A method for improving plant cultivation in saline-alkali soil

Abstract

This invention relates to the field of plant cultivation, and more particularly to a method for improving plant cultivation in saline-alkali land. The method comprises the following steps: excavating planting holes; laying a biodegradable physical isolation layer composed of humic acid-treated plant fibers and biomass adhesives, which has salt-regulating degradation properties; filling the root zone with a root zone improvement substrate composed of topsoil, well-rotted organic fertilizer, vermiculite, and pH-adaptive ammonium sulfate; planting salt-tolerant plant seedlings and watering with potassium humate-containing water for root establishment, using drip irrigation; applying organic fertilizer after one season of plant growth, and returning straw to the field after two seasons. This invention creates a low-salt environment in the root zone through the biodegradable isolation layer, combined with a precisely proportioned improvement substrate, effectively solving the triple stress problems of salt, alkali, and drought in the early stages of seedling transplanting, significantly improving survival rate and improvement efficiency.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation, and more particularly to a method for improving plant cultivation in saline-alkali land. Background Technology

[0002] Saline-alkali soils are a significant obstacle to global agricultural development and ecological security. Their high salinity, high alkalinity, compaction, and poor fertility severely inhibit seed germination, hinder plant root development, and interfere with water and nutrient absorption, making it difficult for conventional plants to survive, resulting in low land productivity and fragile ecosystems.

[0003] Traditional direct planting methods expose the roots of salt-tolerant plant seedlings to the native saline-alkali soil environment immediately after planting. This can easily lead to the seedling roots being subjected to triple stress from salt, alkali and drought, resulting in low seedling survival rate and long recovery period, which seriously affects the initial effectiveness and efficiency of the improvement project. Summary of the Invention

[0004] The present invention aims to provide a method for improving plant cultivation in saline-alkali land, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for improving vegetation cultivation in saline-alkali land includes the following steps: S1. Excavating planting holes: At the planned location of the saline-alkali land to be improved, excavate planting holes with a depth of 30-50cm and a diameter of 20-40cm. S2. Laying a biodegradable physical barrier layer: At the bottom of the planting hole obtained in S1, a biodegradable physical barrier layer is laid as a salt barrier base. The physical barrier layer is composed of plant fibers treated with humic acid solution and biomass adhesive. The degradation characteristics of plant fibers, humic acid solution treatment and biomass adhesive are synergistically designed so that the main structure of the physical barrier layer remains stable for a complete growing season after the plant is planted, and then begins to disintegrate naturally. The physical barrier layer has degradation characteristics regulated by soil salinity: the degradation period is extended to 90 days in high salinity environment and shortened to 30 days in low salinity environment, thereby dynamically adapting to changes in root zone salinity and achieving synergy between barrier and degradation timing. S3. Fill the root zone improvement substrate: On top of the physical isolation layer laid in S2, fill the pre-prepared root zone improvement substrate until the planting hole is filled or slightly higher than the original ground level. S4. Planting and initial management: Plant salt-tolerant pioneer plant seedlings in the root zone improvement substrate prepared in S3. Water them immediately after planting. During the first growing season after planting, use drip irrigation to manage water and keep the root zone improvement substrate moist, avoiding excessive watering. S5. Post-planting soil cultivation: After the plants planted in S4 have completed a full growing season, post-planting soil cultivation is carried out based on the degradation characteristics of the physical isolation layer designed in S2. This is achieved by continuously cultivating the rhizosphere soil by applying organic fertilizer around the plants, promoting the transformation of the isolation layer material, and gradually expanding the scope of improvement.

[0006] Preferably, in step S2, the plant fiber is obtained by cutting rice straw to a length of 5-10 cm and then mechanically crushing and fiberizing it.

[0007] Preferably, in step S2, the coating layer formed on the surface of the plant fiber by the humic acid solution treatment has a thickness of 0.8-1.2 mm; the biomass adhesive is a starch-based adhesive modified by a crosslinking agent, and its degree of crosslinking is controlled at 60%-70%; the plant fiber is pretreated by soaking in an alkaline solution with a concentration of 1%-2% before the humic acid treatment.

