Seepage-proofing, water-locking and fertilizer-retaining sand soil conditioner and preparation method thereof

Abstract

The invention discloses an anti-seepage, water-locking and fertilizer-retaining sandy land soil conditioner, and relates to the technical field of sandy land soil improvement, the anti-seepage, water-locking and fertilizer-retaining sandy land soil conditioner comprises the following raw materials by mass: 50-60% of decomposed cow dung; 15 to 20% of modified straw fiber; 12 to 15% of a sodium carboxymethyl cellulose solution with a concentration of 0.1%; 3 to 5% of bentonite; 1-2% of a microbial agent; 0-15% of a slow-release compound fertilizer; 0.5-1% of polyglutamic acid; and 0.5-1% of a stone-chitosan coating agent. The invention also discloses a preparation method of the anti-seepage, water-locking and fertilizer-retaining sand soil conditioner. The preparation method comprises the following steps: step 1, straw modification; step 2, cow dung decomposition; step 3, preparing a colloidal solution; step 4, mixing and granulating; step 5, coating treatment; and step 6, post-processing. By adopting agricultural wastes as main raw materials, resource utilization of the wastes is realized, and a biodegradable material is introduced to replace synthetic resin, so that the degradation period is shortened to 18-24 months.

Description

Technical Field

[0001] The present invention relates to the technical field of sandy soil improvement, and specifically to a sandy soil conditioner for preventing seepage, locking water and retaining fertilizer and a preparation method thereof. Background Art

[0002] The core contradiction of ecological degradation in arid and semi-arid regions lies in "three lows and three harms":

[0003] The low soil water retention rate (<15%) results in a plant survival rate <30%;

[0004] The low organic matter content (<0.8%) leads to insufficient available nutrients;

[0005] The low wind erosion resistance (critical wind speed <8 m / s) results in an annual wind erosion amount >500 t / km 2 ;

[0006] Drought stress, nutrient loss, and wind erosion hazards are superimposed on each other, forming a vicious cycle of ecological restoration.

[0007] The invention with the publication number CN109628096A discloses a sandy soil conditioner for preventing seepage, locking water and retaining fertilizer and its application, which is composed of the following raw materials in parts by weight: 25-30 parts of sesbania powder, 30-35 parts of water-absorbing resin, 45-50 parts of humic acid, and 1 part of microbial inoculum.

[0008] As shown in the above invention, the water-retaining and fertilizer-retaining agent prepared from the existing soil conditioner, when applied at 20-50 kg per mu, can increase the crop yield by 5-6 times, save 50-60% of water per mu, and increase the soil fertility by 20-30%. In arid areas, it can effectively lock natural precipitation, improve the soil flora, and increase the soil fertility. However, the water-absorbing resin is a non-degradable material of polyacrylamide type, which poses an environmental risk. Sesbania powder needs to be specially planted, which conflicts with the scarce land resources in arid areas. Moreover, the process technology is extensive, and SEM shows that the functional component aggregates >200 μm and the interfacial binding force is weak. Summary of the Invention

[0009] Aiming at the deficiencies of the prior art, the present invention provides a sandy soil conditioner for preventing seepage, locking water and retaining fertilizer and a preparation method thereof, which solves the existing problems.

[0010] To achieve the above objectives, the present invention is realized through the following technical solutions: A sandy soil conditioner for preventing seepage, locking water and retaining fertilizer, which is composed of the following raw materials in mass percentages:

[0011] Rotten cow dung: 50-60%;

[0012] Modified straw fiber: 15-20%;

[0013] Sodium carboxymethyl cellulose (CMC) solution of 0.1%: 12 - 15%;

[0014] Bentonite: 3 - 5%;

[0015] Microbial inoculant: 1 - 2%;

[0016] Slow - release compound fertilizer: 0 - 15%;

[0017] Polyglutamic acid: 0.5 - 1%;

[0018] Paraffin - chitosan coating agent: 0.5 - 1%.

