High-moisture nano-type soil conditioner and preparation method thereof

Abstract

The invention discloses a high-moisture nano-type soil conditioner and a preparation method thereof, and belongs to the field of fertilizers. The high-moisture nano-type soil conditioner is prepared from the following components in parts by weight: urea, monopotassium phosphate, potassium nitrate, anhydrous magnesium sulfate, zinc sulfate, a composite nano-type water-retaining agent and organic matter modified attapulgite. The organic matter modified attapulgite and the composite nano-type water-retaining agent are added into the soil conditioner, so that the water storage capacity of soil is improved, a good soil structure foundation is provided for the organic matter, and adsorption and permeation of water are promoted; the modified attapulgite and the water-retaining agent further enhance the water absorption, storage and release capabilities of the soil; the modified attapulgite and the composite nano water-retaining agent can form a water buffer reservoir in the soil, provide water under drought conditions, absorb excess water under rainfall conditions, maintain proper water content of the soil and improve the soil moisture content of the soil.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and specifically refers to a high-moisture nano-type soil conditioner and a preparation method thereof. Background Art

[0002] With the intensification of agricultural and industrial activities, soil degradation has become increasingly serious and has become an important factor threatening food security and the ecological environment. At present, the main forms of soil degradation include soil salinization, desertification, heavy metal pollution, and loss of organic matter and nutrients. These problems not only reduce the fertility of the soil, but also lead to the imbalance of the ecosystem, seriously affecting the sustainable development of crop growth and agricultural production. Soil conditioners include organic conditioners, inorganic conditioners and composite conditioners; organic conditioners (such as straw, animal manure, humic acid, etc.) are commonly used soil improvement materials in agriculture, which mainly improve soil fertility by supplementing organic matter, promoting microbial activity and improving soil aggregate structure. However, it has the following problems: long degradation cycle: natural organic matter decomposes slowly in the soil, and it is difficult to significantly improve the physical and chemical properties of the soil in a short period of time; heavy metal and pathogen pollution risk: some organic fertilizers of unknown origin may carry pathogens, heavy metals or antibiotic residues, posing a potential threat to soil and crop safety; uneven effect: the nutrient composition of organic conditioners is single and cannot fully meet the diverse needs of soil and crops. Inorganic amendments (such as gypsum, attapulgite, silicate minerals, etc.) are usually used for saline-alkali land improvement, heavy metal pollution remediation and soil pH adjustment. They have a fast improvement effect, but they also face many problems: Difficult to combine multifunctionality: Inorganic amendments are mostly single components, and usually can only solve specific problems, such as adjusting pH or adsorbing specific heavy metals, but have limited effect on improving soil structure, nutrient retention and microbial environment; Poor environmental friendliness: Some inorganic amendments (such as acidic amendments) may inhibit beneficial microorganisms in the soil, causing imbalance in the soil ecosystem; Short action cycle: Since inorganic amendments are easily diluted by water or other soil components, their sustained effect in the soil is limited and requires frequent application. Composite soil amendments usually improve the physical, chemical and biological properties of the soil by combining organic and inorganic components. However, this type of improver still has some problems in practical application: poor component stability: organic components and inorganic components may separate or become incompatible during the compounding process, resulting in the actual effect of the improver being less than expected; high production cost: the preparation process of the composite improver is relatively complicated, resulting in its high cost and difficulty in large-scale promotion and application; single function: existing composite improvers are mostly concentrated on a single function (such as water retention or nutrient supply), lacking systematic and multifunctional improvement effects. Summary of the invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a high-moisture nano-type soil conditioner and a preparation method thereof. The present invention improves the water storage capacity of the soil by adding organic matter @ modified attapulgite and a composite nano-type water-retaining agent to the soil conditioner. The organic matter provides a good soil structural foundation and promotes the adsorption and penetration of water; the modified attapulgite and the water-retaining agent further enhance the soil's ability to absorb, store and release water; the modified attapulgite and the composite nano-type water-retaining agent can form a moisture buffer in the soil, provide moisture under drought conditions, absorb excess moisture under precipitation conditions, maintain the appropriate moisture content of the soil, and improve the soil moisture conditions.

