Method for relieving facility cultivation soil secondary salinization and improving lettuce yield

Abstract

The invention relates to a method for relieving facility cultivation soil secondary salinization and improving lettuce yield, which comprises the following steps: applying a soil conditioner to planting soil, sowing lettuce, and irrigating with hydrogen-rich water until the lettuce is harvested; the soil conditioner comprises a combination of iron modified biochar and humic acid. According to the method, the combination of the iron modified charcoal and the humic acid is adopted as the soil conditioner, and meanwhile, the hydrogen-rich water is adopted for irrigation, so that the salinity of the facility cultivation soil can be quickly and effectively reduced, the soil acidification is slowed down, the yield of lettuce is promoted to be increased, and an economic, environment-friendly and easy-to-popularize mode is provided for improving the conservation of the facility cultivation soil.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. Background Art

[0002] As one of the important methods of modern agricultural production, facility agriculture has played a huge role in the cultivation of vegetables and other important cash crops in my country, and has achieved significant economic and social effects. While the rapid development of facility cultivation agriculture has provided a strong guarantee for increasing vegetable yields, the problem of secondary salinization of facility cultivation soil has become increasingly prominent due to high multiple cropping index, large amounts of fertilizer input, and lack of natural leaching.

[0003] Secondary salinization will disrupt the original acid-base balance of the soil, causing the soil to become acidic, the soil nutrients to be unbalanced, and some nutrients to be unable to be absorbed by crops; it will also cause changes in soil structure, severe compaction, shallower plowing layers, and poorer ventilation and water permeability. Secondary salinization of the soil, due to its high salt concentration, prevents crop roots from effectively absorbing water and nutrients from the soil, resulting in nutrient deficiency symptoms, manifested as weak plant growth, yellowing, wilting, and weak roots. In severe cases, the roots die, causing the entire plant to die, seriously affecting crop growth. In addition, soil salinization causes crop dehydration, affects normal respiration, reduces immunity, and makes it easier to be infected by pathogens, causing leaf and fruit diseases, resulting in reduced yield and quality of the product.

[0004] Lettuce is well-known for its raw food, rich nutrition, crisp taste, and many ways of eating, and is deeply loved by consumers. Lettuce has high economic value, and its planting area has increased year by year, becoming one of the crops with the largest planting area of ​​hydroponic vegetables at home and abroad.

[0005] Therefore, providing a method that can quickly reduce the salinity of facility-cultivated soil, slow down soil acidification, and promote the increase of lettuce yield is a technical problem that needs to be solved urgently in the field. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for alleviating secondary salinization of facility cultivation soil and increasing lettuce yield. The present invention uses a combination of iron-modified biochar and humic acid as a soil conditioner, and uses hydrogen-rich water for irrigation, which can quickly and effectively reduce the salinity of facility cultivation soil, slow down soil acidification, and promote the increase of lettuce yield, providing an economical, environmentally friendly and easy-to-promote method for improving facility cultivation soil conservation.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield, the method comprising: applying a soil conditioner to the planting soil and then sowing lettuce, and irrigating with hydrogen-rich water until the lettuce is harvested; the soil conditioner comprises a combination of iron-modified biochar and humic acid.

[0009] In the present invention, the porous structure of the iron-modified biochar may adsorb more hydrogen-rich water, allowing the hydrogen-rich water to remain in the soil for a long time, continuously affecting the secondary salinization remediation of the soil, and serving as a fertilizer to provide easily absorbed nutrients for lettuce during facility cultivation.

[0010] The present invention uses a combination of iron-modified biochar and humic acid as a soil conditioner, which synergistically enhances the effect of reducing the salinity of facility-cultivated soil and promoting the increase of lettuce yield. At the same time, the present invention creatively uses hydrogen-rich water to replace conventional water, which can further improve the soil and increase the yield of lettuce.

[0011] Preferably, the concentration of hydrogen in the hydrogen-rich water is 0.5-2 ppm, for example, it can be 0.6 ppm, 0.8 ppm, 1 ppm, 1.2 ppm, 1.4 ppm, 1.6 ppm, 1.8 ppm, etc.

[0012] In the present invention, the concentration of hydrogen in hydrogen-rich water will affect the effect of reducing soil salinity and increasing lettuce yield. When the concentration of hydrogen-rich water is within the preferred range of 1.2-1.8 ppm, the irrigation effect can be further improved.

