CN112479778A - Special fertilizer for soilless culture of leaf vegetables and preparation method thereof - Google Patents

Abstract

The application relates to the field of fertilizers, and particularly discloses a special fertilizer for soilless culture of leaf vegetables and a preparation method thereof; a special fertilizer for soilless culture of leaf vegetables is prepared by mixing a fertilizer A, a fertilizer B and a fertilizer C: the fertilizer A is prepared from the following raw materials in parts by weight: calcium nitrate tetrahydrate, EDTA chelated iron and chitosan coated ammonium nitrate; the fertilizer B is prepared from the following raw materials in parts by weight: potassium dihydrogen phosphate, potassium sulfate, magnesium sulfate heptahydrate; the fertilizer C is prepared from the following raw materials in parts by weight: manganese sulfate, zinc sulfate, boric acid, copper sulfate and ammonium molybdate; the effects of reducing the temperature of the matrix layer and promoting the growth of the leaf vegetables under the condition of higher external environment temperature are achieved.

Description

Special fertilizer for soilless culture of leaf vegetables and preparation method thereof

Technical Field

The application relates to the field of fertilizers, in particular to a special fertilizer for soilless culture of leaf vegetables and a preparation method thereof.

Background

The leaf vegetables are fast-growing vegetables which mainly take fresh green leaves, leafstalks and tender stems as products, and comprise lettuce, shallots, rape, leeks and the like, and the common leaf vegetables are yin-loving and cold-tolerant plants, so that the vegetables grow well under the condition of being cooler and moist, and the optimum growth temperature is between 15 and 25 ℃; in summer in the south, the temperature of the matrix layer is higher due to higher external environment temperature, the moisture content of the matrix layer is reduced, and the quantity of trace elements such as moisture, mineral substances and the like absorbed by the root system of the leaf vegetables is reduced, so that the growth of the leaf vegetables is influenced.

Disclosure of Invention

In order to properly reduce the temperature of a matrix layer and promote the growth of leaf vegetables when the temperature of the external environment is higher, the application provides the special fertilizer for the soilless culture of the leaf vegetables and the preparation method thereof.

In a first aspect, the application provides a special fertilizer for soilless culture of leaf vegetables, which adopts the following technical scheme:

a special fertilizer for soilless culture of leaf vegetables is prepared by mixing a fertilizer A, a fertilizer B and a fertilizer C: the fertilizer A is prepared from the following raw materials in parts by weight: 6.5-7.2 parts of calcium nitrate tetrahydrate, 0.1-0.2 part of EDTA chelated iron and 1-2 parts of chitosan coated ammonium nitrate;

the fertilizer B is prepared from the following raw materials in parts by weight: 0.5-0.7 part of monopotassium phosphate, 1.5-2.0 parts of potassium sulfate and 0.4-0.7 part of magnesium sulfate heptahydrate;

the fertilizer C is prepared from the following raw materials in parts by weight: 0.01-0.018 portion of manganese sulfate, 0.003-0.007 portion of zinc sulfate, 0.01-0.015 portion of boric acid, 0.0005-0.0015 portion of copper sulfate and 0.0005-0.0012 portion of ammonium molybdate.

By adopting the technical scheme, the fertilizer A, the fertilizer B and the fertilizer C are mixed and then added with water to prepare the nutrient solution, and the ammonium molybdate and part of chitosan coated ammonium nitrate generate heat absorption effect after being dissolved in water, so that the temperature of the nutrient solution is initially reduced; after nutrient solution is injected into the matrix layer, the chitosan film of the wall material of the residual chitosan coated ammonium nitrate is contacted with moisture in the matrix layer, the chitosan film is gradually broken, the ammonium nitrate in the chitosan film is gradually released, the temperature of the matrix layer is reduced by utilizing the heat absorption effect of the ammonium nitrate dissolved in water, the phenomenon that the temperature of the external environment is too high to influence the root of the leaf vegetables to absorb the moisture and mineral elements of the matrix layer is avoided, and the growth of the leaf vegetables can be promoted by properly reducing the temperature of the matrix layer and matching with various trace elements.

Preferably, the chitosan coated ammonium nitrate is prepared by the following method:

i, weighing 3-5 parts of chitosan, pouring the chitosan into 180-220 parts of acetic acid solution with the mass fraction of 1%, and stirring the mixture for 3-8min at the rotating speed of 300-600r/min to prepare a chitosan solution;

II, weighing 4-8 parts of glycerol and 1-2 parts of polyvinyl alcohol, mixing and stirring, adding 0.5-1.5 parts of glutaraldehyde, and continuing stirring for 0.2-0.8h to prepare chitosan membrane solution;

III, weighing 480 parts of 400-480 parts of ammonium nitrate, spraying the chitosan film liquid prepared in the step II on the surface of the ammonium nitrate through a coating machine, and drying to prepare the chitosan coated ammonium nitrate.

