Acid soil conditioner based on calcium-magnesium multi-component complex and preparation method thereof

Abstract

The invention is suitable for the technical field of soil improvement, and provides an acid soil conditioner based on a calcium-magnesium multi-component complex and a preparation method thereof, the acid soil conditioner comprises the following raw materials by weight: 40-50 parts of dolomite powder, 10-20 parts of gypsum, 5-10 parts of a seaweed extract, 15-30 parts of a humic acid and fulvic acid compound, 3-10 parts of a tea polyphenol and beeswax compound, and 2-6 parts of saponin. A multi-component synergistic improvement system with dolomite powder-humic acid-seaweed extract as a core is provided, efficient ecological improvement of acid soil is achieved through a linkage mechanism of calcium and magnesium slow release, organic buffering, microbial activation and structure improvement, and an innovative solution is provided for agricultural sustainable development.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil improvement, and particularly relates to an acid soil improver based on a calcium-magnesium multi-element compound and a preparation method thereof. BACKGROUND

[0002] About 30% of the arable land in the world has different degrees of acidification problems, especially in the tropical and subtropical red soil regions and the farmland where chemical fertilizers have been used for a long time, the soil pH value can be reduced to below 4.5, resulting in the increased toxicity of heavy metals such as aluminum and manganese, the loss of medium elements such as calcium and magnesium, and the serious inhibition of the root development and nutrient absorption of crops. At present, acid soil improvement mainly relies on alkaline substances such as lime (CaO or Ca(OH)2) to neutralize the acidity, but lime dissolves too quickly, easily causing a sharp fluctuation of the soil pH value, which can be suddenly increased from 4.5 to above 7.0 in a short period of time, destroys the soil microbial community structure, and the pH value falls back after 1-2 years, so repeated application is needed, increasing the cost of cultivation.

[0003] The improvement of saline-alkali and acidification compound soil is more difficult, and such soil not only has a low pH value, but also has problems of sodium ion (Na + ) accumulation and magnesium (Mg 2+ ) deficiency. Although the traditional gypsum (CaSO4·2H2O) improver can replace Na + , it has weak neutralization ability to H + , and cannot supplement magnesium elements, and long-term use can lead to excessive sulfur, inhibiting the absorption of trace elements such as selenium and molybdenum by crops; in addition, the existing improvers mainly focus on chemical acid regulation, ignoring soil structure improvement and microbial activation, resulting in single and unsustainable improvement effect.

[0004] In addition to the deterioration of the physical and chemical properties of the soil, the acid environment also aggravates the activation of heavy metals (such as cadmium and lead). Some improvement technologies use synthetic chelating agents (such as EDTA) to passivate heavy metals, but such chemicals are easy to leach into groundwater and inhibit soil enzyme activity, which has the risk of secondary pollution; at the same time, the abundance of beneficial microorganisms such as actinomycetes and nitrogen-fixing bacteria in acidified soil is significantly reduced, further affecting nutrient cycling and crop stress resistance.

[0005] At present, acid soil improvement products are mainly divided into three categories: Chemical improvers (such as lime and steel slag): short-term effect is significant, but lacks long-term effect and destroys ecological balance; Organic improvers (such as humic acid): pH buffering capacity is limited and cannot solve the problem of magnesium deficiency; Microbial agents: ordinary strains are difficult to tolerate the acid environment, and the function is limited to promoting growth, and cannot simultaneously improve the soil structure.

[0006] The core defects of the prior art are: single function, only for pH adjustment or heavy metal passivation, ignoring soil aggregate structure reconstruction and microbial community recovery; ecological risk, synthetic chemicals or pH sharp fluctuations leading to biodiversity decline; insufficient response to saline-alkali-acidification complex problems, lack of multifunctional improver for simultaneously supplementing calcium and magnesium and regulating sodium ions.

[0007] Therefore, it is of great significance to develop an acid soil ecological improver based on natural minerals and bioactive ingredients, to realize rapid acid adjustment, long-term pH stabilization, heavy metal stabilization and ecological safety through the synergistic effect of slow-release calcium and magnesium, organic buffering, microbial activation and aggregate structure reconstruction, for the treatment of acidified soil and the sustainable development of agriculture. SUMMARY

[0008] The purpose of the embodiment of the present application is to provide an acid soil improver based on calcium-magnesium multi-element complex, aiming to solve the problems raised in the above background art.

