A high-moisture nano soil conditioner and its preparation method

Abstract

The present invention discloses a high-moisture nano-type soil conditioner in the field of fertilizers and its preparation method, which comprises the following components in parts by weight: The soil conditioner comprises the following components in parts by weight: urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate, zinc sulfate, composite nano-type water retainer, organic matter@modified attapulgite. By adding organic matter@modified attapulgite and composite nano-type water retainer to the soil conditioner, the present invention improves the water storage capacity of the soil. The organic matter provides a good soil structure foundation, promoting the adsorption and penetration of water; the modified attapulgite and the water retainer further enhance the soil's ability to absorb, store and release water; the modified attapulgite and the composite nano-type water retainer can form a water buffer reservoir in the soil, providing water under drought conditions and absorbing excess water under precipitation conditions, maintaining the appropriate water content of the soil and improving the soil moisture condition.

Description

Technical Field

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

[0002] With the intensification of agricultural and industrial activities, the problem of soil degradation has become increasingly serious and has become an important factor threatening food security and the ecological environment. Currently, 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 crop growth and the sustainable development of agricultural production. Soil conditioners include organic conditioners, inorganic conditioners, and composite conditioners, etc. 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, they have the following problems: long degradation period: the decomposition rate of natural organic matter in the soil is slow, and it is difficult to significantly improve the physical and chemical properties of the soil in the short term; heavy metal and pathogen pollution risks: some organic fertilizers of unknown origin may carry pathogens, heavy metals or antibiotic residues, posing potential threats to soil and crop safety; uneven effects: the nutrient composition of organic conditioners is single and cannot fully meet the diverse needs of the soil and crops. Inorganic conditioners (such as gypsum, attapulgite, silicate minerals, etc.) are usually used for saline-alkali soil improvement, heavy metal pollution remediation, and adjustment of soil pH value. Their improvement effects are relatively fast, but they also face many problems: it is difficult to have multiple functions: most inorganic conditioners are single components and usually can only solve specific problems, such as adjusting pH value or adsorbing specific heavy metals, and have limited effects on improving soil structure, nutrient retention, and microbial environment; poor environmental friendliness: some inorganic conditioners (such as acidic conditioners) may inhibit beneficial microorganisms in the soil, leading to the imbalance of the soil ecosystem; short action period: since inorganic conditioners are easily diluted by water or other soil components, their continuous effects in the soil are limited and need to be applied frequently. Composite soil conditioners usually combine organic and inorganic components to improve the physical, chemical, and biological properties of the soil at the same time. However, there are still some problems in the actual application of such conditioners: poor component stability: separation or incompatibility may occur between the organic and inorganic components during the compounding process, resulting in the actual effect of the conditioner not meeting expectations; high production cost: the preparation process of composite conditioners is relatively complex, resulting in high costs and difficult to be widely applied on a large scale; single function: existing composite conditioners mostly focus 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, to overcome the defects of the prior art, the present invention provides a high-moisture nano-type soil conditioner and its preparation method. By adding organic matter @ modified attapulgite and composite nano-type water retainers to the soil conditioner, the present invention improves the water storage capacity of the soil. The organic matter provides a good soil structure foundation, promoting the adsorption and penetration of water; the modified attapulgite and water retainers further enhance the soil's ability to absorb, store, and release water; the modified attapulgite and composite nano-type water retainers can form a water buffer reservoir in the soil, providing water under drought conditions and absorbing excess water under precipitation conditions, maintaining the appropriate water content of the soil, and improving the soil moisture condition.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides a high-moisture nano-type soil conditioner, and 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 part of anhydrous magnesium sulfate, 0.1-0.2 part of zinc sulfate, 10-15 parts of composite nano-type water retainer, and 8-12 parts of organic matter @ modified attapulgite;

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

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

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

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

[0009] K2. Add the pretreated attapulgite prepared in step K1 to an iron source solution, place it under sealed conditions, stir at a speed of 150-180 rpm for 30-50 min, raise the temperature to 60-80 °C, continue to stir for 2-3 h, then wash with deionized water and absolute ethanol, and place in an oven to dry at 100-120 °C for 6-8 h to obtain Fe-modified attapulgite;

[0010] Preferably, in step K2, the material-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 includes at least one of ferric sulfate solution, ferric nitrate solution, and ferric chloride solution, and the mass concentration of Fe 3+ in the iron source solution is 1-5 g / L;

