Calcium-magnesium-rich organic fertilizer for macadimia nut garden, preparation method and application

Abstract

The invention belongs to the field of recycling of agricultural wastes and production of organic fertilizers, and provides a calcium-magnesium-rich organic fertilizer for macadimia nut gardens as well as a preparation method and application thereof, and the calcium-magnesium-rich organic fertilizer is prepared from the following raw materials in parts by dry weight: 100 parts of macadimia nut green peels, 25-50 parts of phosphate tailings, 10-20 parts of oil cakes, 3-5 parts of charcoal and 1.4-2.8 parts of a compound microbial agent. The components contained in the organic fertilizer have a synergistic effect, insoluble phosphorus, calcium and magnesium nutrients contained in the phosphate tailings are dissolved by organic acid generated by degrading organic matters of the macadamia nut green peels and the oil cakes, and the added biochar provides a carbon source for microorganisms, intercepts the nutrients and adsorbs heavy metal elements in the phosphate tailings, so that the yield of the phosphate tailings is increased. And a compound microbial agent is inoculated to promote the composting process, so that resource recycling is realized, the orchard is fed back, the production cost is low, the environmental pollution is reduced, the problems of lack of trace elements and low organic matter content in the existing orchard soil are effectively solved, and the fertilizer retention capacity of the soil is improved, thereby improving the yield and fruit quality of Australian fruit trees.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of agricultural waste resource utilization and organic fertilizer production, and relates to a calcium and magnesium-rich organic fertilizer for macadamia nut orchards, a preparation method and application. BACKGROUND

[0002] Macadamia nut, also known as Hawaiian nut, is a low-phosphorus root crop and a south subtropical evergreen perennial fruit tree. Macadamia nut is favored by consumers due to its high nutritional value and unique taste.

[0003] Long-term application of high-concentration chemical fertilizers in macadamia nut orchards leads to a decrease in soil organic matter content, causing soil compaction, especially the supply of high-phosphorus nutrients inhibiting the growth of tree roots. The decline in soil function affects the growth of fruit trees and the quality of fruits. In addition, the soil in the orchard is acidic red soil, and the loss of calcium and magnesium in the soil is serious due to annual humid and rainy weather. From the necessity of plant nutrient elements, the lack of calcium and magnesium elements in fruit trees has become a key factor limiting the yield of nuts.

[0004] Macadamia nut green peel is a waste generated during the processing of fresh macadamia nuts into shelled nuts, with an annual output of 100,000 tons and a utilization rate of less than 30%. It is rich in mineral nutrients and has an organic matter content of about 70%, accounting for about 1 / 2 of the quality of fresh fruits. The macadamia nut green peel is composted into organic fertilizer and applied to macadamia nut orchards, which can theoretically return 50% of nitrogen, 30% of phosphorus and 80% of potassium; nut shells are waste generated during the processing of macadamia nut kernels, accounting for about 2 / 3 of the quality of fresh shelled nuts. Nut shells have a high carbon content and can be used to prepare biochar with strong adsorption capacity; oil cakes are residues after the pressing of seeds containing a large amount of oil components. The fermentation process of oil cakes produces a large amount of organic acids, which promotes the release of nutrients. Direct application of unfermented and decomposed oil cakes to soil can easily cause crop seedling burn and diseases; phosphorus tailings are waste generated during the flotation of phosphorus ore in the phosphorus chemical industry, which is rich in calcium and magnesium lacking in orchard soil and a small amount of phosphorus. Traditional methods for utilizing phosphorus tailings include chemical acidolysis and direct burial, but the acidolysis method is too costly, and direct burial increases soil pollution.

[0005] Currently, macadamia nut green peel is naturally composted to prepare organic fertilizer in orchards, resulting in incomplete decomposition of the fertilizer, low total nutrient content of nitrogen, phosphorus and potassium, and low calcium and magnesium content, and many pathogenic bacteria, which easily cause tree diseases. Therefore, there is an urgent need to develop a calcium and magnesium-rich organic fertilizer specifically for orchards. SUMMARY

[0006] To solve the above problems, the application provides a calcium and magnesium-rich organic fertilizer for macadamia nut orchards, a preparation method and application, which can coordinate soil fertility and fertilizer supply capacity in the orchard, stimulate root distribution of fruit trees, increase soil organic matter content, effectively supplement soil nitrogen, phosphorus, potassium and lacking calcium and magnesium nutrients, and achieve the effects of soil improvement, nut quality improvement and stable and high yield.

[0007] The application is realized by the following technical solutions: The calcium and magnesium-rich organic fertilizer for macadamia nut orchards is made of the following raw materials in parts by mass: 100 parts of macadamia nut green skin, 25-50 parts of phosphorus tailings, 10-20 parts of oil residue, 3-5 parts of biochar and 1.4-2.8 parts of compound microbial agent.

[0008] The compound microbial agent is composed of actinomycetes, bacillus licheniformis and bacillus megaterium at a mass ratio of 0.42-0.84:0.42-0.84:0.56-1.12.

[0009] Preferably, the effective viable count of the actinomycetes is ≥100 billion / g, the effective viable count of the bacillus licheniformis is ≥1000 billion / g, and the effective viable count of the bacillus megaterium is ≥100 billion / g.

[0010] Preferably, the method comprises the following steps: The macadamia nut green skin is crushed to a particle size of 0.5-1 cm, and the moisture content is kept at 60-65%; Phosphorus tailings accounting for 25-50% of the dry weight of the macadamia nut green skin are added, biochar accounting for 3-5% of the dry weight of the macadamia nut green skin is added, and the compound microbial agent accounting for 1.4-2.8% of the dry weight of the macadamia nut green skin is added; The oil residue is crushed to a particle size of 0.5-1 cm, and the moisture content is kept at 5-10%, and the oil residue accounting for 10-20% of the dry weight of the macadamia nut green skin is added to adjust the initial carbon-nitrogen ratio of the pile to 25-30:1; The water content of the pile is adjusted to 55-60%, the pile is mixed evenly for aerobic composting, and the pile is turned over and aerated during the composting; The composted material is dried and sieved to obtain the calcium and magnesium-rich organic fertilizer.

