Soil-like aggregate, preparation method thereof and application of soil-like aggregate in soil improvement

Abstract

The invention belongs to the technical field of agriculture, and relates to a soil-like aggregate, a preparation method thereof and application of the soil-like aggregate in soil improvement. The soil-like aggregate is prepared from the following raw materials: 300 to 350 parts of montmorillonite, 180 to 250 parts of decomposed livestock and poultry manure and 10 to 20 parts of functional microorganisms; the functional microorganisms comprise nitrogen-fixing bacteria, potassium bacteria and phosphate solubilizing bacteria according to an inoculum size ratio of (1-2): (1-2): (1-2); the soil-like aggregate is obtained by mixing montmorillonite and decomposed livestock and poultry manure, reacting at 120-150 DEG C for 2-4 hours, and adding a complex microbial inoculant for culture. Through a special preparation process, the structure of a soil aggregate is ingeniously simulated, so that the composite material can stably exist in a soil environment, the improvement effect of the composite material is ensured to be durable, the soil acidity and alkalinity can be continuously adjusted, the soil fertility can be improved, and more suitable conditions are created for crop growth.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of agricultural technology, and relates to a kind of soil-like aggregate and its preparation method and application in soil improvement. BACKGROUND

[0002] Industrial activities (such as acid deposition) and intensive agricultural practices (such as excessive use of nitrogen fertilizer) have largely led to serious soil acidification. Soil acidification can reduce the availability of soil nutrients and induce aluminum (Al) toxicity in plants. Therefore, slowing down soil acidification is also crucial to ensuring food security.

[0003] In the prior art, there are also cases of using clay minerals and livestock manure to improve acid soil. For example, the prior art CN107446585A discloses a kind of composite biological soil conditioner and its preparation method, including the following steps: 1) preparation of biochar; 2) modification of biochar; 3) fermentation of livestock manure; 4) preparation of ecological organic fertilizer; 5) compounding, the composition of soil conditioner and its weight parts are: modified biochar 130-150 parts, ecological organic fertilizer 250-280 parts, humic acid 30-35 parts, probiotics 5-8 parts, active polypeptide 3-5 parts, water retaining agent 32-38 parts, auxiliary agent 190-220 parts. The soil conditioner of the invention not only can enhance the water holding capacity of soil, but also can improve the soil structure and reduce the soil bulk density.

[0004] The prior art CN109197011A discloses a kind of multi-effect conditioning and improvement method of acid soil, including (1) using hydraulic turnover plough to plough soil, natural ventilation for 3-5 days; (2) evenly spreading composted organic fertilizer on the ploughed soil, sunlight for 2-3 days, and then ploughing the soil again using hydraulic turnover plough; (3) evenly spraying diluted soil conditioner on the soil after ploughing again, and finally ploughing using hydraulic turnover plough; the raw materials of the conditioner include ore, microbial bacteria, polyacrylamide, phenolic resin, polymethyl methacrylate, oyster shell powder, polyvinyl alcohol, polyvinyl acetate, ammonium sulfate, rice husk charcoal, desulfurized gypsum, traditional Chinese medicine residue, sugarcane residue, and corn straw.

[0005] The prior art CN113666788A discloses an organic agricultural acid soil conditioner and its preparation method. The organic agricultural acid soil conditioner comprises, by weight: 3-5 parts of discarded animal bones, 2-4 parts of potassium sulfate, 1-2 parts of magnesium sulfate, 1-2 parts of superphosphate, 2-4 parts of carbonized grass family straw, 5-10 parts of bentonite, 3-5 parts of wood ash, 3-5 parts of livestock manure, 1 part of biological surfactant, and inoculated composite bacterial agent. The acid soil conditioner prepared by the invention has high effective nutrient content, especially high content of nitrogen, phosphorus, potassium, calcium and magnesium, ensuring high yield of crops.

[0006] However, the above prior art is only a simple combination of the two or direct mixing, which leads to the lack of stability of the improvement effect and the difficulty in continuously playing a role for a long time. Often, there will be a return to acid or a gradual weakening of the effect.

[0007] In addition, some improvement technologies focus on the combination of industrial products and livestock manure. However, there is a problem that cannot be ignored, that is, there is a big difference between the nature of industrial products and the soil environment. In the process of using them to improve acidified soil, these industrial products may cause some unexpected damage to the soil structure, such as changing the porosity of the soil, affecting the aggregation of soil particles, etc., which may have a potential negative effect on the ecological function of the soil, thereby affecting the balance and health of the entire soil ecosystem.

