Fertilizer for planting of citrus grandis var.shatang and preparation method thereof
By using a combined fermentation process involving pectinase, cellulase, Bacillus amyloliquefaciens, Saccharomyces cerevisiae, and Lactobacillus plantarum, the problem of citrus fruit waste disposal has been solved, achieving efficient resource utilization. Liquid soil conditioner and liquid micronutrient foliar fertilizer suitable for citrus plants have been prepared, improving the growth of citrus plants and the quality of their fruits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUANGSHAN BAWEI ECOLOGICAL AGRI TECH CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-12
Smart Images
Figure SMS_2
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomass resource utilization and microbial fertilizer technology, specifically relating to a fertilizer for pomelo cultivation and its preparation method. Background Technology
[0002] Citrus fruits (including oranges, grapefruits, lemons, and tangerines) are among the most produced fruit categories in my country. The harvesting, processing (such as orange juice production and canning), and consumption of citrus fruits generate a large amount of waste, mainly including peels, pomace, stems, and rotten fruit. This type of waste accounts for approximately 30%-50% of the total citrus production. Compared to ordinary vegetable waste, citrus fruit waste is characterized by "high pectin content, high acidity, and high water content." These characteristics present unique challenges and difficulties in its treatment. Traditional treatment methods are ineffective, and existing technologies still face numerous bottlenecks, hindering the improvement of its resource utilization level.
[0003] Traditional treatment methods such as landfill and incineration are insufficient to meet the requirements of "reduction, harmlessness, and resource recovery".
[0004] Simple composting is a resource-based treatment method tried in some areas. It involves mixing citrus fruit waste with other organic waste and allowing it to compost naturally, hoping to produce organic fertilizer. However, due to insufficient understanding of the characteristics of citrus fruit waste and a lack of targeted process design, this simple composting method is often ineffective. Firstly, high pectin content leads to poor aeration in the compost pile. Pectin forms colloidal substances within the pile, encapsulating microorganisms and hindering oxygen transfer and microbial metabolic activities. This makes the pile prone to an anaerobic state, prolonging the fermentation cycle (usually 2-3 months, much longer than the composting cycle of ordinary vegetable waste) and producing malodorous gases such as hydrogen sulfide and ammonia, causing secondary pollution. Secondly, the high acidity of citrus fruit waste (pH usually between 3.0 and 4.5) inhibits the activity of microorganisms during composting, especially aerobic microorganisms that produce humus. Their optimal pH is mostly between 6.0 and 8.0. The acidic environment leads to slow microbial growth and reproduction, low organic matter degradation efficiency, and difficulty in achieving the required compost maturity. Due to the unique composition of citrus and other fruit waste, simple compost products often suffer from low organic matter content, unbalanced nutrients, and excessive pathogens, making it difficult to meet the standards for organic fertilizers and unsuitable for agricultural production. Ultimately, they still require secondary processing.
[0005] In areas with a high concentration of citrus processing industries, some companies attempt a simple "extraction-disposal" process for citrus fruit waste. This involves extracting high-value components such as pectin, essential oils, and flavonoids from citrus peels, while the remaining residue is disposed of through landfill or incineration. While this method achieves some resource recovery, it has significant limitations. Firstly, the extraction processes for pectin and essential oils are complex and require advanced equipment and technology, limiting their application to only a few large processing companies. Small and medium-sized enterprises (SMEs) cannot afford the associated equipment investment and operating costs, resulting in a very low adoption rate of less than 5%. Secondly, the extraction process uses large quantities of chemical reagents (such as hydrochloric acid, ethanol, and acetone), which remain in the residue, altering its physicochemical properties. This not only hinders subsequent resource utilization such as fermentation for fertilizer production but also pollutes soil and groundwater during landfilling, increasing environmental risks. Furthermore, the conversion rate of the extraction process is low, typically only extracting 5%-10% of the useful components from citrus fruit waste. A large amount of organic matter is still discarded with the residue, highlighting the continued problem of resource waste.
