Ecological restoration method for improving saline-alkali grassland of photovoltaic power station

Abstract

The invention provides an ecological restoration method for improving saline-alkali grassland of a photovoltaic power station, and belongs to the technical field of ecological restoration. In order to solve the problem of ecological restoration of saline-alkali grassland of a photovoltaic power station, the invention provides a sesbania planting and mobile water storage device synergistic restoration technology system. According to the technology, the saline-alkaline tolerance characteristic of a leguminous plant sesbania and the intelligent water control advantage of a mobile water storage device are fully utilized, and a novel photovoltaic-plant-water coordinated regulation and control remediation mode is constructed. The sesbania effectively improves the physical and chemical properties of the soil by virtue of the strong salt tolerance, rapid growth characteristic and strong nitrogen fixation capability of the sesbania; and in cooperation with accurate moisture management of the movable water storage device, dynamic balance between salt leaching and evaporation inhibition is achieved. The invention provides a feasible technical scheme for solving the contradiction between new energy development and ecological protection, and has remarkable environmental benefits and popularization and application values.

Description

Technical Field

[0001] The present invention belongs to the technical field of ecological restoration, and in particular relates to an ecological restoration method for improving saline-alkali grassland in a photovoltaic power station. Background Art

[0002] The improvement of photovoltaic saline-alkali grasslands is an important topic in the management of saline-alkali land and the utilization of new energy. At present, the ecological restoration of photovoltaic saline-alkali grasslands mainly adopts physical methods, chemical improvement and the planting of salt-tolerant plants, but the following problems still exist: physical methods (concealed pipe salt drainage technology, mulching technology, deep loosening) generally have common problems such as poor adaptability, low cost-effectiveness, and insufficient sustainability; traditional chemical improvement through the application of amendments (such as gypsum and organic fertilizer) has obvious initial effects, but the salt will move upward again with water evaporation, which is difficult to sustain and has high costs; although the planting of salt-tolerant plants (such as Suaeda salsa) can adapt to saline-alkali environments, the community is single, the biomass is low, and the ecological benefits and economic value are insufficient. Therefore, there is an urgent need to develop new ecological restoration methods for the improvement of saline-alkali land that are more economical, efficient, sustainable, and compatible with photovoltaic facilities. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an improved ecological restoration method for saline-alkali grasslands in photovoltaic power stations. Based on the sowing of sesbania + mobile water storage irrigation system, the efficient planting of sesbania in saline-alkali grasslands in photovoltaic power stations can be achieved, the vegetation coverage rate can be increased, the soil structure can be improved, and the ecological benefits of the photovoltaic power station area can be optimized.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] The present invention provides an ecological restoration method for improving saline-alkali grassland in a photovoltaic power station, comprising the following steps: applying a soil conditioner and organic fertilizer, laying a drip irrigation pipe and connecting it to a mobile water storage device; covering with straw after sowing sesbania, and irrigating; crushing the sesbania and returning it to the field; the soil conditioner contains silicate minerals and organic acids; and the organic fertilizer is a fermented and decomposed carbon-containing organic fertilizer.

[0006] Preferably, the amount of soil conditioner applied is 2000-3000 kg / hm2 2 ; The amount of organic fertilizer applied is 2-8t / hm 2 .

[0007] Preferably, the organic fertilizer includes decomposed cow dung, decomposed sheep dung or decomposed pig dung; and the N+P2O5+K2O of the organic fertilizer is ≥4.0%.

[0008] Preferably, the sesbania is soaked in 48-52°C water for 20-28 hours before sowing; the sowing method of the sesbania is drill sowing or broadcast sowing, and the sowing rate is 45-75kg / hm 2, row spacing is 35-45cm, plant spacing is 45-55cm, and sowing depth is 1-2cm.

[0009] Preferably, the straw includes one or more of corn straw, wheat straw, rice straw, cotton straw, and soybean straw; and the straw is processed to 2-3 cm.

[0010] Preferably, the thickness of the covering is 5-8 cm, and the amount of the covering is 40-50 t / hm 2 .

[0011] Preferably, the irrigation time and amount are set according to the growth stage and water requirement of the sesbania and based on the soil matrix potential.

[0012] Preferably, the soil matrix potential is monitored at a depth of 18-22 cm below the dripper; when the control threshold of the sesbania seedlings reaches -8 to -12 kPa, the irrigation water volume is 90-120 m 3 / hm 3 , the time is 4 to 6 hours; when the flowering control threshold reaches -8 to -12 kPa, the irrigation water volume is 100-130m 3 / hm 3 , the time is 5-7h; when the maturity control threshold reaches -18~22kPa, the irrigation water volume is 50-70m 3 / hm 3 , time is 2-3h.

[0013] Preferably, the stubble height of the Sesbania sesbania returned to the field is 2-8 cm; the Sesbania sesbania is chopped and spread on the saline-alkali land of the photovoltaic power station.

