CN111302859A

CN111302859A - Preparation and application of novel soil conditioner

Info

Publication number: CN111302859A
Application number: CN202010230441.6A
Authority: CN
Inventors: 王世伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2020-06-19

Abstract

The invention discloses a preparation method and application of a novel soil conditioner, which is prepared from the following raw materials in percentage by weight: 25-35% of sepiolite, 20-30% of potassium feldspar, 10-20% of chalk soil, 2-5% of mushroom waste, 5-10% of polypropylene oxide-sodium alginate hydrogel, 2-10% of ammonium sulfate, 5-10% of sulfur, 0-2% of an anti-sticking agent and the like; the fertilizer can retain water, resist evaporation, regulate the pH value of soil, resist desertification and water seepage, is beneficial to the absorption of nutrient elements such as nitrogen, phosphorus, potassium and the like and the slow release effect of the nutrient elements, prolongs the fertility of the soil, can improve the yield and quality of agricultural products, protects the health of plant seeds, has no pollutant in preparation, and is energy-saving and environment-friendly.

Description

Preparation and application of novel soil conditioner

Technical Field

The invention belongs to the technical field of soil improvement, and particularly relates to preparation and application of a novel soil improvement agent.

Background

The fertilizer is the most important element for the most investment and yield increase of agricultural production cost, and is directly related to the comprehensive benefit of agriculture. At present, the improvement of the utilization rate of chemical fertilizers, the reduction of pollution caused by fertilization and the development of sustainable and efficient agriculture become the common concern in the world. Slow/controlled release fertilizers have earlier attracted the attention of researchers, and the slow/controlled release is the aim of delaying/controlling the release process of useful ingredients by changing the factors and conditions affecting the release according to the release process and mechanism of the useful ingredients. The sustained/controlled release fertilizer has the main characteristics of synchronous nutrient release and crop absorption, simplified fertilization technology, realization of one-time fertilization, capability of meeting the requirement of the whole growth period of crops, less fertilizer loss, high utilization rate, reduction of the number and times of fertilization, cost saving, suitability for different types of soil and plants, effective prevention of soil hardening, environmental friendliness and improvement of the quality of agricultural products.

The hydrogel contains-COOH, -OH and-NH₂And various functional groups such as-C ═ O and the like, can be combined with various nutrient elements (K, Na, S, N, P and the like), slowly release the nutrient elements in the soil environment, the hydrogel also has the function of buffering the pH value, so that the chemical environment of the soil is influenced, and the hydrogel can generate polymers without biotoxicity after being decomposed, so that the hydrogel is an ideal carrier for the nutrient elements (K, Na, S, N, P and the like).

The existing soil conditioner has a plurality of defects, on one hand, the existing soil conditioner is easy to cause soil hardening and is not beneficial to the development and growth of crop roots; on the other hand, the existing soil conditioner is too high in production cost and is not suitable for wide application, and on the other hand, the existing soil conditioner is single in functionalization and not obvious in slow release effect. Therefore, there is a need for a multifunctional natural non-polluting soil conditioner that slowly releases nutrients.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide a novel soil conditioner which can retain water, resist evaporation, regulate the pH value of soil, resist desertification and water seepage, is beneficial to absorption of nutrient elements such as nitrogen, phosphorus, potassium and the like and slow release of the nutrient elements, prolongs the fertility of soil, can improve the yield and quality of agricultural products, protects the health of plant seeds, does not generate pollutants in preparation, and is energy-saving and environment-friendly.

The technical scheme adopted by the invention for solving the technical problems is as follows: the novel soil conditioner is prepared from the following raw materials in percentage by weight: 25-35% of sepiolite, 20-30% of potassium feldspar, 10-20% of chalk soil, 2-5% of mushroom waste, 5-10% of polypropylene oxide-sodium alginate hydrogel, 2-10% of ammonium sulfate, 5-10% of sulfur and 0-2% of an anti-sticking agent.

Preferably, the novel soil conditioner is prepared from the following raw materials in percentage by weight: 30% of sepiolite, 20% of potassium feldspar, 20% of chalk soil, 5% of mushroom waste, 10% of polypropylene oxide-sodium alginate hydrogel, 5% of ammonium sulfate, 8% of sulfur and 2% of an anti-sticking agent.