[0006] Co-fermentation technology involves mixing citrus fruit waste with other organic wastes for fermentation. This leverages the complementary components of different wastes to improve fermentation conditions and increase processing efficiency. Common mixed raw materials include livestock and poultry manure, garden waste, and kitchen waste. For example, citrus peels and cow manure can be mixed in a 1:3 ratio for aerobic composting. The high carbon-to-nitrogen ratio (C / N ratio of approximately 25-30) and neutral pH of cow manure neutralize the acidity of the citrus fruit waste, adjusting the C / N ratio of the compost pile to a suitable range. Experimental results show that this mixed composting method can shorten the fermentation cycle to about 45 days, with the compost product achieving an organic matter content of 42% and a total nutrient content of 5.8%, essentially meeting the standards for organic fertilizer. However, this technology has limitations. It is highly dependent on the mixed raw materials, requiring a stable supply of resources such as livestock and poultry manure, making it difficult to promote in areas lacking such resources. Furthermore, during mixed fermentation, the degradation rates of different materials vary significantly, easily leading to uneven composting and affecting the quality of the final product. However, how to accurately control the mixing ratio and optimize fermentation parameters to achieve efficient synergistic degradation of different materials remains a key issue that needs to be addressed.
[0007] Although citrus fruit waste is characterized by high pectin content, high acidity, and high moisture content, making it challenging to process, its composition, existing technology, and engineering practices suggest that large-scale application of its fermented fertilizer production is entirely possible through targeted pretreatment technology optimization, efficient microbial strain screening, and fermentation process parameter control. The core of this approach lies in technological innovation to overcome key challenges such as pectin inhibition and acidity effects, fully leveraging the rich organic matter and nutrients in citrus fruit waste to transform waste into valuable resources, thus providing a feasible path for the resource utilization of citrus fruit waste.
[0008] Existing research has also attempted to screen various acid-resistant and enzyme-producing microorganisms, but how to construct synergistic and efficient compound microbial agents and optimize their fermentation process remains a key challenge in achieving efficient fertilizer production from citrus waste. Summary of the Invention
[0009] The inventor is dedicated to the research of fruit and vegetable waste recycling and has designed a fermentation process for citrus fruit waste. This fermentation process can efficiently degrade citrus fruit waste, including peels, seeds, and pectin and acidic substances in the waste fruit, transforming them into liquid soil conditioner and liquid micronutrient foliar fertilizer. Both are particularly suitable for the cultivation of citrus plants.
[0010] This application first discloses a process for preparing fertilizer from citrus fruit waste through fermentation, as follows:
[0011] Step 1: Activate Bacillus amyloliquefaciens, Saccharomyces cerevisiae, and Lactobacillus plantarum separately.
[0012] Step 2: Take citrus fruit waste including peel, seeds and waste fruit, remove impurities, crush, screw press, and adjust the moisture content;
[0013] Step 3: Add pectinase and cellulase evenly to the material obtained in Step 2, mix well, and perform enzymatic hydrolysis;
[0014] Step 4: Cool down the pretreated material obtained in Step 3, add activated Bacillus amyloliquefaciens at fermentation 0; add activated Saccharomyces cerevisiae at fermentation 24 h, add activated Lactobacillus plantarum at fermentation 36 h, maintain 30-35℃, continue fermentation, and stir daily.
[0015] Step 5: Use a filter press to separate solids and liquids, add EDTA-2Na, stir to react, filter and fill to obtain foliar fertilizer;
[0016] Step 6: Readjust the moisture content of the solid residue obtained in Step 5, add bran as nutrients, and stabilize the material temperature. Then, inoculate with *Lactobacillus plantarum* and continue fermentation. Stop fermentation when the material emits a strong sour aroma and the pH value drops below 4.0.
[0017] Step 7: The fermentation product obtained in Step 6 undergoes a second solid-liquid separation. The separated liquid is allowed to stand and mature to obtain liquid soil amendment fertilizer.
