Carbon bacterium synergistic soil saline-alkali modifier as well as preparation method and application thereof

Abstract

The invention provides a carbon-bacterium synergistic soil saline-alkali modifier as well as a preparation method and application thereof. The carbon-bacterium synergistic soil saline-alkali modifier is prepared from peat, a carbon-bacterium composite material, a salt-tolerant microbial agent, an organic material and an auxiliary. According to the carbon and bacterium synergistic soil saline-alkali modifier, a long-acting acid buffer system is formed by utilizing the synergistic effect of carbon and bacteria, the EC value of soil is reduced, the water-stable aggregate content of the soil is increased, breeding of pathogenic bacteria is inhibited, the soil is repaired, and the microbial diversity and the crop survival rate are increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil improvement, in particular to a carbon-microbe synergistic soil salinization improvement agent and a preparation method and application thereof. BACKGROUND

[0002] Salinization soil seriously restricts agricultural production and improvement of ecological environment. According to statistics, the salinization soil in China is mainly distributed in the main agricultural production areas of North China, Northwest China and Northeast China. Such soil has the characteristics of high electrical conductivity (EC value), strong alkaline pH value and hard structure, which leads to low emergence rate of crops, reduced yield and serious threat to food security.

[0003] The core problems of salinization soil include: high concentration of Na + , Cl - inhibits water absorption of crop root system, causes "physiological drought", and at the same time, destroys cell membrane structure, leading to nutrient absorption disorder; a + destroying soil colloid stability, so that the content of water stable aggregate (>0.25mm) is less than 20%, the water permeability is poor, forming a vicious cycle of "upper salt accumulation and lower hardening"; under the stress of salinity and alkalinity, the soil microbial diversity is reduced by more than 50%, the activity of beneficial bacteria such as nitrogen-fixing bacteria and phosphorus-dissolving bacteria is inhibited, the number of pathogenic fungi such as fusarium increases by 2-3 times, and soil-borne diseases occur frequently. The high soil EC value (salinity and alkalinity) leads to soil structure destruction, nutrient availability reduction, inhibition of crop growth, and at the same time, affects the diversity and activity of soil microorganisms, and aggravates the reproduction of soil-borne diseases such as fusarium and other pathogenic fungi.

[0004] Traditional soil salinity improvement methods such as applying gypsum, sulfur and other chemicals can quickly reduce soil pH value and EC value, but have significant defects, such as insufficient long-acting, easy to cause secondary pollution, high cost; physical improvement measures such as deep ploughing and replacement of guest soil face the realistic difficulties of huge engineering quantity, significant ecological damage and unsustainable effect; the use of salt-tolerant plants or microbial remediation has obvious shortcomings, such as long cycle, insufficient synergy and single function. Therefore, carbon-based and microbial synergistic improvement is considered first, and a high-efficiency, environmentally-friendly and long-acting soil salinity improvement agent is developed. Biochar has adsorption and carrier functions, chitosan has aggregate construction ability, and microorganisms have metabolic long-acting, but the combination efficiency of carbon and microorganisms is low, the functional system is single, and the metabolic activity of microorganisms decays quickly.

[0005] In view of the problems of short duration, single function and insufficient synergy of existing soil salinity improvement agents, the present application develops a carbon-microbe synergistic soil salinity improvement agent, which can reduce soil EC value, improve soil water stable aggregate content, inhibit reproduction of pathogenic fungi, repair soil, and improve microbial diversity and crop survival rate. SUMMARY Invention purposes: The present application aims to solve the problems of short duration, single function and insufficient synergy of the existing technology, and provides a carbon-bacterium synergistic soil saline-alkali modifier, a preparation method and application thereof, which can reduce soil EC value, improve soil water stable aggregate content, inhibit pathogenic bacteria reproduction, repair soil, and improve microbial diversity and crop survival rate.

[0006] In order to achieve the above technical purposes, the present application provides a carbon-bacterium synergistic soil saline-alkali modifier, and the raw materials for preparing the carbon-bacterium synergistic soil saline-alkali modifier include peat, carbon-bacterium composite material, salt-tolerant bacterium agent, organic material and auxiliary agent.

[0007] Further, the raw materials for preparing the carbon-bacterium synergistic soil saline-alkali modifier include 20-40 parts of peat, 30-50 parts of carbon-bacterium composite material, 5-15 parts of salt-tolerant bacterium agent, 8-15 parts of organic material and 15-25 parts of auxiliary agent by weight.