[0012] K3. Dissolve humic acid in deionized water, adjust the pH to 8-9, add it to the Fe-modified attapulgite prepared in step K2, place it at 40-50 °C, stir at a speed of 400-500 rpm, after reacting for 8-12 h, filter, collect the solid, wash it with deionized water, and dry it in an oven at 40-50 °C to constant weight to obtain organic matter@modified attapulgite;

[0013] Preferably, in step K3, the mass concentration of the 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-type water retaining agent specifically includes the following steps:

[0016] S1. Dissolve cellulose in 1-butyl-3-methylimidazolium chloride ionic liquid, add 2-bromopropionyl bromide, raise the temperature to 70-80 °C, reflux for 24-48 h, then add deionized water for precipitation treatment, filter, after collecting the precipitate, wash it with deionized water, and dry it at 60 °C to obtain activated cellulose;

[0017] Preferably, in step S1, the mass concentration of the plant cellulose in 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. Dissolve the activated fiber prepared in step S1 in DMSO, raise the temperature to 50-60 °C, stir at 180-220 rpm until the activated cellulose is dissolved, add polyvinyl alcohol, keep the reaction temperature at 40-50 °C, stir and react at a speed of 220-250 rpm for 12-16 h, and freeze-dry to obtain the composite nano-type 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 preparation method of a high-moisture nano soil conditioner, which specifically includes the following steps:

[0023] ① Dissolve the composite nano water retaining agent in an ethanol solution, add organic matter @ modified attapulgite, and stir and react at a speed of 300 - 400 rpm under room temperature conditions for 18 - 24 h. Then, 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 to stir and mix for 20 - 30 min, then dry and crush to obtain the soil conditioner for standby.

[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 soil conditioner. By adding organic matter @ modified attapulgite and a composite nano water retaining agent to the soil conditioner, the present invention improves the water storage capacity of the soil. The organic matter provides a good soil structure 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 water retaining agent can form a water buffer reservoir in the soil, providing water under drought conditions and absorbing excess water under precipitation conditions to maintain the appropriate water content of the soil and improve the soil moisture condition. By modifying the attapulgite, the present invention first performs desilication treatment on the attapulgite to improve its reaction activity, and loads iron ions on the surface of the attapulgite, which can improve the loading amount and release effect of the organic matter through the complexation between iron ions and organic matter humic acid. By using cellulose as the main chain and grafting polyvinyl alcohol on the side chain for modification, the present invention can improve the water holding capacity and stability of the composite nano water retaining agent. Polyvinyl alcohol has a carbon long-chain structure and is relatively rigid, and it is itself insoluble in cold water and is not prone to structural disintegration during the process of absorbing water molecules. Cellulose has hydrophilicity and can improve the water holding capacity and 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 the attapulgite jointly reduce the evaporation and deep leakage of water, and it is especially suitable for use in dryland and desertified areas. It cooperates with the organic matter to improve the soil nutrient supply and root growth environment, and the attapulgite and the water retaining agent improve the soil's ability to retain water and nutrients, thereby greatly improving the water use efficiency of plants and thus improving the soil moisture condition. Description of the Drawings

[0028] Figure 1 This is a comparison chart of the effects of the soil improvers 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 improvers described in Example 1 of the present invention and Comparative Examples 1-2 on plant roots;

[0030] Figure 3 This is a chart of the results of the effects of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on stems and leaves;

[0031] Figure 4 This is a chart of the results of the effects of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on roots;

[0032] Figure 5 This is a chart of the saturated water holding capacity results of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention;

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

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

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

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

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

[0038] Example 1

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

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

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

[0042] K2. Prepare a 5g / mL ferric sulfate solution. Add 7g of the pretreated attapulgite prepared in step K1 to 100mL of the ferric sulfate solution. Place it under sealed conditions and stir at a speed of 150rpm for 30min. Raise the temperature to 80°C and continue to stir for 2h. Then wash with deionized water and anhydrous ethanol, and place it in an oven to dry at 120°C for 6h to obtain Fe-modified attapulgite;

