Rare earth-containing calcium-magnesium synergistic phosphate fertilizer for areca nuts and preparation method thereof

Abstract

The invention relates to a rare earth-containing calcium-magnesium synergistic phosphate fertilizer for areca nuts and a preparation method thereof. The preparation method comprises the following steps: crushing rare earth phosphorite to a submicron level to obtain a submicron-level rare earth mineral raw material; the submicron rare earth mineral raw material and a granulation binder are mixed and granulated to obtain a granular raw material; and uniformly mixing the obtained granular raw material with urea and potassium chloride, and drying to obtain the rare earth calcium magnesium-containing synergistic phosphate fertilizer for areca nuts. The invention aims to solve the problems that the acidification problem of southern soil can be improved by reasonably arranging the formula of each component, the yield of the areca nuts can be increased, and the problems of flower and fruit drop and leaf yellowing of the areca nuts are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut and a preparation method thereof. Background Art

[0002] Betel nut is an important southern medicinal crop in my country and an important tropical specialty crop in Hainan. At present, the province has a planting area of ​​about 2.6 million mu and about 2 million people. In addition, the price of betel nut has been high in recent years and has become the main source of income for many farmers. The output value of the entire industry chain is as high as 20 billion. The original planting areas of betel nut are mainly hillsides. According to the soil survey results of betel nut fields in Hainan Province, the acidification is serious, generally below pH5.5, the soil condition is poor, the organic matter content is mostly below 1%, the nutrient supply is lacking, and the management is extensive. At the same time, due to insufficient rainfall, betel nut production has serious flower and fruit drop. The most fundamental reason is that betel nut is malnourished or has a single nutrient; the tree is weak, causing the betel nut disease and pest to intensify, forming a vicious circle. Therefore, improving the acidity of the soil, providing a reasonable nutrient supply, promoting the normal growth and development of the plant, and improving the ability to protect flowers and fruits are the most important measures for betel nut planting at present. In order to better promote the development of the betel nut industry and increase the yield of betel nut, it is urgently needed to have a low-cost, effective and targeted betel nut fertilizer. Summary of the invention

[0003] In view of this, the main purpose of the present invention is to provide a rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut and a preparation method thereof. The problem to be solved is that by reasonably setting the formula of each component, not only the acidification problem of soil in the south can be improved, but also the yield of betel nut can be increased, and the problems of betel nut flower and fruit drop and leaf yellowing can be reduced.

[0004] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical scheme. The present invention proposes a method for preparing a rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, comprising the following steps:

[0005] 1) crushing rare earth phosphate ore to submicron level to obtain submicron rare earth mineral raw material; mixing and granulating the submicron rare earth mineral raw material with a granulation binder to obtain a granular raw material;

[0006] 2) The granular raw material obtained in step 1) is uniformly mixed with urea and potassium chloride, and dried to obtain the rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut.

[0007] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0008] Preferably, in the aforementioned method for preparing rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, in step 1), the rare earth phosphate rock is primary phosphate rock containing rare earth.

[0009] Preferably, in the aforementioned method for preparing rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, in step 1), the particle size of the submicron rare earth mineral raw material is 10 to 150 μm.

[0010] Preferably, in the aforementioned method for preparing rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, in step 1), the rare earth phosphate rock comprises, by mass percentage: CaO 25-60%; P2O 5 0.4%-16%; MgO 1%-18%, and rare earth 0.5‰-0.8‰.

[0011] Preferably, in the aforementioned method for preparing rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, in step 1), the granulation binder is selected from at least one of humic acid, alginic acid and oligosaccharides.

[0012] Preferably, in the aforementioned method for preparing rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, in step 1), the mass ratio of the rare earth phosphate rock to the granulation binder is 1:(0.2-2).

[0013] Preferably, in the aforementioned method for preparing rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, in step 2), the mass fractions of the granular raw material, urea, and potassium chloride are 30-40 parts, 20-30 parts, and 20-30 parts, respectively.

