A rapid soil improvement process

Abstract

The present invention relates to the technical field of soil remediation, and specifically discloses a rapid soil improvement process, including steps such as parameter acquisition, usage decision-making, and placement and maintenance monitoring: This process first calculates various substances to be input, and then precisely implements the input according to the calculated amount for soil work. After precise calculation, the input cost of soil improvement can be minimized; the semi-cured straw input in this process continues to ferment to the mature stage in the later period, and the heat generated by decomposition is beneficial to increasing the soil temperature, and substances such as ethanol are produced. Under the action of high temperature and ethanol, pathogenic bacteria and nematodes in the soil can be killed. At the same time, carbon dioxide generated during the after-ripening stage of the straw will generate air pressure under the condition of film mulching, breaking the original compacted soil blocks. The polysaccharides, natto gum and other substances produced act together with the straw fibers to form an aggregate structure, further improving the soil improvement effect.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and particularly to a rapid soil improvement process. Background Art

[0002] Soil improvement is an important measure in agricultural production to eliminate or prevent adverse factors that affect crop growth and cause soil degradation, improve soil properties, increase soil fertility, and create good soil environmental conditions for crops. In current engineered soil improvement measures, most implementation cases use commercial organic fertilizers for improvement, but commercial organic fertilizers have problems such as high price, high salt content, and low organic matter content. Straw, as a material rich in organic matter and with a low salt content, has a certain soil improvement effect. However, due to its high degree of fibrosis and slow decomposition rate, its application is limited in engineered soil improvement with a relatively limited implementation period. In recent years, with the development of technology, soil improvement technologies such as straw carbonization and returning to the field have also emerged. However, due to the need for specific equipment for high-temperature treatment, the implementation cost is relatively high. And the chemical activity of straw drops sharply after the carbonization process, and it cannot effectively provide energy for soil microorganisms and act on soil aggregates, so the improvement effect is limited. Summary of the Invention

[0003] Aiming at the defects in the prior art, the purpose of the present invention is to provide a rapid soil improvement process, which can minimize the improvement input cost and at the same time have a better improvement effect.

[0004] The technical solution adopted by the present invention is: a rapid soil improvement process, including the following steps;

[0005] S1. Parameter acquisition: According to the national arable land quality grade assessment standard, determine the inflection point of the marginal effect diminishing of the organic carbon upper-type function in the area where soil improvement is to be implemented, denoted as Oc; the maximum available funds for the soil improvement project are set as Op, and the unit prices of semi-ripe straw and organic fertilizer to be invested are set as Ps and Pm respectively; detect semi-ripe straw, organic fertilizer, and soil respectively. Let the nitrogen content in semi-ripe straw be Ns, the carbon content be Cs, and the salt content be Ss; let the nitrogen content in organic fertilizer be Nm, the carbon content be Cm, and the salt content be Sm; let the carbon content in the soil be Csoil and the salt content be Ssoil; the tillage layer thickness of the soil is D, and the bulk density is ρ;

[0006] S2. Dosage decision: Let the application amount of semi-ripe straw be Ms and the application amount of organic fertilizer be Mm, and initially calculate the application amount of organic fertilizer according to formula (1) based on the application amount of semi-ripe straw;

[0007] Calculate the input amount of semi-ripe straw under three constraint conditions of organic carbon improvement target, maximum salt concentration, and economic input according to formulas (2)-(4), and obtain the final input amount of organic fertilizer according to formula (5).

[0008]

[0009] M s1 × C s1 + M m1 × C m1 + D × ρ × C soil × 666.7 = O c × D × ρ × 666.7 (2)

[0010] D × ρ × 666.7 × S soil + M s2 × S s + M m2 × S m = 0.002(D × ρ × 666.7 + M s2 + M m2 ) (3)

[0011] M s3 × P s + M m3 × P m = O p (4)

[0012] M sf = min{M s1 , M s2 , M s3} (5)

[0013] S3. Placement and curing monitoring: Use a spreader and a rotary tiller to apply semi-ripe straw, organic fertilizer, and microbial agents into the drip irrigation belt in the soil tillage layer according to the calculated amount, and then cover it with plastic film to enter the curing and fermentation stage. During the curing and fermentation stage, use soil temperature and humidity sensors to monitor the soil temperature and humidity. When the soil humidity is lower than 60% of the field water holding capacity, replenish water through drip irrigation. When the accumulated temperature of the soil reaches 1200 °C, the curing and fermentation is completed.