[0018] The activation conditions for Bacillus amyloliquefaciens in step 1 are as follows: using an aqueous solution of 1% glucose, 0.5% peptone, and 0.1% yeast extract as the culture medium, and incubating at 37°C and 200 rpm for 24 hours with shaking.
[0019] In step 1, the activation conditions for the brewing yeast are: culturing in a 5% pasteurized molasses aqueous solution at 32°C on a shaker for 20 hours.
[0020] The activation conditions for Lactobacillus plantarum were anaerobic culture at 37°C for 20 hours on pasteurized MRS broth medium.
[0021] In step 2, the citrus fruit is one or more of the following: pomelo, orange, mandarin orange, bergamot, and lemon.
[0022] The crushing step in step 2 refers to crushing the waste into particles with a diameter of 2-3 mm;
[0023] The step of adjusting the water content in step 2 refers to adjusting the moisture content of the mixture to 60%.
[0024] In step 3, pectinase and cellulase are added at amounts of 1.0‰ and 0.5‰ of the dry weight of the material, respectively.
[0025] In step 3, the enzymatic hydrolysis step refers to maintaining the environment at 48°C for 8 hours.
[0026] In step 4, the material cooling step refers to cooling the pretreated material obtained in step 3 to below 35°C.
[0027] In step 4, the microbial inoculation and fermentation steps are specifically performed as follows:
[0028] Cool the pretreated material obtained in step 3 to below 35°C. Add activated Bacillus amyloliquefaciens at 2% of the dry material mass at fermentation 0 hours. Add activated Saccharomyces cerevisiae at 2% of the dry material mass at fermentation 24 hours. Add activated Lactobacillus plantarum at 1% of the dry material mass at fermentation 36 hours. Maintain 30-35°C and continue fermentation for 5 days, stirring twice a day.
[0029] In step 5, the amount of EDTA-2Na added is 0.1% w / v.
[0030] The specific steps of step 6 are as follows: The moisture content of the solid residue obtained in step 5 is readjusted to 60%, and bran is added as nutrition at 5% of the total mass of the solid residue. Simultaneously, the material temperature is stabilized at 32℃. Then, *Lactobacillus plantarum* is inoculated at 3% of the solid wet weight. The material is compacted, and fermentation continues for 4 days. Fermentation ends when the material emits a strong sour aroma and the pH value drops to 4.0.
[0031] In step 7, humic acid and chitosan oligosaccharide may also be added. The amounts of humic acid and chitosan oligosaccharide added, based on the total liquid volume, are 1% and 0.1%, respectively. The standing maturation time is 24 hours.
[0032] The final disclosure of this application is the application of the above-mentioned liquid soil conditioner and liquid micronutrient foliar fertilizer prepared by fermentation of citrus fruit waste in the cultivation of pomelos, the purpose of which is to promote the growth of pomelos and increase the nutrient content.
[0033] The beneficial effects of this invention are:
[0034] This application first discloses a method for preparing liquid soil conditioner and liquid micronutrient foliar fertilizer based on the fermentation of citrus fruit waste. The method utilizes a combination of pectinase, cellulase, *Saccharomyces cerevisiae*, *Bacillus amyloliquefaciens*, and *Lactobacillus plantarum*. Liquid micronutrient foliar fertilizer is prepared through a primary fermentation, and the solid residue is then subjected to a secondary fermentation to prepare liquid soil conditioner. The resulting fertilizers show significantly reduced pectin and essential oil content. Trace elements such as iron, zinc, and manganese are dissolved in chelated form in the liquid fertilizer, resulting in a significant enrichment of these elements. Comparative trials in a pomelo orchard cultivation base showed that after applying the diluted liquid soil conditioner and liquid micronutrient foliar fertilizer obtained in this application, the substances in the fertilizers were further diluted by the soil, making them more suitable for pomelo growth and significantly improving the nutritional and quality indicators of the pomelo. Detailed Implementation
[0035] The present invention will be further described in detail below through embodiments. These embodiments are illustrative of the invention, but do not limit the invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.