[0008] Mineral-organic combination is the basic structural unit of soil aggregates, which plays a key role in maintaining soil chemical and biological functions. Traditional acidification improvement materials usually interact with native soil components in unpredictable ways, changing their properties and limiting their acid buffering capacity.

[0009] The prior art CN118064159A discloses a soil aggregate, a preparation method and application of the soil aggregate, and an improved plant soil and a preparation method of the improved plant soil. The soil aggregate is a large particle aggregate with a particle size of 10-3mm or a small aggregate with a particle size of 3-0.25mm, which is mainly composed of polyacrylamide, attapulgite, straw, clay and silt. The clay contains 20-25% of clay particles, and the plasticity index is 17-25. The silt contains <7% of clay particles, and the plasticity index is <7. The molecular weight of the polyacrylamide is 6-8 million, and it is anionic. It is applied to different soil types for soil improvement, and is applied to the plant growth hole as a plant growth soil, which has good water permeability, air permeability, water retention, fertilizer retention and heat retention. However, the prior art only mixes all the raw materials simply, which leads to the lack of stability of the improvement effect.

[0010] The prior art CN116874325A provides a kind of soil aggregate material and its application. The soil aggregate material has a three-dimensional porous structure. The pores in the soil aggregate material include micropores, mesopores and macropores, which are sorted by pore size as follows: micropores < mesopores < macropores. However, the soil aggregate material provided by the invention only focuses on the similarity of its pore structure to natural soil aggregates, but does not disclose its composition and preparation method. The soil aggregate material with only pore structure does not have the performance of improving acidified soil. SUMMARY

[0011] The application aims to provide a long-term stable soil aggregate-like body for improving soil acidification, a preparation method thereof and application thereof in soil improvement.

[0012] To achieve the above-mentioned object, the technical scheme adopted by the application is as follows:

[0013] A soil aggregate-like body, raw materials of which include, in parts by weight, 300-350 parts of montmorillonite, 180-250 parts of mature livestock and poultry manure and 10-20 parts of a compound microbial agent.

[0014] The compound microbial agent is composed of nitrogen-fixing bacteria, potassium-dissolving bacteria and phosphorus-dissolving bacteria in a ratio of 1-2:1-2:1-2.

[0015] The soil aggregate-like body is obtained by mixing the montmorillonite and the mature livestock and poultry manure, reacting at 120-150 DEG C for 2-4 hours and then adding the compound microbial agent for cultivation.

[0016] Soil aggregate-like bodies, in particular organic-mineral composite materials, can be used as effective improvers to alleviate soil acidification. These materials not only have the potential to rapidly buffer acidity, but also maintain long-term stability without damaging the structure or function of the soil.

[0017] The application uses clay minerals, livestock and poultry manure and multiple functional microbial groups to synthesize a product similar to the structure of soil aggregate through a special preparation process and proportioning, and the product is applied as an acidification soil improver. The product can reduce soil acidity without damaging the original structure of the soil, and can increase the effective efficiency of soil nutrients and crop yield by combining with functional microorganisms.

[0018] According to the embodiments of the application, the application can be further optimized, and the following is the technical scheme formed after optimization:

[0019] In one preferred embodiment, the potassium-dissolving bacteria are Bacillus subtilis.

[0020] In one preferred embodiment, the nitrogen-fixing bacteria are halophilic nitrogen-fixing bacteria.

[0021] In one preferred embodiment, the phosphorus-dissolving bacteria are Bacillus circulans.

[0022] In one preferred embodiment, the particle size of the montmorillonite is 200-300 mm.

[0023] If the particle size of the montmorillonite is too large, the combination degree of the montmorillonite and the livestock and poultry manure will be reduced; if the particle size of the montmorillonite is too small, the stability of the aggregate-like body will be reduced, the aggregate-like body will be easily migrated with water flow, and the aggregate-like body cannot provide a colonization environment for microorganisms.

[0024] In one preferred embodiment, the matured livestock and poultry manure comprises 200-250 parts by weight of livestock and poultry manure, 40-50 parts by weight of agricultural and forestry biomass, and 40-50 parts by weight of wood ash.

[0025] In one preferred embodiment, the agricultural and forestry biomass comprises straw, sawdust, bagasse, rice husk, tree bark or withered leaves.