By adopting the technical scheme, the chitosan and the acetic acid form macromolecular salt, and the salt compound is dissolved in the water slowly, so that the chitosan film is ensured to be gradually broken, and the ammonium nitrate in the chitosan film is slowly released; the glutaraldehyde is matched as a cross-linking agent, two aldehyde groups of the glutaraldehyde react with amino groups with higher activity in a chitosan molecular chain to form Schiff base to form a network structure, so that reaction sites are improved, the swelling degree of the chitosan membrane is reduced, the hydrophobicity of the chitosan membrane is improved, the slow release property of the chitosan membrane is improved, calcium nitrate in the chitosan membrane can be slowly released, and the root of the leafy vegetable is prevented from being frostbitten at a lower temperature instantly; by slowly releasing ammonium nitrate, the ammonium nitrate is slowly dissolved in the matrix layer to absorb heat, so that the phenomenon that the root of the leaf vegetables is damaged at low temperature is avoided, and the phenomenon that the growth of the leaf vegetables is inhibited at high temperature is avoided.

Preferably, the deacetylation degree of the chitosan in the compound I is 85 percent, and the relative molecular mass is 50 ten thousand.

By adopting the technical scheme, in the dissolving process of chitosan, the chitosan has high deacetylation degree, small relative molecular mass and easy dissolution, and has low deacetylation degree and large relative molecular mass and difficult dissolution, after the chitosan film is mixed with water, in order to ensure that the chitosan film is slowly broken, the ammonium nitrate inside is slowly released, the deacetylation degree of the chitosan is 85 percent, the relative molecular mass is 50 ten thousand, the ammonium nitrate can be ensured not to be released when a large amount of chitosan coated ammonium nitrate is prepared with nutrient solution, and the large amount of ammonium nitrate can be gradually released in the matrix layer, so that the ammonium nitrate absorbs the heat of the matrix layer, properly reduces the temperature of the matrix layer and maintains the temperature, and promotes the growth of leaf vegetables even under the condition of high external environment temperature.

Preferably, the content of iron ions in the EDTA chelated iron is 12%.

By adopting the technical scheme, the content of iron ions is limited to be 12%, so that the prepared fertilizer is absorbed by the roots of the leaf vegetables through the high-content iron element, and the leaf vegetables can absorb enough iron element to promote the growth of the leaf vegetables.

Preferably, the special fertilizer for soilless culture of leaf vegetables further comprises the following raw materials in parts by weight: 1-3 parts of ammonium chloride modified volcanic rock and 0.2-0.6 part of kaolin.

By adopting the technical scheme, the ammonium chloride modified volcanic rock, the kaolin and the chitosan coated ammonium nitrate are matched, so that the matrix layer has a better cooling effect, and the cooling dispersion effect is good, thereby better promoting the growth of the leaf vegetables.

The ammonium chloride modified volcanic rock is arranged in the matrix layer, and the moisture in the matrix layer is gradually contacted with the ammonium chloride in the volcanic rock, so that the ammonium chloride in the volcanic rock primarily absorbs heat, the ammonium chloride absorbs heat and cools at a low rate, the root system of the leafy vegetables in the matrix layer is not greatly influenced, and the ammonium nitrate in the chitosan film gradually permeates along with the gradual fracture of the chitosan film, so that the continuous cooling of the matrix layer is realized, and the growth of the leafy vegetables can be promoted by the continuous cooling of the matrix layer even if the external environment temperature is continuously in a high-temperature state; and the porous structure of volcanic rock and kaolin are matched, so that heat can be absorbed to a greater extent, and meanwhile, the higher dispersity of volcanic rock and kaolin can balance the cooling effect of the matrix layer, so that the condition that the temperature of part of the matrix layer is higher and the temperature of part of the matrix layer is lower is avoided, and the influence on the growth of leaf vegetables is avoided.

Preferably, the ammonium chloride modified volcanic rock is prepared by the following method:

the method comprises the steps of weighing 1-3 parts of ammonium chloride, 75-85 parts of 2% acetone solution and 2-6 parts of volcanic rock, mixing, performing ultrasonic dispersion for 8-12min at the frequency of 20KHz-40KHz, filtering out the volcanic rock, and drying the volcanic rock to obtain the ammonium chloride modified volcanic rock.

By adopting the technical scheme, the ammonium chloride, the acetone and the volcanic rock are mixed and matched with the ultrasonic dispersion, so that the ammonium chloride can be injected into the pores of the volcanic rock, the time and the frequency of the ultrasonic dispersion are limited, and the amount of the ammonium chloride entering the pores of the volcanic rock is increased; through utilizing the lower endothermic degree of ammonium chloride as the buffering of matrix layer, the endothermic effect of cooperation ammonium nitrate for the matrix layer all has the cooling effect in different stages, even external environment temperature is higher, the continuous cooling of matrix layer can make the matrix layer maintain the temperature that is fit for leaf dish to grow, thereby promotes the growth of leaf dish.

Preferably, the ammonium chloride modified volcanic rock is prepared by far infrared drying of the volcanic rock in the process of the preparation at the temperature of 30-50 ℃.

