Improver and improvement method for sandy saline-alkali soil
A soil amendment and layering method using pine needle soil, acid-modified cattle manure charcoal, and bonding materials effectively addresses the challenges of improving saline-alkali soils, enhancing soil structure and preventing salt reversion while supporting plant growth and nutrient retention.
Patent Information
- Application Number
- CN202211461156.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-21
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2042-11-21
AI Technical Summary
The existing saline-alkali land improvement technology has problems such as high cost, slow progress, long-term effectiveness and poor sustainability, especially the repeated use of secondary saline-alkali land for light and moderate saline-alkali land, and the rational use of the improved land is insufficient.
A sandy saline-alkali earth modification agent is used, including pine needle soil, acid modified cow dung charcoal, zeolite powder, inorganic fertilizer, microbial bacteria agent and bonding materials. By layering, salt separator layer and buffer layer are improved and set up, combined with photovoltaic power generation device, the added amount of the modification agent is 10-30%.
Improved soil structure, reduce salt content, meet soil planting requirements, improve soil water and fertilizer retention performance, prevent salt reflux, and achieve efficient land utilization and light energy utilization.
Smart Images
Figure CN115710512B_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of soil structure improvement, and relates to an improver and an improvement method for sandy saline-alkali soil. Background Art
[0002] Soil salinization is a global problem that affects agricultural production and the ecological environment. According to statistics, there are 950 million hectares of salinized land in the world, of which my country has about 99.15 million hectares, making it the country with the third largest distribution of saline-alkali land. my country's saline-alkali land is widely distributed and the harm of salinization is serious, especially in the oasis soil salinization problem in the arid and semi-arid areas in the west where the ecosystem is fragile. At present, the measures for improving saline-alkali land mainly include physical improvement, chemical improvement, water conservancy engineering measures, biological improvement, etc. The core is mainly to achieve regulation by reducing surface evaporation, creating barriers to inhibit the upward movement of salt, promoting salt leaching and accelerating soil salt and drainage.
[0003] The process of improving and utilizing severe saline-alkali land is complex, costly, and slow, while the improvement and utilization of light and moderate saline-alkali land has repeated secondary salinization, which has led to the difficulties in promoting and applying saline-alkali land improvement technology, poor long-term effectiveness and sustainability, and low social participation enthusiasm. Therefore, low-cost, long-lasting and stable improvement technology and the rational use of improved land are crucial.
[0004] With the country's in-depth promotion of the "carbon peak and carbon neutrality" strategy, photovoltaic and other renewable energy power generation methods will have the opportunity to accelerate development in the future. Therefore, on the improved saline-alkali land, through the forest-light complementarity method, on the one hand, it can reduce surface evaporation and inhibit soil salt return, and on the other hand, it can maximize the use of light energy and increase carbon sinks. Summary of the invention
[0005] The purpose of the present application is to provide a sandy saline-alkali soil conditioner that can improve the soil structure, reduce the salt content of the soil, and enable the slightly saline-alkali soil to meet the requirements of planting soil after improvement.
[0006] In order to achieve the above purpose, the technical solution adopted in this application is:
[0007] The technical solution provides a sandy saline-alkali soil improver, comprising the following components by weight: 80-120 parts of pine needle soil, 50-85 parts of acid-modified cow dung charcoal, 3-5 parts of zeolite powder, 0.2-0.4 parts of inorganic fertilizer, 2-4 parts of microbial agents, and 2-4 parts of adhesive materials; the components can be used after being evenly mixed.
[0008] The beneficial technical effects of this technical solution are as follows: After being improved by the soil improver, the sandy saline-alkali soil can improve the soil structure, reduce the salt content of the soil, enable the slightly saline-alkali soil to meet the requirements of planting soil after improvement, and suitable plants can be planted; the cow dung biochar modified by phosphoric acid will not increase the soil pH, but will supplement the phosphorus element in the soil; the binding material can enhance the bonding strength between sandy soil particles, improve the poor physical and chemical properties of sandy soil such as water leakage and fertilizer leakage, and improve the water and fertilizer retention performance of the soil.
