Preparation method of carbon-vinegar organic fertilizer for saline-alkali soil improvement

Abstract

The invention discloses a preparation method of a carbon-vinegar organic fertilizer for improvement of saline-alkali soil, the pH of the organic fertilizer is adjusted and the porosity of the organic fertilizer is increased through the characteristics of acidity of pyroligneous liquor and physical structure of biochar, so that the soil acidity and alkalinity of the saline-alkali soil and the soil hardening condition are improved, meanwhile, the content of organic substances is increased, and the growth conditions of crops are met.

Description

Technical Field

[0001] The invention belongs to the technical field of organic fertilizers, and in particular relates to a method for preparing carbon vinegar organic fertilizer for improving saline-alkali land. Background Art

[0002] Saline-alkali land has the characteristics of high soil salt content, high alkalinity, poor physical structure, poor water permeability and aeration, and lack of nutrients, which are not conducive to soil microbial activity. Its soil characteristics also seriously restrict the growth and development of crops and affect crop yields. Existing studies have shown that organic fertilizers can improve soil physical structure from physical, chemical and microbiological perspectives, increase soil organic matter content, accelerate salt leaching, promote crop growth and development, and increase crop yields.

[0003] The present application proposes a method for preparing charcoal vinegar organic fertilizer for saline-alkali land improvement, which has the advantages of simple preparation method, applicability to saline-alkali land acid-base balance machine land improvement, good use effect, etc. The method adjusts the pH of organic fertilizer and increases the porosity of organic fertilizer through the characteristics of wood vinegar acidity and physical structure of biochar, thereby improving the soil pH and soil compaction in saline-alkali land, and at the same time increasing the organic matter content to meet the conditions for crop growth. Summary of the invention

[0004] The invention discloses a method for preparing a charcoal vinegar organic fertilizer for improving saline-alkali land, which can improve the pH value and soil compaction of the saline-alkali land.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The invention discloses a method for preparing carbon vinegar organic fertilizer for improving saline-alkali land, comprising the following steps: Step 1, biochar preparation: (1-1) Crush the straw into 2-3 cm, spread it flat on a tray and place it in the carbonization chamber in sequence; the straw may be cotton straw; (1-2) Close the door of the carbonization furnace and ensure that the carbonization chamber is in a sealed state in order to control the oxygen supply during the carbonization process; (1-3) Before starting the formal carbonization, preheating is performed to gradually increase the temperature inside the carbonization furnace to prepare for the subsequent carbonization process; (1-4) Control the temperature inside the carbonization furnace to 300°C and keep the temperature constant for 2 hours, so that the raw materials undergo pyrolysis reaction at high temperature and gradually transform into carbonized products; (1-5) After the carbonization process is completed, the carbonized product is allowed to cool in a natural environment for subsequent processing and collection.

[0006] Step 2, preparation of wood vinegar: (2-1) collecting the flue gas through a condensation system, converting it into liquid, and collecting crude wood vinegar; (2-2) The crude wood vinegar is stored in a light-proof container and allowed to stand. The mixture is filtered through a 200-mesh mesh bag once every 24 hours for 1 to 5 times. After standing for 30 days, the mixture is filtered again through a 400-mesh mesh bag for later use.

[0007] Step 3: Preparation of carbon-based organic fertilizer: (3-1) Collection of pig manure raw materials: Collect fresh pig manure from nearby farms, separate the dry and wet parts, and then dry them for later use; (3-2) Straw crushing and collection: crush the straw into 2-3 cm using a small crusher and collect it for later use; the straw can be rice straw; (3-3) Mixing ratio of straw, biochar and pig manure (by mass): 1:1:20; the straw may be rice straw; (3-4) Moisture content is 55%-60%; (3-5) For windrow composting combined with a composting machine, the height of the windrow should not be less than 1.2m, and the remaining stacking dimensions can be adapted to the composting machine; (3-6) The composting cycle is about 49 days until the temperature of the pile is consistent with the ambient temperature, and the moisture content should be less than 10%.

[0008] Step 4, preparation of charcoal vinegar organic fertilizer: After the wood vinegar and charcoal-based organic fertilizer are fully mixed, the pH value is weakly acidic (6-7). The charcoal vinegar organic fertilizer should be stored or granulated after the moisture content is lower than 30%.

[0009] The present invention has the following advantages: The composting method adopts the strip-type film-covered composting, combined with the staged compost turning by the compost turning machine, which can meet the requirements of moisture content and oxygen concentration in the open-air composting process, and has a crushing effect on the organic fertilizer materials, preventing the materials from agglomerating, thereby improving the quality of the organic fertilizer products. Due to the presence of acidic substances (acetic acid, etc.) in wood vinegar, the acidification effect is achieved by fully mixing with carbon-based organic fertilizers; in addition, carbon-based organic fertilizers themselves have the effect of increasing soil porosity. Therefore, the present invention can achieve the goal of improving the pH value and soil compaction of saline-alkali land, while increasing the content of organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a graph showing the change in pH of saline-alkali land over time when carbon vinegar organic fertilizer is used in the examples.