[0014] In the soil improvement method proposed by this technical solution, various substances input are first calculated, and then the input is accurately implemented according to the calculated amount for soil work. After accurate calculation, the input cost of soil improvement can be minimized; the semi-ripe straw input continues to ferment to the mature stage in the later period, and the heat generated by decomposition is beneficial to increasing the soil temperature, and substances such as ethanol are produced. Under the action of high temperature and ethanol, pathogenic bacteria and nematodes in the soil can be killed. At the same time, carbon dioxide produced during the after-ripening stage of the straw will generate air pressure under the film-covered condition, breaking the original compact soil clods. Substances such as polysaccharides and natto gum produced act together with the straw fibers to form an aggregate structure, further improving the soil improvement effect.

[0015] Preferably, in S3, the inoculant application rate is calculated based on more than 200 million effective viable bacteria counts (CFU) per kilogram of semi-cooked straw.

[0016] Preferably, in S3, the drip irrigation tapes in the plough layer are laid at 60 cm intervals.

[0017] Preferably, in S3, the inoculant includes one or a combination of yeast, natto bacteria, and acetic acid bacteria.

[0018] Preferably, in S1 - S3, the semi-cooked straw is the straw with a fermentation temperature reaching 50 °C and lasting for 15 - 20 days.

[0019] Preferably, the plastic film is a colorless and transparent PE film.

[0020] The beneficial effects of the present invention are as follows: The soil improvement method provided by the present invention first calculates various substances to be input, and then precisely implements the input according to the calculated amount for soil work. After precise calculation, the input cost of soil improvement can be minimized; the semi-cooked straw input will continue to ferment to the mature stage later, and the heat generated by decomposition is beneficial to increasing the soil temperature, and substances such as ethanol are produced. Under the action of high temperature and ethanol, pathogenic bacteria and nematodes in the soil can be killed. At the same time, carbon dioxide produced during the after-ripening stage of the straw will generate air pressure under the film-covered condition, breaking the original compacted soil clods. Substances such as polysaccharides and natto gum produced act together with the straw fibers to form an aggregate structure, further improving the soil improvement effect. Description of the Drawings

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts do not necessarily draw to actual scale.

[0022] Figure 1 It is a flowchart of the soil rapid improvement process provided in the embodiment of the present invention. Detailed Embodiments

[0023] The following will describe in detail the embodiments of the technical solutions of the present invention in conjunction with the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0024] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0025] Such as Figure 1As shown in the figure, a specific embodiment of the present invention provides a soil rapid improvement process, including the following steps;

[0026] Step 1. Parameter acquisition: According to the national arable land quality grade evaluation standard, determine the inflection point of the diminishing marginal effect of the organic carbon upper-type function in the area where soil improvement is to be implemented, denoted as Oc; the maximum available funds for the soil improvement project are set as Op, and the unit prices of semi-cured straw and organic fertilizer to be invested are set as Ps and Pm respectively.

[0027] Test semi-cured straw, organic fertilizer, and soil respectively. Let the nitrogen content in semi-cured straw be Ns, the carbon content be Cs, and the salt content be Ss; let the nitrogen content in organic fertilizer be Nm, the carbon content be Cm, and the salt content be Sm; let the carbon content in soil be Csoil and the salt content be Ssoil; the tillage layer thickness of the soil is D, and the bulk density is ρ;

[0028] Step 2. Dosage decision: Let the application amount of semi-cured straw be Ms and the application amount of organic fertilizer be Mm. Use formula (1) to initially calculate the application amount of organic fertilizer based on the application amount of semi-cured straw.

[0029] Calculate the input amount of semi-cured straw under the three constraint conditions of organic carbon improvement target, maximum salt concentration, and economic input using formulas (2)-(4), and obtain the final input amount of organic fertilizer according to formula (5).