[0008] Further, the content of humic acid in the peat is ≥30wt%, and the content of organic acid is ≥5wt%.

[0009] Further, the salt-tolerant bacterium agent includes degrading bacteria and nitrogen-fixing bacteria, and the effective viable count of the salt-tolerant bacterium agent is ≥1×10 9 CFU / g.

[0010] Further, the organic material is one or more of potassium humate, trehalose and carboxymethyl cellulose.

[0011] Further, the auxiliary agent is one or more of sodium alginate, gypsum and attapulgite.

[0012] Further, the carbon-bacterium composite material is a mixture of black aspergillus fermentation liquid modified biomass charcoal and chitosan.

[0013] Further, the preparation method of the carbon-bacterium composite material includes the following steps: (1) Biomass charcoal and black aspergillus fermentation liquid are mixed, and a magnetic stirrer is used to stir at 25-30℃ for 1-2h; (2) The biomass charcoal immersed in step (1) is dried in an oven at 60-70℃ for 18-24h, then uniformly heated to 100-120℃ for 1-2h, cooled to room temperature, washed with ultrapure water until the pH remains stable, then dried in an oven at 60-70℃, to obtain the black aspergillus fermentation liquid modified biomass charcoal; (3) The black aspergillus fermentation liquid modified biomass charcoal prepared in step (2) is mixed with chitosan, and stirred uniformly to prepare the carbon-bacterium composite material.

[0014] Further, the biomass charcoal is rice husk charcoal, the mass ratio of the biomass charcoal to the Aspergillus niger fermentation liquor is 1:1-3, the content of citric acid in the Aspergillus niger fermentation liquor is greater than or equal to 50 g / L, and the degree of deacetylation of the chitosan is greater than or equal to 90%.

[0015] Further, the mass ratio of the modified biomass charcoal of the Aspergillus niger fermentation liquor to the chitosan is 4-6:1.

[0016] The application further provides a preparation method of the carbon-microbe synergistic soil saline-alkali improver. S1: put peat and carbon-microbe composite material into a blender, mix at a speed of 50-80 r / min for 10-15 min, then add salt-tolerant bacteria agent and organic material, and continue mixing for 15-20 min; S2: then add an auxiliary agent, uniformly mix, and then pass through an extrusion granulator with a pore size of 2-4 mm to form particles, thereby obtaining the carbon-microbe synergistic soil saline-alkali improver.

[0017] The application provides application of the carbon-microbe synergistic soil saline-alkali improver in improving saline-alkali soil.

[0018] Application method of the soil saline-alkali improver: Soil application: for saline-alkali soil, the soil saline-alkali improver of the application can be uniformly applied on the surface of the soil at a dosage of 50-100 kg per mu, then ploughed into the soil to a depth of 10-20 cm, so that the improver is fully mixed with the soil. The improver can also be mixed with nitrogen, phosphorus, potassium and other fertilizers for application, so as to improve the nutrient utilization rate.

[0019] Leaf spraying: the soil saline-alkali improver is prepared into a liquid dosage form, diluted by 50-100 times, and then uniformly sprayed on the surface of the crop leaves at a spraying amount of 30-50 L per mu. The spraying can be performed at key periods such as the seedling stage, flowering stage and fruiting stage of the crops, so as to promote the growth of the crops and improve the stress resistance Beneficial effects: The carbon-microbe synergistic soil saline-alkali improver of the application utilizes the carbon-microbe synergistic effect to form a long-acting acid buffer system, reduces the EC value of the soil, improves the water stable aggregate content of the soil, inhibits the reproduction of pathogenic bacteria, repairs the soil, and improves the microbial diversity and the survival rate of crops. DETAILED DESCRIPTION

[0020] The application will be described below in combination with specific embodiments. It should be noted that the following examples are only used to illustrate the application, and are not used to limit the application. Other combinations and various modifications within the concept of the application can be made without departing from the spirit or scope of the application.

[0021] The chemical reagents used in the application are commercially available and are of analytical purity unless otherwise specified.