[0013] Preferably, the irrigation frequency of the hydrogen-rich water is once every 5-10 days (for example, it may be once every 5.5 days, 6 days, 6.5 days, 7 days, 7.5 days, 8 days, 8.5 days, 9 days, etc.).

[0014] Preferably, the hydrogen-rich water is irrigated each time until the soil is soaked to 10-15 cm below the soil layer, for example, it can be 10.5 cm, 11 cm, 11.5 cm, 12 cm, 12.5 cm, 13 cm, 13.5 cm, 14 cm, 14.5 cm, etc.

[0015] Preferably, the application amount of the iron-modified biochar is 45-65 kg / mu, for example, it can be 48 kg / mu, 50 kg / mu, 52 kg / mu, 55 kg / mu, 58 kg / mu, 60 kg / mu, 62 kg / mu, etc.

[0016] Preferably, the application amount of humic acid is 50-150 kg / mu, for example, it can be 60 kg / mu, 70 kg / mu, 80 kg / mu, 90 kg / mu, 100 kg / mu, 110 kg / mu, 120 kg / mu, 130 kg / mu, 140 kg / mu, etc.

[0017] Preferably, the iron-modified biochar is prepared by the following method, which comprises the following steps:

[0018] (1) drying and carbonizing the biomass in sequence to obtain biochar;

[0019] (2) The biochar is immersed in an aqueous solution of iron salt, mixed and heated to obtain iron-modified biochar.

[0020] In the present invention, the iron-modified biochar prepared by the above-mentioned specific preparation method has a more excellent effect of reducing the salinity of facility cultivation soil and increasing lettuce yield.

[0021] Preferably, in step (1), the biomass comprises any one of straw, rice husk, bamboo chips, wood chips or sludge, or a combination of at least two of them.

[0022] Preferably, in step (1), the drying temperature is 50-60°C, for example, 52°C, 54°C, 55°C, 56°C, 58°C, etc.

[0023] Preferably, in step (1), the drying is performed until the biomass mass becomes constant.

[0024] Preferably, in step (1), the carbonization temperature rising program is: initial temperature 20-50°C (for example, it can be 25°C, 30°C, 35°C, 40°C, 45°C, etc.), heating at 10-15°C / min (for example, it can be 10.5°C / min, 11°C / min, 11.5°C / min, 12°C / min, 12.5°C / min, 13°C / min, 13.5°C / min, 14°C / min, 14.5°C / min, etc.) to 300-700°C (for example, it can be 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, etc.), and keeping warm for 1.5-2.5h (for example, it can be 1.6h, 1.8h, 2h, 2.2h, 2.4h, etc.).

[0025] Preferably, in step (1), the carbonization is carried out in a nitrogen atmosphere.

[0026] Preferably, in step (2), based on the amount of biochar used being 1 g, the amount of the iron salt aqueous solution used is 2-3 mL, for example, 2.2 mL, 2.4 mL, 2.5 mL, 2.6 mL, 2.8 mL, etc., and the concentration of the iron salt aqueous solution is 0.05-0.07 M, for example, 0.052 M, 0.055 M, 0.058 M, 0.06 M, 0.062 M, 0.065 M, 0.068 M, etc.

[0027] Preferably, in step (2), the iron salt comprises any one of ferric chloride, ferric sulfate, ferric nitrate or ferric carbonate, or a combination of at least two thereof.

[0028] Preferably, in step (2), the heating temperature program is: initial temperature 20-50°C (for example, it can be 25°C, 30°C, 35°C, 40°C, 45°C, etc.), heating at 8-12°C / min (for example, it can be 8.5°C / min, 9°C / min, 9.5°C / min, 10°C / min, 10.5°C / min, 11°C / min, 11.5°C / min, etc.) to 550-650°C (for example, it can be 560°C, 580°C, 600°C, 620°C, 640°C, etc.), and keeping warm for 20-40min (for example, it can be 22min, 25min, 28min, 30min, 32min, 35min, 38min, etc.).