Wherein the structural formula of the polypropylene oxide-sodium alginate hydrogel is shown as the formula (I):

wherein n is 20-50; m is 20-50;

the preparation method of the novel soil conditioner comprises the following steps:

1) the organic material is prepared by mixing 30% of sepiolite, 20% of potassium feldspar and 20% of chalk soil, grinding uniformly to prepare a mixed material with the granularity of about 100 meshes, adding the mixed material into a closed reaction kettle, stirring uniformly, heating to 150 ℃ and 170 ℃ by using steam, adjusting the pressure to 0.5MP, and reacting for 2 hours to obtain the organic material without harmful bacteria.

2) Opening a discharging valve of the closed reaction kettle, discharging the materials into a reduced pressure reaction kettle by means of internal pressure, stirring for 20 minutes at 40-50 ℃ under normal pressure, then adding 5% of mushroom waste and 8% of sulfur under a stirring state, continuously stirring for 30 minutes, cooling to room temperature, adding 10% of polypropylene oxide-sodium alginate hydrogel, uniformly stirring, adding 2% of an anti-sticking agent, and stirring again to obtain the novel soil conditioner.

The invention aims to provide a preparation method of a novel soil conditioner.

The invention also aims to provide application of the novel soil conditioner, wherein the novel soil conditioner can retain water, resist evaporation, regulate the pH value of soil, resist desertification and water seepage, is favorable for absorption of nutrient elements such as nitrogen, phosphorus, potassium and the like and slow release of the nutrient elements, prolongs the fertility of soil, can improve the yield and quality of agricultural products, protects the health of plant seeds, is free from generating pollutants in preparation, and is energy-saving and environment-friendly.

The invention also aims to provide application of the novel soil conditioner, wherein polypropylene oxide-sodium alginate in the novel soil conditioner is changed into hydrogel when meeting water, so that a large number of nutrient elements are adsorbed and slowly released, and the soil fertility is prolonged.

The sepiolite belongs to non-metallic minerals, is white, looks like a row of white velvet bonded together, and is non-toxic. The performance is as follows: high temperature resistance, heat preservation, strong adsorption capacity, high decolorization capacity, high thermal stability, high temperature resistance of 1500-1700 ℃, good modeling, low shrinkage, difficult cracking, high salinity resistance, corrosion resistance, special radiation resistance and wide application range.

The potassium feldspar is a water-insoluble potassium resource with high potassium content, wide distribution and maximum reserves.

The chalk is a loose white limestone whose main chemical component is CaCO₃The main mineral component is biological mud crystal calcite which has pure texture, the content of the calcite can reach more than 99 percent, and the bioceramic often contains impurities such as quartz, feldspar, clay minerals, glauconite and the like. Under an electron microscope, chalk is mostly composed of calcite fine granular calcareous algae, and is often reacted with potassium feldspar to produce K and Na salts.

The various biological enzymes secreted by the mushroom waste can promote the diversity of floras in the soil, the mushroom waste has a good effect of absorbing heavy metals, and the heavy metal content of the soil after mushroom cultivation is greatly reduced. The waste materials after mushroom cultivation are organic fertilizers with excellent soil, and the organic fertilizers can promote the granular structure of the soil and enhance the soil moisture conservation capability of the soil.

The sodium alginate is a byproduct obtained by extracting iodine and mannitol from brown algae such as herba Zosterae Marinae or Sargassum, and its molecule is formed by connecting β -D-mannuronic acid and α -L-guluronic acidAqueous solutions of sodium acid have a high viscosity and have been used as thickeners, stabilizers, emulsifiers, etc. for food. Sodium alginate is a non-toxic food and has been introduced into the united states pharmacopeia as early as 1938. Sodium alginate contains a large amount of-COO^－Can show polyanion behavior in aqueous solution, has certain adhesiveness, and can realize the function of improving the stability of the product^－When the sodium alginate is converted into-COOH, the ionization degree is reduced, the hydrophilicity of the sodium alginate is reduced, the molecular chain is contracted, the pH value is increased, the-COOH group is continuously dissociated, the hydrophilicity of the sodium alginate is increased, and the molecular chain is stretched. Therefore, sodium alginate has significant pH sensitivity. Sodium alginate can form a gel rapidly under extremely mild conditions.