[0022] The peat used in the present application is purchased from Huizhou Hengdong Hui Industrial Co., Ltd.; the rice hull charcoal is purchased from Shijiazhuang Chongbo Trade Co., Ltd., with a product number of 24; the Aspergillus niger strain is purchased from Shandong Changtai Biological Technology Co., Ltd., with a model number of ST-1; the chitosan is purchased from Henan Bangrun Chemical Product Co., Ltd., with a model number of BR-024; the degrading bacteria are purchased from Shandong Yingfida Biological Technology Co., Ltd., with a model number of YFD-SC-1616; the nitrogen-fixing bacteria are purchased from Hebei Sanpin Fertilizer Co., Ltd.; the bacillus is purchased from Jining Jin Yi Bacteria Biological Technology Co., Ltd.; the attapulgite is purchased from Lingshou County Qiangdong Mine Product Processing Factory, with a product number of qd-286.

[0023] Preparation of Aspergillus niger fermentation broth: 50 g of citric acid is weighed, added to 800 mL of deionized water, stirred until completely dissolved, then 0.2 g of Aspergillus niger strain is added, diluted to 1 L, and shaken uniformly to prepare the Aspergillus niger fermentation broth. The Aspergillus niger fermentation broth can be prepared according to the actual needs by repeating the above method. Note: The following preparation is based on weight parts.

[0024] The preparation method of the carbon bacteria composite material A includes the following steps: (1) 10 kg of rice hull charcoal and 20 kg of Aspergillus niger fermentation broth are mixed, and stirred at 25°C for 2 h using a magnetic stirrer; (2) The rice hull charcoal soaked in step (1) is dried in a 60°C oven for 24 h, then uniformly heated to 120°C and dried for 1 h, cooled to room temperature, washed with ultrapure water until the pH remains stable, then dried in a 60°C oven to obtain the Aspergillus niger fermentation broth modified biomass charcoal; (3) 6 kg of Aspergillus niger fermentation broth modified biomass charcoal prepared in step (2) is mixed with 1 kg of chitosan, and stirred uniformly to obtain the carbon bacteria composite material A.

[0025] Carbon bacteria composite material B: The difference from the preparation of carbon bacteria composite material A is that 6 kg of Aspergillus niger fermentation broth modified biomass charcoal and 1 kg of chitosan are replaced by 4 kg of Aspergillus niger fermentation broth modified biomass charcoal and 1 kg of chitosan (deacetylation degree 95%).

[0026] Carbon bacteria composite material C: The difference from the preparation of carbon bacteria composite material A is that 6 kg of Aspergillus niger fermentation broth modified biomass charcoal and 1 kg of chitosan (deacetylation degree 95%) are replaced by 2 kg of Aspergillus niger fermentation broth modified biomass charcoal and 5 kg of chitosan.

[0027] Carbon bacteria composite material D: The difference between the preparation of the carbon-bacteria composite material A is that 6 kg of the black aspergillus fermentation liquid modified biomass charcoal and 1 kg of chitosan are replaced by 7 kg of the black aspergillus fermentation liquid modified biomass charcoal.

[0028] Carbon-bacteria composite material E: The difference between the preparation of the carbon-bacteria composite material A is that 6 kg of the black aspergillus fermentation liquid modified biomass charcoal and 1 kg of chitosan are replaced by 6 kg of biomass charcoal (rice husk charcoal) and 1 kg of chitosan (deacetylation degree 95%).

[0029] Example 1: The preparation of the carbon-bacteria synergistic soil saline-alkali ameliorant includes the following steps: S1: 25 parts of peat (humic acid content 35 wt%, organic acid content 6 wt%), 40 parts of the carbon-bacteria composite material A are put into a blender, mixed at a speed of 60 r / min for 15 min, then 8 parts of the salt-tolerant bacteria agent (degradation bacteria and nitrogen-fixing bacteria mass ratio = 1:1, total effective viable count 1.2 x 10 9 CFU / g), 10 parts of organic material (potassium humate 8 parts, trehalose 2 parts) are added, and the mixing is continued for 20 min; S2: Then 17 parts of the auxiliary agent (sodium alginate 2 parts, gypsum 10 parts, attapulgite 5 parts) are added, and the mixture is uniformly mixed to form particles through an extrusion granulator with a pore size of 2 mm, thereby preparing the carbon-bacteria synergistic soil saline-alkali ameliorant.