[0029] Preferably, the method comprises: applying 45-65 kg / mu of iron-modified biochar and 50-150 kg / mu of humic acid to the planting soil, then sowing lettuce, irrigating once every 5-10 days with hydrogen-rich water having a hydrogen concentration of 0.5-2 ppm until the lettuce is harvested, and irrigating each time until the soil is soaked to 10-15 cm below the soil layer;

[0030] The iron-modified biochar is prepared by the following method, which comprises the following steps:

[0031] (1) drying the rice straw at 50-60° C. to a constant mass, and then carbonizing the rice straw in a nitrogen atmosphere to obtain biochar; the carbonization temperature program is as follows: an initial temperature of 20-50° C., heating to 300-700° C. at a rate of 10-15° C. / min, and keeping the temperature for 1.5-2.5 h;

[0032] (2) Based on the amount of the biochar being 1 g and the amount of the iron salt aqueous solution being 2-3 mL, the biochar is immersed in a 0.05-0.07 M iron salt aqueous solution, mixed and then heated to obtain iron-modified biochar; the heating program is as follows: initial temperature 20-50° C., heating to 550-650° C. at 8-12° C. / min, and keeping warm for 20-40 min.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The present invention uses a combination of iron-modified biochar and humic acid as a soil conditioner, which synergizes to reduce the salinity of facility-cultivated soil and promote the increase of lettuce yield. At the same time, the present invention creatively uses hydrogen-rich water to replace conventional water, which can further improve the soil and increase the yield of lettuce, providing an economical, environmentally friendly and easy-to-promote method for improving facility-cultivated soil conservation. DETAILED DESCRIPTION

[0035] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0036] The sources of materials used in the following examples are as follows:

[0037] Rice straw was collected from the Zhuangxing Experimental Base of Shanghai Academy of Agricultural Sciences (30°53′N, 121°23′E);

[0038] Organic fertilizer uses pig manure organic fertilizer, with organic matter greater than 70%;

[0039] The herbicide was acetochlor, produced by Source Leaf Company;

[0040] Humic acid is produced by Huanneng Company.

[0041] Preparation Example 1

[0042] This preparation example provides a method for preparing iron-modified biochar, which comprises the following steps:

[0043] (1) The rice straw was dried at 55°C until the mass was constant and then placed in a tubular furnace. The entire pipe was evacuated to a vacuum (-0.5MPa) using an air pump, and then nitrogen was passed until the outlet reached (+0.02MPa). At this time, the pyrolysis atmosphere in the furnace was high-purity nitrogen. The initial temperature was 40°C, the heating rate was 12.5°C / min, the temperature was raised to 500°C, the temperature was kept for 2h, and the biochar was taken out after cooling to room temperature.

[0044] (2) The prepared biochar (16.675 g) was immersed in a FeCl3·H2O (40 mL, 0.06 M) solution and ultrasonically mixed. The temperature was raised to 600°C at a rate of 10°C / min using a drawer-type muffle furnace at an initial temperature of 40°C and a heat preservation rate of 30 min to obtain iron-modified biochar.

[0045] Preparation Example 2

[0046] This preparation example provides a method for preparing iron-modified biochar, which comprises the following steps:

[0047] (1) The rice husk was dried at 50°C until the mass was constant and then placed in a tubular furnace. The entire pipe was evacuated to a vacuum (-0.5MPa) using an air pump, and then nitrogen was passed until the outlet reached (+0.02MPa). At this time, the pyrolysis atmosphere in the furnace was high-purity nitrogen. The initial temperature was 25°C, the heating rate was 10°C / min, the temperature was raised to 300°C, the temperature was kept for 2.5h, and the biochar was taken out after cooling to room temperature.

[0048] (2) The prepared biochar (16.675 g) was immersed in a Fe2(SO4)3 (32 mL, 0.07 M) solution. After ultrasonic mixing, the temperature was raised to 550°C at an initial temperature of 25°C and a heating rate of 8°C / min in a drawer-type muffle furnace. The temperature was kept at this temperature for 40 min to obtain iron-modified biochar.

[0049] Preparation Example 3

[0050] This preparation example provides a method for preparing iron-modified biochar, which comprises the following steps:

[0051] (1) The sawdust was dried at 60°C until the mass was constant and then placed in a tubular furnace. The entire pipe was evacuated to a vacuum (-0.5MPa) using an air pump, and then nitrogen was passed until the outlet reached (+0.02MPa). At this time, the pyrolysis atmosphere in the furnace was high-purity nitrogen. The initial temperature was 50°C, the heating rate was 15°C / min, the temperature was raised to 700°C, the temperature was kept for 1.5h, and the biochar was obtained after cooling to room temperature.

