CN111484369A

CN111484369A - Fertilizer for improving yield and quality of broccoli and preparation method thereof

Info

Publication number: CN111484369A
Application number: CN202010292920.0A
Authority: CN
Inventors: 崔艳兰
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2020-08-04

Abstract

The invention provides a fertilizer for improving the yield and quality of broccoli and a preparation method thereof.

Description

Fertilizer for improving yield and quality of broccoli and preparation method thereof

Technical Field

The invention relates to the technical field of fertilizer preparation, in particular to a fertilizer for improving the yield and quality of broccoli and a preparation method thereof.

Background

Broccoli is a biennial herb, a variety of cabbage. Big leaves, big flower balls formed at the top of the main stem, green or purple green, small flower buds on the surface are not densely gathered together, and small flower balls are generated at the top of the lateral branches. The nutrient components in the broccoli are high in content and complete, and mainly comprise protein, carbohydrate, fat, mineral substances, vitamin C, carotene and the like. According to analysis, each 100 g of fresh broccoli curd contains 3.5-4.5 g of protein, which is 3 times of cauliflower and 4 times of tomato. In addition, the mineral components in broccoli are more comprehensive than those of other vegetables, and the broccoli is rich in calcium, phosphorus, iron, potassium, zinc, manganese and the like and is much higher than the broccoli belonging to the same Cruciferae.

In 1992, the doctor Paul Talalay in the United states, under its continuous effort, extracted the important active substance sulforaphane from broccoli sprouts, which opened the door to cancer prevention research and was also known as one of the 20 th century 100 scientific findings. Sulforaphane is a component widely present in cruciferous vegetables such as broccoli, and the content of sulforaphane is most abundant among the broccoli. Sulforaphane, a precursor of sulforaphane with natural anticancer properties, is activated in intestinal tracts to produce sulforaphane, is a low-molecular-weight and lipophilic substance, and can be better absorbed and utilized by human bodies. The active form of the sulforaphane is a substance with the strongest activation effect of Nrf2 found in fruits and vegetables by human, and the activation capability of the active form of the sulforaphane is 105 times higher than that of resveratrol of famous vessel in red wine and imported health care products, namely the activation capability of an enzyme NQO1 for detoxifying human body weight by Nrf 2. Since the Nrf2 signal pathway is present in all tissue cells of the human body, the health-promoting effects of glucoraphanin are systemic.

However, the content of the sulforaphane in the broccoli seeds or sprouts is high, and the content of the sulforaphane in the mature broccoli which is usually eaten by people is only 1-10% of the content of the broccoli seeds or sprouts, so that the sulforaphane is not a great nutrient loss for people who like to eat the broccoli. Besides sulforaphane, vitamin C is also one of important indexes for broccoli quality measurement, and it is also very necessary to increase the content of vitamin C as much as possible.

In addition, fertilizers specially aiming at broccoli are not available in the market at present, growth of broccoli and expansion of flower balls cannot be promoted in a targeted manner, so that the yield of broccoli is not high, and economic benefits are influenced.

Disclosure of Invention

The invention aims to provide a fertilizer for improving the yield and quality of broccoli and a preparation method thereof, and aims to solve the technical problems of low yield of broccoli, unsatisfactory nutritional quality of glucoraphanin and the like.

In order to achieve the aim, the invention provides a preparation method of a fertilizer for improving the yield and the quality of broccoli, which comprises the following specific steps in parts by weight:

(1) firstly, 10 parts of 100-200 mesh corn straw powder is subjected to hydrothermal reaction to prepare porous microspheres, and then the porous microspheres and 5-6 parts of 40-50 mesh cottonseed hull powder are uniformly mixed to obtain mixed powder;

(2) then dissolving 7-8 parts of polyglutamic acid in 80-100 parts of water, pouring the mixed powder obtained in the step (1), uniformly oscillating by ultrasonic waves, and performing slurry spraying granulation to obtain particles;