[0004] In order to achieve the above-mentioned object, the technical scheme adopted by the present invention is as follows: the present invention proposes a high-moisture nano-type soil conditioner, which comprises the following components in parts by weight: 50-60 parts of urea, 40-50 parts of potassium dihydrogen phosphate, 10-15 parts of potassium nitrate, 0.2-0.3 parts of anhydrous magnesium sulfate, 0.1-0.2 parts of zinc sulfate, 10-15 parts of composite nano-type water-retaining agent, and 8-12 parts of organic matter@modified attapulgite;

[0005] Preferably, the method for preparing the organic matter@modified attapulgite specifically comprises the following steps:

[0006] K1. Add attapulgite to a NaOH aqueous solution, raise the temperature to 70-80° C., stir and react at 180-220 rpm, react for 1-2 hours, filter, wash with deionized water until neutral, and dry in an oven to obtain pretreated attapulgite;

[0007] Preferably, in step K1, the material-liquid ratio (g / mL) between the attapulgite and the NaOH aqueous solution is 0.04-0.06 g / mL;

[0008] Preferably, in step K1, the content of NaOH in the NaOH aqueous solution is 0.1-1 mol / L;

[0009] K2, adding the pretreated attapulgite prepared in step K1 to the iron source solution, placing it under sealing conditions, stirring at a speed of 150-180 rpm for 30-50 min, raising the temperature to 60-80° C., stirring continuously for 2-3 h, washing with deionized water and anhydrous ethanol, placing it in an oven at 100-120° C. and drying it for 6-8 h to obtain Fe-modified attapulgite;

[0010] Preferably, in step K2, the solid-liquid ratio (g / mL) of the pretreated attapulgite in the iron source solution is 0.07-0.09 g / mL;

[0011] Preferably, in step K2, the iron source solution comprises at least one of a ferric sulfate solution, a ferric nitrate solution and a ferric chloride solution, wherein Fe 3+ The mass concentration is 1-5g / L;

[0012] K3, dissolving humic acid in deionized water, adjusting the pH to 8-9, adding to the Fe-modified attapulgite prepared in step K2, placing at 40-50°C, stirring at 400-500 rpm, reacting for 8-12 hours, filtering, collecting the solid, washing with deionized water, placing in an oven at 40-50°C and drying to constant weight, to obtain organic matter@modified attapulgite;

[0013] Preferably, in step K3, the mass concentration of humic acid in deionized water is 10-20 g / L;

[0014] Preferably, in step K3, the mass ratio between the humic acid and the Fe-modified attapulgite is 3-5:5-7.

[0015] Preferably, the preparation method of the composite nano water-retaining agent specifically comprises the following steps:

[0016] S1, dissolving cellulose in 1-butyl-3-methylimidazolium chloride ionic liquid, adding 2-bromopropionyl bromide, raising the temperature to 70-80°C, reflux reaction for 24-48h, adding deionized water for precipitation treatment, filtering, collecting the precipitate, washing with deionized water, and drying at 60°C to obtain activated cellulose;

[0017] Preferably, in step S1, the mass concentration of the plant cellulose in the 1-butyl-3-methylimidazolium chloride ionic liquid is 0.02-0.04 g / mL;

[0018] Preferably, in step S1, the mass ratio between the 2-bromopropionyl bromide and the cellulose is 10-15:1;

[0019] S2, dissolving the activated fiber prepared in step S1 in DMSO, raising the temperature to 50-60°C, stirring at 180-220rpm until the activated cellulose is dissolved, adding polyvinyl alcohol, maintaining the reaction temperature at 40-50°C, stirring at 220-250rpm for 12-16h, and freeze-drying to obtain a composite nano water-retaining agent;