[0009] As an implementation mode of the above technical solution, the preferred components are 100 parts of pine needle soil, 65 parts of acid-modified cow dung biochar, 4 parts of zeolite powder, 0.2 part of inorganic fertilizer, 3 parts of microbial inoculant, and 2.5 parts of binding material. The addition amount of the soil improver is 20% of the weight of the sandy saline-alkali soil to be improved.
[0010] As an implementation mode of the above technical solution, the addition amount of the soil improver is 10%-30% of the weight of the sandy saline-alkali soil.
[0011] As an implementation mode of the above technical solution, the preparation method of the acid-modified cow dung biochar is: impregnate the dry cow dung in an acidic solution, and then calcine it at 400-500 °C to form biochar, which is the acid-modified cow dung biochar. Among them, the acidic solution is a phosphoric acid solution.
[0012] As an implementation mode of the above technical solution, the inorganic fertilizer is one or a combination of several of ammonium sulfate, ammonium nitrate, and calcium nitrate;
[0013] The microbial inoculant is one or a combination of two of Bacillus mucilaginosus and Bacillus subtilis;
[0014] The binding material is one or a combination of several of polyvinyl alcohol, sodium polyacrylate, and sodium carboxymethyl cellulose.
[0015] Another technical solution of this application is to provide a method for improving sandy saline-alkali soil, which includes the following steps:
[0016] S1. Excavate the sandy saline-alkali soil to be improved, and stack the severely saline-alkali soil and the slightly saline-alkali soil separately;
[0017] S2. Spread the severely saline-alkali soil added with desulfurized gypsum and ferrous sulfate in the excavation area of the sandy saline-alkali soil;
[0018] S3. Spread a salt isolation layer on the spread severely saline-alkali soil;
[0019] S4. Spread a layer of slightly saline-alkali soil added with furfural residue on the salt isolation layer to form a buffer layer;
[0020] S5. Backfill the slightly saline-alkali soil improved by adding the soil improver as described in the above technical solution on the buffer layer to make the improved soil meet the standard of planting soil to form a planting layer.
[0021] The beneficial effects of this technical solution are as follows: The heavy saline-alkali soil and the light saline-alkali soil are improved in layers. The main purpose of improving the heavy saline-alkali soil is to reduce the soil pH and salt content. After the light saline-alkali soil is improved, it needs to meet the requirements of planting soil. A separation layer is set between the light and heavy saline-alkali soils to prevent salt return. A buffer layer is set on the salt separation layer to buffer and improve the salt return caused by the upward seepage of water in the lower layer, which is a further guarantee for the salt separation layer, thus ensuring the salt separation effect of the system. The modifier contains cohesive materials, which can enhance the bonding strength between sand particles, improve the poor physical and chemical properties of sand, such as water leakage and fertilizer leakage, and improve the water and fertilizer retention performance of the soil.
[0022] As an implementation mode of the above technical solution, the heavy saline-alkali soil refers to the soil with a total salt content greater than 4 g / kg, and the light saline-alkali soil refers to the soil with a total salt content less than 4 g / kg.
[0023] As an implementation mode of the above technical solution, the thickness of the salt separation layer is 30 - 45 cm. The salt separation layer includes a cobblestone layer with a thickness of 20 - 30 cm in the upper layer and a clay layer with a thickness of 10 - 15 cm in the lower layer, where the particle size of the cobblestones is 1 - 3 cm.
[0024] In this way, the clay layer of the salt separation layer plays a role in water isolation, preventing salt return caused by the rise of groundwater, and the upper cobblestone layer plays a role in hydrophobicity, used to cut off the salt return caused by the evaporation of water in the lower layer.