[0036] Example 1: Preparation of fertilizer based on citrus fruit waste
[0037] Step 1: Use an aqueous solution of 1% glucose, 0.5% peptone, and 0.1% yeast powder as the culture medium and culture at 37°C and 200 rpm for 24 hours to activate Bacillus amyloliquefaciens; use a pasteurized 5% molasses aqueous solution and culture at 32°C on a shaker for 20 hours to activate Saccharomyces cerevisiae; use pasteurized MRS broth medium and culture anaerobically at 37°C for 20 hours to activate Lactobacillus plantarum.
[0038] Step 2: Take the grapefruit fruit waste, including peel, seeds, and waste fruit, remove impurities, crush into 2-3mm particles, press with a screw press, and adjust the moisture content to 60%;
[0039] Step 3: Add pectinase and cellulase evenly to the material obtained in Step 2, with dosages of 1.0‰ and 0.5‰ of the dry weight of the material, respectively. After mixing evenly, maintain the mixture at 48℃ for 8 hours.
[0040] Step 4: Cool the pretreated material obtained in Step 3 to below 35℃. At the 0-hour mark of fermentation, add 2% of the dry material mass of activated Bacillus amyloliquefaciens. At the 24-hour mark of fermentation, add 2% of the dry material mass of activated Saccharomyces cerevisiae. At the 36-hour mark of fermentation, add 1% of the dry material mass of activated Lactobacillus plantarum. Maintain the temperature at 30-35℃ and continue fermentation for 5 days, stirring twice a day.
[0041] Step 5: Separate the solid and liquid using a filter press, add 0.1% EDTA-2Na, stir, filter and fill at 40-45℃ to obtain foliar fertilizer;
[0042] Step 6: Readjust the moisture content of the solid residue obtained in Step 5 to 60%, and add 5% of the total weight of bran as nutrients, while stabilizing the material temperature at 32℃. Then, inoculate with Lactobacillus plantarum at an inoculation amount of 3% of the wet weight of the solids, compact the material, and continue fermentation for 4 days. When the material emits a strong sour aroma and the pH value drops to 4.0, end the fermentation.
[0043] Step 7: The fermentation product obtained in Step 6 undergoes a second solid-liquid separation. After standing and maturing for 24 hours, liquid soil amendment fertilizer can be obtained.
[0044] Note that in step 6, 1 kg of humic acid and 0.1 kg of chitosan oligosaccharide can be added to every 100 L of the separated liquid, and after thorough stirring, liquid soil amendment fertilizer can be obtained.
[0045] Example 2: Fertilizer was prepared by changing the ratio of fermenting microorganisms in the compound microbial agent according to the process of Example 1.
[0046] The fertilizer prepared in this embodiment is exactly the same as that in Example 1, except that the mixing ratio of microbial agents in step 4 is adjusted according to the formula shown in Table 1.
[0047] Table 1. Proportions of different compound microbial agents used in fertilizer preparation (unit: %)
[0048] .
[0049] Example 3: Detection of fertilizers obtained in Examples 1 and 2
[0050] The fertilizers obtained in Examples 1 and 2 were tested according to current standards and methods. Pectin was tested according to GB / T10742–2008 using the carbazole-sulfuric acid method; essential oils were tested according to GB / T 11538-2006, the general method for capillary column gas chromatography.
[0051] Table 2. Detection results of liquid soil conditioner and liquid micronutrient foliar fertilizer obtained in Examples 1 and 2.
[0052]
[0053] The above-mentioned fermentation process produces liquid soil conditioner and foliar fertilizer. Fermentation effectively removes pectin and essential oils from waste materials that are detrimental to plant growth, while enriching them with trace elements that are easily absorbed by plants, laying the foundation for improving crop quality in the future.