[0052] (2) The prepared biochar (16.675 g) was immersed in a Fe(NO3)3 (50 mL, 0.05 M) solution. After ultrasonic mixing, the temperature was raised to 650°C at an initial temperature of 50°C and a heating rate of 12°C / min in a drawer-type muffle furnace. The temperature was kept at this temperature for 20 min to obtain iron-modified biochar.

[0053] Comparative Preparation Example 1

[0054] This comparative preparation example provides a method for preparing biochar, which differs from Preparation Example 1 only in that the modification process of step (2) is not performed to obtain biochar.

[0055] Example 1

[0056] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield, the method comprising:

[0057] Apply 500 kg / mu of organic fertilizer, herbicide (0.05-0.07 liters of 90% acetochlor emulsifiable concentrate per mu, 30-50 kg of water per mu), 55 kg / mu of iron-modified biochar prepared in Preparation Example 1, and 100 kg / mu of humic acid to the planting soil, and then sow lettuce. Every 7 days, irrigate once with 1.5 ppm hydrogen-rich water until the lettuce is harvested, and irrigate until the soil is soaked to 13 cm below the soil layer each time.

[0058] Example 2

[0059] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield, the method comprising:

[0060] Apply 500 kg / mu of organic fertilizer, herbicide (0.05-0.07 liters of 90% sethoxydim emulsifiable concentrate per mu, diluted with 30-50 kg of water per mu), 45 kg / mu of iron-modified biochar prepared in Preparation Example 2, and 150 kg / mu of humic acid to the planting soil, and then sow lettuce. Every 5 days, irrigate once with 1.8 ppm hydrogen-rich water until the lettuce is harvested, and irrigate until the soil is soaked to 15 cm below the soil layer each time.

[0061] Example 3

[0062] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield, the method comprising:

[0063] Apply 500 kg / mu of organic fertilizer, herbicide (0.05-0.07 liters of 90% sethoxydim emulsifiable concentrate per mu, 30-50 kg of water per mu), 65 kg / mu of iron-modified biochar prepared in Preparation Example 3, and 50 kg / mu of humic acid to the planting soil, and then sow lettuce. Every 10 days, irrigate once with 1.2 ppm hydrogen-rich water until the lettuce is harvested, and irrigate until the soil is soaked to 10 cm below the soil layer each time.

[0064] Example 4

[0065] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between this embodiment and Embodiment 1 is that 0.5 ppm hydrogen-rich water is used for irrigation. Other operations refer to Embodiment 1.

[0066] Example 5

[0067] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between this embodiment and Embodiment 1 is that 1 ppm hydrogen-rich water is used for irrigation. Other operations refer to Embodiment 1.

[0068] Example 6

[0069] This embodiment provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between this embodiment and Embodiment 1 is that 2 ppm hydrogen-rich water is used for irrigation. Other operations refer to Embodiment 1.

[0070] Comparative Example 1

[0071] This comparative example provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between it and Example 1 is that the iron-modified biochar prepared in Preparation Example 1 is replaced by the biochar prepared in Comparative Preparation Example 1, and other operations refer to Example 1.

[0072] Comparative Example 2

[0073] This comparative example provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between this comparative example and Example 1 is that iron-modified biochar is not applied, and its application amount is allocated to humic acid. Other operations refer to Example 1.

[0074] Comparative Example 3

[0075] This comparative example provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The only difference between this comparative example and Example 1 is that humic acid is not applied, and its application amount is allocated to iron-modified biochar. Other operations refer to Example 1.

[0076] Comparative Example 4

[0077] This comparative example provides a method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield. The difference between this method and Example 1 is that water is used instead of hydrogen-rich water for irrigation, and other operations refer to Example 1.

[0078] Test Example 1

[0079] Lettuce was planted according to the methods for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield provided in Examples 1-6 and Comparative Examples 1-4, and the yield and soil soluble salt content and other information were statistically analyzed after harvest. The results are shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] The test results show that:

[0084] (1) It can be seen from Examples 1 to 6 that the present invention uses iron-modified biochar and humic acid as soil conditioners and uses hydrogen-rich water for irrigation, which can not only reduce the salt content in facility soil and improve secondary salinization, but also improve the yield and quality of lettuce.