[0009] The embodiment of the present application is implemented in this way, an acid soil improver based on calcium-magnesium multi-element complex, comprising the following raw materials by weight: dolomite powder 40-50 parts, gypsum 10-20 parts, seaweed extract 5-10 parts, humic acid and fulvic acid complex 15-30 parts, tea polyphenol and beeswax complex 3-10 parts, saponin 2-6 parts.

[0010] Another purpose of the embodiment of the present application is to provide a preparation method of an acid soil improver based on calcium-magnesium multi-element complex, comprising the following steps: crushing dolomite powder and gypsum, and then uniformly mixing with seaweed extract, humic acid and fulvic acid complex, tea polyphenol and beeswax complex, and saponin, granulating, and drying at low temperature to a water content of <5%.

[0011] Another purpose of the embodiment of the present application is to provide a use method of an acid soil improver based on calcium-magnesium multi-element complex, comprising the following steps: uniformly spreading the acid soil improver on the surface of the soil at a dosage of 1.0-2.0 tons / ha, and mixing it with the 0-20 cm soil layer.

[0012] The acid soil improver based on calcium-magnesium multi-element complex provided by the embodiment of the present application has the following beneficial effects: Fast and long-acting acid adjustment: dolomite powder slowly releases calcium and magnesium ions, combined with the pH buffering capacity of humic acid, avoiding the problem of pH sharp fluctuation of lime materials, and the effect can last for 2-3 years; Ecological safety: all-natural formula, no synthetic chemicals, seaweed extract activates indigenous microorganisms, avoiding the environmental risk of chelating agents such as EDTA; Multifunctional synergy: Chemical improvement: dolomite powder and gypsum cooperatively supplement calcium, magnesium and sulfur, neutralize acidity and improve salinization; Biological improvement: seaweed extract and humic acid improve microbial activity, and the abundance of nitrogen-fixing bacteria increases by more than 50%; Physical improvement: beeswax and saponin enhance soil aggregate structure, and the bulk density is reduced by 15%-20%.

[0013] Wide application: suitable for red soil, acidified black soil, mine reclamation and other scenes, the cost is more than 30% lower than that of chemical improver, and field tests show that soybean yield increases by 40% and rice root biomass increases by 35% after application.

[0014] In summary, the embodiment of the present application proposes a multi-component synergistic improvement system taking dolomite powder-humic acid-seaweed extract as the core, realizes efficient ecological improvement of acid soil through the linkage mechanism of calcium and magnesium slow release, organic buffer, microbial activation and structure improvement, and provides an innovative solution for sustainable agricultural development. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The morphology of the improver prepared in Example 1 of the present application is shown in Figure 2 The ICP test result of the improver prepared in Example 1 of the present application is shown in Figure 3 The apparent images of the soil with and without the use of the improver provided in Example 1 of the present application are shown in DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0017] The specific implementation of the present application is described in detail below in combination with specific examples.

[0018] Example 1, an acid soil improver based on calcium and magnesium multi-component complex, and its preparation method and application (red soil area rice field improvement in the south): Raw material ratio: dolomite powder 42 parts, gypsum 18 parts, seaweed extract 10 parts, humic acid and fulvic acid compound (fulvic acid accounts for 40%) 28 parts, tea polyphenol 4 parts, beeswax 3 parts, saponin 5 parts; Preparation method: the dolomite powder and gypsum are crushed to 100 mesh, and then mixed uniformly with the seaweed extract, humic acid, tea polyphenol, beeswax and saponin; molding is performed by using an extrusion granulator (particle size 3-5 mm), and low-temperature drying is performed at 55℃ until the water content is less than 5%, the morphology is as shown in Figure 1 , and the ICP test result is as shown in Figure 2As shown; Application method: 7 days before rice transplanting, evenly spread at a dosage of 2.0 tons / ha, and mix the modifier into 0-15 cm soil layer by rotary cultivator, and carry out normal irrigation management; The above rice field applied with the modifier is taken as the treatment group, and the rice field without application of the modifier is taken as the control group. The improvement effect is measured after 60 days of application, and the apparent comparison of the soil is as shown in Figure 3 The data results are shown in Table 1: Table 1