[0014] Preferably, in the aforementioned method for preparing rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, in step 2), the drying temperature is 60-80° C. and the time is 1-2 h.

[0015] Preferably, in the aforementioned method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, in step 2), the pH value of the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut is greater than 7.2 in mass percentage.

[0016] Preferably, the preparation method of the aforementioned rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, wherein in step 2), the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut includes, by mass percentage: CaO 3%-15%; MgO 2%-10%; rare earth 0.6-1.5‰: N+P2O5+K2O 30%-35%; granulation binder 2%-4%; the balance is bentonite.

[0017] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical scheme. The present invention proposes a rare earth calcium magnesium synergistic phosphate fertilizer for betel nut, which comprises, by mass percentage, 3% to 15% CaO; 2% to 10% MgO; 0.6-1.5‰ rare earth; 30% to 35% N+P2O5+K2O; 2% to 4% granulation binder; and the balance is bentonite.

[0018] By means of the above technical scheme, the present invention provides a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut and a preparation method thereof, which has at least the following advantages:

[0019] 1. Improve soil structure

[0020] The rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut of the present invention has a pH value of about 7.5 to 8.5, can effectively regulate soil acidification, promote crop growth, effectively avoid soil compaction caused by long-term use of traditional fertilizers, enhance soil permeability, dredge the soil, and facilitate nutrient absorption.

[0021] 2. Reasonable nutrient ratio

[0022] The invention fully considers the nutrient demand law and planting environment of betel nut, contains middle elements such as magnesium and calcium, has a more reasonable nutrient ratio, and promotes efficient nutrient utilization.

[0023] 3. Improve fertilizer utilization

[0024] The use of acidification technology can complex the calcium element in the soil, improve the absorption and utilization of calcium and phosphorus, adjust the soil rhizosphere pH value, and effectively reduce soil ammonia volatilization; balance the absorption of crop nutrients and enhance crop resistance.

[0025] 4. Reduce the yellowing of betel nut

[0026] Rare earth elements themselves can regulate the physiological process of plant growth, improve the stress resistance and immunity of crops, promote crop development, and provide a balanced supply of nutrients to make plants stronger. They have a significant promoting effect on the leaf development of areca nut, alleviate the yellowing symptoms of areca nut trees, and reduce the number of yellowing leaves by 1-2 per plant.

[0027] 5. Improve yield and quality

[0028] Under the effect of comprehensive fertilizer, the yield of betel nut has increased significantly and the quality has improved. On average, about 15 pieces are needed to reach one catty, while farmers need about 20 pieces to reach one catty.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of a rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut and its preparation method proposed by the present invention are described in detail below in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0031] The following materials or reagents, unless otherwise specified, were commercially available.

[0032] Some embodiments of the present invention provide a method for preparing a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, comprising the following steps:

[0033] 1) crushing rare earth phosphate ore to submicron level to obtain submicron rare earth mineral raw material; mixing and granulating the submicron rare earth mineral raw material with a granulation binder to obtain a granular raw material;

[0034] 2) The granular raw material obtained in step 1) is uniformly mixed with urea and potassium chloride, and dried to obtain the rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut.

[0035] In some optional embodiments, in step 1), the rare earth phosphate rock is a primary phosphate ore containing rare earths; the particle size of the submicron rare earth mineral raw material is 10 to 150 μm; if the particle size is less than 10 μm, the particle size is too low, the cost is high, and the process energy consumption is large; if the particle size is greater than 150 μm, the particle size is too high, the product activity is reduced, and the crop enhancement effect is not obvious.