[0085] (2) By comparing Example 1 with Examples 4-6, it can be seen that when the concentration of hydrogen-rich water is higher or lower, the effect of alleviating soil secondary salinization and increasing lettuce yield will be reduced. The present invention can achieve better technical effects of improving soil and increasing lettuce yield by further controlling the concentration of hydrogen-rich water.

[0086] (3) By comparing Example 1 and Comparative Example 1, it can be seen that the effect of using iron-modified biochar is better than that of unmodified biochar.

[0087] By comparing Example 1 with Comparative Examples 2-3, it can be seen that humic acid and iron-modified biochar are both indispensable and have a synergistic technical effect in reducing soil salinity and increasing lettuce yield.

[0088] By comparing Example 1 with Comparative Example 4, it can be seen that the present invention uses hydrogen-rich water to replace water for irrigation, which helps to improve the secondary salinization level of the soil, and also has the effect of promoting the growth of lettuce and increasing the yield.

[0089] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for alleviating secondary salinization of facility-cultivated soil and increasing lettuce yield, characterized in that: The method comprises: applying a soil conditioner to planting soil, then sowing lettuce, and irrigating with hydrogen-rich water until the lettuce is harvested; the soil conditioner comprises a combination of iron-modified biochar and humic acid.

2. The method according to claim 1, characterized in that The concentration of hydrogen in the hydrogen-rich water is 0.5-2 ppm, preferably 1.2-1.8 ppm.

3. The method according to claim 1 or 2, characterized in that: The irrigation frequency of the hydrogen-rich water is once every 5-10 days, and the hydrogen-rich water is irrigated each time until the soil is soaked to 10-15 cm below the soil layer.

4. The method according to any one of claims 1 to 3, characterized in that: The application amount of the iron-modified biochar is 45-65 kg / mu; Preferably, the application amount of humic acid is 50-150 kg / mu.

5. The method according to any one of claims 1 to 4, characterized in that: The iron-modified biochar is prepared by the following method, which comprises the following steps: (1) drying and carbonizing the biomass in sequence to obtain biochar; (2) The biochar is immersed in an aqueous solution of iron salt, mixed and heated to obtain iron-modified biochar.

6. The method according to claim 5, characterized in that In step (1), the biomass includes any one of straw, rice husk, bamboo chips, wood chips or sludge, or a combination of at least two thereof; Preferably, in step (1), the drying temperature is 50-60°C; Preferably, in step (1), the drying is performed until the biomass mass becomes constant.

7. The method according to claim 5 or 6, characterized in that: In step (1), the carbonization temperature program is: initial temperature 20-50°C, heating to 300-700°C at 10-15°C / min, and keeping warm for 1.5-2.5h; Preferably, in step (1), the carbonization is carried out in a nitrogen atmosphere.

8. The method according to any one of claims 5 to 7, characterized in that: In step (2), based on the amount of the biochar used being 1 g, the amount of the iron salt aqueous solution used is 2-3 mL, and the concentration of the iron salt aqueous solution is 0.05-0.07 M; Preferably, in step (2), the iron salt comprises any one of ferric chloride, ferric sulfate, ferric nitrate or ferric carbonate, or a combination of at least two thereof.

9. The method according to any one of claims 5 to 8, characterized in that: In step (2), the heating program is: initial temperature 20-50°C, heating to 550-650°C at 8-12°C / min, and keeping warm for 20-40min.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises: applying 45-65 kg / mu of iron-modified biochar and 50-150 kg / mu of humic acid to the planting soil, then sowing lettuce, irrigating once every 5-10 days with hydrogen-rich water having a hydrogen concentration of 0.5-2 ppm until the lettuce is harvested, and irrigating each time until the soil is soaked to 10-15 cm below the soil layer; The iron-modified biochar is prepared by the following method, which comprises the following steps: (1) drying the biomass at 50-60° C. to a constant mass, and then carbonizing it in a nitrogen atmosphere to obtain biochar; the carbonization temperature program is: an initial temperature of 20-50° C., heating to 300-700° C. at a rate of 10-15° C. / min, and keeping the temperature for 1.5-2.5 h; (2) Based on the amount of the biochar being 1 g and the amount of the iron salt aqueous solution being 2-3 mL, the biochar is immersed in a 0.05-0.07 M iron salt aqueous solution, mixed and then heated to obtain iron-modified biochar; the heating program is as follows: initial temperature 20-50° C., heating to 550-650° C. at 8-12° C. / min, and keeping warm for 20-40 min.

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