(3) adding 2-3 parts of inorganic fertilizer component, 0.2-0.3 part of mixed bacterial powder and 0.5-0.8 part of corn-Enteromorpha prolifera mixed fermentation product into 40-50 parts of water, uniformly oscillating with ultrasonic waves to obtain an aqueous solution, finally pouring the particles obtained in the step (2) into the aqueous solution, dipping, and freeze-drying in vacuum to obtain the fertilizer for improving the yield and quality of broccoli;

the inorganic fertilizer component is prepared by mixing the following components in parts by weight: 8-10 parts of urea, 3-4 parts of calcium superphosphate, 3-4 parts of borax, 2-3 parts of potassium sulfate and 2-3 parts of magnesium sulfate; the mixed bacterial powder comprises: 40-50 hundred million/g of bacillus subtilis and 20-30 hundred million/g of trichoderma harzianum.

Preferably, in step (1), the preparation method of the porous microspheres comprises the following steps: adding 1 weight part of corn straw powder into a hydrothermal reaction kettle, adding 20-30 weight parts of water, adding 0.5-0.8 weight part of polyvinyl alcohol while stirring, reacting for 4-6 hours at 300-350 ℃, filtering, and drying to obtain the porous microsphere.

Preferably, in the step (2), the particle size of the particles is 2-3 mm.

Preferably, in the step (3), the preparation method of the corn-enteromorpha prolifera mixed fermentation product comprises the following steps:

(A) firstly, crushing 1 part by weight of corn and 2-3 parts by weight of naturally air-dried Enteromorpha prolifera to 100-200 meshes, then adding the crushed materials into 8-10 parts by weight of water together, and heating and stirring the mixture for 5-8 hours at 50-60 ℃;

(B) cooling to 20-30 ℃, adjusting the pH value to 3-4, adding 0.3-0.5 part by weight of polyembryonic protease, stirring for reacting for 2-3 hours, and inactivating enzyme to obtain an enzymatic hydrolysate;

(C) inoculating bacillus subtilis, fermenting, centrifuging and taking supernatant to obtain the corn-enteromorpha mixed fermentation product.

Further preferably, in the step (C), the bacillus subtilis is activated before inoculation, the activation temperature is 35-40 ℃, and the inoculation amount is 2-3% of the volume of the enzymolysis liquid.

More preferably, in the step (C), the fermentation process conditions are that the temperature is 35-40 ℃, the pH value is 7-8, the ventilation speed is 5-8 m L/min, and the fermentation time is 5-8 hours.

Preferably, in the step (3), the dipping time is 2-3 hours.

Preferably, in the step (3), the vacuum freeze-drying process conditions are as follows: firstly, cooling to-40 to-50 ℃, freezing for 8-10 hours, vacuumizing to 2-3 Pa, heating to 25-30 ℃ at a heating rate of 10-12 ℃/min, and preserving heat for 6-8 hours to completely dry the particles.

Preferably, the preparation method of the mixed bacterial powder comprises the following steps:

(A) firstly inoculating bacillus subtilis to a meat soup agar culture medium, inoculating trichoderma harzianum to a PDA culture medium, wherein the inoculation amount is 4-5%, and after culturing for 2-3 days, respectively culturing in a shaking table at 180-200 r/min, and the respective culture conditions are as follows: the culture temperature of the bacillus subtilis is 35-40 ℃, and the culture time is 25-35 hours; the culture temperature of the trichoderma harzianum is 27-29 ℃, and the culture time is 72-75 hours; mixing the obtained fermentation liquor after the culture is finished to obtain mixed fermentation liquor;

(B) then, flocculating by using disodium hydrogen phosphate and calcium chloride, wherein the addition amount of the disodium hydrogen phosphate and the addition amount of the calcium chloride are respectively 1-2% and 0.5-0.8% of the weight of the mixed fermentation liquor;

(C) and finally, performing filter pressing by using a plate frame, drying at 45-50 ℃ until the water content (weight) is 20-30%, performing cyclone separation, crushing by using a crusher, and sieving by using a 30-mesh sieve to obtain the mixed bacterial powder.