[0036] In some optional embodiments, in step 1), the rare earth phosphate rock includes, by mass percentage: CaO 25-60%; P2O5 0.4%-16%; MgO 1%-18%, and rare earth 0.5‰-0.8‰; CaO is used to increase the cell membrane thickness of crops and enhance the ability to resist diseases and pests; P2O5 promotes root development and participates in the physiological metabolism of plants; MgO is used to improve the photosynthesis capacity of crops, increase dry matter accumulation, and reduce the occurrence of yellowing problems; if the rare earth content is less than 0.5‰, the content is too low and may stimulate the physiological process of plants or weaken the stress resistance of plants, which may be poor; if the rare earth content is greater than 0.8‰, the content is too high and may also have an anti-inhibitory effect.

[0037] In some optional embodiments, in step 1), the granulation binder is selected from at least one of humic acid, alginic acid and oligosaccharides; it is used to provide nutrition to various parts of the crop, which is beneficial to the physiological process of the crop.

[0038] In some optional embodiments, in step 1), the mass ratio of the rare earth phosphate ore to the granulation binder is 1:(0.2-2). When it is lower than 1:2, the rare earth phosphate ore ratio is too low and granulation is difficult; when it is higher than 1:0.2, the rare earth phosphate ore ratio is too high and affects the total nutrient concentration.

[0039] In some optional embodiments, in step 2), the mass fractions of the granular raw material, urea, and potassium chloride are 30-40 parts, 20-30 parts, and 20-30 parts, respectively. This setting is to correspond to the nutrient demand characteristics of betel nut to improve the utilization rate of nitrogen, phosphorus, and potassium.

[0040] In some optional embodiments, in step 2), the drying temperature is 60-80°C and the time is 1-2h; if the temperature is higher than 80°C or the time is longer than 2h, the cost is high; if the temperature is lower than 60°C or the time is shorter than 1h, the drying effect is poor.

[0041] In some optional embodiments, in step 2), the pH value of the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut is greater than 7.2. A low pH value will reduce the improvement effect on acidic soil; a high effective calcium content is also conducive to the overall fertilizer effect. The total mass is the sum of the mass of nitrogen, phosphorus and potassium.

[0042] In some optional embodiments, in step 2), the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut includes, by mass percentage: CaO 3% to 15%; MgO 2% to 10%; rare earth 0.6-1.5‰, N+P2O5+K2O 30% to 35%; granulation binder 2% to 4%; the balance is bentonite. If the content of the granulation binder is less than 2wt%, the rooting and leafing effect is not good, or the improvement of physiological and biochemical functions is weak; if the content of the granulation binder is greater than 4wt%, the cost increases and the granulation effect is poor.

[0043] Some embodiments of the present invention also provide a rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, which comprises, by mass percentage: CaO 3%-15%: MgO 2%-10%; rare earth 0.6-1.5‰; N+P2O5+K2O 30%-35%; granulation binder 2%-4%; the remainder is bentonite; the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut is prepared by the above method.

[0044] In the above technical scheme, the present invention can improve the acidification problem of soil in the south by reasonably setting the proportion of each component, and solve the problem of lack of trace elements in the existing special fertilizer for betel nut, which leads to serious flower and fruit drop of betel nut, yellowing of leaves and low yield.

[0045] The specific implementation methods of the present invention are further described in detail below in conjunction with the embodiments, but it should not be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0046] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0047] Embodiment 1:

[0048] This embodiment provides a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, comprising the following steps:

[0049] The rare earth phosphate rock is crushed into 10 μm, and mixed with humic acid and alginic acid in a mass ratio of 1:1:1 to obtain a 2 mm granular raw material; the obtained granular raw material is uniformly mixed with urea and potassium chloride, and the mass fractions thereof are respectively: 30 parts of granular raw material, 20 parts of urea, and 20 parts of potassium chloride; then dried at 70° C. for 2 hours to obtain the rare earth calcium-magnesium-containing synergistic phosphate fertilizer for betel nut, wherein the pH value is 7.3, the content of calcium oxide is 3wt%, the content of magnesium oxide is 10wt%, the content of humic acid is 1wt‰, the content of alginic acid is 1wt‰, and the content of N+P2O5+K2O is 30wt%.