[0019] Preferably, the well - rotted cow dung is made by high - temperature aerobic fermentation at 55 - 65°C for 7 days, containing 22.3% humic acid, 1.8% total nitrogen, and effective viable count > 1×10 8 CFU / g; the modified straw fiber is made by steam explosion of rice straw treated with 1.2 MPa steam for 30 seconds, with the specific surface area increased by 3 times and the water - holding rate increased by 40%.

[0020] Preferably, the microbial inoculant is a compound agent of Bacillus subtilis (1×10 9 CFU / g) and arbuscular mycorrhizal fungi (AMF); in the slow - release compound fertilizer, the ratio of N - P 2 O 5 -K 2 O is 15 - 10 - 10, and 0.5% urease inhibitor hydroquinone is added; the molecular weight of the polyglutamic acid is 50000 - 100000, which is used to chelate medium and trace elements.

[0021] Preferably, in the paraffin - chitosan coating agent, the particle size of the paraffin emulsion < 1μm, the solid content is 30%, the deacetylation degree of chitosan > 90%, the molecular weight is 50000, and the two are mixed at a ratio of 1:1, and the addition amount is 0.5% of the particle mass.

[0022] The present invention also discloses a preparation method of a sandy soil conditioner for preventing seepage, locking water and retaining fertilizer, comprising the following steps:

[0023] Step 1. Straw modification: Straw filaments of 1 - 3 cm are mixed with 2% NaOH solution at a ratio of 1:5, stirred at 50°C for 2 hours, subjected to steam explosion at 1.2 MPa for 3 minutes of pressure holding, and dried to a moisture content < 10%;

[0024] Step 2. Cow dung composting: Fresh cow dung is mixed with straw powder at a C / N ratio of 25:1, 0.2% EM microbial inoculant is added, the stack height is 1.2 m, the stack is turned over every day for the first 10 days and every 3 days for the next 20 days, and composted until C / N < 20 and the seed germination index > 80%;

[0025] Step 3. Preparation of colloidal solution: Dissolve CMC into a 0.1% solution by stirring at 300 rpm in a 40°C water bath for 2 hours, and mix bentonite with the solution at a ratio of 1:10 and disperse ultrasonically for 30 minutes;

[0026] Step 4. Mixing and granulation: First, mix cow dung, straw fiber, and bentonite colloid in a twin-shaft mixer for 15 minutes, then add microbial inoculum and polyglutamic acid and mix for 10 minutes. Control the moisture content at 40% by atomizing water spray (0.3 MPa) with a disk granulator (tilt angle 45°, rotation speed 20 rpm), and classify with a 10-16 mesh sieve;

[0027] Step 5. Coating treatment: Mix paraffin emulsion and chitosan at a ratio of 1:1, and coat in a fluidized bed (inlet air temperature 50°C, air volume 800 m 3 / h) for 15 minutes;

[0028] Step 6. Post-treatment: Dry in a forced-air dryer at 40°C until the moisture content < 12%, and package with a PE film-lined woven bag.

[0029] Preferably, the straw is screened to remove impurities before modification, and 0.1-0.3% of fermentation promoter can be added to the cow dung during composting to accelerate the process.

[0030] Preferably, the ultrasonic dispersion power of the colloidal solution is 200-300 W, and the rotation speed of the stirring blades of the twin-shaft mixer is 150-200 rpm.

[0031] According to different scenarios:

[0032] Treatment of mobile sand dunes: Application rate 800-1000 kg / mu, surface coverage, particle size 8-12 mm;

[0033] Improvement of dry cropland: Application rate 500-700 kg / mu, application depth 10-15 cm, particle size 5-8 mm;

[0034] Vegetation restoration project: Application rate 600-800 kg / mu, mix with seeds at a ratio of 10:1 for sowing, particle size 10-15 mm.

[0035] The present invention provides an anti-seepage, water-locking and fertilizer-preserving sandy soil conditioner and its preparation method. Compared with the prior art, it has the following beneficial effects:

[0036] 1. The anti-seepage, water-locking and fertilizer-preserving sandy soil conditioner and its preparation method adopt agricultural waste (composted cow dung, modified straw fiber) as the main raw material, with a proportion > 75%, realizing the resource utilization of waste. Introduce biodegradable materials (CMC, chitosan) to replace synthetic resins, shorten the degradation period to 18-24 months, and the microbial inoculum and organic matter ferment synergistically, reducing the chemical fertilizer usage by 30% and reducing the risk of non-point source pollution.