[0054] In the aforementioned process, the microbial inoculation ratio is a key factor determining the degradation efficiency of pectin and essential oils in citrus fruit waste. In Example 1, the ratio of *Saccharomyces cerevisiae*, *Bacillus amyloliquefaciens*, and *Lactobacillus plantarum* was 2:2:1, and this ratio performed optimally in the test results of Example 3. The soil amendment fertilizer prepared using this ratio had a pectin content of only 0.04% and an essential oil content of only 0.06%, far below the standard requirement of ≤0.1%, indicating that fermentation was most thorough at this ratio.
[0055] When the proportion of microorganisms changes, the fermentation effect varies significantly. For example, in formula 1 (ratio 1:2:1), the reduced inoculum of Saccharomyces cerevisiae weakened the colonization capacity of the fermentation system in the early stages, failing to create an optimal working environment for subsequent microorganisms. Although the proportion of Bacillus amyloliquefaciens responsible for decomposition remained unchanged, its degradation capacity was not fully utilized, resulting in an increase in pectin and essential oil content in the soil amendment fertilizer to 0.08% and 0.14%, respectively.
[0056] The negative effects of imbalanced proportions were more pronounced in other formulations. The excessively high proportion of brewer's yeast in formulation 2 (3:2:1) may have led to early metabolic imbalance in the fermentation system. In formulations 3 (2:1:1) and 4 (2:3:1), the reduction and relative imbalance of the proportion of Bacillus amyloliquefaciens weakened the key enzyme-producing and decomposition process, respectively, resulting in pectin and essential oil content in their soil amendment fertilizers reaching or exceeding the standard upper limit.
[0057] The fundamental reason for this phenomenon lies in the distinct roles played by the three microorganisms during fermentation, forming a sophisticated synergistic relay. Saccharomyces cerevisiae acts as the pioneer, rapidly consuming oxygen and readily available carbon sources, laying the foundation for fermentation; Bacillus amyloliquefaciens, as the main decomposer, secretes pectinase and other enzymes to directly degrade pectin and essential oil components; and Lactobacillus plantarum acts as the stabilizer, inhibiting unwanted microorganisms through acid production and consolidating the fermentation results. The 2:2:1 ratio in Example 1 precisely achieves an optimal balance among these three functions.
[0058] Therefore, the inoculant ratio in Example 1 is the optimal solution for achieving efficient degradation of pectin and essential oils. Any combination deviating from this golden ratio will disrupt the synergistic effect between microbial communities, leading to incomplete fermentation and ultimately increasing the residual pectin and essential oil content in the fertilizer product. This fully demonstrates that strictly adhering to this inoculation ratio is crucial for ensuring the excellent quality and stability of the final product in industrial production.
[0059] Example 4: Comparative planting experiment of liquid soil conditioner obtained in Example 1 and liquid micronutrient foliar fertilizer in a pomelo or grapefruit base.
[0060] Project Implementing Unit: Xianyou County Tianen Agricultural Professional Cooperative
[0061] Demonstration Location: Qifeng Valley Pomelo and Honey Pomelo Base, Duwei Town, Xianyou County, Fujian Province; Demonstration Area: 150 mu (approximately 10 hectares)
[0062] Table 3. Fertilization records of the ecological and traditional planting areas of the pomelo and honey pomelo base obtained from Example 1 in 2022, including the liquid soil amendment fertilizer and liquid micronutrient foliar fertilizer.
[0063] .
[0064] 1. During the on-site follow-up visit, the person in charge of the base stated that the drought situation was quite severe this year, but the pomelo trees in the base's ecological planting area were less affected. The pomelo leaves were thick, dark green, and the fruiting rate was relatively normal.
[0065] 2. The pomelos grown in the ecological planting area have an excellent taste, are very juicy, and have a low rate of fruit cracking. In contrast, the traditional planting area has a higher rate of fruit cracking, and some pomelos are shriveled with woody flesh.