[0011] Preferably, the method further comprises the following steps: The macadamia nut green skin is crushed to a particle size of 0.5-1 cm, and the moisture content is kept at 60-65%; Phosphorus tailings accounting for 25-50% of the dry weight of the macadamia nut green skin are added, biochar accounting for 3-5% of the dry weight of the macadamia nut green skin is added, and the compound microbial agent accounting for 1.4-2.8% of the dry weight of the macadamia nut green skin is added; The oil core is crushed to a particle size of 0.5 cm to 1 cm, the moisture content is kept at 5% to 10%, 10% to 20% of the oil core is added to the macadamia nut green skin dry weight, and the initial carbon-nitrogen ratio of the pile is adjusted to 25 to 30:1; The moisture content of the pile is adjusted to 55% to 60%, the pile is mixed evenly, and aerobic composting is carried out; On the 15th to 20th day of the composting initial cooling period, a compound microbial agent is added to the material, the pile is mixed evenly, and composting is continued; The composted material is dried and sieved to obtain a calcium and magnesium-rich organic fertilizer; The total amount of the compound microbial agent added accounts for 1.4% to 2.8% of the dry weight of the macadamia nut green skin.

[0012] Preferably, the biochar is obtained by high-temperature anaerobic cracking of macadamia nut shells at 600 DEG C to 800 DEG C.

[0013] Preferably, the phosphorus tailings powder is sieved through a 150 mesh to 200 mesh sieve.

[0014] Preferably, the aerobic composting temperature is 50 DEG C to 65 DEG C, the time is 35 days to 40 days, and the pile turning frequency is once every 5 days.

[0015] The calcium and magnesium-rich organic fertilizer is used for supplementing soil nitrogen, phosphorus, potassium, calcium and magnesium.

[0016] The calcium and magnesium-rich organic fertilizer is used for increasing soil organic matter content and / or improving soil fertility.

[0017] The inventive concept of the present application is as follows: Currently, orchards mostly use the method of natural composting of macadamia nut green skin to prepare organic fertilizer, which results in incomplete composting of the fertilizer, low total nutrient content of nitrogen, phosphorus and potassium, and low calcium and magnesium content, and many pathogenic bacteria are easy to cause tree diseases. Therefore, there is an urgent need to develop a calcium and magnesium-rich organic fertilizer specially used in orchards.

[0018] Based on this, the present application provides a calcium and magnesium-rich organic fertilizer for macadamia nut orchards, which comprises macadamia nut green skin, phosphorus tailings, oil core, biochar and compound microbial agent. On the basis of the prior art, the method of synergistically utilizing fruit shells, oil core and phosphorus tailings waste is adopted to further improve the total nutrient content and calcium and magnesium nutrient content of the organic fertilizer, and to improve the repair and fertility of the soil in the orchard. Among them, the addition of biochar in composting can reduce nutrient volatilization and loss, provide a living space and good carbon source for inoculated microorganisms, and effectively adsorb heavy metal elements of phosphorus tailings; the oil core, as a high-nutrient waste, has a low carbon-nitrogen ratio, can adjust the carbon-nitrogen ratio of the material, and has a high temperature rise during fermentation, which is beneficial to the degradation of organic matter;

[0019] It is found through experimental screening that only when the oil residue accounts for 10-20% of the dry weight of the macadamia green skin, the carbon-nitrogen ratio of the whole material can be kept in the optimal composting range of 25-30:1, the material can be effectively heated during the fermentation process, and the material can reach the state of maturity, so that the calcium and magnesium-rich organic fertilizer is successfully prepared. In addition, the organic acids such as citric acid and oxalic acid generated by the degradation of organic matter in the composting of the macadamia green skin and the oil residue and the phosphate tailings are the main driving force for the activation of the insoluble calcium, magnesium and phosphorus nutrients in the phosphate tailings. If only the phosphate tailings are used, the insoluble calcium, magnesium and phosphorus nutrients in the phosphate tailings cannot be effectively utilized by the fruit trees. In addition, the inoculation of the compound microbial agent provides a variety of functional biological bacteria. Bacillus megaterium can dissolve and activate the insoluble nutrients in the composting material. Bacillus licheniformis can inhibit the reproduction of pathogenic bacteria and reduce soil-borne diseases, especially the pathogenic bacteria in the macadamia green skin and the oil residue, which is beneficial to the efficient composting process.

[0020] Therefore, only by synergistically composting the macadamia green skin, biochar, phosphate tailings, oil residue and compound microbial agent in a specific ratio can the dual goals of efficient utilization of waste resources and nutrient enhancement of the fertilizer be achieved.

[0021] Compared with the prior art, the present application has the following beneficial effects: The present application provides a calcium and magnesium-rich organic fertilizer for a macadamia orchard, which is made of the following raw materials in parts by mass: 100 parts of macadamia green skin, 25-50 parts of phosphate tailings, 10-20 parts of oil residue, 3-5 parts of biochar and 1.4-2.8 parts of compound microbial agent. The compound microbial agent is composed of actinomycetes, Bacillus licheniformis and Bacillus megaterium in a mass ratio of 0.42-0.84:0.42-0.84:0.56-1.12. By synergistically composting the macadamia green skin, fruit shells, phosphate tailings and oil residue to produce the fertilizer, the cost is low, the waste resources are fully utilized, the environmental pollution problem caused by the accumulation of waste is effectively solved, the waste is turned into treasure, the soil nitrogen, phosphorus and potassium and the lacking calcium and magnesium nutrients are supplemented, the soil organic matter content is increased, the soil fertility retention capacity is improved, and thus the yield and quality of the macadamia trees are improved.

