Disclosure of Invention
The invention mainly provides a preparation method of a seedling culture substrate square block, wherein the prepared substrate square block not only improves the porosity, but also can regulate and control the content of water and nutrients, and is a full-biodegradable material. The technical scheme is as follows:
a preparation method of a seedling substrate cube comprises the following steps:
(1) adding 0.5-1mol/L urea and 0.05-0.1mol/L potassium hydroxide mixed aqueous solution into a protein material serving as a raw material, and stirring for reaction at the temperature of 120-150 ℃ to obtain hydrolyzed protein;
(2) mixing a formaldehyde solution and polyvinyl alcohol, heating and stirring to dissolve the polyvinyl alcohol, and adding hydrolyzed protein into the mixed solution;
(3) regulating the pH value of the solution to 7.5-7.8 by using an alkaline solution, adding urea in two batches, and heating and preserving heat;
(4) adjusting pH of the solution to 4.0-5.0 with acidic solution, performing polycondensation reaction, measuring fog point of the solution with water of 26 deg.C, adjusting pH of the solution to 7.5-7.8 with alkaline solution after the fog point is reached, and cooling the solution;
(5) adding the last batch of urea to react to obtain modified urea-formaldehyde resin;
(6) adding a water soluble fertilizer, a foaming agent, a common matrix and a curing agent into the modified urea-formaldehyde resin, uniformly mixing to obtain a foamed modified urea-formaldehyde resin-matrix composite material, then pouring the foamed modified urea-formaldehyde resin-matrix composite material into a mould, and drying to obtain a hollow seedling culture matrix square, wherein the common matrix is prepared by mixing vermiculite, perlite, turf and an organic fertilizer.
Preferably, the protein substances are one or more of soybean meal, corn protein and livestock, poultry and fish product processing byproducts.
Preferably, the mass ratio of the protein substances to the mixed aqueous solution in the step (1) is 1:10, and the solid content of the hydrolyzed protein is 5-10%.
Preferably, the mass ratio of the formaldehyde solution to the polyvinyl alcohol in the step (2) is 90-100:1, and the mass ratio of the addition amount of the hydrolyzed protein to the formaldehyde solution is 1: 2.7-3.0.
Preferably, the alkaline solution in the step (3) is one or more selected from potassium hydroxide, ammonia water and potassium dihydrogen phosphate, and the mass ratio of the addition amount of each batch of urea to the addition amount of the formaldehyde solution is 1: 4.5-5.0.
Preferably, the acidic solution in step (4) is one or more selected from phosphoric acid, ammonium chloride, formic acid and oxalic acid.
Preferably, the mass ratio of the adding amount of the urea to the adding amount of the formaldehyde solution in the step (5) is 1:7-7.5, and the reaction time is 20-30 min.
Preferably, in the step (6), the addition amount of the water-soluble fertilizer accounts for 1-3 per mill of the mass of the modified urea-formaldehyde resin, the addition amount of the foaming agent accounts for 1% of the mass of the modified urea-formaldehyde resin, the addition amount of the common matrix accounts for 1-5% of the mass of the modified urea-formaldehyde resin, and the addition amount of the curing agent accounts for 1-2% of the mass of the modified urea-formaldehyde resin.
Preferably, the foaming agent is ammonium bicarbonate, the common matrix is formed by mixing 0.5-1 part by volume of vermiculite, 0.5-1 part by volume of perlite, 1-2 parts by volume of grass carbon and 0.5-1 part by volume of organic fertilizer, and the curing agent is selected from one or more of phosphoric acid, ammonium chloride, formic acid and oxalic acid.
The seedling substrate square block is applied to vegetable seedling, and specifically, a common substrate which is favorable for germination and sold in the market or a substrate which is obtained by mixing perlite, vermiculite and turf according to a ratio of 1:1:2 is placed in a hollow part of the seedling substrate square block, and foamed modified urea resin-substrate composite materials are arranged on the periphery and the bottom of the seedling substrate square block.
By adopting the scheme, the invention has the following advantages:
the modified urea-formaldehyde resin prepared by the method has good adhesive property to materials rich in hydroxyl, and can be used for bonding substrates into blocks; in addition, the modified urea-formaldehyde resin has good foaming performance under the weak acidic condition, and the porosity is improved and the moisture and nutrient contents can be regulated and controlled after foaming; meanwhile, the foam modified urea-formaldehyde resin is rich in elements such as nitrogen, phosphorus and potassium, is a full-biodegradable material, and can slowly release the nitrogen, phosphorus and potassium in the degradation process.