[0066] 3. The Fujian Academy of Agricultural Sciences Soil Research Institute conducted 11 tests on the contents of pomelos from the two comparative planting areas. The contents of most of the fruits from the ecological planting area were higher than those from the traditional planting area.
[0067] Table 4. Detection of pomelos from ecological and traditional planting areas in 2022
[0068] .
[0069] As shown in the table above, the pomelos grown in the ecological planting area, when treated with liquid soil conditioner and liquid micronutrient foliar fertilizer, showed better performance in quality indicators such as reduced vitamin C, soluble solids, water-soluble total sugar, and some mineral elements (total nitrogen, total potassium, calcium, and sulfur) compared to those grown in the traditional planting area. They were only slightly lower in terms of moisture and some mineral elements (total phosphorus and magnesium). Overall, the ecological planting method (i.e., the application of the liquid soil conditioner and liquid micronutrient foliar fertilizer described in this application) helps to improve some nutritional and quality indicators of pomelos.
[0070] Example 5: Comparative planting experiment of liquid soil conditioner obtained in Example 1 and liquid micronutrient foliar fertilizer in a pomelo or grapefruit base.
[0071] Project Implementing Unit: Xianyou County Tianen Agricultural Professional Cooperative
[0072] Demonstration Location: Qifeng Valley Pomelo and Honey Pomelo Base, Duwei Town, Xianyou County, Fujian Province
[0073] Implementation area: 166 mu
[0074] Table 5. Fertilization records of the liquid soil conditioner and liquid micronutrient foliar fertilizer obtained in Example 1 in 2023 in the ecological and traditional planting areas of the pomelo base.
[0075] .
[0076] 1. The base manager reported that during the spring shoot period, the ecological planting area grew better than the traditional area and other growers next door, and the leaves turned green earlier, and the trees were visibly growing well.
[0077] 2. Compared to traditional planting areas, ecological planting areas produce a larger number of flowers;
[0078] 3. The base manager reported that after the planting area was affected by rain and typhoon, the overall disease incidence in the ecological planting area was relatively low. Some low-lying areas had mild fungal diseases on the trees due to slow drainage. The overall disease incidence in the traditional planting area was higher, and a small amount of fungal stalks appeared due to high temperature and humidity.
[0079] 4. Two types of pomelo fruits from the comparative planting were harvested and sent for testing. The Soil Research Institute of Fujian Academy of Agricultural Sciences conducted content analysis, and the content values of most fruits from the ecological planting area were higher than those from the traditional planting area.
[0080] 5. The compound fertilizer used (15-15-15) is a product of Yingcheng Xindu Chemical Compound Fertilizer Co., Ltd., with a total nutrient content ≥45%, and 15-15-15 = N-P2O5-K2O.
[0081] Table 6. Detection results of pomelos from ecological and traditional planting areas in 2023.
[0082] .
[0083] As shown in the table above, in 2023, pomelos grown in the ecological planting area (using liquid soil amendment fertilizer and liquid micronutrient foliar fertilizer) performed better than those grown in the traditional planting area in terms of soluble solids, vitamin C, total sugar, total acid (low acid), and mineral elements such as calcium, magnesium, and potassium. They were only slightly lower in terms of phosphorus, water, and protein. Overall, the ecological planting method has certain advantages in improving the quality of pomelos in terms of vitamin C, sugar content, and mineral nutrition.
[0084] The foregoing description and embodiments illustrate the basic principles, main features, and advantages of this invention patent application. Those skilled in the art should understand that this invention patent application is not limited to the above embodiments; the embodiments and descriptions in the specification are merely optimal technical solutions. Various changes and modifications can be made to this invention patent application without departing from its spirit and scope, all of which fall within the scope of the claims. The scope of protection of this invention patent application is defined by the appended claims and their equivalents.