The fertilizer for improving the yield and the quality of broccoli is obtained by the preparation method.

The invention has the following beneficial effects:

the preparation method comprises the steps of mixing porous micro powder prepared from corn straw powder with cottonseed hull powder to obtain mixed powder, spraying slurry on the mixed powder and polyglutamic acid for granulation to obtain particles, pouring the particles into an aqueous solution prepared from inorganic fertilizer components, mixed bacterial powder and a mixed fermentation product of corn and Enteromorpha prolifera for impregnation treatment, and finally performing vacuum freeze drying to obtain the fertilizer.

The porous microspheres prepared from the corn straw powder through the hydrothermal reaction have relatively small particle size, the cottonseed hull powder has relatively large particle size, the two are mixed, and the mixture of particles with different particle sizes obtains more pores, enriches the pore size range and the number of the pores, so that the subsequently obtained particles have good slow release and adsorption effects. The slow release effect is beneficial to slow release of inorganic fertilizer components and the like and absorption of the inorganic fertilizer components by broccoli roots, is beneficial to full utilization of nutrient components, has a longer-time nutrient supply effect, promotes growth of broccoli, and ensures yield; the adsorption can adsorb transition metal ions in the planting land, so that the glucoraphanin is prevented from being degraded under the action of the transition metal ions to influence the quality of the broccoli.

The polyglutamic acid is viscous and degradable, can play a role in bonding between the porous microspheres and the cottonseed hull powder, then slowly degrades along with the lapse of time, along with the degradation of the polyglutamic acid, the particles disintegrate, inorganic fertilizer components loaded in the particles are slowly released, nutrition is continuously provided for broccoli, and the yield of broccoli is improved. That is to say, the porous microspheres made of the corn straw powder and the pore structure of the cottonseed hull powder provide an original slow release effect, and the degradation effect of the polyglutamic acid along with the time provides a continuous slow release effect, so that the polyglutamic acid is synergistically used for continuously and slowly releasing the nutrient components, and the nutrition is continuously provided for the broccoli, and the yield of the broccoli is improved.

The inorganic fertilizer component comprises urea, calcium superphosphate, borax, potassium sulfate and magnesium sulfate, and except for basic nutritional requirements, the inorganic fertilizer component is more critical to borax, potassium sulfate and magnesium sulfate, wherein boron in borax has the effect of promoting vitamin C synthesis, but the vitamin C synthesis mainly depends on glucose conversion, and when the potassium fertilizer is excessive, the contents of sucrose, starch, cellulose and lignin are higher, the glucose accumulation is less, and the content of potassium sulfate cannot be excessive. On the other hand, sulfur is an indispensable part for protein and enzyme, participates in the oxidation-reduction reaction process in plants, is an important component of various enzymes, coenzyme and a plurality of physiologically active substances, and the sulfur loss caused by the reduction of the using amount of potassium sulfate is supplemented by magnesium sulfate, so that the contradiction between the synthesis of vitamin C and the required amount of sulfur can be met.

The mixed bacterial powder disclosed by the invention comprises bacillus subtilis and trichoderma harzianum, active substances such as subtilin, polymyxin, nystatin, gramicidin and the like generated in the growth process of bacillus subtilis, and the active substances have an obvious inhibiting effect on pathogenic bacteria or conditional pathogenic bacteria of endogenous infection, so that the pest and disease damage of broccoli is reduced, and the yield of broccoli is increased; the effect of trichoderma harzianum on stimulating the growth of plants is beneficial to the mass accumulation of sugar, provides backup support for the synthesis of vitamin C, and effectively improves the content of the vitamin C in the broccoli. In addition, trichoderma harzianum grows around the root system and forms a protective cover to prevent root pathogenic bacteria from infecting, can secrete enzymes and antibiotic substances and decompose cell walls of the pathogenic bacteria, so the trichoderma harzianum is favorable for providing a better living environment for the growth of bacillus subtilis, synergistically promotes the growth of broccoli and improves the yield of the broccoli. Meanwhile, the gramicidin and the like generated in the growth process of the bacillus subtilis can form hydrogen bond action with sugar, so that the further generation of the sugar is promoted, more accumulation of the sugar by the trichoderma harzianum is facilitated, a backup support is provided for the synthesis of the vitamin C, and the content of the vitamin C in the broccoli is effectively improved.