The middle part of the nutrient customized seedling culture substrate square is a low-nutrient substrate which is favorable for germination, and is favorable for promoting seed imbibition and air permeability, increasing the activity of enzyme, promoting metabolism and improving the germination rate and the germination vigor of seeds. The periphery and the bottom are made of the foamed modified urea-formaldehyde resin-matrix composite material, the porosity is low, the nutrient content is high, and the seedling root system has sufficient nutrient supply and sufficient strength when growing to the periphery. And tidal irrigation is favorable for adjusting the water distribution in the seedling raising blocks and the root growth. The density and nutrient distribution in the seedling raising square blocks are regulated and controlled in time and space, so that the seedling raising square blocks which are suitable for seed germination, root growth promotion and full-automatic transplanting are customized. The substrate block can be applied to seedling raising of solanaceous fruits and can also provide a block-shaped substrate for landscape flowers in three-dimensional shapes.
Detailed Description
The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental reagents and materials involved are conventional biochemical reagents and materials unless otherwise specified.
Example 1
A preparation method of a seedling substrate cube comprises the following steps:
(1) taking 300g of protein substances such as bean pulp and the like as raw materials, adding 3000g of mixed aqueous solution of urea with the final concentration of 0.8mol/L and potassium hydroxide with the final concentration of 0.08mol/L, stirring and reacting for 1h at the temperature of 130 ℃, cooling and discharging to obtain hydrolyzed protein with the solid content of 8%;
(2) heating 7100g of formaldehyde solution and 75g of polyvinyl alcohol to about 50 ℃, stirring until the polyvinyl alcohol is dissolved, and adding 2500g of hydrolyzed protein after the polyvinyl alcohol is dissolved;
(3) then, potassium hydroxide is used for adjusting the pH value of the solution to 7.7, 1500g of first batch of urea is added, the solution is heated to 60 ℃, 1500g of second batch of urea is added, the heating is continued, the temperature rising rate is controlled to be 1-2 ℃/min, and the temperature is kept for 50min when the temperature reaches 90 ℃;
(4) adjusting pH of the solution to 4.5 with phosphoric acid, performing polycondensation reaction, measuring the fog point of the solution with water of 26 deg.C, adjusting the solution to 7.6 with ammonia water after reaching the fog point, and cooling to 80 deg.C;
(5) adding 1000g of third batch of urea, reacting for 25min, cooling to below 40 ℃, and discharging to obtain modified urea-formaldehyde resin;
(6) adding 2 per mill of water soluble fertilizer, 1% of ammonium bicarbonate, 3% of common matrix and 1% of phosphoric acid into the modified urea-formaldehyde resin, uniformly mixing to obtain a foamed modified urea-formaldehyde resin-matrix composite material, then pouring the foamed modified urea-formaldehyde resin-matrix composite material into a mould, and drying to obtain a hollow seedling culture matrix square block, wherein the common matrix is prepared by mixing 0.7 volume part of vermiculite, 0.5 volume part of perlite, 2 volume parts of turf and 0.8 volume part of organic fertilizer.
The molar ratio of the formaldehyde to the urea added in total is 1.3.
When the seedling substrate square block is used for seedling of vegetables, perlite, vermiculite and turf which are beneficial to germination are placed in the hollow part of the seedling substrate square block, the substrate is obtained by mixing the perlite, the vermiculite and the turf according to the ratio of 1:1:2, and the periphery and the bottom of the seedling substrate square block are made of the foamed modified urea resin-substrate composite material.
Example 2
A preparation method of a seedling substrate cube comprises the following steps:
(1) taking 300g of protein substances such as zein and the like as raw materials, adding 3000g of mixed aqueous solution of urea with the final concentration of 1mol/L and potassium hydroxide with the final concentration of 0.05mol/L, stirring and reacting for 1h at 150 ℃, cooling and discharging to obtain hydrolyzed protein with the solid content of 10%;
(2) heating 7500g of formaldehyde solution and 75g of polyvinyl alcohol to about 50 ℃, stirring until the polyvinyl alcohol is dissolved, and adding 2500g of hydrolyzed protein after the polyvinyl alcohol is dissolved;
(3) then, potassium dihydrogen phosphate is used for adjusting the pH value of the solution to 7.8, 1500g of first batch of urea is added, the solution is heated to 60 ℃, 1500g of second batch of urea is added, the heating is continued, the temperature rising rate is controlled to be 1 ℃/min, and the temperature is kept for 50min when the temperature reaches 90 ℃;
(4) adjusting pH of the solution to 4.0 with ammonium chloride, performing polycondensation reaction, measuring the fog point of the solution with water at 26 deg.C, adjusting the solution to 7.5 with potassium hydroxide, and cooling to 80 deg.C;
(5) adding 1000g of third batch of urea, reacting for 30min, cooling to below 40 ℃, and discharging to obtain modified urea-formaldehyde resin;
(6) adding 1 per mill of water soluble fertilizer, 1% of ammonium bicarbonate, 5% of common matrix and 2% of mixture of formic acid and oxalic acid in any ratio into the modified urea-formaldehyde resin, uniformly mixing to obtain a foamed modified urea-formaldehyde resin-matrix composite material, then pouring the foamed modified urea-formaldehyde resin-matrix composite material into a mould, and drying to prepare a hollow seedling culture matrix square, wherein the common matrix is prepared by mixing 0.5 volume part of vermiculite, 1 volume part of perlite, 1 volume part of turf and 0.5 volume part of organic fertilizer.