[0008] Preferably, in step S2, the physical isolation layer is also uniformly mixed with a salt-tolerant microbial agent, which includes Bacillus mucilaginosus. The amount of salt-tolerant microbial agent added is 0.5%-1% of the total mass of the physical isolation layer. It is used to synergistically decompose organic matter and fix salt ions during the degradation process of the physical isolation layer.

[0009] Preferably, in step S3, the composition of the root zone improvement matrix, by mass percentage, includes: Imported soil: 40%-60%; the imported soil is soil taken from non-saline-alkali land or slightly saline-alkali land; Well-rotted organic fertilizer: 25%-35%; the well-rotted organic fertilizer is made from cow and sheep manure and mushroom residue that have been fully decomposed. Soil structure modifier: 10%-20%; the soil structure modifier is vermiculite; Acidic conditioner: 1.5%-4.0%; the acidic conditioner is ammonium sulfate.

[0010] Preferably, in step S3, the amount of ammonium sulfate added is determined according to the following principle: with the goal of adjusting the pH value of the root zone improvement substrate to 6.5-7.5, for every unit higher than 7.5 in the initial pH value of the saline-alkali land to be improved, the mass percentage of ammonium sulfate in the substrate is increased by 0.5%-1.5% within the range of 1.5%-4.0%.

[0011] Preferably, in step S4, the salt-tolerant pioneer plant is a salt-tolerant plant, including but not limited to Suaeda salsa and Sesbania scoparia.

[0012] Preferably, in step S4, potassium humate is added to the root-setting water at a concentration of 0.01%-0.05% to promote seedling root development and alleviate salt stress in the early stage of transplanting.

[0013] Preferably, in step S5, the specific method of applying organic fertilizer around the plant is as follows: with the plant stem as the center, dig a circular trench or 4-6 radial trenches with a depth of 10-15cm within a radius of 20-30cm, apply the organic fertilizer into the trench and then cover it with soil.

[0014] Preferably, in step S5, while applying organic fertilizer, the dead branches and fallen leaves of salt-tolerant pioneer plants are crushed and mixed with organic fertilizer at a mass ratio of 1:2 and applied into the furrow; after the plants have grown for two complete growing seasons, the harvested plant straw is crushed and the entire field is shallowly tilled and returned to the field, with a shallow tillage depth of 5-8cm, in order to promote the accumulation of soil organic matter and improve the structure, and gradually realize the improvement of saline-alkali land from the root zone to the whole area.

[0015] The beneficial effects of this technical solution compared to existing technologies are as follows: (1) This scheme solves the triple stress problem of initial planting in saline-alkali land by setting up a biodegradable physical isolation layer, which greatly improves the success rate and efficiency of planting and avoids secondary pollution. In traditional methods, the seedling roots are directly exposed to the original soil with high salt, high alkali and drought, resulting in low survival rate. In this scheme, a physical isolation layer composed of plant fiber, humic acid and biomass adhesive is laid at the bottom of the planting hole. During the critical period of 30-90 days after planting, it effectively blocks the high salinity in the lower layer from rising directly to the plant root zone through capillary action, thereby physically cutting off the main source of salt stress, improving the survival rate of seedlings, shortening the seedling recovery period, and significantly improving the initial effectiveness and efficiency of the improvement project. At the same time, the isolation layer is made of all biomass material. After fulfilling its salt isolation mission, it will naturally degrade as expected and be converted into soil organic matter, avoiding the white pollution problem caused by the use of plastic film, etc., and achieving the unity of environmental protection and function.

[0016] (2) Precise pH regulation is achieved by setting up a root zone improvement substrate. The root zone improvement substrate uses a compound formula of imported soil, well-rotted organic fertilizer, vermiculite and ammonium sulfate, which can specifically neutralize soil alkalinity and avoid the failure of improvement caused by insufficient or excessive use of a single amendment. At the same time, vermiculite and well-rotted organic fertilizer work together to improve soil aeration and fertilizer retention, providing a comprehensive and suitable root zone environment for plant growth.