[0019] Example 2, an acidic soil modifier based on calcium-magnesium multi-element complex, and a preparation method and application thereof (Jilin acidified black soil corn field improvement): Raw material ratio: dolomite powder 48 parts, gypsum 12 parts, seaweed extract 6 parts, humic acid and fulvic acid complex (fulvic acid accounts for 30%) 22 parts, tea polyphenol 6 parts, beeswax 4 parts, and saponin 2 parts; Preparation method: each component is ultra-finely ground to 120 mesh, 5% starch binder is added, granules (particle size 1-3 mm) are prepared by disc granulator, and fluidized bed drying is carried out at 45°C; Application method: combined with base fertilizer before corn sowing, dosage 1.2 tons / ha, and mix the modifier into 20-30 cm deep soil by subsoiler.

[0020] The above corn field applied with the modifier is taken as the treatment group, and the corn field without application of the modifier is taken as the control group. The improvement effect is measured after the end of the growth season, and the results are shown in Table 2: Table 2

[0021] Example 3, an acidic soil modifier based on calcium-magnesium multi-element complex, and a preparation method and application thereof (Shandong Gaomi facility vegetable greenhouse soil improvement): Raw material ratio: dolomite powder 43 parts (containing CaMg(CO3)2≥90%), gypsum 17 parts, seaweed extract 9 parts (containing alginate≥18%), humic acid and fulvic acid complex (fulvic acid accounts for 35%) 26 parts, tea polyphenol 4 parts, beeswax 5 parts, and saponin 6 parts; Special modification process: melt and mix tea polyphenol and beeswax at a ratio of 1:1.25 at 70°C, adopt spray drying technology to wrap the mixed liquid on the surface of other raw material particles, add 3% diatomite as carrier to improve adsorption performance; Application scheme: apply once at each of the vegetable replacement periods (June and December), dosage: 1.8 tons / ha, adopt deep ploughing (30 cm) + drip irrigation mode for application, and use together with biochar (5 tons / ha).

[0022] The greenhouse soil applied with the above modified agent is taken as a treatment group, and no application of the modified agent is taken as a control group, and the modification effect is determined in a tomato planting season, as shown in Table 3: Table 3

[0023] The nutrient slow release (for 3-4 months) is realized through the beeswax-tea polyphenol coating technology, the saponin content is increased to 6 parts, and the problem of facility soil hardening is effectively solved; in combination with the drip irrigation system, the utilization rate of the modified agent is increased by more than 30%.

[0024] It is suggested that the application is performed in the evening to avoid the influence of strong light on the microbial activity, the soil humidity is maintained at 60-70% within 3 days after the application, the effect is better in combination with the organic fertilizer, and after 3 years of continuous use, the use amount can be maintained (1.0 ton / ha).

[0025] Example 5, comparison experiment with a commercially available soil modification agent: Test materials: the modified agent prepared in Example 1; a commercially available lime-based modification agent (main component: quicklime, purchase unit: Huizhou Balandeng E-commerce Co., Ltd. - Balandeng flagship store; article number: fkl-700); a commercially available microbial agent (main component: Bacillus subtilis + phosphorus solubilizing bacteria, purchase unit: Rizhao Chouqin Biological Technology Co., Ltd.; article number: XLX-DKB2457); a commercially available organic-inorganic compound modification agent (main component: humic acid + calcium dihydrogen phosphate, purchase unit: Shandong Nongda Fertilizer Technology Co., Ltd., article number: ND-SDL-20); Experimental design: Test site: a facility vegetable greenhouse in Shouguang, Shandong (initial soil pH = 4.8, EC = 2.5 mS / cm); Crop: tomato (variety "Jinpen No. 1"); Treatment group: T1: Example 1 modified agent (1.5 tons / ha); T2: commercially available lime-based modification agent (1.5 tons / ha); T3: commercially available microbial agent (according to the dosage in the instruction); T4: commercially available organic-inorganic compound modification agent (1.5 tons / ha); CK: no application of any modification agent; repetition: 3 repetitions for each treatment, random block design; Determination index: soil pH, EC value, available phosphorus content, tomato yield and quality; Determination after the planting season, and the experimental results are shown in Table 4: Table 4