[0030]

[0031] M s1 ×C s1 +M m1 ×C m1 +D×ρ×C soil ×666.7=O c ×D×ρ×666.7 (2)

[0032] D×ρ×666.7×S soil +M s2 ×S s +M m2 ×S m =0.002(D×ρ×666.7+M s2 +M m2 ) (3)

[0033] M s3 ×P s +M m3 ×P m =O p (4)

[0034] M sf =min{M s1 ,M s2 ,Ms3} (5)

[0035] Step 3. Application and curing monitoring: Use a spreader and a rotary tiller to apply the semi-cured straw, organic fertilizer, and microbial inoculum into the drip irrigation belt in the soil tillage layer according to the calculated amount, and then cover it with a plastic film to enter the curing and fermentation stage. During the curing and fermentation stage, use a soil temperature and humidity sensor to monitor the soil temperature and humidity. When the soil humidity is lower than 60% of the field capacity, replenish water through drip irrigation. When the accumulated temperature of the soil reaches 1200 °C, the curing and fermentation is completed.

[0036] In the soil improvement method provided in this embodiment, various substances input are first calculated, and then the input is precisely implemented according to the calculated amount for soil work. After precise calculation, the input cost of soil improvement can be minimized; the heat generated by the continuous fermentation of the input semi-cured straw to the mature stage is beneficial to increasing the soil temperature, and substances such as ethanol are produced. Under the action of high temperature and ethanol, pathogenic bacteria and nematodes in the soil can be killed. At the same time, carbon dioxide generated during the after-ripening stage of the straw will generate air pressure under the film-covered condition, breaking the original compacted soil clods. The polysaccharides, natto gum, and other substances produced act together with the straw fibers to form the aggregate structure, further improving the soil improvement effect.

[0037] In step 3 of the improvement process, the input amount of the microbial inoculum is calculated based on more than 200 million effective viable bacteria (CFU) per kilogram of semi-cured straw. At the same time, the input microbial inoculum includes one or a combination of yeast, natto bacteria, and acetic acid bacteria. In this way, using a variety of microbial inoculums can improve the fermentation quality of various substances after being input into the soil.

[0038] Since various improvement substances need to be input into the drip irrigation belt in the soil, in practical applications, to improve the improvement effect, the drip irrigation belts in the tillage layer are laid at intervals of 60 cm. Laying the drip irrigation belts at uniform intervals improves the uniformity of the soil improvement area.

[0039] In soil improvement, the semi-cured straw refers to the straw that has completed the initial composting of the straw, started to enter the temperature-rising stage, but is not fully composted. The identification standard is that the fermentation temperature reaches 50 °C and lasts for 15 - 20 days. In this way, the semi-cured straw can continue to ferment after being input, and carbon dioxide will also be produced during the continuous fermentation, thereby breaking the original compacted soil clods. The polysaccharides, natto gum, and other substances produced act together with the straw fibers to form the aggregate structure; at the same time, the semi-cured straw can generate heat during the after-ripening stage, which is beneficial to increasing the soil temperature, and substances such as ethanol are produced. Under the action of high temperature and ethanol, pathogenic bacteria and nematodes in the soil can be killed, and the production cost can be reduced by more than 20% - 30%; when the plastic film laid on the ground surface uses a colorless transparent PE film.

[0040] The problems with using fully composted and unfermented straw are as follows:

[0041] If fully decomposed straw is used, the following problems will occur: due to the long fermentation time, the cost is relatively high, and the heat released by the fully mature straw will be dissipated in the fermentation factory and will not act on the soil; the carbon dioxide produced will be dissipated, and substances such as polysaccharides and natto gum cannot react with soil aggregates during the fermentation process, resulting in poor aggregate promotion effect.

[0042] If unfermented straw is used, there are problems such as slow decomposition rate. When a large amount is input, it will cause the tillage layer of the soil to be lifted and problems such as competition between microorganisms and crops for nitrogen. Especially when the input per mu is more than 1 ton, there will be a risk of yield reduction, and it cannot significantly increase the organic matter in the short term.

[0043] The applicant took the conventional soil improvement decision of using only organic fertilizer as a control and compared and studied the beneficial effects of the decision-making method of this scheme; the soil data of the test plots are shown in Table 1.