[0050] The rare earth phosphate ore comprises, by mass percentage, 25% CaO; 0.4% P2O; 1% MgO; and 0.5wt‰ rare earth.

[0051] Embodiment 2:

[0052] This embodiment provides a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, and the raw material components by weight are as follows:

[0053] The rare earth phosphate rock is crushed into 10 μm, and mixed with oligosaccharides in a mass ratio of 1:1 to obtain a 2 mm granular raw material; the obtained granular raw material is uniformly mixed with urea and potassium chloride, and the mass fractions thereof are respectively: 40 parts of granular raw material, 30 parts of urea, and 30 parts of potassium chloride; then dried at 60° C. for 2 hours to obtain the rare earth calcium-magnesium-containing synergistic phosphate fertilizer for betel nut, which has a pH value of 8.0, a calcium oxide content of 15wt%, a magnesium oxide content of 8.0wt%, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 35wt%.

[0054] The rare earth phosphate ore comprises, by mass percentage, 60% CaO, 16% P2O5, 18wt% MgO, and 0.8wt‰ rare earth.

[0055] Embodiment 3:

[0056] This embodiment provides a rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, and the raw material components by weight are as follows:

[0057] The rare earth phosphate rock is crushed into 10 μmm, and mixed with humic acid, alginic acid and oligosaccharide in a mass ratio of 1:0.5:0.5:0.5 to obtain a 3 mm granular raw material; the obtained granular raw material is uniformly mixed with urea and potassium chloride, and the mass fractions thereof are respectively: 35 parts of granular raw material, 25 parts of urea, and 25 parts of potassium chloride; then the granular raw material is dried at 80°C for 1 hour to obtain the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut, which has a pH value of 7.5, a calcium oxide content of 4.0wt%, a magnesium oxide content of 9wt%, a humic acid content of 1wt‰, a alginic acid content of 1wt‰, an oligosaccharide content of 1‰, and an N+P2O5+K2O content of 33%.

[0058] The rare earth phosphate ore comprises, by mass percentage, 50wt% CaO, 10% P2O5, 9% MgO and 0.6‰ rare earth.

[0059] Example 4

[0060] The difference between this embodiment and embodiment 1 is that the mass ratio of rare earth phosphate rock, humic acid and alginic acid in this embodiment is 1:0.5:0.5, and the remaining steps and parameters are the same as those in embodiment 1.

[0061] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.2, a calcium oxide content of 3wt%, a magnesium oxide content of 12wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, and a N+P2O5+K2O content of 32wt%.

[0062] Example 5

[0063] The difference between this embodiment and embodiment 1 is that the mass ratio of rare earth phosphate rock, humic acid and alginic acid in this embodiment is 1:0.1:0.1, and the remaining steps and parameters are the same as those in embodiment 1.

[0064] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.3, a calcium oxide content of 4wt%, a magnesium oxide content of 11wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, and a N+P2O5+K2O content of 33wt%.

[0065] Example 6

[0066] The difference between this embodiment and embodiment 2 is that the mass ratio of rare earth phosphate rock to oligosaccharide in this embodiment is 1:0.2, and the remaining steps and parameters are the same as those in embodiment 2.

[0067] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.2, a calcium oxide content of 4wt%, a magnesium oxide content of 12wt%, a humic acid content of 1wt‰, a oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 35wt%.

[0068] Example 7

[0069] The difference between this embodiment and embodiment 2 is that the mass ratio of rare earth phosphate rock to oligosaccharide in this embodiment is 1:2, and the remaining steps and parameters are the same as those in embodiment 2.

[0070] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.3, a calcium oxide content of 5wt%, a magnesium oxide content of 5wt%, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 34wt%.