[0020] Preferably, in step S2, the mass concentration of the activated cellulose in DMSO is 50-60 g / L;

[0021] Preferably, in step S2, the mass ratio between the activated cellulose and the polyvinyl alcohol is 1:2-3;

[0022] The present invention also provides a method for preparing a high-moisture content nano-type soil conditioner, which specifically comprises the following steps:

[0023] ① Dissolve the composite nano water retaining agent in an ethanol solution, add organic matter @ modified attapulgite, stir and react at a speed of 300-400 rpm at room temperature for 18-24 hours, remove the organic solvent by vacuum distillation, wash with deionized water, and dry to obtain a mixture;

[0024] Preferably, in step ①, the mass concentration of the composite nano water-retaining agent in the ethanol solution is 10-20 g / L;

[0025] ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate and zinc sulfate in deionized water and keep the temperature at 30-40°C. Stir at a speed of 1000-1200 pm until the solution is uniform. Add the mixture prepared in step ①, continue stirring and mixing for 20-30 minutes, dry and crush to obtain a soil conditioner for later use.

[0026] The beneficial effects achieved by the present invention are as follows:

[0027] The present invention provides a preparation method of a high-moisture nano-type soil conditioner. The present invention improves the water storage capacity of the soil by adding organic matter, modified attapulgite and a composite nano-type water-retaining agent to the soil conditioner. The organic matter provides a good soil structural foundation and promotes the adsorption and penetration of water; the modified attapulgite and the water-retaining agent further enhance the soil's ability to absorb, store and release water; the modified attapulgite and the composite nano-type water-retaining agent can form a water buffer in the soil, provide water under drought conditions, absorb excess water under precipitation conditions, maintain the appropriate water content of the soil, and improve the soil moisture conditions; the present invention modifies the attapulgite, first desiliconizes the attapulgite, improves the reaction activity of the attapulgite, and uses iron ions to load the surface of the attapulgite, which can be achieved through the complexation between the iron ions and the organic humic acid The invention can improve the water holding capacity and the release effect of organic matter by using cellulose as the main chain and grafting polyvinyl alcohol on the side chain for modification, so as to improve the water holding capacity and the stabilizer of the composite nano water retaining agent. Polyvinyl alcohol has a carbon long chain structure and is rigid. It is dissolved in cold water by itself. In the process of absorbing water molecules, the structure is not easy to disintegrate. Cellulose is hydrophilic and can improve the water holding capacity and the water retention capacity of the composite nano water retaining agent. The gel network structure of the composite nano water retaining agent and the adsorption effect of attapulgite jointly reduce the evaporation and deep leakage of water. It is particularly suitable for use in arid and desertified areas. It is combined with organic matter to improve the nutrient supply and root growth environment of the soil. The attapulgite and the water retaining agent improve the soil's ability to retain water and nutrients, thereby greatly improving the water utilization efficiency of plants, thereby improving soil moisture. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a comparison diagram of the effects of the soil conditioner described in Example 1 of the present invention and Comparative Examples 1-2 on plant stems and leaves;

[0029] Figure 2 This is a comparison chart of the effects of the soil conditioner described in Example 1 of the present invention and Comparative Examples 1-2 on plant roots;

[0030] Figure 3 The results of the soil conditioner prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on stems and leaves are shown in FIG.

[0031] Figure 4 The results of the soil conditioner prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on the root system are shown in FIG.

[0032] Figure 5 The saturated water holding capacity result diagram of the soil conditioner prepared by Examples 1-3 and Comparative Examples 1-2 of the present invention;

[0033] Figure 6 This is a graph showing the cumulative water evaporation rate results of the soil conditioners prepared in Examples 1-3 of the present invention and Comparative Examples 1-2.

[0034] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0037] The experimental methods in the following examples are conventional methods unless otherwise specified; the experimental materials and test strains used in the following examples are purchased from commercial channels unless otherwise specified.