The novel soil conditioner is prepared by adopting a traditional method, namely, grinding raw materials according to a certain mass percentage to the particle size of about 100 meshes, and uniformly mixing; or a granulator by a granulator. 1 ton of the soil conditioner is prepared, the power consumption is less than 1 kilowatt hour, and the manufacturing cost is low. The dosage is 50-100Kg per mu. It is suitable for sandy soil, saline-alkali soil, acid soil, rock desert, desert land, wet land and other common soil.

Compared with the prior art, the invention has the following advantages:

1. the soil conditioner is beneficial to reducing the evaporation of soil moisture, improving the field water capacity (20.3%) of sandy soil, enhancing the drought resistance of crops, and reducing irrigation, and the field water capacity of the sandy soil without the soil conditioner is only 9.8%;

2. the product adopts natural nontoxic polypropylene oxide-sodium alginate hydrogel as an adsorbent of nitrogen, phosphorus, potassium and other nutrient elements, has the capability of slowly releasing various nutrient elements, the content of the nutrient elements in the soil after the soil conditioner is added after 65 days and after 95 days is almost unchanged, and the nutrient elements obtained by crops are also almost unchanged, thereby showing that the novel soil conditioner can slowly release the nutrients, the release and the absorption of the crops are synchronous, the requirement of the whole growth period of the crops can be met by one-time fertilization, the fertilization times and the fertilization amount are reduced, and the product after the hydrogel decomposition has no pollution to the environment;

3. the product can improve soil fertility, increase soil aggregate structure, effectively improve pH value of alkaline soil, and increase yield of wheat by 12% after the product acts on sandy loam with moderate fertility;

4. the preparation is simple and easy, and the application method is simple and convenient.

The novel soil conditioner prepared by adopting the technical scheme can preserve water and resist evaporation, adjust the pH value of soil, resist desertification and water seepage, is beneficial to absorption of nutrient elements such as nitrogen, phosphorus and potassium and slow release effect of the nutrient elements, prolongs the fertility of the soil, can improve the yield and quality of agricultural products, protects the health of plant seeds, has no pollutant in preparation, and is energy-saving and environment-friendly.

The following will clearly and completely describe the technical scheme of the embodiment of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Drawings

FIG. 1 is a bar graph showing the effect of the novel soil amendment on the content of nutrient elements in soil after 65 days of action.

FIG. 2 is a bar graph showing the effect of the novel soil amendment on the content of nutrient elements in soil after the novel soil amendment acts for 95 days.

FIG. 3 is a bar graph of the effect of novel soil amendment on alkaline soil pH.

Detailed description of the preferred embodiments

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

The synthesis method of polypropylene oxide-sodium alginate comprises the following steps:

3, 3-Dithiodipropionic acid (8.41g, 40mmol), sodium alginate (1.93g, 5mmol) and 4-dimethylaminopyridine (0.0386g, 0.316mmol) were weighed out and dissolved in 20mL of anhydrous tetrahydrofuran. Dicyclohexylcarbodiimide (3.09g, 15mmol) was then added to anhydrous tetrahydrofuran (5mL) and added dropwise to the ice bath. The resulting mixture was stirred at 30 ℃ for 12h, the reaction was filtered, the solvent was removed by rotary evaporation, and the product was purified by recrystallization from ethyl acetate to give a white solid.

Weighing the white solid product (3.5mmol) obtained in the first step and 1.32g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (6.9mmol) to dissolve in 20mL of absolute ethanol, and stirring for 50 minutes to activate carboxyl; 0.4g of sodium alginate and 0.079g N-hydroxysuccinimide (0.687mmol) are dissolved in 20mL of deionized water, and the mixed solution of the N-hydroxysuccinimide and the sodium alginate is slowly added into the aqueous solution of the white solid product obtained in the first step after the carboxyl group is activated, and the dropping time is controlled at 8 min. Stirring for 10h in the dark. Dialyzing with 8000-14000 molecular weight dialysis bag for 3 days, and freeze drying to obtain blue solid formula (I).