Through adopting above-mentioned technical scheme, at the stoving in-process, inject stoving temperature and stoving mode and be the far infrared stoving, avoid ammonium chloride to be heated in volcanic rock hole and decompose on the one hand, on the other hand avoids air-dry condition to descend the hole that ammonium chloride powder blows away from volcanic rock to can improve drying efficiency, make ammonium chloride comparatively stable attached to in the hole of volcanic rock.

In a second aspect, the application provides a preparation method of a special fertilizer for soilless culture of leaf vegetables, which adopts the following technical scheme: a preparation method of a special fertilizer for soilless culture of leaf vegetables comprises the following steps:

s1, weighing calcium nitrate tetrahydrate, EDTA chelated iron and chitosan coated ammonium nitrate, fully mixing and uniformly stirring, and placing in a packaging bag A to obtain fertilizer A;

s2, weighing potassium dihydrogen phosphate, potassium sulfate and magnesium sulfate heptahydrate, mixing, and placing in a packaging bag B to obtain fertilizer B;

s3, weighing manganese sulfate, zinc sulfate, boric acid, copper sulfate and ammonium molybdate, fully mixing uniformly, and placing in a C packaging bag to obtain a C fertilizer;

s4, and the weight ratio is 1 (0.6-1.2): (0.7-1.3) mixing the fertilizer A, the fertilizer B and the fertilizer C to obtain a finished fertilizer.

By adopting the technical scheme, the fertilizer A, the fertilizer B and the fertilizer C are respectively prepared by mixing the raw materials, and then the fertilizer A, the fertilizer B and the fertilizer C are mixed according to the weight ratio to prepare the finished fertilizer.

In summary, the present application has the following beneficial effects:

1. the chitosan coated ammonium nitrate, the ammonium chloride modified volcanic rock and the kaolin are matched, when the nutrient solution is prepared, a part of chitosan film of the chitosan coated ammonium nitrate is broken, a part of ammonium nitrate is released, the temperature of the nutrient solution is reduced, the ammonium chloride part in the sodium chloride modified volcanic rock is contacted with water, the ammonium chloride is dissolved in the water to absorb heat, and the temperature of the nutrient solution is reduced again; after nutrient solution is injected into the matrix layer, the matrix layer is preliminarily cooled, ammonium chloride further absorbs heat along with the contact of moisture in the matrix layer and volcanic rocks, the matrix layer is cooled, the chitosan film is contacted with water in the matrix layer, the chitosan film is gradually broken to release ammonium nitrate, so that the matrix layer is continuously cooled, and when the external environment temperature is higher, the prepared fertilizer can reduce the temperature of the matrix layer, so that the growth of leaf vegetables is promoted.

2. Manganese sulfate, zinc sulfate, boric acid, copper sulfate, magnesium sulfate heptahydrate and potassium sulfate are matched, when the nutrient solution is prepared, the heat release state appears when the nutrient solution is dissolved in water, the chitosan coated ammonium nitrate, ammonium chloride modified volcanic rock and kaolin are matched, the temperature rise condition of the nutrient solution can be balanced, the temperature of the nutrient solution is reduced, and the matrix layer can be preliminarily cooled when the nutrient solution is contacted with the matrix layer.

3. After the fertilizer A, the fertilizer B and the fertilizer C are mixed, the soilless culture fertilizer for the leaf vegetables has more trace elements for promoting the growth of the leaf vegetables, EDTA chelated iron provides higher-content iron elements for the leaf vegetables, and the Fe with the mass fraction of 12% can better promote the normal growth of the leaf vegetables without generating an inhibiting effect on the growth of the leaf vegetables; magnesium sulfate, manganese sulfate, zinc sulfate and copper sulfate can provide S elements for the leaf vegetables and can also provide trace elements such as magnesium, manganese, zinc, copper and the like, a potassium fertilizer can provide higher potassium elements for the leaf vegetables, and calcium nitrate tetrahydrate is matched with ammonium molybdate to provide N elements for the leaf vegetables; the calcium nitrate tetrahydrate is matched with the chitosan coated ammonium nitrate to provide calcium for the growth of the leafy vegetables; the normal growth of the leaf vegetables can be promoted by reasonably matching the trace elements and properly reducing the temperature of the matrix layer.

4. The porous structures of the kaolin and the volcanic rock are utilized, so that the matrix layer has good air permeability and water permeability, and high water and fertilizer retention capacity, and the growth of the leaf vegetables can be promoted.

Detailed Description

The present application will be described in further detail with reference to examples.

Preparation example of chitosan-coated ammonium nitrate

The chitosan in the following raw materials is purchased from food-grade chitosan produced by Qiyun biotechnology limited company in Guangzhou city; glacial acetic acid is selected from analytical reagent produced by Guangzhou chemical reagent factory; glutaraldehyde was purchased from the Fochen chemical reagent factory, Tianjin; polyvinyl alcohol was purchased from Guangzhou east New chemical Co., Ltd; ammonium nitrate is purchased from open-market attention chemical company, ltd; other raw materials and equipment are all sold in the market.