[0026] In one preferred embodiment, the preparation method of the matured livestock and poultry manure comprises the following steps: mixing raw materials, adjusting the moisture content to 30-50%, covering with a film, composting, turning over several times, and fermenting for 6-8 days to obtain the matured livestock and poultry manure.

[0027] In one preferred embodiment, the composting process is performed by turning over every 2-3 days.

[0028] Based on the same inventive concept, the application also claims the preparation method of the soil-like aggregate, comprising the following steps:

[0029] S1, uniformly mixing montmorillonite with livestock and poultry manure, adjusting the moisture content to 30-40%, and culturing at 120-150℃ for 2-3h under stirring to obtain a pre-aggregate;

[0030] S2, adding functional microorganisms to the pre-aggregate, and culturing for 10 days to obtain the soil-like aggregate.

[0031] In one preferred embodiment, the addition sequence of the composite microbial agent is: first adding nitrogen-fixing bacteria, culturing for 3-4 days, then adding phosphorus-solubilizing bacteria, culturing for 6-7 days, and then adding potassium-solubilizing bacteria, culturing for 4-5 days.

[0032] In one preferred embodiment, the culturing temperature is 25-30℃.

[0033] In one preferred embodiment, the stirring speed in step S1 is 200-500rpm.

[0034] Based on the same inventive concept, the application also claims the application of the soil-like aggregate in improving acidified soil.

[0035] Based on the same inventive concept, the application also claims an acidified soil improver comprising the soil-like aggregate.

[0036] Compared with the prior art, the application has the following beneficial effects:

[0037] This invention utilizes a composite material synthesized from montmorillonite, livestock manure, and functional microorganisms, employing a unique preparation process to cleverly mimic the structure of soil aggregates. This design allows the composite material to exist stably in the soil environment, ensuring its long-lasting improvement effect. It can continuously regulate soil pH, improve soil fertility, and create more suitable conditions for crop growth. Adhering to the core concept of "treating soil with soil," this invention fully respects the natural properties and ecological balance of the soil. Compared to traditional improvement methods, this approach avoids the potential damage to soil structure caused by the improper introduction of exogenous substances. It effectively improves acidified soil while maintaining soil health and sustainability, providing a green, environmentally friendly, and efficient solution for the healthy development of agricultural ecology. Attached Figure Description

[0038] Figure 1 These are scanning electron microscope images of soil-like aggregates from Example 1 and Comparative Examples 1-3;

[0039] Figure 2 These are scanning electron microscope images of real soil.

[0040] Figure 3 These are UV test curves of soil-like aggregates prepared by adding different microorganisms in different sequences;

[0041] Figure 4 This is a graph showing the adsorption capacity of soil-like aggregates prepared at different synthesis temperatures for H+.

[0042] Figure 5 Al is a soil-like aggregate prepared at different synthesis temperatures. 3 + Adsorption capacity test curve. Detailed Implementation

[0043] This invention is not limited to the specific embodiments listed below. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any modifications or alterations made to the design structure and concept of this invention fall within the protection scope of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0044] Example 1

[0045] Preparation of soil-like aggregates

[0046] 1. Preparation of soil-like aggregates without the addition of functional microorganisms

[0047] Preparation of composted livestock and poultry manure: 200 parts of livestock and poultry manure, 50 parts of straw, sawdust or dry leaves, and 50 parts of wood ash were mixed together, and the moisture content was adjusted to 45%. The mixture was covered with a film and turned over every 2 days. After 8 days of fermentation, the livestock and poultry manure was completely composted.

[0048] 300 parts of montmorillonite (particle size of 200-250 mm) and 180 parts of livestock and poultry manure were mixed uniformly, and an appropriate amount of deionized water was slowly added to adjust the moisture content to 30%-40%. The mixture was incubated at 150°C for 3 h to allow physical and chemical changes to occur in the high-temperature environment, forming a composite material simulating soil aggregates. When the temperature decreased to room temperature, the soil aggregate-like material without functional microorganisms was obtained.

[0049] The mineral content of the soil aggregate-like material was 87%, the organic matter content was 5.2%, the nitrogen content was 2.2%, the phosphorus content was 0.15%, and the potassium content was 1.1%.