[0043] K3. Take 2g of humic acid and dissolve it in 100mL of deionized water. Adjust the pH to 9, add it to 2g of the Fe-modified attapulgite prepared in step K2, place it at 50°C, and stir at a speed of 400rpm. After reacting for 12h, filter, collect the solid, wash with deionized water, and place it in an oven to dry at 50°C 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. Take 2g of cellulose and dissolve it in 100mL of 1-butyl-3-methylimidazolium chloride ionic liquid. Add 20g of 2-bromopropionyl bromide, raise the temperature to 70°C, and reflux and react for 48h. Then add deionized water for precipitation treatment. Filter, collect the precipitate, wash with deionized water, and place it in an oven to dry at 60°C to obtain activated cellulose;

[0046] S2. Take 1g of the activated fiber prepared in step S1 and dissolve it in 20mL of DMSO. Raise the temperature to 50°C and stir at 180rpm until the activated cellulose dissolves. Add 3g of polyvinyl alcohol, keep the reaction temperature at 50°C, and stir and react at a speed of 250rpm for 12h. After freeze-drying, obtain the composite nano water-retaining agent;

[0047] This embodiment also provides a preparation method of the high-moisture nano soil conditioner, which specifically comprises the following steps:

[0048] ① Dissolve 1 g of the composite nano - type water - retaining agent in 100 mL of 75 vol% ethanol solution. Add 1.2 g of organic matter @ modified attapulgite, and stir - react at a speed of 400 rpm under room - temperature conditions for 24 h. Then, remove the organic solvent by reduced - pressure distillation, wash with deionized water, and dry to obtain a mixed material.

[0049] ② Place urea, potassium dihydrogen phosphate, potassium nitrate, anhydrous magnesium sulfate, and zinc sulfate in deionized water, keep the temperature at 30 °C, stir at a speed of 1000 pm until the solution is uniform. Add the mixed material prepared in step ①, continue to stir and mix for 30 min, then dry and crush to obtain a soil conditioner for standby.

[0050] Example 2

[0051] This example provides a high - moisture nano - type soil conditioner, which includes the following components in parts by weight: 60 parts of urea, 40 parts of potassium dihydrogen phosphate, 10 parts of potassium nitrate, 0.3 part of anhydrous magnesium sulfate, 0.2 part 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 the organic matter @ modified attapulgite specifically includes 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 the NaOH aqueous solution. Raise the temperature to 70 °C, stir - react at 1800 rpm. After reacting for 1 h, filter, wash with deionized water until neutral, and then place it in an oven to dry to obtain pretreated attapulgite.

[0054] K2. Prepare a 3 g / mL ferric sulfate solution. Add 8 g of the pretreated attapulgite prepared in step K1 to 100 mL of the ferric sulfate solution, place it under sealed conditions, stir at a speed of 180 rpm for 50 min, raise the temperature to 60 °C, continue to stir for 3 h, then wash with deionized water and anhydrous ethanol, and place it in an oven to dry at 100 °C for 8 h 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 1.5 g of the Fe - modified attapulgite prepared in step K2, place it at 40 °C, stir at a speed of 500 rpm, react for 8 h, filter, collect the solid, wash with deionized water, and place it in an oven to dry at 40 °C to constant weight to obtain organic matter @ modified attapulgite.

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

[0057] S1. Dissolve 4 g of cellulose in 100 mL of 1-butyl-3-methylimidazolium chloride ionic liquid, add 60 g of 2-bromopropionyl bromide, raise the temperature to 70 °C, reflux for 36 h, then add deionized water for precipitation treatment. After filtration, collect the precipitate, wash it with deionized water, and dry it at 60 °C to obtain activated cellulose;

[0058] S2. Dissolve 1.2 g of the activated fiber prepared in step S1 in 20 mL of DMSO, raise the temperature to 50 °C, stir at 200 rpm until the activated cellulose dissolves, add 3 g of polyvinyl alcohol, keep the reaction temperature at 50 °C, stir and react at a speed of 240 rpm for 14 h, and then freeze-dry to obtain a composite nano-type water-retaining agent;

[0059] This example also provides a preparation method of a high-entropy nano-type soil conditioner, which specifically includes the following steps:

[0060] ① Dissolve 1.5 g of the composite nano-type water-retaining agent in 100 mL of 75 vol% ethanol solution, add 1.0 g of organic matter@modified attapulgite, stir and react at a speed of 300 rpm at room temperature for 20 h, then 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, continue to stir and mix for 20 min, then dry and crush to obtain a soil conditioner for standby.