Preparation example 1: the chitosan coated ammonium nitrate is prepared by the following method:

i, weighing 4kg of chitosan, pouring the chitosan into 200kg of acetic acid solution with the mass fraction of 1%, and stirring at the rotating speed of 500r/min for 5min to prepare a chitosan solution; the deacetylation degree of the chitosan is 85 percent, and the relative molecular weight is 50 ten thousand;

II, weighing 6kg of glycerol and 1.5kg of polyvinyl alcohol, mixing and stirring, adding 1kg of glutaraldehyde, continuously stirring for 0.5h, and then carrying out ultrasonic filtration and deaeration for 2min to prepare chitosan membrane solution;

III, weighing 450kg of ammonium nitrate, placing the ammonium nitrate in a pot body of a coating machine, opening the coating machine to blow air, and preheating the ammonium nitrate for 2min at the temperature of 80 ℃ at the speed of 20 r/min; and (3) placing the chitosan film liquid prepared in the step (II) in a liquid cup of a liquid spraying device of a coating machine, spraying the chitosan film liquid on the surface of the ammonium nitrate by the coating machine, naturally cooling, and drying for 30min at the temperature of 80 ℃ to prepare the chitosan coated ammonium nitrate.

Preparation example 2: the chitosan coated ammonium nitrate is prepared by the following method:

weighing 3kg of chitosan, pouring the chitosan into 180kg of acetic acid solution with the mass fraction of 1%, and stirring the chitosan solution for 3min at the rotating speed of 300r/min to prepare chitosan solution; the deacetylation degree of the chitosan is 90 percent, and the relative molecular weight is 20 ten thousand;

II, weighing 4kg of glycerol and 1kg of polyvinyl alcohol, mixing and stirring, adding 0.5kg of glutaraldehyde, continuing stirring for 0.2h, and then carrying out ultrasonic filtration and deaeration for 2min to prepare chitosan membrane solution;

III, weighing 400kg of ammonium nitrate, placing the ammonium nitrate in a pot body of a coating machine, opening the coating machine to blow air, and preheating the ammonium nitrate for 2min at the temperature of 80 ℃ at the speed of 20 r/min; and (3) placing the chitosan film liquid prepared in the step (II) in a liquid cup of a liquid spraying device of a coating machine, spraying the chitosan film liquid on the surface of the ammonium nitrate by the coating machine, naturally cooling, and drying for 30min at the temperature of 80 ℃ to prepare the chitosan coated ammonium nitrate.

Preparation example 3: the chitosan coated ammonium nitrate is prepared by the following method:

i, weighing 5kg of chitosan, pouring the chitosan into 220kg of acetic acid solution with the mass fraction of 1%, and stirring at the rotating speed of 600r/min for 8min to prepare a chitosan solution; the deacetylation degree of the chitosan is 85 percent, and the relative molecular weight is 5 ten thousand;

II, weighing 8kg of glycerol and 2kg of polyvinyl alcohol, mixing and stirring, adding 1.5kg of glutaraldehyde, continuing stirring for 0.8h, and then carrying out ultrasonic filtration and deaeration for 2min to obtain chitosan membrane solution;

III, weighing 480kg of ammonium nitrate, placing the ammonium nitrate in a pot body of a coating machine, opening the coating machine to blow air, and preheating the ammonium nitrate for 2min at the temperature of 80 ℃ at the speed of 20 r/min; and (3) placing the chitosan film liquid prepared in the step (II) in a liquid cup of a liquid spraying device of a coating machine, spraying the chitosan film liquid on the surface of the ammonium nitrate by the coating machine, naturally cooling, and drying for 30min at the temperature of 80 ℃ to prepare the chitosan coated ammonium nitrate.

Preparation example of ammonium chloride-modified volcanic rock

The volcanic rock in the following raw materials is purchased from Henan Zhien water purification materials Co., Ltd, and the particle size is 2-4 mm; the ammonium chloride is purchased from the chemical company of Shenxin, Tianjin, and has the analytical purity of 99 percent; other raw materials and equipment are all sold in the market.

Preparation example 4: the ammonium chloride modified volcanic rock is prepared by the following method:

the method comprises the steps of weighing 2kg of ammonium chloride, 80kg of 2% acetone solution and 4kg of volcanic rock, mixing, performing ultrasonic wave dispersion for 10min at the frequency of 30KHz, filtering out the volcanic rock, and performing far infrared drying on the volcanic rock for 18min at the temperature of 40 ℃ to obtain the ammonium chloride modified volcanic rock.

Preparation example 5: the ammonium chloride modified volcanic rock is prepared by the following method:

the method comprises the steps of weighing 1kg of ammonium chloride, 75kg of 2% acetone solution and 2kg of volcanic rock, mixing, performing ultrasonic wave dispersion for 8min at the frequency of 20KHz, filtering out the volcanic rock, and performing far infrared drying on the volcanic rock for 15min at the temperature of 30 ℃ to obtain the ammonium chloride modified volcanic rock.