[0050] 2. Preparation of montmorillonite-based soil aggregate-like material (order of adding microorganisms: nitrogen-fixing bacteria → phosphorus-solubilizing bacteria → potassium-solubilizing bacteria)

[0051] The soil aggregate-like material without functional microorganisms obtained in Example 1 was adjusted to a moisture content of 30%-40%, and 12 parts of a composite microbial agent were added. The order of adding the composite microbial agent was as follows: 10 6 cfu / g of salt-tolerant nitrogen-fixing bacteria were added first, 10 6 cfu / g of phosphorus-solubilizing bacteria Bacillus subtilis were added after 3 days of incubation, and 10 6 cfu / g of potassium-solubilizing bacteria Bacillus circulans were added after 6 days of incubation. The weight ratio of salt-tolerant nitrogen-fixing bacteria, Bacillus subtilis, and Bacillus circulans was 1:1:1. After 4 days of further incubation, a montmorillonite-based soil aggregate-like material was obtained.

[0052] The salt-tolerant nitrogen-fixing bacteria were purchased from the Beijing Biological Preservation Center, and the strain preservation number was AS1.2391. The Bacillus subtilis was purchased from the China Culture Collection Center, and the strain preservation number was CCTCC AB 130047. The Bacillus circulans was purchased from the China Culture Collection Center, and the strain preservation number was CCTCC NB 20083561.

[0053] Example 2

[0054] Montmorillonite and composted livestock and poultry manure were mixed uniformly, and an appropriate amount of deionized water was slowly added to adjust the moisture content to 30%-40%. The mixture was incubated at 120°C for 3 h, and the other steps were the same as in Example 1.

[0055] Comparative Example 1

[0056] Montmorillonite and rotten livestock and poultry manure were mixed evenly, and a proper amount of deionized water was slowly added to adjust the moisture content to 30%-40%, and then incubated at 30°C for 3h, and the rest was the same as in Example 1.

[0057] Comparative Example 2

[0058] Montmorillonite and rotten livestock and poultry manure were mixed evenly, and a proper amount of deionized water was slowly added to adjust the moisture content to 30%-40%, and then incubated at 60°C for 3h, and the rest was the same as in Example 1.

[0059] Comparative Example 3

[0060] Montmorillonite and rotten livestock and poultry manure were mixed evenly, and a proper amount of deionized water was slowly added to adjust the moisture content to 30%-40%, and then incubated at 180°C for 3h, and the rest was the same as in Example 1.

[0061] The soil-like aggregates and real soil of the above examples and comparative examples were analyzed as follows:

[0062] 1. The soil-like aggregates and real soil of the above examples and comparative examples were analyzed by scanning electron microscopy. The real soil was collected from farmland soil in Yueyang County, Yueyang City, Hunan Province. Red soil is the most widely distributed soil in southern China, and this region is a typical acidified soil in southern China. The soil sampling depth was 0-20cm, and the roots and stones were removed and passed through a 2mm sieve.

[0063] The results are shown in Figure 1 and Figure 2 .

[0064] The results show that the soil-like aggregates prepared at different temperatures have significant differences. The soil-like aggregates synthesized at 120°C-150°C are the most compact, have high stability, and have the most similar microstructure to real soil. At 30°C and 60°C, smooth mineral (montmorillonite) surfaces can be observed, indicating that the combination of montmorillonite and other components is not tight. At 180°C, due to the high temperature, a band-like structure appears, which may be caused by the collapse of the structure due to the loss of water from montmorillonite at high temperature. In this case, the internal physical and chemical properties of the composite material have changed adversely, resulting in unstable improvement effect in the actual application of soil improvement, making it difficult to continuously and effectively repair and improve acidified soil.

[0065] The basic properties of the soil-like aggregates of Example 1 and real soil were analyzed, and the results showed that the basic properties of real soil were: soil mineral content 88%, organic matter content 4.6%, total nitrogen 0.2%, total phosphorus 0.1%, and total potassium 2%. The composition of real soil is basically equivalent to that of the soil-like aggregates prepared in Example 1.

[0066] 2. The soil-like aggregates prepared in Example 1 and Comparative Examples 1-3 were subjected to H+ The capability analysis is as follows:

[0067] Take 2g of the soil-like aggregates from Examples 1-2 and Comparative Examples 1-3 respectively, add them to 20ml of deionized water, and adjust the pH to the same value of 5.9 (simulating the pH of weakly acidic soil) with NaOH. Observe the pH change using an automatic titrator via HNO3. The results are as follows: Figure 4 As shown.