The molar ratio of the formaldehyde to the urea added in total is 1.3.
When the seedling substrate square block is used for seedling of vegetables, a commercially available common substrate which is favorable for germination is placed in the hollow part of the seedling substrate square block, and the periphery and the bottom of the seedling substrate square block are made of a foamed modified urea resin-substrate composite material.
Example 3
A preparation method of a seedling substrate cube comprises the following steps:
(1) taking 300g of protein substances such as processing byproducts of products such as livestock, poultry and fish and the like as raw materials, adding 3000g of mixed aqueous solution of urea with the final concentration of 0.5mol/L and potassium hydroxide with the final concentration of 0.1mol/L, stirring and reacting for 1h at the temperature of 120 ℃, cooling and discharging to obtain hydrolyzed protein with the solid content of 5%;
(2) heating 6750g of formaldehyde solution and 75g of polyvinyl alcohol to about 50 ℃, stirring until the polyvinyl alcohol is dissolved, and adding 2500g of hydrolyzed protein after the polyvinyl alcohol is dissolved;
(3) then regulating the pH value of the solution to 7.5 by using a mixed solution of potassium hydroxide and ammonia water, adding 1500g of first batch of urea, heating to 60 ℃, adding 1500g of second batch of urea, continuing heating, controlling the temperature rise rate to be 1.5 ℃/min, and keeping the temperature for 50min when the temperature reaches 90 ℃;
(4) adjusting pH of the solution to 5.0 with formic acid, performing polycondensation reaction, measuring the fog point of the solution with water of 26 deg.C, adjusting the solution to 7.5 with potassium hydroxide after reaching the fog point, and cooling to 80 deg.C;
(5) adding 900g of third batch of urea, reacting for 20min, cooling to below 40 ℃, and discharging to obtain modified urea-formaldehyde resin;
(6) adding 3 per mill of water soluble fertilizer, 1% of ammonium bicarbonate, 1% of common matrix and 1.5% of phosphoric acid into the modified urea-formaldehyde resin, uniformly mixing to obtain a foamed modified urea-formaldehyde resin-matrix composite material, then pouring the foamed modified urea-formaldehyde resin-matrix composite material into a mould, and drying to obtain a hollow seedling culture matrix square block, wherein the common matrix is prepared by mixing 1 volume part of vermiculite, 0.5 volume part of perlite, 2 volume parts of turf and 0.9 volume part of organic fertilizer.
The molar ratio of the formaldehyde to the urea added in total is 1.3.
When the seedling substrate square block is used for seedling of vegetables, perlite, vermiculite and turf which are beneficial to germination are placed in the hollow part of the seedling substrate square block, the substrate is obtained by mixing the perlite, the vermiculite and the turf according to the ratio of 1:1:2, and the periphery and the bottom of the seedling substrate square block are made of the foamed modified urea resin-substrate composite material.
Example 4
1. Modified urea-formaldehyde resin-matrix composite nutrient release rate detection
The nutrient release rate of the foam modified urea-formaldehyde resin-matrix composite material of example 1 was measured and the results are shown in fig. 1. As can be seen from FIG. 1, the composite material has a high release rate of nitrogen, and is beneficial to seedling culture.
2. Basic performance detection of seedling raising matrix block
The seedling substrate blocks prepared in example 1 were taken and measured for their properties, as shown in Table 1.
TABLE 1 basic Properties of the seedling substrate cubes
Porosity of air flow%
|
Porosity of water holding capacity%
|
Total porosity%
|
Compressive strength Mpa
|
22.5
|
48.3
|
70.8
|
0.2 |
3. Comprehensive index detection of seedling culture matrix block
The seedling substrate cubes prepared in example 1 were used for growing pepper seedlings and compared with a common commercially available substrate, and the results are shown in table 2.
TABLE 2 comprehensive index of pepper seedlings
Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present invention.