[0011] Figure 2 This is a graph showing the change in salinity of saline-alkali land over time using carbon vinegar organic fertilizer in the example.

[0012] Figure 3 This is a graph showing the change of organic matter in saline-alkali land over time with carbon vinegar organic fertilizer in the example.

[0013] Figure 4The growth conditions of seeds in saline-alkali soil in the examples are shown in Figure 2, which were returned to the field for one month and which were not returned to the field.

[0014] Figure 5 Basic properties of soil.

[0015] Figure 6 The basic properties of charcoal vinegar organic fertilizer. DETAILED DESCRIPTION

[0016] The above contents of the present invention are further described in detail below through embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Embodiment 1: This embodiment discloses a method for preparing a carbon vinegar organic fertilizer as follows, comprising the following steps: (1) Raw material collection: Cotton straw and rice straw were collected from farmland around the 12th Regiment of Alar; pig manure was collected from the breeding farm of the 12th Regiment of Alar.

[0018] (2) Raw material processing: Cotton straw and rice straw are crushed to 2-3 cm respectively; pig manure is piled up after dry and wet separation.

[0019] (3) Biochar preparation: Use a drawer-type carbonization furnace for pyrolysis. Spread 8 kg of crushed cotton straw onto a tray and place it in the carbonization chamber one by one. Close the door of the carbonization furnace to ensure that the carbonization chamber is in a sealed state. Before starting formal carbonization, preheat the furnace to gradually increase the temperature inside the carbonization furnace. Control the temperature inside the carbonization furnace to 300 °C and keep it at a constant temperature for 2 hours to allow the raw materials to undergo pyrolysis reaction at high temperature and gradually convert into charcoal or other carbonized products. After the carbonization process is completed, allow the carbonized product to cool in a natural environment for subsequent processing and collection.

[0020] (4) Preparation of wood vinegar: The flue gas is collected by a condensation system and converted into liquid to obtain crude wood vinegar; the crude wood vinegar is stored in a light-proof container and allowed to stand, filtered once every 24 hours through a 200-mesh mesh bag, and filtered 1-5 times respectively. After standing for 30 days, it is filtered again through a 400-mesh mesh bag and set aside. The pH value of the obtained wood vinegar is about 5.18-7.00.

[0021] (5) Preparation of carbon-based organic fertilizer: crushed rice straw, biochar and pig manure after dry-wet separation are mixed in a mass ratio of 1:1:20 to form a 2m wide, 1.5m high and 20m long strip pile. Slots are opened in the pile and water is added to the pile until the moisture content is 55-60%. After the mixture is evenly mixed with a composting machine, it is turned on the 1st, 3rd, 7th, 14th, 21st, 28th, 35th, 42nd and 49th day. The composting cycle is 49 days in total. In view of the dry weather in Xinjiang, plastic film is used for moisturizing during composting. After composting, the moisture content of the carbon-based organic fertilizer should be naturally dried to 10%. The pH value of the obtained carbon-based organic fertilizer should be between 7 and 9.

[0022] (6) Preparation of charcoal vinegar organic fertilizer: After wood vinegar and charcoal-based organic fertilizer are fully mixed in a turning machine at a mass ratio of 2:10, the pH value is weakly acidic (6-7). The charcoal vinegar organic fertilizer should be stored or granulated after the moisture content is lower than 30%.

[0023] (7) A micro-area experiment was conducted in a farmland near Tarim University (cotton planting). The prepared charcoal vinegar organic fertilizer (500 kg) was applied to the demarcated land area (10×10 m), and the soil was turned over to allow the organic fertilizer to be fully mixed with the soil. The mixing depth was within 30 cm from the surface. Soil pH, salinity, and organic matter index parameters were tested. The five-point sampling method was used. After sampling, 500 g of the samples were evenly mixed. Sampling was performed every 4 days, for a total of 7 times.

[0024] (8) pH was measured using a conventional electronic pH meter, salinity was measured using an ECS-3C EC meter, and organic matter content was measured using the potassium dichromate volumetric method-dilution heat method. The initial value ranges of various indicators of saline-alkali soil and charcoal vinegar organic fertilizer are as follows: Figure 5 , Figure 6 shown.