Preparation example 6: the ammonium chloride modified volcanic rock is prepared by the following method:

the method comprises the steps of weighing 3kg of ammonium chloride, 85kg of 2% acetone solution and 6kg of volcanic rock, mixing, performing ultrasonic wave dispersion for 12min at the frequency of 40KHz, filtering out the volcanic rock, and performing far infrared drying on the volcanic rock for 20min at the temperature of 50 ℃ to obtain the ammonium chloride modified volcanic rock.

Examples

Calcium nitrate tetrahydrate in the following examples was purchased from Nanjing chemical reagents, Inc.; EDTA chelated iron was purchased from Demmer; monopotassium phosphate was purchased from cornification products, ltd, Henan; potassium sulfate was purchased from cornification products, inc; magnesium sulfate heptahydrate is purchased from cigarette Taiwan Sanding chemical Co Ltd; manganese sulfate was purchased from cornification products, inc; the zinc sulfate is purchased from zinc sulfate heptahydrate produced by Henan Xin chemical products Co., Ltd; boric acid was purchased from cornification products, inc; copper sulfate was purchased from Henan Xin chemical products, Inc.; ammonium molybdate was purchased from gorda chemical ltd, south of the river; other raw materials and equipment are all sold in the market.

Example 1: a preparation method of a special fertilizer for soilless culture of leaf vegetables comprises the following steps:

s1, weighing 6.92kg of calcium nitrate tetrahydrate and 0.13525kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1200r/min for 10min, adding 1.6kg of chitosan coated ammonium nitrate prepared in the preparation example 1, stirring at the rotating speed of 300r/min for 5min, uniformly stirring, and placing in a packaging bag A to prepare a fertilizer A; the content of iron ions in the EDTA chelated iron is 12 percent;

s2, weighing 0.68kg of monopotassium phosphate, 1.85kg of potassium sulfate and 0.56kg of magnesium sulfate heptahydrate, mixing at the rotating speed of 800r/min, stirring for 10min, and then placing in a B packaging bag to obtain a B fertilizer;

s3, weighing 0.01275kg of manganese sulfate, 0.00543kg of zinc sulfate, 0.01075kg of boric acid, 0.00094kg of copper sulfate and 0.00091kg of ammonium molybdate, mixing, stirring for 5min at the rotating speed of 1000r/min, and then placing in a C packaging bag to obtain a C fertilizer;

s4, mixing the fertilizer A, the fertilizer B and the fertilizer C according to the weight ratio of 1:1:1 to obtain the finished fertilizer.

Example 2: a preparation method of a special fertilizer for soilless culture of leaf vegetables comprises the following steps:

s1, weighing 6.5kg of calcium nitrate tetrahydrate and 0.1kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1000r/min for 15min, adding 1kg of chitosan coated ammonium nitrate prepared in preparation example 2, stirring at the rotating speed of 350r/min for 8min, uniformly stirring, and placing in a packaging bag A to prepare a fertilizer A; the content of iron ions in the EDTA chelated iron is 15 percent;

s2, weighing 0.5kg of monopotassium phosphate, 1.5kg of potassium sulfate and 0.4kg of magnesium sulfate heptahydrate, mixing at the rotating speed of 800r/min, stirring for 10min, and then placing in a B packaging bag to obtain a B fertilizer;

s3, weighing 0.01kg of manganese sulfate, 0.003kg of zinc sulfate, 0.01kg of boric acid, 0.0005kg of copper sulfate and 0.0005kg of ammonium molybdate, mixing, stirring at the rotating speed of 1000r/min for 5min, and then placing in a C packaging bag to obtain a C fertilizer;

s4, mixing the fertilizer A, the fertilizer B and the fertilizer C according to the weight ratio of 1:0.6:0.7 to obtain the finished fertilizer.

Example 3: a preparation method of a special fertilizer for soilless culture of leaf vegetables comprises the following steps:

s1, weighing 7.2kg of calcium nitrate tetrahydrate and 0.2kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1500r/min for 5min, adding 2kg of chitosan coated ammonium nitrate prepared in preparation example 3, stirring at the rotating speed of 400r/min for 10min, uniformly stirring, and placing in a packaging bag A to prepare a fertilizer A; the content of iron ions in the EDTA chelated iron is 10 percent;

s2, weighing 0.7kg of monopotassium phosphate, 1.5kg of potassium sulfate and 0.4kg of magnesium sulfate heptahydrate, mixing at the rotating speed of 800r/min, stirring for 10min, and then placing in a B packaging bag to obtain a B fertilizer;

s3, weighing 0.018kg of manganese sulfate, 0.007kg of zinc sulfate, 0.015kg of boric acid, 0.0015kg of copper sulfate and 0.0012kg of ammonium molybdate, mixing, stirring for 5min at the rotating speed of 1000r/min, and then placing in a C packaging bag to obtain a fertilizer C;

s4, mixing the fertilizer A, the fertilizer B and the fertilizer C according to the weight ratio of 1:1.2:1.3 to obtain the finished fertilizer.