[0038] Example 1

[0039] The present embodiment provides a high-moisture nano-type soil conditioner, comprising the following components in parts by weight: 50 parts of urea, 50 parts of potassium dihydrogen phosphate, 15 parts of potassium nitrate, 0.2 parts of anhydrous magnesium sulfate, 0.1 parts of zinc sulfate, 10 parts of composite nano-type water-retaining agent, and 12 parts of organic matter@modified attapulgite;

[0040] The preparation method of organic matter@modified attapulgite specifically comprises the following steps:

[0041] K1. Prepare a 0.1 mol / L NaOH aqueous solution, take 10 g of 100-mesh attapulgite and add it to 250 mL of NaOH aqueous solution, raise the temperature to 80° C., stir and react at 220 rpm, react for 1 hour, filter, wash with deionized water until neutral, and dry in an oven to obtain pretreated attapulgite;

[0042] K2, prepare 5g / mL ferric sulfate solution, add 7g of the pretreated attapulgite prepared in step K1 into 100mL of ferric sulfate solution, place under sealing conditions, stir at 150rpm for 30min, raise the temperature to 80°C, continue stirring for 2h, wash with deionized water and anhydrous ethanol, place in an oven and dry at 120°C for 6h to obtain Fe-modified attapulgite;

[0043] K3, dissolve 2 g of humic acid in 100 mL of deionized water, adjust the pH to 9, add to 2 g of Fe-modified attapulgite prepared in step K2, place at 50° C., stir at 400 rpm, react for 12 h, filter, collect the solid, wash with deionized water, place in an oven at 50° C. and dry to constant weight to obtain organic matter@modified attapulgite;

[0044] The preparation method of the composite nano water-retaining agent specifically comprises the following steps:

[0045] S1, dissolving 2 g of cellulose in 100 mL of 1-butyl-3-methylimidazolium chloride ionic liquid, adding 20 g of 2-bromopropionyl bromide, raising the temperature to 70°C, reflux reacting for 48 hours, adding deionized water for precipitation treatment, filtering, collecting the precipitate, washing with deionized water, and drying at 60°C to obtain activated cellulose;

[0046] S2, dissolving 1 g of the activated fiber prepared in step S1 in 20 mL of DMSO, raising the temperature to 50°C, stirring at 180 rpm until the activated cellulose is dissolved, adding 3 g of polyvinyl alcohol, maintaining the reaction temperature at 50°C, stirring at 250 rpm for 12 h, and freeze-drying to obtain a composite nano-type water-retaining agent;

[0047] This embodiment also provides a method for preparing a high-moisture nano-type soil conditioner, which specifically includes the following steps:

[0048] ① Dissolve 1 g of the composite nano water-retaining agent in 100 mL of 75 vol% ethanol solution, add 1.2 g of organic matter@modified attapulgite, stir at 400 rpm for 24 h at room temperature, remove the organic solvent by vacuum distillation, wash with deionized water, and dry to obtain a mixture;

[0049] ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate and zinc sulfate in deionized water and keep the temperature at 30°C. Stir at a speed of 1000 pm until the solution is uniform. Add the mixture prepared in step ① and continue stirring and mixing for 30 minutes. After drying and crushing, a soil conditioner is obtained and set aside.

[0050] Example 2

[0051] The present embodiment provides a high-moisture nano-type soil conditioner, comprising the following components in parts by weight: 60 parts of urea, 40 parts of potassium dihydrogen phosphate, 10 parts of potassium nitrate, 0.3 parts of anhydrous magnesium sulfate, 0.2 parts of zinc sulfate, 15 parts of composite nano-type water-retaining agent, and 10 parts of organic matter@modified attapulgite;

[0052] The preparation method of organic matter@modified attapulgite specifically comprises the following steps:

[0053] K1. Prepare a 1 mol / L NaOH aqueous solution, take 8 g of 100-mesh attapulgite and add it to 250 mL of NaOH aqueous solution, raise the temperature to 70° C., stir and react at 1800 rpm, react for 1 hour, filter, wash with deionized water until neutral, and dry in an oven to obtain pretreated attapulgite;

[0054] K2, prepare 3g / mL ferric sulfate solution, add 8g of the pretreated attapulgite prepared in step K1 into 100mL of ferric sulfate solution, place under sealing conditions, stir at 180rpm for 50min, raise the temperature to 60°C, continue stirring for 3h, wash with deionized water and anhydrous ethanol, place in an oven and dry at 100°C for 8h to obtain Fe-modified attapulgite;

[0055] K3, dissolve 1 g of humic acid in 100 mL of deionized water, adjust the pH to 8, add to 1.5 g of Fe-modified attapulgite prepared in step K2, place at 40°C, stir at 500 rpm, react for 8 hours, filter, collect the solid, wash with deionized water, place in an oven at 40°C and dry to constant weight to obtain organic matter@modified attapulgite;

[0056] The preparation method of the composite nano water-retaining agent specifically comprises the following steps:

[0057] S1, dissolving 4 g of cellulose in 100 mL of 1-butyl-3-methylimidazolium chloride ionic liquid, adding 60 g of 2-bromopropionyl bromide, raising the temperature to 70°C, reflux reacting for 36 hours, adding deionized water for precipitation treatment, filtering, collecting the precipitate, washing with deionized water, and drying at 60°C to obtain activated cellulose;

[0058] S2, dissolving 1.2 g of the activated fiber prepared in step S1 in 20 mL of DMSO, raising the temperature to 50° C., stirring at 200 rpm until the activated cellulose is dissolved, adding 3 g of polyvinyl alcohol, maintaining the reaction temperature at 50° C., stirring at 240 rpm for 14 h, and freeze-drying to obtain a composite nano-type water-retaining agent;

[0059] This embodiment also provides a method for preparing a high-moisture nano-type soil conditioner, which specifically includes the following steps:

[0060] ① Dissolve 1.5 g of the composite nano water-retaining agent in 100 mL of 75 vol% ethanol solution, add 1.0 g of organic matter@modified attapulgite, stir at 300 rpm for 20 h at room temperature, remove the organic solvent by vacuum distillation, wash with deionized water, and dry to obtain a mixture;

[0061] ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate and zinc sulfate in deionized water and keep the temperature at 40°C. Stir at a speed of 1200 pm until the solution is uniform. Add the mixture prepared in step ① and continue stirring and mixing for 20 minutes. After drying and crushing, a soil conditioner is obtained and set aside.

[0062] Example 3

[0063] The present embodiment provides a high-moisture nano-type soil conditioner, comprising the following components in parts by weight: 55 parts of urea, 45 parts of potassium dihydrogen phosphate, 12 parts of potassium nitrate, 0.2 parts of anhydrous magnesium sulfate, 0.2 parts of zinc sulfate, 12 parts of composite nano-type water-retaining agent, and 8 parts of organic matter@modified attapulgite;

[0064] The preparation method of organic matter@modified attapulgite specifically comprises the following steps:

[0065] K1. Prepare a 0.5 mol / L NaOH aqueous solution, take 1.2 g of 100-mesh attapulgite and add it to 200 mL of NaOH aqueous solution, raise the temperature to 80° C., stir and react at 200 rpm, react for 1 hour, filter, wash with deionized water until neutral, and dry in an oven to obtain pretreated attapulgite;

[0066] K2, prepare 1g / mL ferric sulfate solution, add 9g of the pretreated attapulgite prepared in step K1 into 100mL of ferric sulfate solution, place under sealing conditions, stir at 180rpm for 40min, raise the temperature to 70°C, continue stirring for 3h, wash with deionized water and anhydrous ethanol, place in an oven and dry at 120°C for 6h to obtain Fe-modified attapulgite;