[0062] Example 3

[0063] This example provides a high-entropy nano-type soil conditioner, which includes the following components in parts by weight: 55 parts of urea, 45 parts of potassium dihydrogen phosphate, 12 parts of potassium nitrate, 0.2 part of anhydrous magnesium sulfate, 0.2 part 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 includes the following steps:

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

[0066] K2. Prepare a ferric sulfate solution with a concentration of 1 g / mL. Add 9 g of the pretreated attapulgite prepared in step K1 to 100 mL of the ferric sulfate solution, place it under sealed conditions, stir at a speed of 180 rpm for 40 min, raise the temperature to 70 °C, continue stirring for 3 h, wash with deionized water and absolute ethanol, and dry in an oven at 120 °C for 6 h 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 7 g of the Fe-modified attapulgite prepared in step K2, place it at 50 °C, stir at a speed of 500 rpm, after reacting 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] A preparation method of a composite nano-type water retaining agent specifically includes the following steps:

[0069] S1. Dissolve 3 g of cellulose in 100 mL of 1-butyl-3-methylimidazolium chloride ionic liquid, add 36 g of 2-bromopropionyl bromide, raise the temperature to 80 °C, reflux and react for 24 h, then add deionized water for precipitation treatment, filter, collect the precipitate, wash with deionized water, and dry at 60 °C to obtain activated cellulose;

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

[0071] This example also provides a preparation method of a high-entropy nano-type soil conditioner, specifically including the following steps:

[0072] ① Dissolve 1.2 g of the composite nano-type water retaining agent in 60 mL of 75 vol% ethanol solution, add 0.8 g of organic matter@modified attapulgite, stir and react at a speed of 350 rpm at room temperature for 24 h, then 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, continue to stir and mix for 20 min, then dry and crush to obtain a soil conditioner for standby.

[0074] Comparative Example 1

[0075] This comparative example provides a soil conditioner and its preparation method. The difference from Example 1 is only that the composite nano-type water retaining agent is replaced with cellulose of the same mass fraction, and the other components and their content are the same as those in Example 1.

[0076] Comparative Example 2

[0077] This comparative example provides a soil conditioner and its preparation method. The difference from Example 1 is only that the organic matter@modified attapulgite is replaced with humic acid + attapulgite of the same weight fraction, and the mass ratio between the humic acid and the attapulgite is 1:2, and the other components and their content are the same as those in Example 1.

[0078] Experimental Example 1

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

[0080] Climate of the test field:

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

[0082] Test treatment:

[0083] On December 1, 2023 - December 18, 2023, the land was prepared, weeded, and plowed; on December 19, 2023, base fertilizer was applied to the test field; on December 20, 2023, sowing was carried out, and the harvest was on April 7, 2024:

[0084] 40 kg of 15-15-15 Kyle Supreme nitro-sulfur-based compound fertilizer + 80 kg of soil conditioner were applied per mu of land as base fertilizer;

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

[0086] Figure 1 This is the comparison chart of the influence of the soil conditioners described in Example 1 of the present invention and Comparative Examples 1-2 on the plant stems and leaves, Figure 2 This is the comparison chart of the influence of the soil conditioners described in Example 1 of the present invention and Comparative Examples 1-2 on the plant roots. Among them, 1 is the spinach treated with Comparative Example 2, 2 is the spinach treated with Comparative Example 1, and 3 is the spinach treated with Example 1. As shown in the figure, it can be clearly seen that the soil conditioner described in Example 1 has an obvious promoting effect on the root length and the growth of the stems and leaves of spinach;

[0087] Figure 3 This is the result chart of the influence of the soil conditioners prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on the stems and leaves; Figure 4This is the result graph of the influence of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention on the roots; as shown in the figure, the soil improvers prepared in Examples 1-3 can significantly improve the growth ability of the stems, leaves and roots of spinach. Compared with Comparative Example 2, since the organic matter@attapulgite can continuously provide humic acid organic matter in the soil, it can improve the soil fertility, thereby improving the growth ability of spinach; compared with the comparative examples, the soil improver prepared by the present invention can significantly increase the water requirement of the soil. When the water is excessive, it can improve the water absorption capacity to avoid waterlogging of seedlings. When the water content is low, it can provide a moist soil environment to avoid water shortage of spinach seedlings.