As for another important index of broccoli quality, sulforaphane, which is synthesized in broccoli, is formed under the catalysis of different enzyme systems in the presence of sulfur-containing compounds with amino acids as substrates. Sulforaphane belongs to aliphatic glucosinolate, and the corresponding amino acid substrate is methionine. According to the invention, the corn-Enteromorpha prolifera mixed fermentation product is introduced, the corn contains a large amount of germ protein, the corn can be degraded in a large amount under the action of polyembryonic protease to obtain methionine, and the large amount of methionine contained in the Enteromorpha prolifera is added, so that the corn-Enteromorpha prolifera mixed fermentation product and the Enteromorpha prolifera provide enough substrates for the synthesis of glucoraphanin, and the glucoraphanin content in broccoli is ensured.

Glucoraphanin is present in cellular vacuoles, and when plant tissues are damaged by external destruction, glucoraphanin degradation is caused because myrosinase is contained in cytoplasm and can catalyze glucoraphanin hydrolysis. When plant cells are broken, the physical isolation between the glucoraphanin and the myrosinase is broken, the glucoraphanin is hydrolyzed to generate the sulforaphane due to mutual contact of the glucoraphanin and the myrosinase, the sulforaphane is very unstable and is very easy to be broken and decomposed at normal temperature, and the nutrient loss is caused (the most ideal state is that the glucoraphanin and the myrosinase are degraded into the glucoraphanin after entering the gastrointestinal tract of a human body and are absorbed by the human body). The abundant vitamin C in broccoli just can activate myrosinase, so the problem of plant injury in broccoli planting is very important. According to the method, diseases and insect pests are prevented by the bacillus subtilis, the growth of broccoli is continuously stimulated by the trichoderma harzianum, and comprehensive nutrition support of inorganic fertilizer components is realized, so that broccoli plants are more robust, the occurrence of self damage can be reduced as far as possible, the degradation loss of the glucoraphanin is reduced, and the glucoraphanin content in the mature broccoli is ensured.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below.

Detailed Description

The following is a detailed description of embodiments of the invention, but the invention can be implemented in many different ways, as defined and covered by the claims.

The trichoderma harzianum, ACCC30371, related by the invention is purchased from China agricultural microorganism strain preservation management center; bacillus subtilis ATCC6633, available from Tokyo (Shanghai) Biotech, Inc.; polyembryonic protease, purchased from Wuhanxin Jiali Biotech, Inc.

Example 1:

a preparation method of a fertilizer for improving the yield and quality of broccoli comprises the following specific steps in parts by weight:

(1) firstly, 10 parts of 100-mesh corn straw powder is subjected to hydrothermal reaction to prepare porous microspheres, and then the porous microspheres and 6 parts of 40-mesh cottonseed hull powder are uniformly mixed to obtain mixed powder;

(2) then 8 parts of polyglutamic acid is dissolved in 80 parts of water, the mixed powder obtained in the step (1) is poured, ultrasonic oscillation is carried out uniformly, and slurry spraying granulation is carried out to obtain particles;

(3) adding 3 parts of inorganic fertilizer component, 0.2 part of mixed bacterial powder and 0.8 part of corn-Enteromorpha prolifera mixed fermentation product into 40 parts of water, uniformly oscillating by ultrasonic waves to obtain an aqueous solution, finally pouring the particles obtained in the step (2) into the aqueous solution, dipping, and carrying out vacuum freeze drying to obtain the fertilizer for improving the yield and the quality of broccoli;

the inorganic fertilizer component is prepared by mixing the following components in parts by weight: 10 parts of urea, 3 parts of calcium superphosphate, 4 parts of borax, 2 parts of potassium sulfate and 3 parts of magnesium sulfate; the mixed bacterial powder comprises: 40 hundred million/g of bacillus subtilis and 30 hundred million/g of trichoderma harzianum.