[0030] Example 2: The preparation of the carbon-bacteria synergistic soil saline-alkali ameliorant includes the following steps: S1: 30 parts of peat (humic acid content 35 wt%, organic acid content 6 wt%), 35 parts of the carbon-bacteria composite material A are put into a blender, mixed at a speed of 60 r / min for 15 min, then 10 parts of the salt-tolerant bacteria agent (degradation bacteria and nitrogen-fixing bacteria mass ratio = 1:1, total effective viable count 2 x 10 9 CFU / g), 10 parts of organic material (potassium humate 8 parts, carboxymethyl cellulose 2 parts) are added, and the mixing is continued for 20 min; S2: Then 15 parts of the auxiliary agent (sodium alginate 3 parts, gypsum 7 parts, attapulgite 5 parts) are added, and the mixture is uniformly mixed to form particles through an extrusion granulator with a pore size of 2 mm, thereby preparing the carbon-bacteria synergistic soil saline-alkali ameliorant.

[0031] Example 3: The difference between the preparation of the carbon-bacteria synergistic soil saline-alkali ameliorant in this example and in Example 1 is that the carbon-bacteria composite material A is replaced by the carbon-bacteria composite material B.

[0032] Example 4: The difference between this embodiment and the preparation of the carbon-bacterial synergistic soil salinity improver in Embodiment 1 is that carbon-bacterial composite material A is replaced with carbon-bacterial composite material C.

[0033] Example 5: The difference between this embodiment and the preparation of the carbon-bacterial synergistic soil salinity improver in Embodiment 1 is that carbon-bacterial composite material A is replaced with carbon-bacterial composite material D.

[0034] Example 6: The difference between this embodiment and the preparation of the carbon-bacterial synergistic soil salinity improver in Embodiment 1 is that carbon-bacterial composite material A is replaced with carbon-bacterial composite material E.

[0035] Example 7: The difference between this preparation example and Example 1 (carbon-bacterial synergistic soil salinity conditioner) is that the salt-tolerant bacteria agent is replaced with Bacillus (effective viable count 2 × 10⁻⁶). 9 CFU / g).

[0036] Performance testing methods: 1. Reduction rate of soil EC value: Severe saline-alkali soil (initial EC = 8.5 mS / cm) was treated with soil conditioner at 2% of its mass, while the control group was not treated. The soil was incubated at 25℃ with water control at 60% of field capacity. After 60 days, the soil was collected and a soil-water ratio of 1:5 was prepared and shaken for 30 minutes. The extract was obtained by centrifugation and filtration. The EC value was measured using a conductivity meter. The reduction rate of EC value (%) = (initial EC value - measured EC value) / initial EC value × 100%.

[0037] 2. Water-stable aggregate content: 30 days after the application of the soil conditioner, soil samples were collected from the top 20cm layer, and the proportion of 0.25mm-2mm aggregates was determined by wet sieving (2mm, 1mm, 0.5mm, and 0.25mm sieves).

[0038] 3. Crop survival rate: Corn was planted in pots with 3 plants per pot. 2% soil conditioner was applied, with no conditioner as a control. The number of surviving plants was recorded 30 days after emergence, and the survival rate was calculated as follows: Survival rate (%) = Number of surviving plants / Number of planted plants × 100%.

[0039] Performance test results table 1:

[0040] As shown in Table 1, the carbon-bacterial synergistic soil salinity conditioner of the present invention can effectively improve the EC value of severely saline-alkali soil, increase the content of water-stable aggregates in the soil, and improve crop survival rate. Specifically, the EC value reduction rate of Examples 1-3 is 65%-71%, the aggregate content reaches 52%-58%, and the crop survival rate reaches 85%-92%. The conditioner can effectively reduce soil salinity, significantly improve soil structure, increase aggregate stability, alleviate saline-alkali stress, and promote root development. A comparison of Example 4 and Example 1 shows that when the relative content of chitosan in the carbon-bacterial composite material is too high, the conditioner's ability to reduce soil EC value, the content of water-stable aggregates, and the crop survival rate all decrease, indicating that the chitosan ratio needs to be controlled within a reasonable range. In Example 5, the carbon-bacterial composite material does not contain chitosan, and its various indicators are further reduced, compared with Example 1. The difference is even more obvious, fully demonstrating the synergistic effect between chitosan and Aspergillus niger fermentation broth modified biochar. In Example 6, the carbon-bacterial composite material was replaced with unmodified original rice husk char, and the EC value reduction rate, aggregate content, and crop survival rate decreased significantly, only slightly higher than the blank control. This indicates that the modification treatment of Aspergillus niger fermentation broth is the key to improving the function of biochar. Unmodified biochar cannot achieve the synergistic effect of carbon and bacteria and cannot achieve the expected results. In Example 7, Bacillus subtilis was used to replace the salt-tolerant compound bacterial agent, and the improvement effect was significantly weakened. This indicates that the compound bacterial agent achieves a synergistic effect through functional complementarity, with degrading bacteria reducing salt ion toxicity and nitrogen-fixing bacteria improving soil fertility.