[0017] (3) By adding potassium humate to the root-setting water and using drip irrigation management, adding a low concentration of potassium humate (0.01%-0.05%) when watering the seedlings can directly act on the seedling roots, stimulate root growth and alleviate the osmotic impact caused by salt stress, forming a triple protection with the physical isolation layer and the improved substrate. At the same time, strictly stipulating the use of drip irrigation in the first growing season, precise water supply is achieved, which can not only keep the root zone moist and promote growth, but also effectively inhibit salt accumulation and soil compaction caused by flood irrigation, thus consolidating the initial improvement results from the perspective of water management.

[0018] (4) By applying organic fertilizer after the growing season and mixing it with plant litter, the rhizosphere soil is cultivated. After two years of plant growth, the harvested straw is crushed and the entire field is shallowly tilled and returned to the soil. This series of operations transforms the huge biomass produced by the plants themselves into raw materials for improving the original soil, realizing the internal cycle of organic matter and nutrients. As a result, the improvement effect can be radiated and expanded to the surrounding soil year by year and circle by circle, based on each successful plant, and finally achieve the goal of low-cost and sustainable ecological restoration of saline-alkali land from local root zone improvement to whole-area soil cultivation. Attached Figure Description

[0019] Figure 1 A flowchart of the method provided by the present invention; Detailed Implementation The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: A method for improving vegetation cultivation in saline-alkali land includes the following steps: S1. Excavate planting holes: At the planned location of the saline-alkali land to be improved, excavate planting holes with a depth of 30-50cm and a diameter of 20-40cm. S2. Laying a biodegradable physical barrier layer: At the bottom of the planting hole obtained in S1, a biodegradable physical barrier layer is laid as a salt-barrier base. The physical barrier layer is composed of plant fibers treated with humic acid solution and biomass adhesive. The degradation characteristics of the plant fibers, humic acid solution treatment, and biomass adhesive are synergistically designed so that the main structure of the physical barrier layer remains stable for a complete growing season after plant establishment, after which it begins to disintegrate naturally. "A complete growing season" is typically 90 to 180 days under the temperate to warm temperate saline-alkali climate conditions applicable to this invention. The plant fibers are obtained by cutting rice straw to a length of 5-10 cm and mechanically crushing it into fibers. Subsequently, the plant fibers are pretreated with an alkaline solution (1%-2% sodium hydroxide) for 1-2 hours to break down the waxy layer on the fiber surface, improving its subsequent biodegradability while preserving the main fiber structure. This allows the fibers to naturally disintegrate within 15-30 days under the action of salt-tolerant microbial agents after the humic acid coating layer fails and the adhesive degrades, precisely coinciding with the plant's growth cycle. The pretreated plant fibers are then treated with a humic acid solution to form a coating layer with a thickness controlled at 0.8-1.2 mm. This thickness is designed to match the natural dissolution period of humic acid in the soil with the 90-180 day growing season. Specifically, by controlling this thickness, the dissolution period of the humic acid coating layer falls within this time range. The humic acid dissolution rate slows down under high salinity and accelerates under low salinity, ensuring that the coating layer gradually fails after the seedlings survive, releasing the internal plant fibers. The biomass adhesive is a starch-based adhesive modified with a crosslinking agent. By adding 0.3%-0.5% citric acid as a crosslinking agent, its crosslinking degree is controlled at 60%-70%. This crosslinking degree is designed to ensure that the degradation cycle of the adhesive also falls within the time range of 90 to 180 days, which is coordinated with the dissolution cycle of the humic acid coating layer. This avoids the adhesive from degrading too early, causing the isolation layer to break prematurely, or degrading too late, hindering the decomposition of plant fibers.