[0022] In addition, the present application provides a preparation method of the calcium and magnesium-rich organic fertilizer for a macadamia orchard, which is a high-nutrient, calcium and magnesium-rich organic fertilizer prepared by aerobic composting method, using the macadamia green skin, phosphate tailings and oil residue as the main materials, and adding the biochar prepared from fruit shells as the auxiliary material. The results of the examples show that the N:P2O5:K2O weight ratio in the calcium and magnesium-rich organic fertilizer prepared by the present application is 2.7:2.7:1.5, the total nutrient content is ≥6.9%, the water-soluble phosphorus content is increased by 1.4623g / kg compared with that at the initial stage (0th day) of composting, and the effective calcium and magnesium contents are 3.19% and 1.05% respectively, which are significantly higher than those of the macadamia green skin organic fertilizer prepared by natural composting. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Fig. 1 This is a comparison graph showing the temperature changes during composting in Example 1 and Comparative Example 2.

[0025] Fig. 2 This is a comparison chart showing the changes in the compost germination index during the composting process of Example 1 and Comparative Example 2.

[0026] Fig. 3 This is a comparison chart showing the changes in total nutrients in compost during the composting process of Example 1 and Comparative Example 2.

[0027] Fig. 4 This is a comparison chart showing the changes in water-soluble phosphorus nutrients in compost during the composting process of Example 1 and Comparative Example 2. Detailed Implementation

[0028] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] The macadamia nut green husk is crushed to a particle size of 0.5 cm to 1 cm, and the moisture content of the green husk is ensured to be 60% to 65%. The particle size of the crushed macadamia nut green husk is preferably 0.5 cm. Phosphorus tailing powder is added, and the amount of the phosphorus tailing powder is 25% to 50% of the dry weight of the green husk. The amount of the phosphorus tailing powder added in the present application is preferably 50%, and the phosphorus tailing powder is sieved through a 200-mesh sieve. Biochar is added, and the amount of the biochar is 3% to 5% of the dry weight of the green husk. The amount of the biochar added in the present application is preferably 5%, and the biochar is obtained by high-temperature anaerobic cracking of macadamia nut shells at 700 DEG C. A compound microbial agent is added, and the amount of the compound microbial agent is 1.4% to 2.8% of the dry weight of the green husk. The compound microbial agent includes actinomycetes, Bacillus licheniformis, and Bacillus megaterium. The amount of the compound microbial agent added in the present application is preferably 1.4%. The oil dregs are crushed to a particle size of 0.5 cm to 1 cm, and the moisture content is ensured to be 5% to 10%. The particle size of the crushed oil dregs is preferably 0.5 cm. The oil dregs are added, and the amount of the oil dregs is 10% to 20% of the dry weight of the green husk. The initial carbon-nitrogen ratio of the pile is adjusted to be 25:1 to 30:1. The water content of the pile is adjusted to be 55% to 65%, and the water content is preferably 60%. The composting is performed after the pile is mixed uniformly. The pile is turned over and oxygen is supplied during the composting. During the initial cooling period of the composting, the compound microbial agent is added to the materials, and the amount of the compound microbial agent is 1.4% to 2.8% of the dry weight of the green husk. The amount of the compound microbial agent added in the present application is preferably 1.4%. The composting is continued after the pile is mixed uniformly. The calcium and magnesium-rich organic fertilizer is obtained after the composted materials are dried and sieved.

[0031] In the present application, the content of organic matter in the green husk is ≥70% by dry weight, and the nitrogen content in the green husk is ≥1%. The content of organic matter in the oil dregs is ≥80% by dry weight, and the nitrogen content in the oil dregs is ≥5%. The effective viable count of the actinomycetes is ≥100 billion / g, the effective viable count of the Bacillus licheniformis is ≥1000 billion / g, and the effective viable count of the Bacillus megaterium is ≥100 billion / g. The compound microbial agent is composed of actinomycetes, Bacillus licheniformis, and Bacillus megaterium at a mass ratio of (0.42 to 0.84):(0.42 to 0.84):(0.56 to 1.12), and the mass ratio is preferably 0.42:0.42:0.56. The compound microbial agent is added during the initial period and the cooling period of the composting.

[0032] In the present application, the time of the aerobic composting is preferably 35 to 40 days, and the time is preferably 35 days. The standard for the end of the composting is that the seed germination index GI of the composted materials reaches more than 70%. In the examples of the present application, the fermentation temperature is maintained at 50 DEG C to 65 DEG C for at least 10 days, and the turning frequency of the pile is once every 5 days.

[0033] The carbon-nitrogen ratio of the green skin is (40-45):1, the carbon content is high (the total carbon content is 40.60%), and the nitrogen content is low (the total nitrogen content is 1.01%). The appropriate carbon-nitrogen ratio in compost is usually 25-30:1, and a too high carbon-nitrogen ratio leads to poor fermentation effect of compost and difficulty in composting. The carbon-nitrogen ratio of the oil dry is (9-15):1, the nitrogen content is high (the total nitrogen content is 5.04%), and the carbon content is high (the total carbon content is 46.41%). Therefore, the oil dry with a low carbon-nitrogen ratio is added to adjust the overall material carbon-nitrogen ratio and promote the scientific composting.

[0034] In the following examples, comparative examples and application examples, the total nitrogen, phosphorus and potassium are determined according to NY / T 525-2021, and the sample is digested by sulfuric acid-hydrogen peroxide to obtain the test solution. The nitrogen is determined by Kjeldahl method, the phosphorus is determined by molybdenum-antimony anti-colorimetric method, and the potassium is determined by flame photometry; the water-soluble phosphorus and effective calcium and magnesium are determined according to Composite Fertilizer (GB / T 15063-2020), and the water-soluble phosphorus is determined by molybdenum-antimony anti-spectrophotometric method, and the effective calcium and magnesium are determined by inductively coupled plasma atomic emission spectrometry.