Claims
1. A process for fermenting citrus fruit waste to prepare fertilizer, as follows: Step 1: Activate Bacillus amyloliquefaciens, Saccharomyces cerevisiae, and Lactobacillus plantarum separately; Step 2: Collect citrus fruit waste, including peel, seeds, and waste fruit, remove impurities, crush, press using a screw press, and adjust the moisture content to 60%; Step 3: Add pectinase and cellulase evenly to the material obtained in Step 2, mix well, and perform enzymatic hydrolysis; Step 4: Cool down the pretreated material obtained in Step 3, add activated Bacillus amyloliquefaciens at fermentation 0; add activated Saccharomyces cerevisiae at fermentation 24 h, add activated Lactobacillus plantarum at fermentation 36 h, maintain 30-35℃, continue fermentation, and stir daily. Step 5: Use a filter press to separate solids and liquids, add EDTA-2Na, stir to react, filter and fill to obtain foliar fertilizer; Step 6: Readjust the moisture content of the solid residue obtained in Step 5, add bran as nutrition, stabilize the material temperature, then inoculate with Lactobacillus plantarum and continue fermentation for 4 days. When the material emits a strong sour aroma and the pH value drops below 4.0, end the fermentation. Step 7: The fermentation product obtained in Step 6 undergoes a second solid-liquid separation and is left to stand and mature to obtain liquid soil amendment fertilizer; characterized in that In step 4, the amounts of activated Bacillus amyloliquefaciens, activated Saccharomyces cerevisiae, and activated Lactobacillus plantarum added are 2%, 2%, and 1% of the dry material mass, respectively.
2. The process as described in claim 1, characterized in that, In step 1, the activation conditions for Bacillus amyloliquefaciens were as follows: cultured in an aqueous solution of 1% glucose, 0.5% peptone, and 0.1% yeast extract at 37°C with shaking at 200 rpm for 24 hours; the activation conditions for Saccharomyces cerevisiae were as follows: cultured in a pasteurized 5% molasses aqueous solution at 32°C with shaking on a shaker for 20 hours; and the activation conditions for Lactobacillus plantarum were as follows: cultured in pasteurized MRS broth at 37°C with anaerobic culture for 20 hours.
3. The process as described in claim 1, characterized in that, In step 2, the citrus fruit refers to one or more of the following: grapefruit, orange, mandarin orange, bergamot, and lemon. The crushing step in step 2 refers to crushing the waste into particles with a diameter of 2-3 mm.
4. The process as described in claim 1, characterized in that, In step 3, pectinase and cellulase are added at amounts of 1.0‰ and 0.5‰ of the dry weight of the material, respectively. In step 3, the enzymatic hydrolysis step refers to maintaining the process at 48℃ for 8 hours.
5. The process as described in claim 1, characterized in that, In step 4, the material cooling step refers to cooling the pretreated material obtained in step 3 to below 35°C.
6. The process as described in claim 1, characterized in that, In step 4, the microbial inoculation and fermentation steps are specifically operated as follows: at fermentation 0, add 2% of the dry material mass of activated Bacillus amyloliquefaciens; at fermentation 24 h, add 2% of the dry material mass of activated Saccharomyces cerevisiae; at fermentation 36 h, add 1% of the dry material mass of activated Lactobacillus plantarum; maintain 30-35℃ and continue fermentation for 5 days, stirring twice a day.
7. The process as described in claim 1, characterized in that, In step 5, the amount of EDTA-2Na added is 0.1% w / v.
8. The process as described in claim 1, characterized in that, The specific steps of step 6 are as follows: readjust the moisture content of the solid residue obtained in step 5 to 60%, add bran as nutrition at 5% of the total mass of the solid residue, stabilize the material temperature at 32℃, then inoculate with Lactobacillus plantarum at 3% of the wet weight of the solid, compact the material, and continue fermentation for 4 days. When the material emits a strong sour aroma and the pH value drops to 4.0, the fermentation is ended.
9. The process for preparing fertilizer by fermentation as described in claim 1, characterized in that, The obtained liquid soil conditioner and foliar fertilizer contain ≤0.1% essential oil (w / v) and ≤0.1% pectin (w / v).