Example 4: the present embodiment is different from embodiment 1 in that:

s1, weighing 6.92kg of calcium nitrate tetrahydrate, 0.13525kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1200r/min for 10min, adding 1.6kg of chitosan coated ammonium nitrate prepared in preparation example 1, 2kg of ammonium chloride modified volcanic rock prepared in preparation example 4 and 0.4kg of kaolin, stirring at the rotating speed of 300r/min for 5min, uniformly stirring, and placing in a packaging bag A to obtain the fertilizer A.

Example 5: the present embodiment is different from embodiment 1 in that:

s1, weighing 6.92kg of calcium nitrate tetrahydrate, 0.13525kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1200r/min for 10min, adding 1.6kg of chitosan coated ammonium nitrate prepared in preparation example 1, 1kg of ammonium chloride modified volcanic rock prepared in preparation example 5 and 0.2kg of kaolin, stirring at the rotating speed of 300r/min for 5min, uniformly stirring, and placing in a packaging bag A to obtain the fertilizer A.

Example 6: the present embodiment is different from embodiment 1 in that:

s1, weighing 6.92kg of calcium nitrate tetrahydrate, 0.13525kg of EDTA chelated iron, mixing, stirring at the rotating speed of 1200r/min for 10min, adding 1.6kg of chitosan coated ammonium nitrate prepared in preparation example 1, 3kg of ammonium chloride modified volcanic rock prepared in preparation example 6 and 0.6kg of kaolin, stirring at the rotating speed of 300r/min for 5min, uniformly stirring, and placing in a packaging bag A to obtain the fertilizer A.

Preparation example applied to comparative example

Preparation example 7: the difference between the preparation example and the preparation example 1 is that: glutaraldehyde is not added to the raw materials.

Preparation example 8: the difference between the preparation example and the preparation example 1 is that: polyvinyl alcohol was not added to the raw materials.

Preparation example 9: the difference between the preparation example and the preparation example 4 is that: the method comprises the steps of weighing 2kg of ammonium chloride, 80kg of 2% acetone solution and 4kg of volcanic rock, mixing, performing ultrasonic wave dispersion for 10min at the frequency of 30KHz, filtering out the volcanic rock, and performing far infrared drying on the volcanic rock for 18min at the temperature of 80 ℃ to obtain the ammonium chloride modified volcanic rock.

Preparation example 10: the difference between the preparation example and the preparation example 4 is that: the method comprises the steps of weighing 2kg of ammonium chloride, 80kg of 2% acetone solution and 4kg of volcanic rock, mixing, performing ultrasonic wave dispersion for 10min at the frequency of 30KHz, filtering out the volcanic rock, and performing air drying on the volcanic rock for 18min at the temperature of 40 ℃ to obtain the ammonium chloride modified volcanic rock.

Comparative example

Comparative example 1: this comparative example differs from example 4 in that chitosan-coated ammonium nitrate was not added to the feed.

Comparative example 2: this comparative example differs from example 4 in that the ammonium chloride was replaced by an equal mass of kaolin in the feed to modify the volcanic rock.

Comparative example 3: this comparative example differs from example 4 in that the kaolin was replaced with an equal mass of ammonium chloride modified volcanic rock in the feed.

Comparative example 4: the comparative example is different from example 4 in that chitosan-coated ammonium nitrate prepared in preparation example 7 was used as the chitosan-coated ammonium nitrate.

Comparative example 5: the comparative example is different from example 4 in that chitosan-coated ammonium nitrate prepared in preparation example 8 was used as the chitosan-coated ammonium nitrate.

Comparative example 6: this comparative example is different from example 4 in that ammonium chloride-modified volcanic rock prepared in preparation example 9 was used.

Comparative example 7: this comparative example is different from example 4 in that ammonium chloride-modified volcanic rock prepared in preparation example 10 was used.

Performance test

1. Detection of cooling performance of special fertilizer for soilless culture of leaf vegetables

The preparation methods of the embodiments 1-6 and the comparative examples 1-7 are respectively adopted to prepare the special fertilizer for soilless culture of the leaf vegetables, the fertilizer and water are mixed according to the weight ratio of 1:15 to prepare the nutrient solution, the nutrient solution is immediately sprayed on the surface of the base layer after the preparation is finished, the environment temperature outside the base layer is adjusted to 35 ℃, thermometers are used for detecting the temperature of the substrate layer before the nutrient solution is poured and 1h, 2h and 5h after the nutrient solution is poured respectively, and data are recorded.

Note: the temperature of the matrix layer is 15-25 deg.C, which is the optimum temperature for leaf vegetable growth.

TABLE 1 testing table for cooling performance of special fertilizer for soilless culture of leaf vegetables

2. Leaf vegetable growth test

Preparing special fertilizer for soilless culture of leaf vegetables by adopting the preparation methods of the embodiments 1-6 and the comparative examples 1-7 respectively, mixing the fertilizer and water according to the weight ratio of 1:15 to prepare nutrient solution, immediately irrigating a matrix layer after the preparation of the nutrient solution is finished, measuring the length of a main root in 2 days, 10 days and 25 days respectively at the external environment temperature of 35 ℃, and recording data; and the leaf vegetable growth was scored.