[0025] As an implementation mode of the above technical solution, the following steps are also included: S6. According to the slope of the sandy saline-alkali soil, a water channel is excavated at the lower slope. The bottom of the water channel is located in the clay layer of the salt separation layer. The water channel is used to drain the excess precipitation of the sandy saline-alkali soil, preventing soil salt return caused by waterlogging. For the sandy saline-alkali soil with a large area after sand improvement, a water channel can also be excavated in the middle to accelerate drainage during rainfall.
[0026] In this way, a water channel is set at the foot of the slope of the improved saline-alkali soil. The excess water in the improved body seeps down to the salt separation layer, is drained through the cobblestone layer into the water channel, and then the excess accumulated water is drained away through the water channel.
[0027] As an implementation mode of the above technical solution, the slope of the water channel is 0.1 - 1%. A barrier wall is built with bricks or stones on the side of the water channel. The bottom of the barrier wall is pressed on the cobblestone layer in the salt separation layer. In this way, the barrier wall is used to block soil erosion without blocking drainage.
[0028] As an implementation mode of the above technical solution, the slopes of the heavy saline-alkali soil, the salt separation layer, the buffer layer, and the light saline-alkali soil are all 1 - 3%. Preferably, the slope of each layer of the improved saline-alkali soil is 2%.
[0029] As an implementation of the above technical solution, the addition amount of desulfurized gypsum added to the heavy saline-alkali soil is 1.0%-2.0% of the weight of the heavy saline-alkali soil, and the addition amount of ferrous sulfate is 0.5%-3% of the weight of the heavy saline-alkali soil;
[0030] The addition amount of furfural residue in the buffer layer is 0.5%-1.0% of the weight of the light saline-alkali soil in the buffer layer, and the thickness of the buffer layer is 10-15 cm.
[0031] As an implementation of the above technical solution, the following steps are further included: S7. Install a photovoltaic power generation device on the planting layer. The row spacing of the photovoltaic panels is greater than 2 m. Plant more shade-tolerant plants under the photovoltaic panels and light-loving plants in the gaps.
[0032] In this way, a photovoltaic power generation device is installed on the planting layer, and plants are planted under the photovoltaic panels and in the gaps, so as to make the most of light energy in the way of forest-light complementarity, improve the utilization rate of the improved saline-alkali soil, and at the same time, this utilization method can also reduce surface evaporation and prevent soil salinization. Description of the Drawings
[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly describe the drawings required for the description of the embodiments:
[0034] Figure 1 It is a schematic diagram of the soil structure after improvement by the improved method of sandy saline-alkali soil in an embodiment of the present application.
[0035] Description of the reference numerals:
[0036] 1 - Improved heavy saline-alkali soil; 2 - Clay layer; 3 - Cobblestone layer; 4 - Buffer layer; 5 - Improved light saline-alkali soil; 6 - Barrier wall; 7 - Water channel; 8 - Photovoltaic power generation device; 9 - Plant. Detailed Embodiments
[0037] The following will clearly and completely describe the concept, specific structure and technical effects generated by the present application in combination with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
[0038] In addition, all the connection / linkage relationships involved in the patent do not solely refer to direct connection of components, but rather refer to the formation of a more optimal connection structure by adding or reducing connection accessories according to specific implementation circumstances. The descriptions of orientations such as up, down, left, and right in this application are only relative to the mutual positional relationships of the components of this application in the attached drawings. Each technical feature in this application can be combined interactively on the premise of not conflicting with each other.
[0039] Example 1
[0040] This example provides a modifier for sandy saline-alkali soil, which includes the following components by weight: 100 parts of pine needle soil, 65 parts of acid-modified cow dung charcoal, 4 parts of zeolite powder, 0.2 part of inorganic fertilizer, 3 parts of microbial inoculum, and 2.5 parts of binding material; the components are mixed evenly and reserved for use.
[0041] Among them, the preparation method of the acid-modified cow dung charcoal is: impregnate the dry cow dung in a phosphoric acid solution for 24 hours, and then calcine it at 500 °C to obtain biochar, which is the acid-modified cow dung charcoal. The cow dung charcoal modified by phosphoric acid will not increase the soil pH, but will supplement the soil phosphorus element.