[0035] The beneficial effects of the present application are illustrated by the following specific examples.

[0036] The sources of the raw materials in the present application are as follows: The green skin and the nut shell of macadamia are obtained from the macadamia planting base of Greenfield Group in Xishuangbanna Dai Autonomous Prefecture, Yunnan Province during the fruit harvesting period; the phosphorus tailings are obtained from Yunnan Kunming Yuntianhua Co., Ltd.; the oil dry is obtained from Dali Bai Autonomous Prefecture, Yunnan Province; and the three kinds of bacteria in the compound microbial agent, i.e., actinomycetes, bacillus licheniformis and bacillus megaterium, are purchased from Wuhan Gray Algae Biotechnology Co., Ltd.

[0037] Example 1 A kind of preparation of calcium and magnesium-rich organic fertilizer, comprising the following steps: (1) take 50 kg of macadamia green skin from macadamia factory, and the dry weight of the macadamia green skin is 20 kg, which is crushed to a particle size of 0.5 cm, and the moisture content is maintained at 60%.

[0038] (2) according to the dry weight of the macadamia green skin, add 10 kg of phosphorus tailings powder, which is sieved through a 150 mesh sieve; add 1 kg of biochar, which is obtained by anaerobic pyrolysis of macadamia nut shell at 700 DEG C; and add 0.28 kg of compound microbial agent, which includes actinomycetes, bacillus licheniformis and bacillus megaterium. The effective viable count of actinomycetes is 100 billion / g, and the addition amount is 84g; the effective viable count of bacillus licheniformis is 100 billion / g, and the addition amount is 84g; and the effective viable count of bacillus megaterium is 100 billion / g, and the addition amount is 112g.

[0039] (3) The oil-poor powder is crushed to a particle size of 0.5 cm, and the moisture content is maintained at 10%. By adding 4.44 kg of oil-poor, the oil-poor is 4 kg in dry weight, and the initial carbon-nitrogen ratio of the pile is adjusted to 25:1.

[0040] (4) Spray 22.48 kg of water to adjust the moisture content of the material from 46.3% to 55%, mix well, and use a 160L, 98cm high compost reactor for aerobic composting. The fermentation temperature is maintained at 50℃, and the time is 35 days. Turn over every 5 days, and the oxygen flow is 0.3L·kg·DM -1 ·min -1 . According to the actual dry weight of the material after each turning, adjust by gas flow meter.

[0041] (5) On the 15th day of composting, add 0.28 kg of compound microbial agent to the compost material. The compound microbial agent includes actinomycetes, bacillus licheniformis and bacillus megaterium. The effective viable count of actinomycetes is 10 billion / g, and the addition amount is 84g; the effective viable count of bacillus licheniformis is 100 billion / g, and the addition amount is 84g; the effective viable count of bacillus megaterium is 100 billion / g, and the addition amount is 112g.

[0042] (6) The composting time is 35 days, and the composted material is dried to a moisture content of ≤30%, and then sieved to obtain a calcium and magnesium-rich organic fertilizer. The germination index GI of the calcium and magnesium-rich organic fertilizer is ≥112.1%, the weight ratio of N:P2O5:K2O is 2.7:2.7:1.5, the total nutrient content is ≥6.9%, the water-soluble phosphorus content is increased by 1.4623g / kg compared with the initial composting (0th day), and the effective calcium and magnesium contents are 3.19% and 1.05%, respectively.

[0043] Example 2 A method for preparing a calcium and magnesium-rich organic fertilizer, comprising the following steps: (1) Take 50 kg of macadamia nut green skin from a macadamia nut factory, and crush the macadamia nut green skin to a particle size of 0.5 cm, with a dry weight of 20 kg, and maintain the moisture content at 65%.

[0044] (2) Add 10 kg of phosphorus tailings powder, which is sieved through a 200 mesh sieve, and 1 kg of biochar, which is obtained by anaerobic pyrolysis of macadamia nut shells at 700℃, to the macadamia nut green skin, which has a dry weight of 20 kg. Add 0.56 kg of compound microbial agent, which includes actinomycetes, bacillus licheniformis and bacillus megaterium. The effective viable count of actinomycetes is 100 billion / g, and the addition amount is 168g; the effective viable count of bacillus licheniformis is 1000 billion / g, and the addition amount is 168g; the effective viable count of bacillus megaterium is 100 billion / g, and the addition amount is 224g.

[0045] (3) The oil cake is crushed to a particle size of 0.5 cm, and the moisture content is maintained at 10%. By adding 4.44 kg of oil cake, the oil cake is 4 kg in dry weight, and the initial carbon-nitrogen ratio of the pile is adjusted to 25:1.

[0046] (4) Spray 22.90 kg of water to adjust the moisture content of the material from 46.1% to 60%, mix well, and use a 160L, 98cm high compost reactor for aerobic composting. The fermentation temperature is maintained at 65℃, and the time is 40 days. Turn the pile every 5 days, and the oxygen flow is 0.3L·kg·DM -1 ·min -1 . According to the actual dry weight of the material after each turning, adjust it through the gas flow meter.

[0047] (5) The composting time is 35 days, and the composted material is dried to a moisture content of ≤30%, and then sieved to obtain a calcium and magnesium-rich organic fertilizer. The germination index GI of the calcium and magnesium-rich organic fertilizer is ≥108.2%, the N:P2O5:K2O weight ratio is 2.5:2.4:1.4, the total nutrient content is ≥6.5%, the water-soluble phosphorus content is increased by 1.3823g / kg compared with the initial composting (0th day), and the effective calcium and magnesium contents are 3.15% and 0.97%, respectively.