[0068] The results showed that titration experiments on different soil aggregates revealed that as the pH decreased from 5.9 to 5.3, the H₂ consumed by different soil aggregates increased. + The results were approximately the same; however, when the pH was below 5.0, the differences in soil-like aggregates became significant. Soil-like aggregates synthesized at low temperatures (0-60℃) consumed the same amount of H₂. + At that time, the pH of the material was significantly lower, and the soil-like aggregates synthesized at 30℃ consumed only 168 mmol / kg H₂. + The pH subsequently dropped to 4.3, indicating that it had completely lost its effectiveness; similarly, the soil-like aggregates synthesized at 60℃ consumed 250 mmol / kg H₂O. + It then lost its effect. Increased temperature increases the resistance of H-like aggregates. + The adsorption capacity of the materials synthesized at 120℃ and 150℃ was similar, with the best performance observed at a consumption of 335 mmol / kg H₂. + The effect only diminished after a short time, far superior to soil-like aggregates synthesized under low-temperature conditions. Furthermore, the soil-like aggregates synthesized at 180℃ were less effective than those synthesized at 120℃ and 150℃. Electron microscopy revealed that the aggregates synthesized at low temperatures (30-60℃) had a significantly lower degree of binding than those synthesized at high temperatures (120-150℃). However, excessively high temperatures (180℃) also disrupted the compactness of the soil-like aggregates, reducing their adsorption of H₂. + The ability.

[0069] 3. Al adsorption was performed on the soil-like aggregates prepared in Example 1 and Comparative Examples 1-3. 3+ The capability analysis is as follows:

[0070] Take 2g of the soil-like aggregates from Examples 1-2 and Comparative Examples 1-3 respectively, and place them in 20ml of Al solution with concentrations of 0, 2, 4, 8, 10, 20, 40 and 80 mg / L respectively. 3+ After culturing the solution for 1 day, the Al content in the solution was measured. 3+ Concentration. Results as follows Figure 5 As shown.

[0071] The results showed that the maximum Al of soil-like aggregates at 120℃ and 150℃ was...3+ The adsorption capacity is about 41.6 mg / g, which is much greater than 33.4 mg / g at 180℃, 31.16 mg / g at 60℃ and 27.73 mg / g at 30℃. The adsorption capacity of Al 3+ to the soil-like aggregate shows that the soil-like aggregate prepared at 120℃ and 150℃ has better ability to alleviate the aluminum toxicity of the soil.

[0072] The H + and Al 3+ test results of the soil-like aggregate show that the modifier synthesized at the specific temperature of the application has better effect, compared with the modifier synthesized at other temperatures, which can absorb more H + and Al 3+ , representing that it has stronger acid adjusting effect and stronger ability to alleviate the aluminum toxicity of the acidified soil.

[0073] Comparative Example 4

[0074] During the preparation of the soil-like aggregate, the order of adding the microorganisms is: potassium-lysing bacteria → nitrogen-fixing bacteria → phosphorus-lysing bacteria.

[0075] The soil-like aggregate without functional microorganisms is adjusted to have a moisture content of 30%-40%, 10 6 cfu / g of potassium-lysing bacteria is added, and after 3 days of culture, 10 6 cfu / g of halophilic nitrogen-fixing bacteria is added, and after 6 days of culture, 10 6 cfu / g of phosphorus-lysing bacteria is added, and after 4 days of further culture, the soil-like aggregate based on montmorillonite is obtained. The other conditions are the same as in Example 1.

[0076] Comparative Example 5

[0077] During the preparation of the soil-like aggregate, the order of adding the microorganisms is: phosphorus-lysing bacteria → potassium-lysing bacteria → nitrogen-fixing bacteria.

[0078] The soil-like aggregate without functional microorganisms is adjusted to have a moisture content of 30%-40%, 10 6 cfu / g of phosphorus-lysing bacteria is added, and after 3 days of culture, 10 6 cfu / g of potassium-lysing bacteria is added, and after 6 days of culture, 10 6 cfu / g of halophilic nitrogen-fixing bacteria is added, and after 4 days of further culture, the soil-like aggregate based on montmorillonite is obtained. The other conditions are the same as in Example 1.