[0042] The inorganic fertilizer is ammonium sulfate, the microbial inoculum is Bacillus mucilaginosus and Bacillus subtilis, and the binding material is polyvinyl alcohol.
[0043] The slightly saline-alkali soil (total salt content less than 4 g / kg) in a certain place in Inner Mongolia is used as the soil to be improved for the test. The pH of this soil is 9.08, showing strong alkalinity, the total salt content is 2.67 g / kg, it is slightly saline-alkali soil, the organic matter content is 1.54 g / kg, the available phosphorus is 6.7 mg / kg, the available potassium is 200.54 mg / kg, and the alkali-hydrolyzable nitrogen is 25.83 mg / kg. Except for the available potassium, other nutrients are far lower than the "Standard for Greening Planting Soil".
[0044] The soil to be improved is crushed to less than 2 cm, and the modifier in this example is added. The addition amount of the modifier is 20% of the weight of the soil to be improved. The specific process is as follows: Take 50 g of soil sample and place it in a 1 L plastic bottle container. Add the prepared modifier according to the addition amount of 20%, adjust the water content to 30%, stir evenly again, cover with plastic wrap for maintenance, and take samples to detect the physical and chemical properties of the soil after 7 days. The obtained results are shown in Table 1.
[0045] Table 1 Physical and Chemical Properties of Saline-Alkali Soil after Improvement
[0046]
[0047] As can be seen from Table 1, after adding the modifier to this slightly saline-alkali soil, all the nutrient indexes in the soil have reached the standards of greening planting soil, and the soil pH and total salt content have also reached the standards.
[0048] Example 2
[0049] This example provides a modifier for sandy saline-alkali soil. Compared with the modifier in Example 1, except for not adding binder materials, other components are the same as in Example 1.
[0050] Using the soil to be improved and the modifier in Example 1 and the modifier in this example, a control group test was set up. The uniformly stirred soil to be improved and the modifier were filled into a plastic container with holes at the bottom. The initial water content of the soil was adjusted to 30%. Then, water was added to each treatment on the 7th, 14th, and 21st days of cultivation to ensure the same amount of watering. At the same time, the soil leachate at the bottom of the container was collected, and the ammonium nitrogen content in the leachate was measured to determine the fertilizer retention of the soil. The results are shown in Table 2.
[0051] Table 2 Ammonium nitrogen content in soil leachate (mg / L)
[0052] Day 7 Day 14 Day 21 Sample of Example 1 3.14 3.31 3.39 Sample of Example 2 3.46 3.58 3.65
[0053] As can be seen from Table 2, adding binder materials to the modifier reduced the ammonium nitrogen content in the soil leachate on the 7th, 14th, and 21st days by 9.25%, 7.54%, and 7.12% respectively, improving the fertilizer retention of the soil. Binder materials can enhance the bonding strength between sand grains, improve the poor physical and chemical properties of sandy soil, such as water leakage and fertilizer leakage, and improve the water and fertilizer retention performance of the soil.
[0054] Example 3
[0055] As Figure 1 shown, this example provides a method for improving sandy saline-alkali soil, including the following steps:
[0056] S1: Excavate the saline-alkali area to be improved, stack the upper-layer severely saline-alkali soil and the lower-layer slightly saline-alkali soil separately, add desulfurized gypsum and ferrous sulfate to the severely saline-alkali soil, and then spread it on the excavation area.
[0057] S2: Lay a salt isolation layer on the spread severely saline-alkali soil, with a thickness of 30 - 45 cm.
[0058] S3: Lay a layer of slightly saline-alkali soil added with furfural residues on the salt isolation layer to form a buffer layer to buffer the salt return caused by water evaporation and the rise of groundwater. Its thickness is about 10 - 15 cm.
[0059] S4: Backfill slightly saline-alkali soil on the buffer layer, add a modifier for improvement to make the improved slightly saline-alkali soil meet the standard of planting soil, and form a planting layer.