[0067] K3, dissolve 3 g of humic acid in 200 mL of deionized water, adjust the pH to 8, add to 7 g of Fe-modified attapulgite prepared in step K2, place at 50° C., stir at 500 rpm, react for 10 h, filter, collect the solid, wash with deionized water, and dry in an oven at 45° C. to constant weight to obtain organic matter@modified attapulgite;

[0068] The preparation method of the composite nano water-retaining agent specifically comprises the following steps:

[0069] S1, dissolving 3 g of cellulose in 100 mL of 1-butyl-3-methylimidazolium chloride ionic liquid, adding 36 g of 2-bromopropionyl bromide, raising the temperature to 80°C, reflux reacting for 24 hours, adding deionized water for precipitation treatment, filtering, collecting the precipitate, washing with deionized water, and drying at 60°C to obtain activated cellulose;

[0070] S2, take 1.5g of the activated fiber prepared in step S1 and dissolve it in 30mL of DMSO, raise the temperature to 60°C, stir at 220rpm until the activated cellulose is dissolved, add 4.5g of polyvinyl alcohol, keep the reaction temperature at 50°C, stir at 220rpm for 12h, and freeze-dry to obtain a composite nano-type water-retaining agent;

[0071] This embodiment also provides a method for preparing a high-moisture nano-type soil conditioner, which specifically includes the following steps:

[0072] ① Dissolve 1.2 g of the composite nano water-retaining agent in 60 mL of 75 vol% ethanol solution, add 0.8 g of organic matter@modified attapulgite, stir at 350 rpm for 24 h at room temperature, remove the organic solvent by vacuum distillation, wash with deionized water, and dry to obtain a mixture;

[0073] ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate and zinc sulfate in deionized water and keep the temperature at 40°C. Stir at a speed of 1200 pm until the solution is uniform. Add the mixture prepared in step ① and continue stirring and mixing for 20 minutes. After drying and crushing, a soil conditioner is obtained and set aside.

[0074] Comparative Example 1

[0075] This comparative example provides a soil conditioner and a preparation method thereof, which differs from Example 1 only in that the composite nano water retaining agent is replaced with cellulose in the same mass fraction, and the remaining components and component contents are the same as those in Example 1.

[0076] Comparative Example 2

[0077] This comparative example provides a soil conditioner and a preparation method thereof, which differs from Example 1 only in that the organic matter@modified attapulgite is replaced by the same weight of humic acid+attapulgite, the mass ratio between the humic acid and the attapulgite is 1:2, and the other components and component contents are the same as those in Example 1.

[0078] Experimental Example 1

[0079] This experimental example is to verify the regulation of soil and crops by Examples 1-3 and Comparative Examples 1-2:

[0080] Test site climate:

[0081] Dongpo District belongs to the subtropical humid climate zone, with no severe cold in winter, no extreme heat in summer, seldom frost and snow, distinct four seasons, abundant rainfall, and rich light and temperature resources. The annual average temperature is 17.2℃, the frost-free period is 318 days, the annual average rainfall is 1057.5 mm, and the annual average sunshine hours are 1193.8 hours.

[0082] Test treatment:

[0083] Land preparation, weeding and tillage will be carried out from December 1, 2023 to December 18, 2023; base fertilizer will be applied to the experimental field on December 19, 2023; sowing will be carried out on December 20, 2023, and harvesting will be carried out on April 7, 2024:

[0084] Apply 40kg 15-15-15 Kail Supreme Nitrate-Sulfur Compound Fertilizer + 80kg Soil Improver as base fertilizer per mu of land;

[0085] Test subjects: Spinach grown locally in Meishan was used as the test subject;