[0044] Soil organic carbon content Salt content Soil bulk density Tillage depth Inflection point of organic carbon marginal effect 12.5 g / kg 0.15％ <![CDATA[1.25g / cm 3 > 30 cm 16.06 g / kg

[0045] Table 1

[0046] The commercial organic fertilizer used for implementation has an organic carbon content of 38.6%, a nitrogen content of 4.5%, and a salt content of 1.5%; the semi-mature straw has an organic carbon content of 44%, a nitrogen content of 0.72%, and a salt content of 0.13%. The unit price of the commercial organic fertilizer is 800 yuan / ton, the unit price of the semi-mature straw is 500 yuan / ton, and the cost of soil improvement is 1000 yuan / mu.

[0047] Under the above background, the decision result of the conventional decision-making method is to apply 1.25 tons of commercial organic fertilizer per mu, while the decision result of using this scheme is to apply 1.27 tons of semi-mature straw per mu and 0.45 tons of commercial organic fertilizer per mu. Implement soil improvement with the above input results, and monitor the soil after implementation. The monitoring results are shown in Table 2.

[0048]

[0049] Table 2

[0050] Therefore, it can be clearly concluded from the above table that this decision-making method can significantly increase the organic carbon storage in the plough layer, reduce the soil compactness and the soil salt storage in the plough layer compared with the conventional improvement method under the same investment amount; effectively improve soil compaction and reduce the risk of secondary salinization.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A rapid soil improvement process, characterized in that: The steps include: S1. Parameter acquisition: According to the national arable land quality rating standard, the marginal effect decreasing inflection point of the organic carbon Rongshang function in the area where soil improvement is planned to be implemented is determined, recorded as Oc; the maximum investment funds for soil improvement projects are set as Op, and the unit prices of semi-mature straw and organic fertilizer to be invested are set as Ps and Pm respectively; Semi-mature straw, organic fertilizer and soil were tested respectively. The nitrogen content in semi-mature straw was Ns, the carbon content was Cs and the salt content was Ss; the nitrogen content in organic fertilizer was Nm, the carbon content was Cm and the salt content was Sm; the carbon content in soil was Csoil and the salt content was Ssoil; the thickness of the tillage layer of soil was D and the bulk density was ρ; S2. Usage decision: Assume that the application amount of half-mature straw is Ms, and the application amount of organic fertilizer is Mm. Formula (1) is used to preliminarily calculate the application amount of organic fertilizer based on the application amount of half-mature straw; Formulas (2)-(4) were used to calculate the input amount of semi-mature straw under the three constraints of organic carbon improvement target, maximum salt concentration and economic input, and the final input amount of organic fertilizer was obtained according to formula (5); M s1 ×C s1 +M m1 ×C m1 +D×ρ×C soil ×666.7=O c ×D×ρ×666.7 (2) Dxρ×666.7×S soil +M s2 ×S s +M m2 ×S m =0.002(D×ρ×666.7+M s2 +M m2 ) (3) M s3 ×P s +M m3 ×P m =O p (4) M sf =min{M s1 ,M s2 ,M s3 } (5); S3. Placement and maintenance monitoring: Use a spreader and a rotary tiller to apply the calculated amount of half-mature straw, organic fertilizer and microbial agent into the drip irrigation belt of the soil plow layer, then cover it with plastic film and enter the maintenance and fermentation stage. During the maintenance and fermentation stage, use soil temperature and humidity sensors to monitor the soil temperature and humidity. When the soil humidity is lower than 60% of the field water holding capacity, drip irrigation is used to replenish water. When the accumulated soil temperature reaches 1200℃, the maintenance and fermentation is completed.

2. The rapid soil improvement process according to claim 1, characterized in that: In S3, the amount of microbial agent input is calculated based on the application of more than 200 million effective live bacteria (CFU) per kilogram of semi-mature straw.

3. The rapid soil improvement process according to claim 1, characterized in that: In S3, drip irrigation tapes were laid at 60 cm intervals in the tillage layer.

4. The rapid soil improvement process according to claim 1, characterized in that: In S3, the bacterial agent includes one or a combination of yeast, natto bacteria, and acetic acid bacteria.

5. The rapid soil improvement process according to claim 1, characterized in that: In S1-S3, the semi-mature straw is the straw fermented at a temperature of 50°C for 15-20 days.

6. The rapid soil improvement process according to claim 1, characterized in that: The plastic film is a colorless and transparent PE film.

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