[0060] S5: Along the slope of the improved plot, dig a water channel at the foot of the slope to drain the excess precipitation in the rainy season, thereby preventing soil salt return caused by waterlogging in the upper layer.
[0061] S6: Install a photovoltaic power generation device on the planting layer, and then plant shade-tolerant plants under and in the gaps of the photovoltaic panels.
[0062] In this embodiment, heavy saline-alkali soil refers to soil with a total salt content greater than 4 g / kg, and light saline-alkali soil refers to soil with a total salt content less than 4 g / kg.
[0063] In this embodiment, the addition amount of desulfurized gypsum added to the heavy saline-alkali soil is 1.0%-2.0% of the weight of the heavy saline-alkali soil, and the addition amount of ferrous sulfate is 0.5%-3% of the weight of the heavy saline-alkali soil.
[0064] In this embodiment, the salt isolation layer includes two layers. The upper layer is 20-30 cm of cobblestones with a particle size of about 2 cm, and the lower layer is 10-15 cm of clay layer. The lower clay layer plays a role in water isolation to prevent salt return caused by the rise of groundwater. The upper cobblestones play a role in hydrophobicity to cut off the salt return caused by the evaporation of moisture in the lower layer.
[0065] In this embodiment, the addition amount of furfural residue in the buffer layer is 0.5%-1.0% of the weight of the light saline-alkali soil in the buffer layer, and the thickness of the buffer layer is 10-15 cm. The buffer layer is mainly used to buffer and improve the salt return caused by the upward seepage of moisture in the lower layer, which is a further guarantee for the salt isolation layer, thus ensuring the salt isolation effect of the system.
[0066] In this embodiment, uniformly spread light saline-alkali soil on the buffer layer with a spreading thickness of 0.5-1.0 m, and then apply a modifier. The modifier is 80-120 parts of pine needle soil, 50-85 parts of acid-modified cow dung charcoal, 3-5 parts of zeolite powder, 0.2-0.4 parts of inorganic fertilizer, 2-4 parts of microbial inoculum, and 2-4 parts of adhesive material. The addition amount of the modifier is 10%-30%. After improving the light saline-alkali soil, on the one hand, it can meet the nutritional needs of plant growth, and on the other hand, the components of the added modifier can enhance the bonding strength between sand grains and increase the water and fertilizer retention of the soil.
[0067] Among them, the inorganic fertilizer is one or more of ammonium sulfate, ammonium nitrate or calcium nitrate, the microbial inoculum is Bacillus mucilaginosus and Bacillus subtilis, and the adhesive material is one or more of polyvinyl alcohol, sodium polyacrylate and sodium carboxymethylcellulose. The preparation method of acid-modified cow dung charcoal is to impregnate dry cow dung in a 45% phosphoric acid solution for 24 hours, and then calcine it at 500 °C to obtain biochar, which is acid-modified cow dung charcoal. The biochar modified by phosphoric acid will not increase the soil pH, but will also supplement the soil phosphorus element.
[0068] In this embodiment, the slopes of the heavy saline-alkali land improvement layer, the salt isolation layer, the buffer layer, and the light saline-alkali land improvement layer are all 2% to prevent waterlogging from causing local salt return.
[0069] In this embodiment, the bottom of the water channel is located in the clay layer of the salt isolation layer, the top of the water channel is higher than the cobblestone layer, the slope of the water channel is 0.1%, and a barrier wall is built with bricks or stones on the side of the water channel. The bottom of the barrier wall is pressed on the cobblestone layer in the salt isolation layer.
[0070] In this way, the barrier wall is used to prevent soil erosion without preventing drainage. Since there is a certain slope in the entire soil layer after improvement, the excess precipitation infiltrates into the water isolation layer and then converges along the cobblestone layer to the foot of the slope and enters the water channel. The slope of the water channel facilitates the timely drainage of the water in the water channel. In addition, a barrier wall with its bottom pressed on the severely saline-alkali soil is built at the edge with a relatively high slope of the improved saline-alkali soil.