Example 2

The synthesis method of the novel soil conditioner comprises the following steps:

Example 3

Influence of novel soil conditioner on field water capacity

The soil conditioner prepared by the invention is used for applying soybean planted on sandy soil as base fertilizer, and the application amount is 50kg/hm²Spraying water on sandy soil to saturate the soil, spraying water on the other group until the soil is saturated by water without applying a soil conditioner, and mounting the two groups of samples by a cutting ring; then the bottom cover (cover with hole) of the cutting ring of the soil sample is removed, and the secondary cutting ring together with the filter paper is put on the cutting ring filled with the air-dried soil. In order to make the contact tight, bricks can be used for compaction, after 8 hours of water absorption process, 15-20g of undisturbed soil in the upper cutting ring is taken and put into an aluminum box, the aluminum box is immediately weighed, the accuracy rate is 0.01g, the water content is measured by drying, and compared with the water holding capacity in sandy soil without the soil conditioner prepared by the invention, the sandy field water holding capacity after the soil conditioner prepared by the invention is acted is found to be 20.3 percent, and the value is 9.8 percent higher than the field water holding capacity of the sandy soil without the soil conditioner, which indicates that the soil conditioner prepared by the invention can improve the field water holding capacity of the sandy soil.

Example 4

Influence of novel soil conditioner on contents of K, N, P and S in soil

Two experimental groups are arranged, the first group is used for uniformly mixing the conditioner disclosed by the invention with soil, and the second group is only added with soil; meanwhile, 0.7g of urea and 0.7g of dipotassium hydrogen phosphate are applied to each pot to serve as base fertilizers and then the pots are loaded, 2.0kg of each pot is loaded, the water content of the uniformly mixed soil is adjusted to be 65% of the field water capacity, and the planting is carried out in a balanced way for one week. Selecting full soybean seeds with uniform size, sterilizing with 1% NaClO for 30min, washing with a large amount of deionized water, spreading the seeds on wet filter paper, and performing germination acceleration in an incubator in dark environment at 18 ℃ for two days. Placing 20 germinated seeds in each pot, carrying out unscheduled thinning in the initial stage of seedling emergence, and finally, reserving three seedlings with equivalent growth vigor in each pot, carrying out greenhouse culture and natural illumination. And (3) irrigating with deionized water every day during the whole growth period to keep a certain soil water holding capacity, harvesting soybeans after 65 days, and collecting corresponding soil samples at the same time, and continuously harvesting soybeans after 95 days and collecting corresponding soil samples at the same time.

Returning the plant samples 65 days later and 95 days later to the laboratory, cleaning with tap water and deionized water, placing in a 105 deg.C oven for 30min, drying at 75 deg.C to constant weight, pulverizing with a small pulverizer, weighing 0.15-0.20g pulverized soybean sample in a triangular flask, respectively adding 5mL HNO₃And 0.5mL 30% H₂O₂Each flask was placed in a curved funnel for cold digestion overnight. The next day, the mixture was heated to near dryness and appeared white or yellow. After cooling, the funnel was rinsed with ultra-pure water and 5mL of 25% HCl was addedThe solid was dissolved and then transferred to a volume to be measured in a 25ml volumetric flask. The heavy metals in the solution were measured using a graphite furnace atomic absorption spectrophotometer, and the experimental results are shown in fig. 1.

And after 65 days and 95 days, collecting the soil, naturally drying in the air, grinding, sieving with a 10-mesh nylon sieve and a 100-mesh nylon sieve respectively, weighing 9-10g of the soil sample sieved with the 100-mesh nylon sieve into a 50mL centrifuge tube, adding 25mL of 0.005mol/L DTPA solution leaching liquor, and shaking at 25 ℃ for 2 hours. Then, centrifuging at 4000 rpm for 10min, filtering with 0.45 μm filter membrane, and adding one drop of concentrated HNO to each filtrate₃And storing in a refrigerator at 4 ℃ for testing. The nutrient elements in the solution were measured by graphite furnace atomic absorption spectrophotometer, and the experimental results are shown in fig. 2.