[0037] 2. The anti-seepage, water-locking and fertilizer-preserving sandy soil conditioner and its preparation method. Through straw fiber (water holding rate 120%) + cow dung humic acid (water holding rate 300%) + CMC-bentonite colloid (water holding rate 500%), the saturated water absorption rate reaches 450%. The humic acid-polyglutamic acid chelation system adopted reduces the nitrogen leaching rate by 82% and extends the slow-release fertilizer efficiency period to 90 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the 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 the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Refer to Figure 1 , the present invention provides the following multiple technical solutions:

[0041] The first embodiment: Special conditioner for ecological restoration (Type H1)

[0042] 1. Material ratio (mass percentage)

[0043] Fully decomposed cow dung: 60%;

[0044] Modified rice straw fiber: 18%;

[0045] 0.1% CMC solution: 15%;

[0046] Bentonite: 4%;

[0047] Microbial inoculant (Bacillus subtilis + AMF): 1.5%;

[0048] Polyglutamic acid: 0.8%;

[0049] Paraffin-chitosan coating agent: 0.7%.

[0050] 2. Preparation steps

[0051] Straw modification:

[0052] 1-3 cm rice straw filaments are mixed with 2% NaOH solution at a ratio of 1:5, stirred at 50°C for 2 hours, treated with steam explosion at 1.2 MPa for 3 minutes, and dried to a moisture content of 8%.

[0053] Cow dung composting:

[0054] Fresh cow dung + straw powder (C / N = 25:1) + 0.2% EM bacterial agent, stacked to a height of 1.2 m, turned over daily for the first 10 days and every 3 days for the next 20 days. End point of composting: C / N = 18, seed germination index 85%.

[0055] Preparation of colloidal solution:

[0056] Dissolve CMC in a 40°C water bath (stirring at 300 rpm for 2 hours), mix bentonite with the CMC solution at a ratio of 1:10, and disperse ultrasonically at 250 W for 30 minutes.

[0057] Mixing and granulation:

[0058] Mix cow dung, straw fiber, and bentonite colloid in a twin - shaft mixer at 180 rpm for 15 minutes, add microbial bacterial agent and polyglutamic acid, mix at 150 rpm for 10 minutes, atomize and spray water (0.3 MPa) for granulation using a disk granulator (tilt angle 45°, rotation speed 20 rpm), and classify through a 10 - 16 mesh sieve. Particle diameter: 8 - 12 mm.

[0059] Coating treatment:

[0060] Mix paraffin emulsion and chitosan at a ratio of 1:1, and coat in a fluidized bed (50°C, 800 m 3 / h) for 15 minutes.

[0061] Post - treatment:

[0062] Dry in a forced - air dryer at 40°C until the moisture content reaches 10%, and package in a PE - lined woven bag.

[0063] 3. Application method

[0064] Treatment of mobile sand dunes: Cover the surface at 800 kg / mu.

[0065] Supporting measures: Use in combination with straw checkerboards and plant Caragana korshinskii.

[0066] The second implementation method: Dry - farming agricultural improver (Type H2)

[0067] 1. Material ratio (mass percentage)

[0068] Composted cow dung: 50%;

[0069] Modified straw fiber: 15%;

[0070] 0.1% CMC solution: 12%;

[0071] Bentonite: 5%;

[0072] Microbial bacterial agent: 2%;

[0073] Slow - release compound fertilizer (15 - 10 - 10): 15%;

[0074] Polyglutamic acid: 0.5%;

[0075] Paraffin-chitosan coating agent: 0.5%.

[0076] 2. Preparation method

[0077] Same as Example 1, with the addition of: synchronous mixing of slow-release compound fertilizer and raw materials.

[0078] 3. Application method

[0079] Maize planting: 600 kg / mu, plowed into the soil to a depth of 10 cm.