[0071] In this embodiment, the row spacing between the photovoltaic power generation panels of the photovoltaic power generation device is greater than 2 m. Shade-tolerant plants can be planted under the photovoltaic power generation panels, and light-loving plants can be planted in the gaps to maximize the utilization of light energy in the form of forest-light complementarity, improve the utilization rate of the improved saline-alkali soil, and at the same time this utilization method can also reduce surface evaporation and prevent soil salinization.
[0072] The above is only a preferred embodiment of the present application, but the present application is not limited to the described embodiment. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included in the scope defined by the claims of the present application.
Claims
1. A method for improving sandy saline-alkali soil, characterized in that It includes the following steps: S1. Excavate the sandy saline-alkali soil to be improved, and stack the severely saline-alkali soil and the slightly saline-alkali soil separately. Among them, the severely saline-alkali soil refers to the soil with a total salt content greater than 4 g / kg, and the slightly saline-alkali soil refers to the soil with a total salt content less than 4 g / kg; S2. Spread the severely saline-alkali soil added with desulfurized gypsum and ferrous sulfate in the excavation area of the sandy saline-alkali soil; S3. Spread a salt isolation layer on the spread severely saline-alkali soil; S4. Spread a layer of slightly saline-alkali soil added with furfural residue on the salt isolation layer to form a buffer layer; S5. Backfill the slightly saline-alkali soil improved with a modifier on the buffer layer to make the improved soil meet the standard of planting soil to form a planting layer; Among them, the modifier includes the following components by weight: 80-120 parts of pine needle soil, 50-85 parts of acid-modified cow dung charcoal, 3-5 parts of zeolite powder, 0.2-0.4 parts of inorganic fertilizer, 2-4 parts of microbial inoculum, 2-4 parts of binding material.
2. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that The addition amount of the modifier is 10%-30% of the weight of the sandy saline-alkali soil.
3. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that, The preparation method of the acid-modified cow dung charcoal is: impregnate the dry cow dung in an acidic solution, and then calcine it at 400-500 °C to form biochar, which is the acid-modified cow dung charcoal.
4. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that, The inorganic fertilizer is one or a combination of ammonium sulfate, ammonium nitrate and calcium nitrate; The microbial inoculum is one or a combination of Bacillus mucilaginosus and Bacillus subtilis; The binding material is one or a combination of polyvinyl alcohol, sodium polyacrylate and sodium carboxymethyl cellulose.
5. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that, The severely saline-alkali soil refers to the soil with a total salt content greater than 4 g / kg, and the slightly saline-alkali soil refers to the soil with a total salt content less than 4 g / kg.
6. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that The salt isolation layer includes a cobblestone layer with a thickness of 20-30 cm in the upper layer and a clay layer with a thickness of 10-15 cm in the lower layer, and the particle size of the cobblestones is 1-3 cm.
7. The improvement method of sandy saline-alkali soil according to claim 6, characterized in that, It also includes the following steps: S6. According to the slope of the sandy saline-alkali soil, excavate a water channel at the lower slope. The bottom of the water channel is located in the clay layer of the salt isolation layer. The water channel is used to drain the excess precipitation of the sandy saline-alkali soil and prevent soil salt return caused by waterlogging.
8. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that, The slopes of the severely saline-alkali soil, the salt isolation layer, the buffer layer and the slightly saline-alkali soil are all 1%-3%.
9. The improvement method of sandy saline-alkali soil according to claim 1, characterized in that The addition amount of the desulfurized gypsum added to the severely saline-alkali soil is 1.0%-2.0% of the weight of the severely saline-alkali soil, and the addition amount of the ferrous sulfate is 0.5%-3% of the weight of the severely saline-alkali soil; The addition amount of the furfural residue in the buffer layer is 0.5%-1.0% of the weight of the slightly saline-alkali soil in the buffer layer.