[0086] Figure 1 This is a comparison chart of the effects of the soil conditioner described in Example 1 of the present invention and Comparative Examples 1-2 on plant stems and leaves. Figure 2 This is a comparison diagram of the effects of the soil conditioner described in Example 1 of the present invention and Comparative Examples 1-2 on plant roots, wherein 1 is spinach treated with Comparative Example 2, 2 is spinach treated with Comparative Example 1, and 3 is spinach treated with Example 1. As shown in the figure, it can be clearly seen that the soil conditioner described in Example 1 has a significant promoting effect on the root length and stem and leaf growth of spinach;

[0087] Figure 3 The results of the soil conditioner prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on stems and leaves are shown in FIG. Figure 4The soil conditioner prepared by Examples 1-3 of the present invention and Comparative Examples 1-2 has an effect on the root system. As shown in the figure, the soil conditioner prepared by Examples 1-3 can significantly improve the growth ability of the stems, leaves and roots of spinach. Compared with Comparative Example 2, the organic matter @attapulgite can continuously provide humic acid organic matter in the soil, thereby improving the fertility of the soil and thus improving the growth ability of spinach. Compared with the comparative example, the soil conditioner prepared by the present invention can significantly increase the soil's need for water. When there is too much water, it can increase the water absorption capacity to avoid flooding the seedlings. When the water content is low, it can provide a moist soil environment to avoid water shortage in the spinach seedlings.

[0088] Experimental Example 2

[0089] In this experimental example, the soil conditioner prepared in Example 1-3 and Comparative Example 1-2 was subjected to a soil cultivation test, using a potted plant simulation method. Specifically, 500 g of air-dried sandy soil was taken, and the soil conditioner was added to the air-dried sandy soil at an addition amount of 2 wt %. The blank group was set without adding the soil conditioner. After 30 days of cultivation, the maximum saturated water holding capacity of the soil and the daily cumulative water loss of the soil were measured.

[0090] Figure 5 The saturated water holding capacity result diagram of the soil conditioner prepared by Examples 1-3 and Comparative Examples 1-2 of the present invention is shown in the figure. As shown in the figure, the soil conditioner prepared by Examples 1-3 can increase the saturated water holding capacity of air-dried sandy soil and improve the soil moisture condition. Figure 6 The cumulative moisture evaporation rate result graph of the soil conditioner prepared by Examples 1-3 of the present invention and Comparative Examples 1-2 shows that the moisture evaporation of the soil improved by the soil conditioner prepared by Examples 1-3 of the present invention is slow in the initial and final stages, while the moisture evaporates rapidly in the middle stage; compared with Comparative Example 1, the moisture in the treatment group has an obvious evaporation phenomenon in the early stage, and the speed tends to decrease in the later stage. Due to the hydrophilic effect of cellulose, it can absorb more free water, but the free water is easy to dissipate, resulting in rapid evaporation of moisture; while the evaporation rate of the soil treated with the soil conditioner prepared by Comparative Example 2 is slow in the early stage, while the moisture evaporates rapidly after the middle stage, which may be because the soil cellulose contains modified attapulgite, and the loaded organic matter can increase the soil's ability to retain moisture. After the organic matter diffuses into the soil, the porous structure in the modified attapulgite is conducive to moisture retention.