[0079] Comparative Example 6

[0080] Preparation of the soil-like aggregate based on montmorillonite (simultaneous addition of three kinds of functional bacteria)

[0081] The soil-like aggregate without functional microorganisms is adjusted to a moisture content of 30%-40%, and 3%-6% of a simple mixed composite microbial inoculant is added, wherein the salt-dwelling nitrogen-fixing bacteria, phosphorus-dissolving bacteria and potassium-dissolving bacteria are composed according to an inoculation ratio of 1:1:1, fermented for 3 days, and dried to a moisture content of 20%. Finally, the soil-like aggregate based on montmorillonite is obtained after being cultured for another 10 days. The other conditions are the same as in Example 1.

[0082] The soil-like aggregates prepared in Example 1 and Comparative Examples 4-6 are analyzed, and the specific analysis is as follows:

[0083] 2 g of the soil-like aggregates in Example 1 and Comparative Examples 4-6 are respectively taken and added into 20 ml of deionized water, and the value at OD600 is tested, and the results are shown in Table 1. Figure 3 The results show that the curve trends are similar after the three functional bacteria are added in different orders, but the OD600 value of the soil-like aggregate in which the nitrogen-fixing bacteria, phosphorus-dissolving bacteria and potassium-dissolving bacteria are sequentially added is the highest, and the OD600 value is 2.11 after being cultured for 10 days; the OD600 value of the soil-like aggregate in which the potassium-dissolving bacteria, nitrogen-fixing bacteria and phosphorus-dissolving bacteria are sequentially added is 1.81 after being cultured for 10 days; the OD600 value of the soil-like aggregate in which the phosphorus-dissolving bacteria, potassium-dissolving bacteria and nitrogen-fixing bacteria are sequentially added is 1.65 after being cultured for 10 days; and the OD600 value of the simple mixed bacteria is the highest in the early stage, but the colonization degree is the lowest in the later stage, and the OD600 value is 1.57. Therefore, through the comparison experiment, the soil-like aggregate in which the nitrogen-fixing bacteria, phosphorus-dissolving bacteria and potassium-dissolving bacteria are sequentially added is selected in the present application. In the soil-like aggregate, the activity of the microorganisms in the components is different due to different addition orders of the microorganisms, which causes the change of the synergistic effect of the microorganism-montmorillonite-livestock and poultry manure. In the soil-like aggregate in which the nitrogen-fixing bacteria, phosphorus-dissolving bacteria and potassium-dissolving bacteria are sequentially added, the synergistic effect of the microorganism-montmorillonite-livestock and poultry manure is the best, and is also the closest to the microstructure and composition of the real soil.

[0084] Example 7

[0085] Indoor soil crop planting test:

[0086] Acidic soils in three different regions (Dongkou County, Xiangyin County and Yueyang County in Hunan Province) are selected for culture test, and the collected soil is the soil layer above 20 cm. The indoor planting pots are 20 cm in diameter and 35 cm in height, and 10 kg of soil is added into each pot for indoor planting test.

[0087] The acidified soil in Dongkou County is divided into six components, component 1 does not add soil-like aggregate, component 2 adds the soil-like aggregate of Comparative Example 1, component 3 adds the soil-like aggregate of Comparative Example 2, component 4 adds the soil-like aggregate of Comparative Example 3, component 5 adds the soil-like aggregate of Example 1, and component 6 adds the soil-like aggregate of Example 2. The addition amount of the modifier is 10 g / kg.

[0088] The acidified soil of Yueyang County was divided into 6 groups, group 1 without adding the artificial soil aggregate, group 2 adding the artificial soil aggregate of Comparative Example 1, group 3 adding the artificial soil aggregate of Comparative Example 2, group 4 adding the artificial soil aggregate of Comparative Example 3, group 5 adding the artificial soil aggregate of Example 1, and group 6 adding the artificial soil aggregate of Example 2. The adding amount of the soil conditioner was 10 g / kg.

[0089] The acidified soil of Xiangyin County was divided into 6 groups, group 1 without adding the artificial soil aggregate, group 2 adding the artificial soil aggregate of Comparative Example 1, group 3 adding the artificial soil aggregate of Comparative Example 2, group 4 adding the artificial soil aggregate of Comparative Example 3, group 5 adding the artificial soil aggregate of Example 1, and group 6 adding the artificial soil aggregate of Example 2. The adding amount of the soil conditioner was 10 g / kg. The basic physicochemical properties of the soil of the three regions were shown in Table 1.

[0090] Table 1 Basic properties of acidified soil of three regions

[0091]

[0092] Rice was planted in the acidified soil of the three regions, and the basic physicochemical properties of the soil and the yield of rice were counted, and the specific conditions were shown in Table 2.