The leaf vegetable growth condition scoring standard is as follows: 7-10 minutes, the growth state of the leaf vegetables is good, and the growth speed is high; 4-7 minutes, the growth state of the leaf vegetables is better, and the growth speed is higher; 0-4 minutes, the growth state of the leaf vegetables is poor, and the growth speed is slow.

TABLE 2 leaf vegetable growth test table (taking leek as an example)

It can be seen from the combination of examples 1-3 and examples 4-6 and table 1 that the ammonium chloride modified volcanic rock and kaolin are added to the raw materials of examples 4-6, compared with examples 1-3, the cooling effect of the fertilizer prepared in comparative examples 4-6 is better than that of the fertilizer prepared in examples 1-3, which indicates that the chitosan coated ammonium nitrate, the ammonium chloride modified volcanic rock and kaolin are matched, in the initial stage, the ammonium chloride modified volcanic rock absorbs heat in the matrix layer, the chitosan film is gradually broken along with the time, the ammonium nitrate in the chitosan film is gradually released, and the released ammonium nitrate continuously absorbs the redundant heat of the matrix layer, so that the cooling effect of the matrix layer is achieved, and the growth of the leafy vegetables is promoted at the proper temperature of about 20 ℃.

It can be seen from the combination of examples 4 to 6 and comparative examples 1 to 7 and table 1 that, the chitosan coated ammonium nitrate is not added to the raw material of comparative example 1, compared with example 4, the temperature reduction effect of the fertilizer prepared in comparative example 1 is weakened compared with that of the fertilizer prepared in example 4, and the temperature of the substrate layer returns to the initial temperature basically after the fertilizer is poured for 5 hours in comparative example 1, which indicates that the chitosan coated ammonium nitrate has good temperature reduction effect in the substrate layer, and the chitosan film is gradually broken along with the time, so that the substrate layer can be kept in a low temperature state continuously.

Compared with the example 4, the fertilizer prepared in the comparative example 2 has a reduced cooling effect compared with the fertilizer prepared in the example 4, and the temperature rise rate of the substrate layer of the comparative example 2 after being irrigated for 1h, 2h and 5h is obviously higher than that of the substrate layer of the example 4 along with the increase of time; the ammonium chloride modified volcanic rock, the kaolin and the chitosan coated ammonium nitrate are matched, so that the temperature of the matrix layer can be kept in a stable state, the matrix layer has a good cooling effect, and the growth of leaf vegetables can be promoted.

Compared with the example 4, the cooling effect of the fertilizer prepared in the comparative example 3 is weakened compared with that of the fertilizer prepared in the example 4 by replacing kaolin with ammonium chloride modified volcanic rock with equal mass in the raw material in the comparative example 3, and the heating rates of the substrate layers of the comparative example 3 after being irrigated for 1h, 2h and 5h are obviously higher than that of the substrate layer of the example 4 along with the prolonging of time; the kaolin is matched with the ammonium chloride modified volcanic rock, so that the matrix layer has a good heat preservation effect, and the matrix layer has good water preservation and ventilation effects, thereby promoting the growth of the leaf vegetables.

Comparative example 4 when chitosan coated ammonium nitrate was prepared, glutaraldehyde was not added to the raw materials, compared to example 4, the cooling effect of the fertilizer prepared in comparative example 4 was reduced compared to example 4, and as the time was prolonged, the heating rates of the substrate layers of comparative example 4 after 1h, 2h and 5h after pouring were significantly higher than that of example 4; the glutaraldehyde is matched with the chitosan, so that the prepared chitosan membrane has good slow release property, the ammonium nitrate in the chitosan membrane is slowly released, the matrix layer can be continuously cooled, and the matrix layer is kept in a lower-temperature state, so that the growth of leaf vegetables is promoted.

Comparative example 5 when chitosan coated ammonium nitrate was prepared, polyvinyl alcohol was not added to the raw materials, compared to example 4, the cooling effect of the fertilizer prepared in comparative example 5 was reduced compared to example 4, and as time goes on, the heating rate of the substrate layer of comparative example 5 after 1h, 2h and 5h after irrigation was significantly higher than that of example 4; the polyvinyl alcohol is matched with the glycerol, so that the chitosan film has good toughness, the elongation at break of the chitosan film is improved, the chitosan film is not easy to break even if being swelled, and ammonium nitrate in the chitosan film is slowly released, thereby promoting the growth of leaf vegetables.

Comparative example 6 when preparing ammonium chloride modified volcanic rock, the volcanic rock is dried for 18min under the condition of 80 ℃, compared with example 4, the cooling effect of the fertilizer prepared in comparative example 6 is weakened compared with example 4, and the heating rate of the substrate layer of comparative example 6 after 1h, 2h and 5h after irrigation is obviously higher than that of the substrate layer of example 4 along with the prolonging of time; the drying under the condition of higher temperature is proved to be easy to decompose the ammonium chloride, thereby reducing the ammonium chloride content in pores of the volcanic rock and influencing the cooling condition of the matrix layer.