[0071] Example 8

[0072] The difference between this embodiment and embodiment 3 is that the mass ratio of rare earth phosphate rock, humic acid, alginic acid and oligosaccharide in this embodiment is 1:0.09:0.09:0.09, and the remaining steps and parameters are the same as those in embodiment 3.

[0073] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.3, a calcium oxide content of 15wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 35wt%.

[0074] Example 9

[0075] The difference between this embodiment and embodiment 3 is that the mass ratio of rare earth phosphate rock, humic acid, alginic acid and oligosaccharide in this embodiment is 1:0.66:0.66:0.66, and the remaining steps and parameters are the same as those in embodiment 3.

[0076] The rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut obtained in this embodiment has a pH value of 7.3, a calcium oxide content of 12wt%, a magnesium oxide content of 8wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 34wt%.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that the mass ratio of rare earth phosphate rock, humic acid and alginic acid in this comparative example is 1:0.05:0.05, and the remaining steps and parameters are the same as those in Example 1.

[0079] The phosphate fertilizer obtained in this comparative example has a pH value of 7.3, a calcium oxide content of 3wt%, a magnesium oxide content of 11wt%, a humic acid content of 0.09wt‰, an alginic acid content of 0.09wt‰, and a N+P2O5+K2O content of 30wt%.

[0080] Comparative Example 2

[0081] The difference between this comparative example and Example 1 is that the mass ratio of rare earth phosphate rock, humic acid and alginic acid in this comparative example is 1:1.5:1.5, and the remaining steps and parameters are the same as those in Example 1.

[0082] The phosphate fertilizer obtained in this comparative example has a pH value of 7.3, a calcium oxide content of 3wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginic acid content of 1wt‰, and a N+P2O5+K2O content of 31wt%.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 2 is that the mass ratio of rare earth phosphate rock to oligosaccharide in this comparative example is 1:3, and the remaining steps and parameters are the same as those in Example 2.

[0085] The phosphate fertilizer obtained in this comparative example has a pH value of 7.3, a calcium oxide content of 3wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginic acid content of 1wt‰, and a N+P2O5+K2O content of 35wt%.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 2 is that the mass ratio of rare earth phosphate rock to oligosaccharide in this comparative example is 1:0.1, and the remaining steps and parameters are the same as those in Example 2.

[0088] The phosphate fertilizer obtained in this comparative example has a pH value of 7.3, a calcium oxide content of 3wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginic acid content of 1wt‰, and a N+P2O5+K2O content of 33wt%.

[0089] Comparative Example 5

[0090] The difference between this comparative example and Example 3 is that the mass ratio of rare earth phosphate rock, humic acid, alginic acid and oligosaccharide in this comparative example is 1:0.03:0.03:0.03, and the remaining steps and parameters are the same as those in Example 3.

[0091] The phosphate fertilizer obtained in this comparative example has a pH value of 7.2, a calcium oxide content of 3wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 30wt%.

[0092] Comparative Example 6

[0093] The difference between this comparative example and Example 3 is that the mass ratio of rare earth phosphate rock, humic acid, alginic acid and oligosaccharide in this comparative example is 1:1:1:1, and the remaining steps and parameters are the same as those in Example 3.

[0094] The phosphate fertilizer obtained in this comparative example has a pH value of 7.2, a calcium oxide content of 10wt%, a magnesium oxide content of 10wt%, a humic acid content of 1wt‰, an alginate content of 1wt‰, an oligosaccharide content of 1wt‰, and a N+P2O5+K2O content of 30wt%.

[0095] Comparative Example 7

[0096] The fertilizer type in this comparative example is compound fertilizer (15-15-15); the fertilizer dosage of comparative example 1 is determined according to the local farmers' usual dosage, 3 kg per plant / year,

[0097] The application effects of the above Examples 1-3 and Comparative Example 1 are shown in Table 1 below.