[0088] Experimental Example 2

[0089] In this experimental example, soil culture tests were carried out on the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2. The potting simulation method was used. For the specific test method, 500 g of air-dried desertified soil was taken, and the soil improver was added to the air-dried desertified soil at an addition amount of 2 wt%. The group without adding the soil improver was set as the blank group. After culturing for 30 days, the maximum saturated water holding capacity of the soil and the daily cumulative water loss of the soil were measured;

[0090] Figure 5 This is the result graph of the saturated water holding capacity of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention. As shown in the figure, the soil improvers prepared in Examples 1-3 can increase the saturated water holding capacity of the air-dried desertified soil, which has an improving effect on the soil moisture content. Figure 6 This is the result graph of the cumulative water evaporation rate of the soil improvers prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention. It can be seen that the soil improved by the soil improvers prepared in Examples 1-3 of the present invention has a slower water evaporation rate in the initial stage and the final stage, while there is a rapid water evaporation in the middle stage; compared with Comparative Example 1, the water in its treatment group has an obvious evaporation phenomenon in the initial stage, and the evaporation rate decreases in the later stage. Due to the hydrophilic effect of cellulose, it can adsorb more free water, but the free water is easily lost, resulting in rapid water evaporation; for the soil treated with the soil improver prepared in Comparative Example 2, the evaporation rate is slower in the initial stage, and the water evaporates rapidly after the middle stage. This may be because the soil cellulose contains modified attapulgite, and the loaded organic matter can increase the water holding performance of the soil. After the organic matter diffuses into the soil, the porous structure in the modified attapulgite is conducive to water retention.

[0091] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

[0092] The above description of the present invention and its implementation manners is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual applications are not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design in a non-creative way similar ways and embodiments to the technical solution, they shall fall within the protection scope of the present invention.

Claims

1. A high-moisture nano 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 part of anhydrous magnesium sulfate, 0.1-0.2 part of zinc sulfate, 4-6 parts of composite nano 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 into an aqueous NaOH solution, raise the temperature to 70-80 °C, stir and react at 180-220 rpm. After reacting for 1-2 h, filter, wash with deionized water until neutral, and then place in an oven to dry to obtain pretreated attapulgite; K2. Add the pretreated attapulgite prepared in step K1 into an iron source solution, place it under sealed conditions, stir at a speed of 150-180 rpm for 30-50 min, raise the temperature to 60-80 °C, continuously stir for 2-3 h, wash with deionized water and absolute ethanol, and place in an oven to dry at 100-120 °C for 6-8 h to obtain Fe-modified attapulgite; K3. Dissolve humic acid in deionized water, adjust the pH to 8-9, add it to the Fe-modified attapulgite prepared in step K2, place it at 40-50 °C, stir at a speed of 400-500 rpm, react for 8-12 h, filter, collect the solid, wash with deionized water, and place in an oven to dry at 40-50 °C 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. Dissolve cellulose in 1-butyl-3-methylimidazolium chloride ionic liquid, add 2-bromopropionyl bromide, raise the temperature to 70-80 °C, reflux and react for 24-48 h, then add deionized water for precipitation treatment, filter, collect the precipitate, wash with deionized water, and place in an oven to dry 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 180-220 rpm until the activated cellulose is dissolved, add polyvinyl alcohol, keep the reaction temperature at 40-50 °C, stir and react at a speed of 220-250 rpm for 12-16 h, and then freeze-dry to obtain the composite nano water retaining agent; The preparation method of the high-moisture nano soil conditioner specifically comprises the following steps: ① Dissolve the composite nano water retaining agent in an ethanol solution, add the organic matter@modified attapulgite, stir and react at a speed of 300-400 rpm at room temperature for 18-24 h, then distill off the organic solvent under reduced pressure, 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, 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 to stir and mix for 20-30 min, then dry and crush to obtain the soil conditioner for standby.

2. The high-entropy nano soil conditioner according to claim 1, wherein: In step K1, the material-liquid ratio between the attapulgite and the NaOH aqueous solution is 0.04 - 0.06 g / mL; in the NaOH aqueous solution, the content of NaOH is 0.1 - 1 mol / L.

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

4. The high-entropy nano 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 Fe 3+ in the iron source solution is 1-5 g / L.

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

6. The high-entropy nano soil conditioner according to claim 5, characterized in that: In step S1, the mass concentration of the cellulose in 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. A high-entropy nano 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 between the activated cellulose and the polyvinyl alcohol is 1:2 - 3.

8. The high-entropy nano soil conditioner according to claim 7, characterized in that: In step ①, the mass concentration of the composite nano-type water retaining agent in the ethanol solution is 10 - 20 g / L.

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