[0048] Example 3 A calcium and magnesium-rich organic fertilizer is prepared, comprising the following steps: (1) Take 50 kg of macadamia nut green skin from a macadamia nut factory, and crush the macadamia nut green skin to a particle size of 1 cm, with a dry weight of 20 kg, and maintain the moisture content at 60%.

[0049] (2) Add 5 kg of phosphorus tailings powder, which is sieved through a 150 mesh sieve, based on the dry weight of the macadamia nut green skin; add 1 kg of biochar, which is obtained by high-temperature anaerobic cracking of macadamia nut shells at 700℃; and add 0.56 kg of a composite microbial agent, which includes actinomycetes, Bacillus licheniformis, and Bacillus megaterium. The effective viable count of actinomycetes is 100 billion / g, and the addition amount is 168g; the effective viable count of Bacillus licheniformis is 100 billion / g, and the addition amount is 168g; and the effective viable count of Bacillus megaterium is 100 billion / g, and the addition amount is 224g.

[0050] (3) The oil cake is crushed to a particle size of 1 cm, and the moisture content is maintained at 10%. By adding 4.44 kg of oil cake, the oil cake is 4 kg in dry weight, and the initial carbon-nitrogen ratio of the pile is adjusted to 25:1.

[0051] (4) Spraying 15.40 kg of water to adjust the moisture content of the material from 49.9% to 55%, mixing and turning over, using an aerobic composting reactor with a volume of 160 L and a height of 98 cm, maintaining the fermentation temperature at 50℃ for 35 days. Turning over every 5 days, the oxygen flow rate is 0.3 L·kg·DM -1 ·min -1 . According to the actual dry weight of the material after each turning over, adjust the oxygen flow rate through the gas flow meter.

[0052] (5) The composting time is 35 days, and the mature material is dried to a moisture content of ≤30%, and then sieved to obtain a calcium and magnesium-rich organic fertilizer. The germination index GI of the calcium and magnesium-rich organic fertilizer is ≥105.3%, the weight ratio of N:P2O5:K2O is 2.8:1.9:1.8, the total nutrient content is ≥6.7%, the water-soluble phosphorus content is increased by 1.1913 g / kg compared with the initial composting (0th day), and the effective calcium and magnesium contents are 2.59% and 0.79%, respectively.

[0053] Example 4 A method for preparing a calcium and magnesium-rich organic fertilizer, comprising the following steps: (1) Take 50 kg of macadamia nut green skin from a macadamia nut factory, and the dry weight of the macadamia nut green skin is 20 kg. Crush the macadamia nut green skin to a particle size of 1 cm, and maintain the moisture content at 65%.

[0054] (2) Add 5 kg of phosphorus tailings powder, which is sieved through a 200 mesh sieve, 1 kg of biochar, which is obtained by high-temperature anaerobic cracking of macadamia nut shells at 700℃, and 0.28 kg of a compound microbial agent, which includes actinomycetes, Bacillus licheniformis, and Bacillus megaterium, based on the dry weight of the macadamia nut green skin. The effective viable count of the actinomycetes is 100 billion / g, and the addition amount is 84 g. The effective viable count of the Bacillus licheniformis is 100 billion / g, and the addition amount is 84 g. The effective viable count of the Bacillus megaterium is 100 billion / g, and the addition amount is 112 g.

[0055] (3) Crush the oil dregs to a particle size of 1 cm, and maintain the moisture content at 10%. Add 2.22 kg of oil dregs, of which 2 kg is based on the dry weight, to adjust the initial carbon-nitrogen ratio of the pile to 30:1.

[0056] (4) Spraying 14.98 kg of water to adjust the moisture content of the material from 50.1% to 60%, mixing and turning over, using an aerobic composting reactor with a volume of 160 L and a height of 98 cm, maintaining the fermentation temperature at 65℃ for 40 days. Turning over every 5 days, the oxygen flow rate is 0.3 L·kg·DM -1 ·min -1 . According to the actual dry weight of the material after each turning over, adjust the oxygen flow rate through the gas flow meter.

[0057] (5) The composting time was 35 days. The decomposed material was dried to a moisture content of ≤30% and then sieved to obtain calcium- and magnesium-rich organic fertilizer. The germination index (GI) of the calcium- and magnesium-rich organic fertilizer was determined to be ≥101.3%, the N:P2O5:K2O weight ratio was 2.7:1.9:1.7, the total nutrient content was ≥6.4%, the water-soluble phosphorus content increased by 1.1515 g / kg compared with the initial composting stage (day 0), and the effective calcium and magnesium contents were 2.54% and 0.77%, respectively.

[0058] Comparative Example 1 The preparation of a calcium- and magnesium-rich organic fertilizer includes the following steps: (1) Take 50kg of macadamia nut green husks from the macadamia nut factory. The dry weight of the macadamia nut green husks is 20kg. Crush them to a particle size of 0.5cm~1cm.

[0059] (2) Based on the dry weight of macadamia nut green skin, add 5 kg of phosphate tailings powder, which is passed through a 200-mesh sieve; add 0.28 kg of compound microbial agent, which includes actinomycetes, Bacillus licheniformis, and Bacillus megaterium. The effective viable count of actinomycetes is 10 billion / g, and the amount added is 84 g; the effective viable count of Bacillus licheniformis is 100 billion / g, and the amount added is 84 g; the effective viable count of Bacillus megaterium is 10 billion / g, and the amount added is 112 g.

[0060] (3) Crush the oil cake to a particle size of 1cm, keep the moisture content at 10%, and adjust the initial carbon-nitrogen ratio of the pile to 27:1 by adding 4.44kg of oil cake (4kg on dry weight).