[0091] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

[0092] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A high-moisture nano-type soil conditioner, characterized in that: The soil conditioner comprises the following components in parts by weight: 50-60 parts of urea, 40-50 parts of potassium dihydrogen phosphate, 10-15 parts of potassium nitrate, 0.2-0.3 parts of anhydrous magnesium sulfate, 0.1-0.2 parts of zinc sulfate, 4-6 parts of composite nano-type water-retaining agent, and 1-2 parts of organic matter@modified attapulgite; The preparation method of the organic matter@modified attapulgite specifically comprises the following steps: K1. Add attapulgite to a NaOH aqueous solution, raise the temperature to 70-80° C., stir and react at 180-220 rpm, react for 1-2 hours, filter, wash with deionized water until neutral, and dry in an oven to obtain pretreated attapulgite; K2, adding the pretreated attapulgite prepared in step K1 to the iron source solution, placing it under sealing conditions, stirring at a speed of 150-180 rpm for 30-50 min, raising the temperature to 60-80° C., stirring continuously for 2-3 h, washing with deionized water and anhydrous ethanol, placing it in an oven at 100-120° C. and drying it for 6-8 h to obtain Fe-modified attapulgite; K3, dissolving humic acid in deionized water, adjusting the pH to 8-9, adding to the Fe-modified attapulgite prepared in step K2, placing at 40-50°C, stirring at 400-500 rpm, reacting for 8-12 hours, filtering, collecting the solid, washing with deionized water, placing in an oven at 40-50°C and drying to constant weight, to obtain organic matter@modified attapulgite; The preparation method of the composite nano water-retaining agent specifically comprises the following steps: S1, dissolving cellulose in 1-butyl-3-methylimidazolium chloride ionic liquid, adding 2-bromopropionyl bromide, raising the temperature to 70-80°C, reflux reaction for 24-48h, adding deionized water for precipitation treatment, filtering, collecting the precipitate, washing with deionized water, and drying at 60°C to obtain activated cellulose; S2. Dissolve the activated fiber prepared in step S1 in DMSO, raise the temperature to 50-60°C, stir at 180-220rpm until the activated cellulose is dissolved, add polyvinyl alcohol, maintain the reaction temperature at 40-50°C, stir at 220-250rpm for 12-16h, and freeze-dry to obtain a composite nano-type water-retaining agent.

2. A high-moisture nano-type soil conditioner according to claim 1, characterized in that: In step K1, the material-liquid ratio (g / mL) between the attapulgite and the NaOH aqueous solution is 0.04-0.06 g / mL; the content of NaOH in the NaOH aqueous solution is 0.1-1 mol / L.

3. A high-moisture nano-type soil conditioner according to claim 2, characterized in that: In step K2, the solid-liquid ratio (g / mL) of the pretreated attapulgite in the iron source solution is 0.07-0.09 g / mL.

4. A high-moisture content nano-type soil conditioner according to claim 3, characterized in that: In step K2, the iron source solution includes at least one of ferric sulfate solution, ferric nitrate solution and ferric chloride solution, and the mass concentration of Fe3+ in the iron source solution is 1-5 g / L.

5. The high-moisture content nano-type soil conditioner according to claim 4, characterized in that: In step K3, the mass concentration of the humic acid in deionized water is 10-20 g / L; the mass ratio of the humic acid to the Fe-modified attapulgite is 3-5:5-7.

6. The high-moisture nano-type soil conditioner according to claim 5, characterized in that: In step S1, the mass concentration of the plant cellulose in the 1-butyl-3-methylimidazolium chloride ionic liquid is 0.02-0.04 g / mL; in step S1, the mass ratio between the 2-bromopropionyl bromide and the cellulose is 10-15:

1.

7. The high-moisture nano-type soil conditioner according to claim 6, characterized in that: In step S2, the mass concentration of the activated cellulose in DMSO is 50-60 g / L; the mass ratio of the activated cellulose to polyvinyl alcohol is 1:2-3.

8. A method for preparing the high-moisture content nano-type soil conditioner according to claim 7, characterized in that: The specific steps include: ① Dissolve the composite nano water retaining agent in an ethanol solution, add organic matter @ modified attapulgite, stir and react at a speed of 300-400 rpm at room temperature for 18-24 hours, remove the organic solvent by vacuum distillation, wash with deionized water, and dry to obtain a mixture; ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate and zinc sulfate in deionized water and keep the temperature at 30-40°C. Stir at a speed of 1000-1200 pm until the solution is uniform. Add the mixture prepared in step ①, continue stirring and mixing for 20-30 minutes, dry and crush to obtain a soil conditioner for later use.

9. The method for preparing the high-moisture content nano-type soil conditioner according to claim 8, characterized in that: In step ①, the mass concentration of the composite nano water-retaining agent in the ethanol solution is 10-20 g / L.

Images