[0093] Table 2 Basic physicochemical properties of soil and yield of rice

[0094]

[0095]

[0096] The results of Table 2 show that in different acid soils, the soil-like aggregates prepared by the present application have a significant improvement on soil pH and rice yield, but the improvement effect of component 5 (150°C) and component 6 (120°C) is more obvious, and there is no significant difference between the two. In Dongkou County soil, the soil pH of components 5 and 6 is improved from 4.76 to 5.33-5.35, and the rice yield is improved from 28.1 g to 33.4 g-34 g, compared with other soil-like aggregate treatments; the improvement effect of components 5 and 6 on soil pH is better by 4.2-5.1%, and the improvement effect on rice yield is better by 7.1-13.6%. In Xiangyin County soil, the soil pH of components 5 and 6 is improved from 5.08 to 5.78-5.83, and the rice yield is improved from 30.7 g to 35.2 g-35.4 g, compared with other soil-like aggregate treatments; the improvement effect of components 5 and 6 on soil pH is better by 7.3-9%, and the improvement effect on rice yield is better by 6.2-9.1%. In Yueyang County soil, the soil pH of components 5 and 6 is improved from 4.99 to 6.11-6.13, and the rice yield is improved from 31.6 g to 36 g-36.3 g, compared with other soil-like aggregate treatments; the improvement effect of components 5 and 6 on soil pH is better by 6.2-7.6%, and the improvement effect on rice yield is better by 6.3-8.8%. Therefore, the soil-like aggregates of components 5 (120°C) and 6 (150°C) have the best effect on acid soil improvement, which is consistent with the results of H + and Al 3+ , proving that the soil-like aggregates at 120-150°C have good acid adjusting effect.

[0097] Through indoor potting test, it is shown that when the addition order of microorganisms is: nitrogen-fixing bacteria-phosphorus-solubilizing bacteria-potassium-solubilizing bacteria, the effect of the soil-like aggregates prepared on acidified soil is more obvious. At the same time, the pH of acidified soil in different regions is obviously improved. Therefore, functional microorganisms also play a crucial role in soil.

[0098] Example 8

[0099] Outdoor rice planting test:

[0100] Taking the farmland with serious soil acidification in a certain area of Yueyang County as the experimental object, the amount of soil-like aggregates is 1.5 kg / m 2 , the experimental area is 30 m 2 for each component, and the types of soil-like aggregates used in each component are consistent with the indoor planting experiment; the rotary tiller is used to mix the components 1 and the comparative examples with the plough layer soil obtained within 20 cm from the surface.

[0101] The outdoor soil was divided into 5 components, component 1 without adding the artificial soil aggregate, component 2 adding the artificial soil aggregate of Comparative Example 4, component 3 adding the artificial soil aggregate of Comparative Example 6, component 4 adding the artificial soil aggregate of Comparative Example 5, component 5 adding the artificial soil aggregate of Example 1, and component 6 adding the artificial soil aggregate of Example 2. The adding amount of the artificial soil aggregate was 300 kg / ha. The rice was planted in the acidified soil, and the basic physicochemical properties of the soil and the yield of the rice were counted, and the specific conditions are shown in Table 3 and Table 4.

[0102] Table 3 Basic physicochemical properties of the soil and the yield of the rice

[0103]

[0104] Table 4 Basic physicochemical properties of the soil and the yield of the rice

[0105]

[0106] It can be seen from the results that the results of component 5 and component 6 prove that the artificial soil aggregate has the best multifunctional improvement effect on the soil in the temperature range of 120-150°C, the soil pH is improved from 5.26 to 5.87-5.89, which significantly improves the field soil pH, and the improvement of soil nutrients shows that the improvement effect of component 5 and component 6 on total nitrogen, available phosphorus and available potassium in the soil is obviously better than that of other components; the total nitrogen is improved from 1.88 g / kg to 2.03-2.03 g / kg, the available phosphorus is improved from 30.61 mg / kg to 34.42-34.53 mg / kg, and the available potassium is improved from 96.37 mg / kg to 115.41-118.23 mg / kg. The results of the influence on the soil environmental microorganisms show that the addition of the artificial soil aggregate has a significant improvement effect on the richness and diversity of the microorganisms; the improvement effect of component 5 and component 6 on the richness and diversity of the soil microorganisms is more obvious; the richness index is improved from 5770 to 65.09-6532, the OUT number is improved from 4324 to 5059-5078, the Shannon coefficient is improved from 7.78 to 9.31-9.45, and the lineage diversity index is improved from 223 to 259-262. The product of the rice of component 5 and component 6 is also more significantly improved than other components, from 439.5 kg / acre to 496.1-503.3 kg / acre. The outdoor results prove that the addition order of the functional bacteria will lead to different multifunctional effects of the artificial soil aggregate, and the addition of the nitrogen-fixing bacteria, the phosphorus-solubilizing bacteria and the potassium-solubilizing bacteria in turn has the best effect of the artificial soil aggregate. At the same time, the results of component 5 and component 6 show that the effect of the artificial soil aggregate is the best when it is synthesized in the temperature range of 120-150°C, and the synthesis temperature of the artificial soil aggregate and the addition and culture method of the functional bacteria are crucial for the improvement effect of the acidified soil.