[0025] (9) Explanation of pH, salinity, and total organic matter rules: Figure 1 As shown in the figure, after the saline-alkali soil and charcoal vinegar organic fertilizer were fully mixed, the initial pH was significantly reduced due to the acidity and alkalinity of the material itself; however, as time went by, the pH gradually increased, which may be due to the H + With alkaline OH in the soil - Neutralization, resulting in H + The release and loss of organic fertilizers and microorganisms in the soil in this area may have achieved acid-base balance control. Figure 2 As shown in the figure, after the saline-alkali soil and the charcoal vinegar organic fertilizer were fully mixed, the initial salinity was reduced to a certain extent due to the salinity of the material itself; later, due to high temperature and drought, the soil moisture was lost, causing the salinity to fluctuate and increase over time. Figure 3As shown in the figure, after the saline-alkali soil and charcoal vinegar organic fertilizer were fully mixed, the initial total organic matter was greatly increased due to the organic matter content of the material itself; during the first 8 days, the total organic matter content showed a downward trend, which may be due to the presence of charcoal vinegar organic fertilizer, which improved the microbial environment and consumed part of the organic matter in its metabolic activities; starting from the 8th day, the total organic matter content increased and then fluctuated steadily, which may be due to the fact that microorganisms degraded the residual straw and branches returned to the farmland soil, causing the content to show an increasing trend.

[0026] (10) Seed growth: Weigh samples of saline-alkali soil that had been returned to the field for one month and saline-alkali soil that had not been returned to the field, add 100 ml of distilled water, shake at room temperature for 1 hour, let stand for 24 hours, filter, and draw 5 ml of the filtrate into a 9 cm culture dish covered with a layer of filter paper. Evenly arrange 20 plump cabbage seeds in the culture dish, and culture in a constant temperature incubator at 28°C for 48 hours to observe the growth of the seeds. Figure 4 As shown, the overall length of seed sprouts and roots in the saline-alkali soil that had been returned to the field for one month was better than that in the saline-alkali soil that had not been returned to the field, and the overall average length was 1.105 cm higher.

[0027] (11) Conclusion: Within one month of returning charcoal vinegar organic fertilizer to the field, the soil pH and salinity were improved to varying degrees compared with the saline-alkali soil that had not been returned to the field, and the organic matter content was also increased.

Claims

1. A method for preparing charcoal vinegar organic fertilizer for improving saline-alkali land; comprising the following steps: Step 1: preparing biochar and wood vinegar: crushing the straw, spreading it on a tray and sequentially placing it in the carbonization chamber of the drawer-type carbonization furnace to obtain solid biochar and liquid wood vinegar; Step 2: Evenly mix the biochar, straw and pig manure prepared in step 1, and then perform windrow aerobic composting to obtain carbon-based organic fertilizer; Step 3: Evenly mix the wood vinegar obtained in step 1 and the carbon-based organic fertilizer obtained in step 2 to obtain carbon vinegar organic fertilizer.

2. The method for preparing carbon vinegar organic fertilizer for improving saline-alkali land according to claim 1, characterized in that: The straw in step 1 is cotton straw, which is crushed to 2-3 cm, and the pyrolysis temperature in the drawer-type carbonization furnace is 300° C. and the temperature is kept constant for 2 hours.

3. The method for preparing carbon vinegar organic fertilizer for improving saline-alkali land according to claim 1, characterized in that: The straw used in step 2 is rice straw.

4. The method for preparing carbon vinegar organic fertilizer for improving saline-alkali land according to claim 1, 2 or 3, characterized in that: In the step 2, the mass ratio of biochar, straw and pig manure is 1:1:20; the straw is crushed to 1-2 cm; the pig manure needs to be separated into dry and wet parts; the moisture content of the mixed compost is 55-60%; the natural stacking height of the pile should not be less than 1.2 m, and the other stacking dimensions can be adapted to the spiral composting machine; the composting rules are carried out according to the composting days of 49 days, and the composting is carried out on the 1st, 3rd, 7th, 14th, 21st, 28th, 35th, 42nd and 49th days respectively; the film treatment is adopted during the composting period, and the moisture content of the charcoal-based organic fertilizer should be ensured to be below 10% after the composting is completed.

5. The method for preparing carbon vinegar organic fertilizer for improving saline-alkali land according to claim 1, characterized in that: The wood vinegar obtained in the step 1 should be stored in a light-proof container and allowed to stand, filtered once every 24 hours through a 200-mesh mesh bag, filtered 1-5 times respectively, and then allowed to stand for 30 days and then filtered again through a 400-mesh mesh bag for standby use; after the standby wood vinegar is fully mixed with the charcoal-based organic fertilizer, the pH value is weakly acidic (6-7), and the charcoal-based organic fertilizer should be stored after the moisture content is lower than 30%.

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