Comparative example 7 when preparing ammonium chloride modified volcanic rock, the volcanic rock is air-dried for 18min at 40 ℃, compared with example 4, the temperature reduction effect of the fertilizer prepared in comparative example 7 is weakened compared with example 4, and the temperature rise rate of the substrate layer of comparative example 7 after being irrigated for 1h, 2h and 5h is obviously higher than that of the substrate layer of example 4 along with the prolonging of time; the air drying operation is easy to blow the ammonium chloride in the volcanic pores away from the volcanic pores, so that the content of the ammonium chloride in the volcanic pores is reduced, the cooling effect of the matrix layer is influenced, and the growth of the leafy vegetables is influenced.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims (8)

1. The special fertilizer for soilless culture of leaf vegetables is characterized by being prepared by mixing a fertilizer A, a fertilizer B and a fertilizer C:

the fertilizer A is prepared from the following raw materials in parts by weight: 6.5-7.2 parts of calcium nitrate tetrahydrate, 0.1-0.2 part of EDTA chelated iron and 1-2 parts of chitosan coated ammonium nitrate;

the fertilizer B is prepared from the following raw materials in parts by weight: 0.5-0.7 part of monopotassium phosphate, 1.5-2.0 parts of potassium sulfate and 0.4-0.7 part of magnesium sulfate heptahydrate;

the fertilizer C is prepared from the following raw materials in parts by weight: 0.01-0.018 portion of manganese sulfate, 0.003-0.007 portion of zinc sulfate, 0.01-0.015 portion of boric acid, 0.0005-0.0015 portion of copper sulfate and 0.0005-0.0012 portion of ammonium molybdate.

2. The special fertilizer for soilless culture of leaf vegetables according to claim 1, which is characterized in that: the chitosan coated ammonium nitrate is prepared by the following method:

i, weighing 3-5 parts of chitosan, pouring the chitosan into 180-220 parts of acetic acid solution with the mass fraction of 1%, and stirring the mixture for 3-8min at the rotating speed of 300-600r/min to prepare a chitosan solution;

II, weighing 4-8 parts of glycerol and 1-2 parts of polyvinyl alcohol, mixing and stirring, adding 0.5-1.5 parts of glutaraldehyde, and continuing stirring for 0.2-0.8h to prepare chitosan membrane solution;

III, weighing 480 parts of 400-480 parts of ammonium nitrate, spraying the chitosan film liquid prepared in the step II on the surface of the ammonium nitrate through a coating machine, and drying to prepare the chitosan coated ammonium nitrate.

3. The special fertilizer for soilless culture of leafy vegetables according to claim 2, wherein the degree of deacetylation of chitosan in said I is 85%, and the relative molecular mass is 50 ten thousand.

4. The special fertilizer for soilless culture of leafy vegetables according to claim 1, wherein the content of iron ions in the chelated iron of EDTA is 12%.

5. The special fertilizer for soilless culture of leaf vegetables according to claim 1, wherein the special fertilizer for soilless culture of leaf vegetables further comprises the following raw materials in parts by weight: 1-3 parts of ammonium chloride modified volcanic rock and 0.2-0.6 part of kaolin.

6. The special fertilizer for soilless culture of leafy vegetables according to claim 5, wherein the ammonium chloride modified volcanic rock is prepared by the following method:

the method comprises the steps of weighing 1-3 parts of ammonium chloride, 75-85 parts of 2% acetone solution and 2-6 parts of volcanic rock, mixing, performing ultrasonic dispersion for 8-12min at the frequency of 20KHz-40KHz, filtering out the volcanic rock, and drying the volcanic rock to obtain the ammonium chloride modified volcanic rock.

7. The special fertilizer for soilless culture of leaf vegetables according to claim 6, characterized in that the intermediate volcanic rock is subjected to far infrared drying at 30-50 ℃ to prepare ammonium chloride modified volcanic rock.

8. The preparation method of the special fertilizer for soilless culture of the leaf vegetables as claimed in any one of claims 1 to 7, which is characterized by comprising the following steps:

s1, weighing calcium nitrate tetrahydrate, EDTA chelated iron and chitosan coated ammonium nitrate, fully mixing and uniformly stirring, and placing in a packaging bag A to obtain fertilizer A;

s2, weighing potassium dihydrogen phosphate, potassium sulfate and magnesium sulfate heptahydrate, mixing, and placing in a packaging bag B to obtain fertilizer B;

s3, weighing manganese sulfate, zinc sulfate, boric acid, copper sulfate and ammonium molybdate, fully mixing uniformly, and placing in a C packaging bag to obtain a C fertilizer;

s4, and the weight ratio is 1 (0.6-1.2): (0.7-1.3) mixing the fertilizer A, the fertilizer B and the fertilizer C to obtain a finished fertilizer.