The results shown in fig. 1 and fig. 2 show that the novel soil conditioner of the present invention can increase the content of K, N, P, and S in the soil, and the content of the nutrient elements in the soil after the soil conditioner is added after 65 days and after 95 days is two times higher than that of the soil without the soil conditioner, and the nutrient elements obtained by the crops are almost unchanged, which indicates that the novel soil conditioner of the present invention can slowly release nutrients, release and crop absorption are synchronous, and the requirement of the crops in the whole growth period can be satisfied by implementing one-time fertilization.

Example 5

Influence of novel soil conditioner on soil pH

Two experimental groups are arranged, the first group is used for uniformly mixing the conditioner disclosed by the invention with alkaline soil, and the second group is only added with the alkaline soil; meanwhile, 0.7g of urea and 0.7g of dipotassium hydrogen phosphate are applied to each pot to serve as base fertilizers and then the pots are loaded, 2.0kg of each pot is loaded, the water content of the uniformly mixed soil is adjusted to be 65% of the field water capacity, and the planting is carried out in a balanced way for one week. Selecting full soybean seeds with uniform size, sterilizing with 1% NaClO for 30min, washing with a large amount of deionized water, spreading the seeds on wet filter paper, and performing germination acceleration in an incubator in dark environment at 18 ℃ for two days. 20 germinated seeds are put in each pot, and irregular thinning, greenhouse culture and natural illumination are carried out at the initial seedling stage. The soil was watered with deionized water daily throughout the growth period to maintain a certain soil water holding capacity, and corresponding soil samples were collected 65 days later.

After the soil sample is taken back to a laboratory, the soil sample is washed by tap water and deionized water, is put into a 105 ℃ oven for 30min, is dried to constant weight at 75 ℃, is crushed by a small crusher, 0.15-0.20g of crushed soil is weighed into a triangular flask, is soaked by deionized water with the ratio of 1 to 1, is uniformly stirred, and is measured by a pH meter, and the experimental result is shown in figure 3.

As can be seen from the experimental results shown in fig. 3, the pH of the alkaline soil of the five groups to which the novel soil conditioner is added is about 7, while the pH of the alkaline soil of the five groups to which the novel soil conditioner is not added is about 12.

Example 6

Influence of novel soil conditioner on wheat harvest

The soil quality of the test field and the control field is sandy loam, the fertility is moderate and moderate, each field is 1 mu, the wheat variety is sunshine 818, 50kg of ammonium bicarbonate and calcium superphosphate are applied to the base fertilizer of each mu of the control field, 50kg of the soil conditioner is applied to the test field, and the test result shows that the yield is increased by 41.8 kg as shown in the following table.

Claims

1. The preparation method of the novel soil conditioner is characterized in that the novel soil conditioner is prepared from the following raw materials in percentage by weight: 25-35% of sepiolite, 20-30% of potassium feldspar, 10-20% of chalk soil, 2-5% of mushroom waste, 5-10% of polypropylene oxide-sodium alginate hydrogel, 2-10% of ammonium sulfate, 5-10% of sulfur and 0-2% of an anti-sticking agent;

the structural formula of the polypropylene oxide-sodium alginate hydrogel is shown as the formula (I):

wherein n is 20-50; m is 20-50;

1) the preparation method comprises the following steps of mixing 30% of sepiolite, 20% of potassium feldspar and 20% of chalk soil, uniformly grinding to prepare a mixed material with the granularity of about 100 meshes, adding the mixed material into a closed reaction kettle, uniformly stirring, heating to the temperature of 150 ℃ plus 170 ℃ by using steam, adjusting the pressure to 0.5MP, and reacting for 2 hours to obtain an organic material without harmful bacteria;

2. The application of the novel soil conditioner in soil modification is characterized in that the conditioner can retain water, resist evaporation, adjust the pH value of soil, improve the yield of crops and slowly release nutrient elements such as nitrogen, phosphorus, potassium and the like.

3. The use of a novel soil amendment according to claim 2 for soil modification, wherein the amendment is used for growing crops on sandy, loamy or clayey soil.

4. The use of a novel soil amendment according to claim 2 for soil modification, wherein the crop is wheat.