[0041] This invention can also be implemented in various other ways. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A carbon bacteria synergistic soil salinity ameliorant characterized in that, The raw materials for preparing the carbon-bacteria synergistic soil saline-alkali improvement agent include peat, carbon-bacteria composite material, salt-tolerant bacteria agent, organic material, and auxiliary agent.

2. The carbon-based microbial synergistic soil salinity ameliorant according to claim 1, characterized in that, The raw materials for preparing the carbon-bacteria synergistic soil saline-alkali improvement agent include 20-40 parts of peat, 30-50 parts of carbon-bacteria composite material, 5-15 parts of salt-tolerant bacteria agent, 8-15 parts of organic material, and 15-25 parts of auxiliary agent.

3. The carbon-based microbial synergistic soil salinity ameliorant according to claim 1, characterized in that, The content of humic acid in the peat is ≥30 wt%, and the content of organic acid is ≥5 wt%. The salt-tolerant bacterial agent comprises degrading bacteria and nitrogen-fixing bacteria, and the effective viable bacterial count of the salt-tolerant bacterial agent is ≥1×10 9 CFU / g.

4. The carbon-based microbial synergistic soil salinity ameliorant according to claim 1, characterized in that, The organic material is one or more of potassium humate, trehalose, and carboxymethyl cellulose. The auxiliary agent is one or more of sodium alginate, gypsum, and attapulgite.

5. The carbon-based microbial consortium soil salinity ameliorant according to claim 1, wherein, The carbon-bacteria composite material is a mixture of black aspergillus fermentation liquid modified biomass charcoal and chitosan.

6. The carbon-based microbial consortium soil salinity amendment of claim 1, wherein, The preparation method of the carbon-bacteria composite material includes the following steps: (1) mixing biomass charcoal and black aspergillus fermentation liquid, and stirring at 25-30°C for 1-2 h using a magnetic stirrer; (2) drying the biomass charcoal immersed in step (1) in an oven at 60-70°C for 18-24 h, then uniformly heating to 100-120°C for 1-2 h, cooling to room temperature, washing with ultrapure water until the pH remains stable, and then drying in an oven at 60-70°C to obtain the black aspergillus fermentation liquid modified biomass charcoal; (3) mixing the black aspergillus fermentation liquid modified biomass charcoal prepared in step (2) with chitosan, and stirring uniformly to obtain the carbon-bacteria composite material.

7. The carbon-based microbial consortium soil salinity ameliorant according to claim 5, characterized in that, The biomass charcoal is rice husk charcoal, and the mass ratio of the biomass charcoal to the black aspergillus fermentation liquid is 1:1-3; the content of citric acid in the black aspergillus fermentation liquid is ≥50 g / L; and the degree of deacetylation of the chitosan is ≥90%.

8. The carbon-based microbial consortium soil salinity amendment of claim 5, wherein, The mass ratio of the black aspergillus fermentation liquid modified biomass charcoal to chitosan is 4-6:

1.

9. The method for preparing the carbon-microbe synergistic soil salinity ameliorant according to any one of claims 1-8, characterized in that, The method includes the following steps: S1: placing peat and carbon-bacteria composite material into a blender, mixing at a speed of 50-80 r / min for 10-15 min, then adding salt-tolerant bacteria agent and organic material, and continuing to mix for 15-20 min; S2: then adding auxiliary agent, mixing uniformly, and then passing through an extrusion granulator with a pore size of 2-4 mm to form particles, thereby obtaining the carbon-bacteria synergistic soil saline-alkali improvement agent.

10. The carbon-bacteria synergistic soil saline-alkali improvement agent according to any one of claims 1-8 for use in improving saline-alkali soil.

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