In the step (1), the preparation method of the porous microspheres comprises the following steps: adding 1 weight part of corn straw powder into a hydrothermal reaction kettle, adding 20 weight parts of water, adding 0.8 weight part of polyvinyl alcohol while stirring, reacting for 6 hours at 300 ℃, filtering and drying to obtain the porous microsphere.

In the step (2), the particle size of the particles is 2 mm.

In the step (3), the preparation method of the corn-enteromorpha prolifera mixed fermentation product comprises the following steps:

(A) firstly, crushing 1 part by weight of corn and 3 parts by weight of naturally air-dried Enteromorpha prolifera into 100 meshes, then adding the crushed materials into 10 parts by weight of water together, and heating and stirring the mixture for 8 hours at 50 ℃;

(B) cooling to 20 ℃, adjusting the pH value to 4, adding 0.3 part by weight of polyembryonic protease, stirring for reaction for 3 hours, and inactivating enzyme to obtain an enzymatic hydrolysate;

In the step (C), the bacillus subtilis is activated before inoculation, the activation temperature is 35 ℃, and the inoculation amount is 3% of the volume of the enzymolysis liquid.

In the step (C), the fermentation process conditions are that the temperature is 35 ℃, the pH value is 8, the ventilation air flow rate is 5m L/min, and the fermentation time is 8 hours.

In the step (3), the dipping time was 2 hours.

In the step (3), the process conditions of vacuum freeze drying are as follows: cooling to-50 deg.C, freezing for 8 hr, vacuumizing to 3Pa, heating to 30 deg.C at a heating rate of 10 deg.C/min, and holding for 6 hr to dry the particles completely.

The preparation method of the mixed bacterial powder comprises the following steps:

(A) firstly inoculating bacillus subtilis to a meat soup agar culture medium, inoculating trichoderma harzianum to a PDA culture medium, wherein the inoculation amount is 5%, culturing for 2 days, and then respectively culturing in a shaking table at 200r/min, wherein the respective culture conditions are as follows: the culture temperature of the bacillus subtilis is 35 ℃, and the culture time is 35 hours; the culture temperature of the trichoderma harzianum is 27 ℃, and the culture time is 75 hours; mixing the obtained fermentation liquor after the culture is finished to obtain mixed fermentation liquor;

(B) then, carrying out flocculation by using disodium hydrogen phosphate and calcium chloride, wherein the addition amounts of the disodium hydrogen phosphate and the calcium chloride are respectively 1% and 0.8% of the weight of the mixed fermentation broth;

(C) and finally, performing filter pressing by using a plate frame, drying at 45 ℃ until the water content (weight) is 30%, performing cyclone separation, crushing by using a crusher, and sieving by using a 30-mesh sieve to obtain the mixed bacterial powder.

Example 2:

(1) firstly, 10 parts of 200-mesh corn straw powder is subjected to hydrothermal reaction to prepare porous microspheres, and then the porous microspheres and 5 parts of 50-mesh cottonseed hull powder are uniformly mixed to obtain mixed powder;

(2) then dissolving 7 parts of polyglutamic acid in 100 parts of water, pouring the mixed powder obtained in the step (1), oscillating uniformly by ultrasonic waves, spraying slurry and granulating to obtain granules;

(3) adding 2 parts of inorganic fertilizer component, 0.3 part of mixed bacterial powder and 0.5 part of corn-Enteromorpha prolifera mixed fermentation product into 50 parts of water, uniformly oscillating by ultrasonic waves to obtain an aqueous solution, finally pouring the particles obtained in the step (2) into the aqueous solution, dipping, and carrying out vacuum freeze drying to obtain the fertilizer for improving the yield and the quality of broccoli;

the inorganic fertilizer component is prepared by mixing the following components in parts by weight: 8 parts of urea, 4 parts of calcium superphosphate, 3 parts of borax, 3 parts of potassium sulfate and 2 parts of magnesium sulfate; the mixed bacterial powder comprises: 50 hundred million/g of bacillus subtilis and 20 hundred million/g of trichoderma harzianum.