[0080] Supporting measures: Drip irrigation system, with the irrigation amount reduced by 40%.

[0081] The third implementation method: Special soil conditioner for vegetation restoration 1. Material ratio (mass percentage)

[0082] Decomposed cow dung: 60%;

[0083] Modified straw fiber: 20%;

[0084] 0.1% CMC solution: 15%;

[0085] Bentonite: 3%;

[0086] Microbial inoculant: 1%;

[0087] Polyglutamic acid: 1%;

[0088] Paraffin-chitosan coating agent: 0% (no coating).

[0089] 2. Preparation method

[0090] Same as Example 1, cancel the coating step

[0091] 3. Application method

[0092] Seabuckthorn sowing: 700 kg / mu mixed with seeds at a ratio of 10:1.

[0093] Sowing depth: 5 cm, row spacing 50 cm.

[0094] The fourth implementation method: Comparative example 1: Traditional plastic film mulching

[0095] 1. Material composition

[0096] Polyethylene plastic film (thickness 0.01 mm).

[0097] 2. Application method

[0098] Cover the ground surface and fix the edges with soil pressure.

[0099] Dosage: 8 kg / mu.

[0100] The Fifth Embodiment: Comparative Example 2: Single Organic Fertilizer Covering 1. Material Composition

[0101] Unrotted cow dung: 70%;

[0102] Common straw powder: 30%.

[0103] 2. Preparation Method

[0104] Simple mixing and natural air drying.

[0105] 3. Application Method

[0106] Surface covering at 500 kg / mu.

[0107] Comparison of Implementation Effects

[0108]

[0109] Verification of Key Technical Parameters

[0110] 1. Water Retention Performance

[0111] Example 1: Saturated water absorption rate 380%, evaporation rate 0.35 g / cm 2 ·h. Comparative Example 1: Saturated water absorption rate 220%, evaporation rate 0.65 g / cm 2 ·h.

[0112] 2. Nutrient Retention

[0113] Example 2: NH 4 + Adsorption capacity 350 mg / g, effective phosphorus release period 60 days.

[0114] Comparative Example 2: NH 4 + Adsorption capacity 80 mg / g, effective phosphorus release period 15 days.

[0115] Implementation Cases

[0116] Case 1: Kubuqi Desert in Inner Mongolia

[0117] Applying 800 kg / mu of the modifier in Example 1.

[0118] Combined with straw checkerboard, the vegetation coverage rate increased from 5% to 32% (after 1 year).

[0119] Soil organic matter increased from 0.6% to 1.2%.

[0120] Case 2: Dry Farming Farmland in Ningxia

[0121] Applying 600 kg / mu of the modifier in Example 2 + drip irrigation.

[0122] The corn yield is 780 kg per mu, with an 85% increase compared to the control.

[0123] The irrigation water volume is reduced by 40%.

[0124] Case 3: Vegetation reconstruction in Gansu

[0125] In Example 3, 700 kg per mu of the modifier is mixed and sown with seabuckthorn seeds.

[0126] The emergence rate is increased from 15% to 62%.

[0127] A stable shrub community is formed after 3 years.

[0128] Through the above examples and comparative verification, the sandy soil modifier of the present invention is significantly superior to traditional materials in key properties such as water retention, fertilizer retention, and wind erosion resistance, and has good ecological and economic benefits.

[0129] At the same time, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited, and conventional equipment can be used.

[0130] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0131] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sandy soil conditioner with anti-seepage, water-locking and fertilizer-retaining properties, characterized in that: It is composed of the following raw materials in percentage by weight: Composted cow dung: 50-60%; Modified straw fiber: 15-20%; 0.1% sodium carboxymethylcellulose (CMC) solution: 12-15%; Bentonite: 3-5%; Microbial agents: 1-2%; Slow-release compound fertilizer: 0-15%; Polyglutamic acid: 0.5-1%; Stone-chitosan coating agent: 0.5-1%.