[0061] (4) Spray 13.48 kg of water to adjust the moisture content of the material from 50.9% to 55%, turn the pile and mix it evenly. Use a 160L, 98cm high composting reactor for aerobic composting, and maintain the fermentation temperature at 50~65℃ for at least 10 days. Turn the pile every 5 days, and the oxygen supply is 0.3L·kg·DM. -1 ·min -1 The flow rate is adjusted using a gas flow meter based on the actual dry weight of the material being turned over each time.

[0062] (5) The composting time was 35 days. The decomposed material was dried to a moisture content of ≤30% and then sieved to obtain calcium- and magnesium-rich organic fertilizer. The germination index (GI) of the calcium- and magnesium-rich organic fertilizer was determined to be ≥94.4%, the N:P2O5:K2O weight ratio was 2.7:1.8:1.6, the total nutrient content was ≥6.1%, the water-soluble phosphorus content increased by 1.0738 g / kg compared with the initial composting stage (day 0), and the effective calcium and magnesium contents were 2.47% and 0.71%, respectively.

[0063] Comparative Example 2 Natural composting includes the following steps: (1) Take 50 kg of macadamia nut green husk from a macadamia nut factory, with a dry weight of 20 kg. Crush the macadamia nut green husk to a particle size of 1 cm. The initial carbon-nitrogen ratio of the macadamia nut green husk during natural composting is 40:1, and no other raw materials are added.

[0064] (2) The initial moisture content of the macadamia nut green husk is 60%. Aerobic composting is carried out using a 160L, 98cm-high composting reactor. Turn the compost every 5 days, with an oxygen flow rate of 0.3L·kg·DM -1 ·min -1 . Adjust the flow rate according to the actual dry weight of the material after each turning.

[0065] (3) The composting time is 35 days. After drying the composted material to a moisture content of ≤30%, sieving is performed to obtain natural composting organic fertilizer. The germination index GI of the organic fertilizer is ≥71.7%, the N:P2O5:K2O weight ratio is 1.3:0.4:2.0, the total nutrient content is ≥3.8%, the water-soluble phosphorus content is increased by 0.0938g / kg compared to the initial composting period (day 0), and the effective calcium and magnesium contents are 0.66% and 0.03%, respectively.

[0066] Comparative Example 3 In this comparative example, no oil cake is added to prepare calcium and magnesium-rich organic fertilizer, and the remaining steps are exactly the same as in Example 1.

[0067] After 35 days of composting, it is found that the composting has not reached the mature state, and the calcium and magnesium-rich organic fertilizer cannot be successfully prepared.

[0068] Comparative Example 4 In this comparative example, only 1.9 kg of dry oil cake is added to prepare calcium and magnesium-rich organic fertilizer, and the remaining steps are exactly the same as in Example 1.

[0069] Comparative Example 5 In this comparative example, only 1.7 kg of dry oil cake is added to prepare calcium and magnesium-rich organic fertilizer, and the remaining steps are exactly the same as in Example 1.

[0070] Comparative Example 6 In this comparative example, only 1.5 kg of dry oil cake is added to prepare calcium and magnesium-rich organic fertilizer, and the remaining steps are exactly the same as in Example 1.

[0071] Comparative Example 7 In this comparative example, only 1 kg of dry oil cake is added to prepare calcium and magnesium-rich organic fertilizer, and the remaining steps are exactly the same as in Example 1.

[0072] After 35 days of composting, it is found that the composting has not reached the mature state, and the calcium and magnesium-rich organic fertilizer cannot be successfully prepared.

[0073] Comparative Example 8 The calcium and magnesium rich organic fertilizer is prepared by adding oil residue with a dry weight of 4 kg in the present comparative example, and the remaining steps are completely same as those in example 1.

[0074] Comparative example 9 The calcium and magnesium rich organic fertilizer is prepared by adding oil residue with a dry weight of 4.1 kg in the present comparative example, and the remaining steps are completely same as those in example 1.

[0075] Comparative example 10 The calcium and magnesium rich organic fertilizer is prepared by adding oil residue with a dry weight of 4.3 kg in the present comparative example, and the remaining steps are completely same as those in example 1.

[0076] Comparative example 11 The calcium and magnesium rich organic fertilizer is prepared by adding oil residue with a dry weight of 4.5 kg in the present comparative example, and the remaining steps are completely same as those in example 1.

[0077] Comparative example 12 The calcium and magnesium rich organic fertilizer is prepared by adding oil residue with a dry weight of 5 kg in the present comparative example, and the remaining steps are completely same as those in example 1.

[0078] It is found that the composting does not reach the composting state after 35 days, and the calcium and magnesium rich organic fertilizer cannot be successfully prepared.

[0079] As can be seen from comparative examples 3 to 12, the calcium and magnesium rich organic fertilizer can be prepared only when the dry weight of the oil residue is added in an amount of 2 kg to 4 kg and the carbon-nitrogen ratio is adjusted to 25 to 30:1.

[0080] It should be noted that the biochar used in the above examples and comparative examples is obtained by high-temperature anaerobic cracking of macadamia nut shells at 600 to 800 DEG C. The content of organic matter in the green husk is greater than or equal to 70% by dry weight, and the nitrogen content in the green husk of macadamia nut is greater than or equal to 1% by dry weight. The content of organic matter in the oil residue is greater than or equal to 80% by dry weight, and the nitrogen content in the oil residue is greater than or equal to 5%. The effective viable number of actinomycetes in the compound microbial agent is greater than or equal to 100 billion / g; the effective viable number of bacillus licheniformis is greater than or equal to 100 billion / g; and the effective viable number of bacillus megaterium is greater than or equal to 100 billion / g.