In the step (1), the preparation method of the porous microspheres comprises the following steps: adding 1 weight part of corn straw powder into a hydrothermal reaction kettle, adding 30 weight parts of water, adding 0.5 weight part of polyvinyl alcohol while stirring, reacting for 4 hours at 350 ℃, filtering and drying to obtain the porous microsphere.

In the step (2), the particle size of the particles is 3 mm.

(A) firstly, crushing 1 part by weight of corn and 2 parts by weight of naturally air-dried Enteromorpha prolifera into 200 meshes, then adding the crushed materials into 8 parts by weight of water together, and heating and stirring the mixture for 5 hours at 60 ℃;

(B) cooling to 30 ℃, adjusting the pH value to 3, adding 0.5 part by weight of polyembryonic protease, stirring for reaction for 2 hours, and inactivating the enzyme to obtain an enzymatic hydrolysate;

In the step (C), the bacillus subtilis is activated before inoculation, the activation temperature is 40 ℃, and the inoculation amount is 2% of the volume of the enzymolysis liquid.

In the step (C), the fermentation process conditions are that the temperature is 40 ℃, the pH value is 7, the ventilation air flow rate is 8m L/min, and the fermentation time is 5 hours.

In the step (3), the dipping time was 3 hours.

In the step (3), the process conditions of vacuum freeze drying are as follows: cooling to-40 deg.C, freezing for 10 hr, vacuumizing to 2Pa, heating to 25 deg.C at a rate of 12 deg.C/min, and holding for 8 hr to dry the particles completely.

(A) firstly inoculating bacillus subtilis to a meat soup agar culture medium, inoculating trichoderma harzianum to a PDA culture medium, wherein the inoculation amount is 4%, culturing for 3 days, and then respectively culturing in a shaking table at 180r/min, wherein the respective culture conditions are as follows: the culture temperature of the bacillus subtilis is 40 ℃, and the culture time is 25 hours; the culture temperature of the trichoderma harzianum is 29 ℃, and the culture time is 72 hours; mixing the obtained fermentation liquor after the culture is finished to obtain mixed fermentation liquor;

(B) then, the disodium hydrogen phosphate and the calcium chloride are utilized for flocculation, and the adding amount of the disodium hydrogen phosphate and the calcium chloride is respectively 2 percent and 0.5 percent of the weight of the mixed fermentation liquor;

(C) and finally, performing filter pressing by using a plate frame, drying at 50 ℃ until the water content (weight) is 20%, performing cyclone separation, crushing by using a crusher, and sieving by using a 30-mesh sieve to obtain the mixed bacterial powder.

Example 3:

(1) firstly, 10 parts of 200-mesh corn straw powder is subjected to hydrothermal reaction to prepare porous microspheres, and then the porous microspheres and 5 parts of 40-mesh cottonseed hull powder are uniformly mixed to obtain mixed powder;

(2) then dissolving 7.5 parts of polyglutamic acid in 90 parts of water, pouring the mixed powder obtained in the step (1), uniformly oscillating by ultrasonic waves, spraying slurry and granulating to obtain granules;

(3) adding 2.5 parts of inorganic fertilizer component, 0.25 part of mixed bacterial powder and 0.6 part of corn-Enteromorpha prolifera mixed fermentation product into 45 parts of water, uniformly oscillating by ultrasonic waves to obtain an aqueous solution, finally pouring the particles obtained in the step (2) into the aqueous solution, dipping, and carrying out vacuum freeze drying to obtain the fertilizer for improving the yield and the quality of broccoli;

the inorganic fertilizer component is prepared by mixing the following components in parts by weight: 9 parts of urea, 3.5 parts of calcium superphosphate, 3.5 parts of borax, 2.5 parts of potassium sulfate and 2.5 parts of magnesium sulfate; the mixed bacterial powder comprises: 45 hundred million/g of bacillus subtilis and 25 hundred million/g of trichoderma harzianum.