[0020] The physical isolation layer also contains a uniformly mixed salt-tolerant microbial agent, including Bacillus mucilaginosus. The amount of salt-tolerant microbial agent added is 0.5%-1% of the total mass of the physical isolation layer. It is used to synergistically decompose organic matter and fix salt ions during the degradation process of the physical isolation layer.

[0021] The physical barrier layer exhibits a degradation rate regulated by soil salinity: the degradation rate slows down under high salinity conditions, extending the stable period of the main structure to 150-180 days; the degradation rate accelerates under low salinity conditions, shortening the stable period of the main structure to 90-120 days, both covering the 90-180 day growing season. This allows it to dynamically adapt to changes in root zone salinity, ensuring that the barrier layer only completely disintegrates after the seedlings have survived and passed through the critical growth period. It should be noted that the degradation of the physical isolation layer does not occur uniformly. Its disintegration process is characterized by a preference for the lower surface: the lower layer of undisturbed saline-alkali soil lacks organic matter, so microorganisms will concentrate their metabolism on the lower surface of the isolation layer as the main carbon source; while the upper root zone improved substrate is rich in organic matter, so microorganisms will preferentially utilize the substrate nutrients. Therefore, during the critical period of plant growth, the upper surface of the isolation layer will not disintegrate prematurely due to microbial activity, thus ensuring the salt isolation effect.

[0022] S3. Fill the root zone improvement substrate: On top of the physical isolation layer laid in S2, fill the pre-prepared root zone improvement substrate until the planting hole is filled or slightly higher than the original ground level. The composition of the root zone improvement substrate, by mass percentage, includes: Topsoil: 40%-60%; Topsoil is soil taken from non-saline-alkali land or slightly saline-alkali land, and its function is to introduce a benign soil microbial community and a safe physical carrier. Well-rotted organic fertilizer: 25%-35%; Well-rotted organic fertilizer is made from cow and sheep manure and mushroom residue after full decomposition. Cow and sheep manure provides comprehensive nutrients and fiber, while mushroom residue is rich in mycelium and trace elements. After decomposition, both can quickly improve the fertility of the substrate and promote the formation of granular structure. Soil structure conditioner: 10%-20%; the soil structure conditioner is vermiculite, which has excellent water retention, fertilizer retention and ion exchange capacity, and can buffer salt and alkali stress; Acidic conditioner: 1.5%-4.0%; the acidic conditioner is ammonium sulfate.

[0023] Ammonium sulfate is a water-soluble salt that immediately dissociates into ammonium ions and sulfate ions upon application to the soil. Its acidification effect originates from the absorption of ammonium ions by plant roots and microorganisms. Each absorbed ammonium ion releases a hydrogen ion. This process is synchronized with plant growth and metabolism; therefore, the release of acidity is mild, slow, and biologically regulated, completely avoiding the risk of damage to seedling roots from the formation of localized strong acids. Simultaneously, it provides nitrogen and sulfur, essential nutrients for plants.

[0024] The amount of ammonium sulfate added is determined based on the following principle: the goal is to adjust the pH of the root zone improvement substrate to 6.5-7.5, which is the suitable range for most salt-tolerant pioneer plants. Specifically, the adjustment is based on the initial pH of the saline-alkali land to be improved: with a pH of 7.5 as the baseline, for every unit increase in the initial pH above 7.5, the mass percentage of ammonium sulfate in the substrate should be increased by 0.5%-1.5% within the range of 1.5%-4.0%.

[0025] The amount of ammonium sulfate to be added can be calculated using the following formula: in, The adjustment factor is between 0.5% and 1.5%, and the total addition amount does not exceed 4.0%; This is the baseline addition amount at pH=7.5.