[0081] Application example 1 The material temperature, total nutrient content, water-soluble phosphorus content, effective calcium and magnesium content and seed germination index GI in the composting process of example 1, example 2, example 3, example 4 and comparative example 1 and comparative example 2 are determined by the following specific method. Determination method: The determination method of the material temperature is as follows: on the 0th day to the 35th day of composting, the material temperature at the center (0.5 m) of the composting reactor is determined by using a digital thermometer at 9:00 am and 15:00 pm every day, and the average value is taken.

[0082] The determination method of total nutrient content and seed germination index GI: During the 0-35 days of composting, after uniform turning every 5 days, the samples were mixed after horizontal multi-point sampling. The total nutrient content was detected according to the determination method specified in the People's Republic of China Agricultural Industry Standard NY / T 525-2021.

[0083] The determination method of water-soluble phosphorus content and effective calcium and magnesium content: During the 0-35 days of composting, after uniform turning every 5 days, the samples were mixed after horizontal multi-point sampling. The effective calcium and magnesium content was detected according to the determination method specified in the People's Republic of China Agricultural Industry Standard National Standard Composite Fertilizer (GB / T 15063-2020).

[0084] The determination results are shown in Tables 1-6 and Figs. 1-4 .

[0085] Table 1 Determination results of material temperature during composting of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 and Comparative Example 2 (℃) Table 2 Determination results of total nutrients during composting of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 and Comparative Example 2, Table 3 Determination results of water-soluble phosphorus during composting of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 and Comparative Example 2, g / kg Table 4 Determination results of effective calcium and magnesium during composting of Example 1, Example 2, and Example 3, Table 5 Determination results of effective calcium and magnesium during composting of Example 4 and Comparative Example 1 and Comparative Example 2, Table 6 Determination results of germination index GI during composting of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 and Comparative Example 2, According to Tables 1-4 and Figs. 1-4It can be known that the pile temperature of the composting method in the embodiment 1 to the embodiment 3 is higher than that of the comparative example 1, and is significantly higher than that of the natural composting of the comparative example 2. The seed germination index GI of the embodiment 1 to the embodiment 4 is more than 70% on the 15th day of aerobic fermentation, while the seed germination index GI of the comparative example 1 is 68.5%, and the seed germination index GI of the comparative example 1 is only 53.2%, and the germination index GI of the comparative example 2 is only 71.7% until the 35th day of composting. The N:P2O5:K2O weight ratio of the calcium and magnesium rich organic fertilizer obtained by the embodiment 1 is 2.7:2.7:1.5, the total nutrient content is greater than or equal to 6.9%, the water-soluble phosphorus content is 2.0879g / kg, and the effective calcium and magnesium contents are 3.19% and 1.05% respectively. The N:P2O5:K2O weight ratio of the calcium and magnesium rich organic fertilizer obtained by the comparative example 1 is 2.7:1.8:1.6, the total nutrient content is greater than or equal to 6.1%, the water-soluble phosphorus content is 1.4924g / kg, and the effective calcium and magnesium contents are 2.47% and 0.71% respectively; the N:P2O5:K2O weight ratio of the natural composting organic fertilizer obtained by the comparative example 2 is 1.3:0.4:2.0, the total nutrient content is greater than or equal to 3.8%, the water-soluble phosphorus content is 0.2872g / kg, and the effective calcium and magnesium contents are 0.66% and 0.03% respectively. Compared with the comparative example 1 and the comparative example 2, the total nutrient content of the embodiment 1 is increased by 12.82% compared with the comparative example 1 and by 80.52% compared with the comparative example 2; the water-soluble phosphorus content is increased by 0.5955g / kg compared with the comparative example 1 and by 1.8007g / kg compared with the comparative example 2; the effective calcium and magnesium contents are increased by 0.72% and 0.34% respectively compared with the comparative example 1, and are increased by 2.53% and 1.02% respectively compared with the comparative example 2. The composting process of the embodiment 1 intensifies the composting material, and significantly improves the composting quality. The composting of the embodiment 1 for 35 days can obtain the organic fertilizer meeting the national standard “NYT 4076-2022”.

[0086] Application example 1 The application example 1 of the present application is tested in an Australian nut orchard of more than 10 years, and the fruit tree variety is O.C (Ownchoice). Five fruit trees with basically consistent growth are randomly selected in each treatment group, and the specific grouping is as follows: Treatment group 1: the organic fertilizer of the embodiment 1 is applied, the dry weight is converted to 10kg, and is applied by the method of ditch fertilization in November. The subsequent chemical fertilizer is applied in February, May and July of the next year, and the fruit is harvested in September of the next year.

[0087] Treatment group 2: the organic fertilizer of the comparative example 2 is applied, the dry weight is converted to 10kg, and is applied by the method of ditch fertilization in November. The subsequent chemical fertilizer is applied in the same way as treatment group 1.

[0088] The total yield, fresh weight of green skin fruit, horizontal and vertical diameter of green skin fruit, fresh weight of shell fruit, horizontal and vertical diameter of shell fruit, dry weight of kernel, and the internal quality of fat, protein and total sugar content of the macadamia trees in the treatment group 1 and the treatment group 2 are determined.

[0089] The determination method of total yield is as follows: in the fruit ripening period, the single macadamia tree in each treatment group is picked and weighed to calculate the average yield of green skin fruit.

[0090] The determination method of fresh weight of green skin fruit, fresh weight of shell fruit and dry weight of kernel is as follows: 30 fruits are randomly selected from each macadamia tree, and the single green skin fruit is weighed by an electronic balance to obtain the average value; after the green skin is removed, the weight of the single shell fruit is determined. Then the shell fruit is transferred into an oven and baked at 38 DEG C for 48 hours, then baked at 45 DEG C for 48 hours, and finally baked at 60 DEG C for 48 hours. The kernels of the 30 baked shell fruits are taken out by an opener, and the weight of the single kernel is weighed to obtain the average value.