In the step (1), the preparation method of the porous microspheres comprises the following steps: adding 1 weight part of corn straw powder into a hydrothermal reaction kettle, then adding 25 weight parts of water, then adding 0.7 weight part of polyvinyl alcohol while stirring, stirring and reacting for 5 hours at 320 ℃, filtering and drying to obtain the porous microsphere.

In the step (2), the particle size of the particles is 2 mm.

(A) firstly, crushing 1 part by weight of corn and 2.5 parts by weight of naturally air-dried Enteromorpha prolifera into 200 meshes, then adding the crushed materials into 9 parts by weight of water together, and heating and stirring the mixture for 6 hours at 55 ℃;

(B) cooling to 25 ℃, adjusting the pH value to 3, adding 0.4 part by weight of polyembryonic protease, stirring for reaction for 2 hours, and inactivating the enzyme to obtain an enzymatic hydrolysate;

In the step (C), the bacillus subtilis is activated before inoculation, the activation temperature is 38 ℃, and the inoculation amount is 2.5% of the volume of the enzymolysis liquid.

In the step (C), the fermentation process conditions are that the temperature is 38 ℃, the pH value is 7.5, the ventilation air flow rate is 6m L/min, and the fermentation time is 7 hours.

In the step (3), the dipping time was 2.5 hours.

In the step (3), the process conditions of vacuum freeze drying are as follows: cooling to-45 deg.C, freezing for 9 hr, vacuumizing to 2Pa, heating to 28 deg.C at a heating rate of 11 deg.C/min, and maintaining for 7 hr to dry the particles completely.

(A) firstly inoculating bacillus subtilis to a meat soup agar culture medium, inoculating trichoderma harzianum to a PDA culture medium, wherein the inoculation amount is 4.5%, and after 2 days of culture, respectively culturing in a shaking table at 190r/min, and the respective culture conditions are as follows: the culturing temperature of the bacillus subtilis is 38 ℃, and the culturing time is 30 hours; the culture temperature of the trichoderma harzianum is 28 ℃, and the culture time is 73 hours; mixing the obtained fermentation liquor after the culture is finished to obtain mixed fermentation liquor;

(B) then, the disodium hydrogen phosphate and the calcium chloride are utilized for flocculation, and the adding amount of the disodium hydrogen phosphate and the calcium chloride is respectively 1.5 percent and 0.7 percent of the weight of the mixed fermentation liquor;

(C) and finally, performing filter pressing by using a plate frame, drying at 48 ℃ until the water content (weight) is 25%, performing cyclone separation, crushing by using a crusher, and sieving by using a 30-mesh sieve to obtain the mixed bacterial powder.

Comparative example 1

The porous microspheres in step (1) are omitted.

The rest is the same as example 1.

Comparative example 2

The cottonseed hull powder in step (1) is omitted.

The rest is the same as example 1.

Comparative example 3

Replacing the corn-Enteromorpha prolifera mixed fermentation product with the corn fermentation product.

The rest is the same as example 1.

Comparative example 4

The magnesium sulfate is replaced by potassium sulfate in the inorganic fertilizer components.

The rest is the same as example 1.

Comparative example 5

The Trichoderma harzianum was replaced with Bacillus subtilis.

The rest is the same as example 1.

Test examples

Randomly dividing a piece of land with the same physical and chemical properties into 9 pieces with the same area, planting middle and late maturing variety of 90 broccoli, managing according to the same method, sowing on the same day, carrying out seedling raising and field planting at the same time, applying fertilizer for the first time after field planting, applying fertilizer once per week (the fertilizer application amount is 10 kg/mu) until harvesting on the same day, wherein 8 pieces of the fertilizer are applied to the examples 1-3 and the fertilizers in the comparative examples 1-5 respectively, and the rest is used as a control group and is not applied with fertilizer.