[0026] S4. Planting and Initial Management: Plant salt-tolerant pioneer plant seedlings in the root zone improvement substrate configured in S3. These seedlings are salt-tolerant plants, including but not limited to *Suaeda salsa* and *Senecio scandens*, with a salt tolerance threshold ≥0.8% (soil salinity), a growth cycle of 90-180 days (matching the stabilization period of the physical isolation layer), and possess nitrogen-fixing or soil structure-improving functions. Water immediately after planting to help the roots establish. Potassium humate is added to the root-setting water at a concentration of 0.01%-0.05% to promote seedling root development and alleviate salt stress in the early stages of transplanting. Potassium humate possesses the modifying properties of humic acid and the nutritional and stress-resistance functions of potassium ions. Its low molecular weight fulvic acid stimulates root growth and improves cell membrane stability; the potassium ions it carries can regulate osmotic pressure and enhance seedling tolerance to salt stress. This component works synergistically with the root zone improvement substrate and physical isolation layer to ensure a high survival rate in the early stages of transplanting. The root-setting water is prepared by dissolving potassium humate solution at the required concentration in the irrigation water and stirring thoroughly.

[0027] Immediately after planting the seedlings, water them. The amount of water should be enough to fully moisten the root zone of the improved substrate, with a slight seepage: 2-3 liters per hole when the planting hole is 30-40cm deep; 3-5 liters per hole when the depth is 40-50cm deep, adjusting flexibly according to the hole depth. During the first growing season after planting, use drip irrigation to manage water, keeping the root zone of the improved substrate moist and avoiding excessive watering.

[0028] S5. Post-planting soil cultivation: After the plants planted in S4 have completed a full growing season, the physical isolation layer designed in S2 has entered the disintegration stage based on its degradation characteristics. Post-planting soil cultivation is then carried out: First, the rhizosphere soil is continuously cultivated by applying organic fertilizer around the plants to promote the transformation of the isolation layer material and gradually expand the scope of improvement.

[0029] The specific method for applying organic fertilizer around the plant is as follows: with the plant stem as the center, dig a circular trench or 4-6 radial trenches with a depth of 10-15cm within a radius of 20-30cm around the root zone. Apply the organic fertilizer into the trench, then cover it with soil and compact it lightly. The amount of organic fertilizer applied can be adjusted according to the plant growth and soil fertility.

[0030] While applying organic fertilizer, crush the dead branches and fallen leaves of salt-tolerant pioneer plants and mix them with organic fertilizer at a mass ratio of 1:2 and apply them into the furrows. After that, when the plants have grown for two complete growing seasons, carry out the second round of cultivation: crush the harvested plant straw and shallowly cultivate the whole field to return it to the field. The shallow cultivation depth is 5-8cm, which promotes the accumulation of soil organic matter and structural improvement, and gradually realizes the improvement of saline-alkali land from the root zone to the whole area.

[0031] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for improving plant cultivation in saline-alkali land, characterized in that, Includes the following steps: S1. Excavating planting holes: At the planned location of the saline-alkali land to be improved, excavate planting holes with a depth of 30-50cm and a diameter of 20-40cm. S2. Laying a biodegradable physical barrier layer: At the bottom of the planting hole obtained in S1, a biodegradable physical barrier layer is laid as a salt barrier base. The physical barrier layer is composed of plant fibers treated with humic acid solution and biomass adhesive. The degradation characteristics of plant fibers, humic acid solution treatment and biomass adhesive are synergistically designed so that the main structure of the physical barrier layer remains stable for a complete growing season after the plant is planted, and then begins to disintegrate naturally. The physical barrier layer has degradation characteristics regulated by soil salinity: the degradation period is extended to 90 days in high salinity environment and shortened to 30 days in low salinity environment, thereby dynamically adapting to changes in root zone salinity and achieving synergy between barrier and degradation timing. S3. Fill the root zone improvement substrate: On top of the physical isolation layer laid in S2, fill the pre-prepared root zone improvement substrate until the planting hole is filled or slightly higher than the original ground level. S4. Planting and initial management: Plant salt-tolerant pioneer plant seedlings in the root zone improvement substrate prepared in S3. Water them immediately after planting. During the first growing season after planting, use drip irrigation to manage water and keep the root zone improvement substrate moist, avoiding excessive watering. S5. Post-planting soil cultivation: After the plants planted in S4 have completed a full growing season, post-planting soil cultivation is carried out based on the degradation characteristics of the physical isolation layer designed in S2. This is achieved by continuously cultivating the rhizosphere soil by applying organic fertilizer around the plants, promoting the transformation of the isolation layer material, and gradually expanding the scope of improvement.

