Stir and mix for the first time, mix the raw materials to form a mixture A, and the mixture is in a state of being able to form a ball when held by hand and to fall apart when released; Step 2: Inoculation and fermentation: adding a composite fermentation agent to the mixture A and performing moisturizing fermentation; Step 3: maturation: spreading and maturing the fermented mixed material A; Step 4: secondary mixing, adding the remaining raw materials to the matured mixed material A and mixing them thoroughly to form mixed material B; Step 5: Pile under shading and use living adult earthworms for biological treatment; Step 6: crushing, fermenting and performing secondary maturation, inoculating the remaining composite fermentation bacteria, and repeating steps 2 and 3 for secondary maturation; Step 7: Drying treatment: drying and crushing the secondary matured mixed material B; Step eight, post-processing, granulating and packaging the dried mixed material B to complete the preparation.

5. The method for preparing the composite microbial organic fertilizer according to claim 4, characterized in that: In step one, during the first stirring and mixing, livestock and poultry manure, leaf mold, lignite, seaweed residue, tea seed cake and Synechococcus are stirred and mixed. During the mixing, an appropriate amount of water is added according to the humidity to form a state in which the mixture can be grasped into a ball and loosened when released, thereby forming a mixture A. When the livestock and poultry manure is used, it is first dried in the sun for 7-14 days before use.

6. The method for preparing the composite microbial organic fertilizer according to claim 4, characterized in that: In step two, during inoculation and fermentation, two-thirds of the composite fermentation agent is added to the mixed material A, and during fermentation, light shading and moisture retention are carried out, and the fermentation time is controlled within 30-60 days. In step three, during maturation, the maturation cycle is controlled within 7-14 days, and during the maturation process, the material is turned over 2-3 times.

7. The method for preparing the composite microbial organic fertilizer according to claim 4, characterized in that: In step 4, during secondary mixing, diatom mud, peat, porous volcanic stone powder and modified biochar are added to the matured mixture A. After mixing, live adult earthworms are added according to the weight of the mixed matrix, and then step 5 is performed. In step 5, the mixture is stacked into long strips and watered. The humidity is maintained at 60%-80%, and the stacking time is controlled at 10-20 days.

8. The method for preparing the composite microbial organic fertilizer according to claim 1, wherein: In step six, the mixture containing live adult earthworms is crushed to kill the live adult earthworms, and the remaining one-third of the composite fermentation agent is inoculated, and then mixed to form a mixture B. After mixing, steps two and three are repeated.

9. The method for preparing the composite microbial organic fertilizer according to claim 1, wherein: In step seven, during drying, a fluidized bed dryer is used for drying, and after drying, crushing is performed, and after crushing, post-processing treatment of step eight is performed to complete the preparation.

Images