The average diameter of the broccoli curd (optionally measured by 10 plants, averaged) and the yield were examined and the results are shown in Table 1.

The average contents of sulforaphane and vitamin C in broccoli were examined (optionally 10 plants were measured and averaged), and the results are shown in table 2.

TABLE 1 Broccoli yield and bulb diameter investigation

	Yield (kg/mu)	Ball diameter (cm)
			Example 1	2987	17.8
Example 2	2993	17.9
			Example 3	3012	18.1
Comparative example 1	2011	15.1
			Comparative example 2	2004	14.8
Comparative example 3	2458	16.2
			Control group	1569	11.5

TABLE 2 Broccoli quality investigation

As can be seen from tables 1 and 2, broccoli with large flower ball diameter can be obtained in high yield after the fertilizer of examples 1-3 is applied, and the broccoli has high content of glucoraphanin and vitamin C and high nutritional value.

The porous microspheres in the step (1) are omitted in the comparative example 1, the cottonseed hull powder in the step (1) is omitted in the comparative example 2, mutual matching of different particle sizes is avoided, the pore distribution is poor, the slow release and adsorption effects of the fertilizer are affected, the yield is low, and the content of the glucoraphanin is low.

The comparative example 3 replaces the mixed fermentation product of corn and Enteromorpha prolifera with the corn fermentation product, the supply of methionine is obviously reduced, the content of glucoraphanin is obviously reduced, and the nutrient composition is changed, thus influencing the yield of broccoli.

The replacement of magnesium sulfate with potassium sulfate in the inorganic fertilizer composition of comparative example 4 resulted in an excessively high potassium content, affecting the synthesis of vitamin C, resulting in a significant decrease in vitamin C content in broccoli.

Comparative example 5 replacing trichoderma harzianum with bacillus subtilis affects sugar accumulation, resulting in a significant decrease in vitamin C content in broccoli.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The preparation method of the fertilizer for improving the yield and the quality of broccoli is characterized by comprising the following specific steps in parts by weight:

2. The method according to claim 1, wherein in the step (1), the porous microspheres are prepared by: adding 1 weight part of corn straw powder into a hydrothermal reaction kettle, adding 20-30 weight parts of water, adding 0.5-0.8 weight part of polyvinyl alcohol while stirring, reacting for 4-6 hours at 300-350 ℃, filtering, and drying to obtain the porous microsphere.

3. The method according to claim 1, wherein in the step (2), the particle size of the particles is 2 to 3 mm.

4. The preparation method according to claim 1, wherein the corn-Enteromorpha prolifera mixed fermentation product is prepared in the step (3) by the following method:

(B) cooling to 20-30 ℃, adjusting the pH value to 3-4, adding 0.3-0.5 part by weight of polyembryonic protease, stirring for reaction for 2-3 hours, and inactivating enzyme to obtain an enzymatic hydrolysate;

5. The method according to claim 4, wherein the Bacillus subtilis is activated before inoculation in the step (C), wherein the activation temperature is 35-40 ℃ and the inoculation amount is 2-3% of the volume of the enzymolysis solution.

6. The preparation method according to claim 4, wherein in the step (C), the fermentation process conditions comprise a temperature of 35-40 ℃, a pH of 7-8, a ventilation air flow rate of 5-8 m L/min, and a fermentation time of 5-8 hours.

7. The method according to claim 1, wherein in the step (3), the dipping time is 2 to 3 hours.

8. The preparation method according to claim 1, wherein in the step (3), the vacuum freeze-drying process conditions are as follows: firstly, cooling to-40 to-50 ℃, freezing for 8-10 hours, vacuumizing to 2-3 Pa, heating to 25-30 ℃ at a heating rate of 10-12 ℃/min, and preserving heat for 6-8 hours to completely dry the particles.

9. The method according to claim 1, wherein the mixed fungal powder is prepared by the following steps:

10. A fertilizer for improving the yield and quality of broccoli, which is obtained by the preparation method of any one of claims 1 to 9.