[0107] The improved effect of the soil-like aggregate of the present application is further verified by outdoor and indoor rice planting tests. In addition to the synthesis temperature of the soil-like aggregate, the order of adding microorganisms in the soil-like aggregate is also particularly important. The addition of nitrogen-fixing bacteria first, followed by phosphorus-solubilizing bacteria, and finally potassium-solubilizing bacteria to prepare the improver is most obvious for increasing the yield of rice. In the outdoor planting test, the yield of rice is increased by 12.9-14.6%; the soil pH is increased from 5.26 to 5.87-5.89; the soil nutrient content is also significantly increased; the microbial richness and diversity in the soil environment are also significantly increased; and a soil environment more conducive to crop growth is created.

[0108] It should be noted that the above examples are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can also be made by those of ordinary skill in the art. Here, it is impossible to exhaust all the embodiments. Any obvious changes or variations derived from the technical scheme of the present application are still within the scope of protection of the present application.

Claims

1. A soil-like aggregate, characterized in that, The raw materials include, by weight parts: 300-350 parts of montmorillonite, 180-250 parts of matured livestock and poultry manure, and 10-20 parts of compound microbial agent. The compound microbial agent is composed of nitrogen-fixing bacteria, potassium-dissolving bacteria and phosphorus-dissolving bacteria at a ratio of 1-2:1-2:1-2 by inoculation amount; and the soil-like aggregate is obtained by mixing the montmorillonite and the matured livestock and poultry manure, reacting at 120-150℃ for 2-4h, and then adding the compound microbial agent for culture.

2. The soil-like soil aggregate of claim 1, wherein, The potassium-dissolving bacteria are Bacillus subtilis, the nitrogen-fixing bacteria are halophilic nitrogen-fixing bacteria, and the phosphorus-dissolving bacteria are Bacillus circulans.

3. The soil-like soil aggregate of claim 1, wherein, The particle size of the montmorillonite is 200-300mm.

4. The soil-like soil aggregate of claim 1, wherein, The matured livestock and poultry manure includes, by weight parts, 200-250 parts of livestock and poultry manure, 40-50 parts of agricultural and forestry biomass, and 40-50 parts of wood ash.

5. The soil-like soil aggregate of claim 1, wherein, The preparation method of the matured livestock and poultry manure includes: mixing raw materials, adjusting the moisture content to 30-50%, covering with a film for composting, turning the compost several times, and fermenting for 6-8 days to obtain the matured livestock and poultry manure.

6. A method of preparing soil-like aggregates according to any one of claims 1 to 5, characterized in that, The method includes the following steps: S1, uniformly mixing the montmorillonite and the livestock and poultry manure, adjusting the moisture content to 30-40%, and culturing at 120-150℃ for 2-4h under stirring to obtain a pre-aggregate; S2, adding functional microorganisms to the pre-aggregate, and culturing for 10 days to obtain the soil-like aggregate.

7. The method of preparing soil-like aggregates according to claim 6, wherein The order of adding the functional microorganisms is: first adding the nitrogen-fixing bacteria, culturing for 3-4 days, then adding the phosphorus-dissolving bacteria, culturing for another 6-7 days, and then adding the potassium-dissolving bacteria, and culturing for another 4-5 days.

8. The method of preparing soil-like aggregates according to claim 7, wherein The culture temperature is 25-30℃, and the stirring speed in step S1 is 200-500rpm.

9. Use of the soil-like aggregate according to any one of claims 1-5 in improving acidified soil.

10. An acidified soil amendment characterized in that, The method includes the soil-like aggregate according to any one of claims 1-5.

Images