2. The anti-seepage, water-locking, fertilizer-retaining sandy soil conditioner according to claim 1, characterized in that: The decomposed cow dung is prepared by aerobic fermentation at 55-65°C for 7 days, and contains 22.3% humic acid, 1.8% total nitrogen, and an effective live bacterial count of more than 1×10 8 CFU / g; the modified straw fiber is made by steam explosion of rice straw treated with 1.2MPa steam for 30 seconds, with the specific surface area increased by 3 times and the water holding rate increased by 40%.

3. The anti-seepage, water-locking, fertilizer-retaining sandy soil conditioner according to claim 1, characterized in that: The microbial agent is a compound of Bacillus subtilis and arbuscular mycorrhizal fungi; the ratio of N-P2O5-K2O in the slow-release compound fertilizer is 15-10-10, and 0.5% of urease inhibitor hydroquinone is added; the molecular weight of the polyglutamic acid is 50000-100000, and it is used for chelating trace elements.

4. The anti-seepage, water-locking, fertilizer-retaining sandy soil conditioner according to claim 1, characterized in that: In the paraffin-chitosan coating agent, the paraffin emulsion particle size is less than 1 μm, the solid content is 30%, the chitosan deacetylation degree is greater than 90%, the molecular weight is 50000, the two are mixed in a ratio of 1:1, and the addition amount is 0.5% of the particle mass.

5. A method for preparing an anti-seepage, water-locking, and fertilizer-retaining sandy soil conditioner, based on the anti-seepage, water-locking, and fertilizer-retaining sandy soil conditioner according to claims 1-4, characterized in that: The following steps are involved: Step 1: Straw modification: 1-3 cm straw filaments were mixed with 2% NaOH solution at a ratio of 1:5, stirred at 50°C for 2 hours, steam exploded at 1.2 MPa for 3 minutes, and dried to a moisture content of <10%; Step 2: Cow dung composting: fresh cow dung and straw powder are mixed at a C / N ratio of 25:1, 0.2% EM inoculant is added, the pile is piled to a height of 1.2m, and the pile is turned every day for the first 10 days and every 3 days for the next 20 days until the C / N ratio is less than 20 and the seed germination index is greater than 80%; Step 3, preparation of colloidal solution: dissolve CMC into 0.1% solution in a 40°C water bath at 300 rpm for 2 hours, mix bentonite and solution at a ratio of 1:10 and disperse by ultrasonic for 30 minutes; Step 4, mixing and granulation: a double-shaft mixer is used to mix cow dung, straw fiber and bentonite colloid for 15 minutes, and then microbial agents and polyglutamic acid are added and mixed for 10 minutes. A disc granulator is used to spray water to control the moisture content to 40%, and a 10-16 mesh screen is used for grading. Step 5: Coating treatment: paraffin wax emulsion and chitosan were mixed in a ratio of 1:1 and the fluidized bed (inlet air temperature 50°C, air volume 800m 3 / h) Encapsulation for 15 minutes; Step 6. Post-processing: Dry with forced air at 40℃ until the moisture content is less than 12%, and pack in woven bags lined with PE film.

6. The method for preparing a seepage-proof, water-locking, and fertilizer-retaining sandy soil conditioner according to claim 5, characterized in that: Before the straw is modified, impurities are first removed by screening, and 0.1-0.3% fermentation promoter is added to the cow dung to speed up the process.

7. The method for preparing a seepage-proof, water-locking, and fertilizer-retaining sandy soil conditioner according to claim 5, characterized in that: The ultrasonic dispersion power of the colloidal solution is 200-300W, and the rotation speed of the stirring blades of the double-shaft stirrer is 150-200rpm.

8. The method for preparing a seepage-proof, water-locking, and fertilizer-retaining sandy soil conditioner according to claim 5, characterized in that: According to different scenarios: Shifting sand treatment: application amount 800-1000kg / mu, surface coverage, particle size 8-12mm; Improvement of dryland farmland: application amount 500-700kg / mu, application depth 10-15cm, particle size 5-8mm; Vegetation reconstruction project: application amount 600-800kg / mu, mixed with seeds at a ratio of 10:1, particle size 10-15mm.

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