2. The method for improving vegetation cultivation in saline-alkali land as described in claim 1, characterized in that: In step S2, the plant fiber is obtained by cutting rice straw to a length of 5-10cm and mechanically crushing it into fiber.

3. The method for improving vegetation cultivation in saline-alkali land as described in claim 2, characterized in that: In step S2, the humic acid solution treatment forms a coating layer on the surface of the plant fiber with a thickness of 0.8-1.2 mm; the biomass adhesive is a starch-based adhesive modified with a crosslinking agent, and its degree of crosslinking is controlled at 60%-70%; before the humic acid treatment, the plant fiber is pretreated by soaking in an alkaline solution with a concentration of 1%-2%.

4. The method for improving vegetation cultivation in saline-alkali land as described in claim 1, characterized in that: In step S2, the physical isolation layer is also uniformly mixed with a salt-tolerant microbial agent, which includes Bacillus mucilaginosus. The amount of salt-tolerant microbial agent added is 0.5%-1% of the total mass of the physical isolation layer. It is used to synergistically decompose organic matter and fix salt ions during the degradation process of the physical isolation layer.

5. The method for improving vegetation cultivation in saline-alkali land as described in claim 1, characterized in that, In step S3, the composition of the root zone improvement matrix, by mass percentage, includes: Imported soil: 40%-60%; the imported soil is soil taken from non-saline-alkali land or slightly saline-alkali land; Well-rotted organic fertilizer: 25%-35%; the well-rotted organic fertilizer is made from cow and sheep manure and mushroom residue that have been fully decomposed. Soil structure modifier: 10%-20%; the soil structure modifier is vermiculite; Acidic conditioner: 1.5%-4.0%; the acidic conditioner is ammonium sulfate.

6. The method for improving vegetation cultivation in saline-alkali land as described in claim 5, characterized in that, In step S3, the amount of ammonium sulfate added is determined according to the following principle: with the goal of adjusting the pH value of the root zone improvement substrate to 6.5-7.5, for every unit higher than 7.5 in the initial pH value of the saline-alkali land to be improved, the mass percentage of ammonium sulfate in the substrate within the range of 1.5%-4.0% is increased by 0.5%-1.5%.

7. The method for improving vegetation cultivation in saline-alkali land as described in claim 1, characterized in that: In step S4, the salt-tolerant pioneer plant is a salt-tolerant plant, including but not limited to Suaeda salsa and Sesbania scoparia.

8. The method for improving vegetation in saline-alkali land as described in claim 1, characterized in that: In step S4, potassium humate is added to the root-setting water at a concentration of 0.01%-0.05% to promote seedling root development and alleviate salt stress in the early stage of transplanting.

9. The method for improving vegetation cultivation in saline-alkali land as described in claim 1, characterized in that, In step S5, the specific method of applying organic fertilizer around the plant is as follows: with the plant stem as the center, dig a circular trench with a depth of 10-15cm or 4-6 radial trenches within a radius of 20-30cm, apply the organic fertilizer into the trench and then cover it with soil.

10. The method for improving vegetation cultivation in saline-alkali land as described in claim 9, characterized in that: In step S5, while applying organic fertilizer, the dead branches and fallen leaves of salt-tolerant pioneer plants are crushed and mixed with organic fertilizer at a mass ratio of 1:2 and applied into the furrow. After the plants have grown for two complete growing seasons, the harvested plant straw is crushed and the entire field is shallowly tilled and returned to the field. The shallow tillage depth is 5-8cm, which promotes the accumulation of soil organic matter and structural improvement, and gradually realizes the improvement of saline-alkali land from the root zone to the whole area.

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