[0026] Comparison analysis: pH adjustment effect: the pH of the soil treated with the embodiment 1 modifier (T1) was increased to 6.3, which is in the optimal range (6.0-6.5) for crops; the pH of the soil treated with the lime-based modifier (T2) was increased to 7.1, which may cause trace element deficiency; Salt control: the EC value of the soil treated with the embodiment 1 modifier (T1) was reduced by 48%, which is significantly better than other treatments; the EC value of the soil treated with the lime-based modifier (T2) was reduced to a limited extent due to the presence of soluble salt; Phosphorus activation ability: the effective phosphorus content of the soil treated with the embodiment 1 modifier (T1) was increased by 163%, which is due to the synergistic effect of the dolomite powder-humic acid-seaweed extract; the phosphorus solubilizing effect of the microbial agent (T3) is lagging, and long-term application is required to achieve the effect; Comprehensive benefits: The embodiment 1 modifier (T1) increased the yield by 50% and the fruit quality was the best; among the commercially available products, the organic-inorganic compound modifier (T4) was the second best, but the cost was 20% higher than that of the embodiment; it can be seen that the modifier prepared in the embodiment is significantly better than the mainstream products on the market in terms of acid adjustment, salt reduction, growth promotion and quality improvement, and is especially suitable for the repair needs of high-intensity soil utilization in facility agriculture and the like.

[0027] In summary, the modifier prepared in the embodiment has significant effects in different soil types and crop systems, and precise improvement can be achieved by adjusting the component ratio and application method; The seaweed extract and humic acid synergistically promote the increase of the abundance of beneficial microorganisms such as actinomycetes and nitrogen-fixing bacteria; the synergistic effect of beeswax and saponin reduces the soil bulk density and increases the proportion of aggregate structure (>0.25 mm); the synergistic effect of dolomite powder and humic acid increases the soil pH from 4.5-5.0 to 6.0-6.5 within 30 days and maintains the stability for 2-3 years; the humic acid and fulvic acid can effectively chelate heavy metals such as cadmium and lead, reducing the effective content by 40%-60%; when the acid soil ecological modifier is used to improve the acid soil, the application amount can be adjusted according to the acidification degree of the soil and the demand of the target crop; In addition, the application method of the modifier includes but is not limited to base application, topdressing or mixed use with organic fertilizer, and the modifier can be prepared in common forms such as powder, granule or liquid suspension.

[0028] The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An acidic soil conditioner based on calcium-magnesium poly-complexes, characterized in that, The acid soil improver comprises the following raw materials by weight: dolomite powder 40-50 parts, gypsum 10-20 parts, seaweed extract 5-10 parts, humic acid and fulvic acid compound 15-30 parts, tea polyphenol and beeswax compound 3-10 parts, and saponin 2-6 parts.

2. The acid soil improver based on calcium-magnesium poly-complexes according to claim 1, characterized in that, The particle size of the dolomite powder is 80-100 mesh.

3. The acid soil improver based on calcium-magnesium poly-complexes according to claim 1, characterized in that, The seaweed extract is derived from brown algae and contains ≥5% fucoidan and ≥0.1% natural auxin.

4. The acid soil improver based on calcium-magnesium polycomplexes according to claim 3, characterized in that, The natural auxin is indole acetic acid.

5. The acid soil improver based on calcium-magnesium poly-complexes according to claim 1, characterized in that, The content of humic acid in the humic acid and fulvic acid compound is ≥60%.

6. The acid soil improver based on calcium-magnesium poly-complexes according to claim 1, characterized in that, The mass ratio of tea polyphenol to beeswax in the tea polyphenol and beeswax compound is 1:0.6-2.

7. The acid soil improver based on calcium-magnesium poly-complexes according to claim 1, characterized in that, The content of saponin in the saponin is ≥80%.

8. A method of preparing the acid soil conditioner based on the calcium-magnesium poly-complex according to any one of claims 1 to 7, characterized in that, The acid soil improver comprises the following steps: The dolomite powder and gypsum are crushed, and then mixed with the seaweed extract, humic acid and fulvic acid compound, tea polyphenol and beeswax compound, and saponin, granulated, and dried at low temperature until the water content is less than 5%.

9. A method of using the acid soil conditioner based on the calcium-magnesium poly-complex according to any one of claims 1 to 7, characterized in that, The acid soil improver comprises the following steps: The acid soil improver is uniformly applied on the surface of the soil at a dosage of 1.0-2.0 tons per hectare, and mixed with the 0-20 cm soil layer.

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