[0098] Location: Baisha, Hainan; Variety: local betel nut; Soil: brick red soil;

[0099] Plan: The three fertilizers of Examples 1-3 were applied at the test site. The fertilizer dosage was determined according to the local farmers' usual dosage, 6 catties per plant per year, and the fertilization method was the farmers' usual method. The fertilizers were applied three times in March, June and November: the fertilizer dosages were 0.9 kg, 0.9 kg and 2.4 kg respectively.

[0100] Table 1

[0101]

[0102]

[0103] The data in Table 1 show that, under the conditions of equal application, the application of the rare earth calcium magnesium synergistic phosphate fertilizer for betel nut provided by Examples 1-9 of the present invention significantly increased the betel nut yield compared with Comparative Examples 1-7: for example, compared with Comparative Example 7, under the conditions of equal application, the application of the rare earth calcium magnesium synergistic phosphate fertilizer for betel nut provided by Examples 1-9 of the present invention increased the betel nut yield by 12.2%-54.3%, and also performed well in reducing leaf yellowing, reducing 1-5 problematic leaves; an average of 15 betel nuts per kilogram were obtained by applying the rare earth calcium magnesium synergistic phosphate fertilizer for betel nut provided by Examples 1-9 of the present invention, and long-term use may further reduce the yellowing problem and increase the fruit-bearing life of betel nut fruit-bearing trees.

[0104] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0105] The numerical range described in the present invention includes all the numerical values ​​within the range, and includes the range value formed by any two numerical values ​​within the range. Different numerical values ​​of the same indicator appearing in all embodiments of the present invention can be arbitrarily combined to form a range value.

[0106] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0107] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut, characterized in that: The following steps are involved: 1) crushing rare earth phosphate ore to submicron level to obtain submicron rare earth mineral raw material; mixing and granulating the submicron rare earth mineral raw material with a granulation binder to obtain a granular raw material; 2) The granular raw material obtained in step 1) is uniformly mixed with urea and potassium chloride, and dried to obtain the rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut.

2. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut as claimed in claim 1, characterized in that: In step 1), the rare earth phosphate rock is a primary phosphate rock containing rare earth.

3. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut as claimed in claim 1, characterized in that: In step 1), the particle size of the submicron rare earth mineral raw material is 10 to 150 μm.

4. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut as claimed in claim 1, characterized in that: In step 1), the rare earth phosphate ore comprises, by mass percentage: CaO 25-60%; P2O 5 0.4%-16%; MgO 1%-18%; and rare earth 0.5‰-0.8‰.

5. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut as claimed in claim 1, characterized in that: In step 1), the granulation binder is selected from at least one of humic acid, alginic acid and oligosaccharides.

6. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut according to claim 1, characterized in that: In step 1), the mass ratio of the rare earth phosphate rock to the granulation binder is 1:(0.2-2).

7. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut as claimed in claim 1, characterized in that: In step 2), the mass fractions of the granular raw material, urea and potassium chloride are 30-40 parts, 20-30 parts and 20-30 parts respectively; the drying temperature is 60-80° C. and the drying time is 1-2 hours.

8. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut according to claim 1, characterized in that: In step 2), the pH value of the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut is greater than 7.2 in terms of mass percentage.

9. The method for preparing the rare earth calcium and magnesium synergistic phosphate fertilizer for betel nut according to claim 1, characterized in that: In step 2), the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut comprises, by mass percentage: CaO 3%-15%; MgO 2%-10%; rare earth 0.6-1.5‰; N+P2O5+K2O 30%-35%; granulation binder 2%-4%; and the balance is bentonite.

10. A rare earth calcium and magnesium-containing synergistic phosphate fertilizer for betel nut, characterized in that: Calculated by mass percentage, the rare earth calcium-magnesium synergistic phosphate fertilizer for betel nut comprises: CaO 3%-15%; MgO 2%-10%; rare earth 0.6-1.5‰; N+P2O5+K2O 30%-35%; granulation binder 2%-4%; and the balance is bentonite.

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