[0091] The determination method of horizontal and vertical diameter of green skin fruit and shell fruit is as follows: the horizontal and vertical diameter of each green skin fruit is measured by a vernier caliper; after the green skin is removed, the horizontal and vertical diameter of the shell fruit is measured.

[0092] The determination method of fat, protein and total sugar content is as follows: the baked kernel is crushed and sieved through a 20 mesh sieve, and then the fat content, protein content and total sugar content of the kernel are determined by a near infrared spectrometer (NIRS).

[0093] In the field test of the present application, the total yield, fresh weight of green skin fruit, horizontal and vertical diameter of green skin fruit, fresh weight of shell fruit, horizontal and vertical diameter of shell fruit, dry weight of kernel and the internal quality of fat, protein and total sugar of the macadamia trees in the treatment group 1 applying the organic fertilizer of example 1 are higher than those in the treatment group 2 applying the natural composted fertilizer of comparative example 2. The application effect of the different treatment groups of example 1 is shown in table 7.

[0094] Table 7 Application effect of different treatment groups of example 1 Note: different letters represent that the difference reaches 5% significant level.

[0095] In summary, the calcium and magnesium rich organic fertilizer for macadamia orchard provided by the present application can scientifically utilize the macadamia green skin, shell, phosphorus tailings and oil dregs, improve the total nutrient content and total calcium and magnesium nutrient content of the organic fertilizer, fully utilize the waste resources, effectively solve the environmental pollution problem caused by waste accumulation, and has low cost, waste utilization, and can repay the orchard, supplement the soil nitrogen, phosphorus, potassium and lack of calcium and magnesium nutrients, increase the soil organic matter content, improve the soil fertility, and thus improve the yield and fruit quality of the macadamia trees.

[0096] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

[0097] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict each other, they shall be considered as the scope described in the specification.

[0098] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, however, it shall not be understood as the limitation on the patent scope of the present application. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and they shall be included in the protection scope of the present application. Therefore, the patent protection scope of the present application shall be subject to the appended claims.

Claims

1. A calcium and magnesium enriched organic fertilizer for macadamia nut orchards, characterized in that, The raw materials are made of 100 parts of macadamia green skin, 25-50 parts of phosphorus tailings, 10-20 parts of oil residue, 3-5 parts of biochar, and 1.4-2.8 parts of compound microbial agent by dry weight; The compound microbial agent is composed of actinomycetes, bacillus licheniformis and bacillus megaterium in a mass ratio of 0.42-0.84:0.42-0.84:0.56-1.

12.

2. The calcium and magnesium-rich organic fertilizer according to claim 1, wherein, The effective viable count of the actinomycetes is ≥100 billion / g, the effective viable count of the bacillus licheniformis is ≥100 billion / g, and the effective viable count of the bacillus megaterium is ≥100 billion / g.

3. The method of claim 1, wherein the calcium and magnesium enriched organic fertilizer is prepared by the steps of: The method comprises the following steps: ​ The macadamia green skin is crushed to a particle size of 0.5-1 cm, and the moisture content is maintained at 60-65%; The phosphorus tailings account for 25-50% of the dry weight of the macadamia green skin, the biochar accounts for 3-5% of the dry weight of the macadamia green skin, and the compound microbial agent accounts for 1.4-2.8% of the dry weight of the macadamia green skin; The oil residue is crushed to a particle size of 0.5-1 cm, the moisture content is maintained at 5-10%, and the oil residue accounts for 10-20% of the dry weight of the macadamia green skin, and the initial carbon-nitrogen ratio of the pile is adjusted to 25-30:1; The moisture content of the pile is adjusted to 55-60%, and aerobic composting is carried out by turning and mixing the pile evenly, and oxygen is supplied during the turning and mixing process; The composted material is dried and sieved to obtain the calcium and magnesium-rich organic fertilizer.

4. The method for preparing calcium- and magnesium-rich organic fertilizer as described in claim 1, characterized in that, The method further comprises the following steps: The macadamia green skin is crushed to a particle size of 0.5-1 cm, and the moisture content is maintained at 60-65%; The phosphorus tailings account for 25-50% of the dry weight of the macadamia green skin, the biochar accounts for 3-5% of the dry weight of the macadamia green skin, and the compound microbial agent accounts for 1.4-2.8% of the dry weight of the macadamia green skin; The oil residue is crushed to a particle size of 0.5-1 cm, the moisture content is maintained at 5-10%, and the oil residue accounts for 10-20% of the dry weight of the macadamia green skin, and the initial carbon-nitrogen ratio of the pile is adjusted to 25-30:1; The moisture content of the pile is adjusted to 55-60%, and aerobic composting is carried out by turning and mixing the pile evenly, and oxygen is supplied during the turning and mixing process; The compound microbial agent is added to the material during the initial temperature reduction period of 15-20 days of composting, and the composting is continued by turning and mixing the material evenly; The composted material is dried and sieved to obtain the calcium and magnesium-rich organic fertilizer. The total amount of the compound microbial agent added accounts for 1.4-2.8% of the dry weight of the macadamia green skin.

5. The method of any one of claims 3-4, wherein, The biochar is obtained by high-temperature anaerobic pyrolysis of macadamia nut shells at 600-800°C.

6. The method according to any one of claims 3 to 4, wherein, The phosphorus tailings are sieved through a 150-200 mesh screen.

7. The method of any one of claims 3-4, wherein, The temperature of the aerobic composting is 50-65°C, the time is 35-40 days, and the turning frequency is once every 5 days.

8. The calcium and magnesium-rich organic fertilizer of claim 1 is used for supplementing soil nitrogen, phosphorus, potassium, calcium and magnesium.

9. The calcium and magnesium-rich organic fertilizer of claim 1 is used for increasing the content of soil organic matter and / or improving the soil's ability to retain nutrients.

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