[0014] The present invention provides application of the ecological restoration method in improving saline-alkali grassland in a photovoltaic power station.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention proposes a collaborative restoration technology system of "Sesbania sesbania planting + mobile water storage irrigation system". This technology makes full use of the salt-alkali tolerance of the legume plant Sesbania sesbania and the intelligent water control advantages of the mobile water storage device to construct a new restoration model of photovoltaic-plant-water collaborative regulation. Sesbania sesbania effectively improves the physical and chemical properties of the soil with its strong salt tolerance, rapid growth characteristics and strong nitrogen fixation ability; combined with the precise water management of the mobile water storage device, a dynamic balance between salt leaching and evaporation suppression is achieved. This model aims to make full use of the resources of saline-alkali land, while improving the soil environment, promoting vegetation restoration, and achieving a comprehensive improvement in ecological, economic and social benefits. It provides a practical technical solution to resolve the contradiction between new energy development and ecological protection, and has significant environmental benefits and promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the ecological restoration layout of saline-alkali grasslands near improved photovoltaic power stations. DETAILED DESCRIPTION

[0018] The present invention provides an ecological restoration method for improving saline-alkali grasslands in photovoltaic power plants, comprising the following steps: applying soil conditioners and organic fertilizers, laying drip irrigation pipes connected to mobile water reservoirs; sowing sesbania, covering with straw, and irrigating; crushing the sesbania, and returning it to the field; the soil conditioners contain silicate minerals and organic acids; and the organic fertilizer is fermented and decomposed carbon-containing organic fertilizer. This method integrates photovoltaic technology with saline-alkali grassland ecosystems to create an ecological model that fully utilizes saline-alkali land resources, improves the soil environment, and promotes vegetation restoration, achieving comprehensive improvements in ecological, economic, and social benefits.

[0019] In the present invention, the branch pipes of the drip irrigation pipe are laid along the sesbania row spacing, with the spacing between the branch pipes being 35-45 cm, preferably 37-43 cm, and more preferably 40 cm. The drippers of the branch drip irrigation pipes of the present invention are aligned with the position of the sesbania plants, and the drippers are spaced 45-55 cm, preferably 46-53 cm, and more preferably 50 cm apart. The mobile water reservoirs of the present invention are located on the main drip irrigation pipe, and the spacing between the mobile water reservoirs is 40-55 cm, preferably 42-53 cm, and more preferably 48 cm.

[0020] In the present invention, soil conditioners and organic fertilizers are applied in conjunction with land preparation. The source of the soil conditioners described in the present invention is not specified and is purchased through commercial channels well known in the art. The soil conditioners described in the present invention (containing silicate minerals, organic acids, microbial agents, etc.) are preferably sourced from Beijing Bennong Technology Development Co., Ltd. The application rate of the soil conditioners described in the present invention is 2000-3000 kg / hm 2 , preferably 2200-2900kg / hm 2 , more preferably 2500kg / hm 2 The application of the soil conditioner in the present invention mainly regulates the soil pH, alleviates saline-alkali hazards, and at the same time improves the effectiveness of nutrients and increases the soil's fertilizer retention capacity.

[0021] In the present invention, the organic fertilizer comprises decomposed cow dung, wherein the N+P2O5+K2O content of the decomposed cow dung is ≥4.0%. The application amount of the organic fertilizer in the present invention is 2-8 t / hm 2 , preferably 3-7t / hm 2 , more preferably 5t / hm 2The decomposed cow dung of the present invention is prepared by a preparation method well known in the art, or purchased through commercial channels well known in the art, and the decomposed cow dung is preferably obtained from a farm. The decomposed cow dung of the present invention provides nutrients necessary for plant growth, and promotes the formation of soil aggregate structure, making the soil loose and breathable.

[0022] In the present invention, the sesbania is soaked in 48-52°C water for 20-28 hours, preferably in 49-51°C water for 21-26 hours, and more preferably in 50°C water for 24 hours before sowing; soaking the sesbania in hot water is beneficial to seed germination. The sesbania sowing method of the present invention is drill sowing or broadcast sowing, and the sowing rate is 45-75 kg / hm 2 The row spacing is 35-45cm, the plant spacing is 45-55cm, the sowing depth is 0.5-2.5cm; broadcast sowing is preferred, and the sowing rate is 50-70kg / hm 2 , row spacing is 37-43cm, plant spacing is 46-54cm, sowing depth is 0.8-2.3cm; further preferred is drill sowing, sowing rate is 60kg / hm 2 The row spacing is 40 cm, the plant spacing is 50 cm, and the sowing depth is 1-2 cm. The drill sowing of the present invention is suitable for mechanized operation and post-management; appropriate row spacing and plant spacing can avoid overlapping of plant branches and leaves, maximizing photosynthetic efficiency; appropriate sowing amount ensures biomass; appropriate sowing depth is conducive to the emergence of sesbania seeds, and sowing too deep will delay or prevent seedlings; excessive sowing, narrow row spacing, and deep sowing will affect the growth and

[0023] In the present invention, the straw includes one or more of corn straw, wheat straw, rice straw, cotton straw, and soybean straw, preferably corn straw or rice straw, and more preferably corn straw. The straw is processed to a thickness of 2-3 cm. The straw mulch used in the present invention has a thickness of 5-8 cm, preferably 5.5-7.5 cm; the mulch volume is 40-50 t / hm2. 2 , preferably 42-48t / hm 2 , more preferably 45t / hm 2 The present invention covers the sesbania with straw after sowing, has a moisture-retaining effect, effectively reduces soil moisture evaporation, and creates a moist environment for sesbania seed germination and seedling growth.

[0024] In the present invention, according to the growth stage and water requirement of Sesbania sesbania, the irrigation time and irrigation amount are set based on the soil matrix potential. The present invention monitors the soil matrix potential at a depth of 18-22 cm below the dripper by a vacuum negative pressure gauge, and the control threshold (soil matrix potential) during the seedling and flowering stages is -8 to -12 kPa, and the control threshold (soil matrix potential) during the maturity stage is -18 to -22 kPa, and the irrigation system is started. When the control threshold during the seedling stage of the Sesbania sesbania of the present invention reaches -8 to -12 kPa, the irrigation water amount is 90-120 m 3 / hm 3 , the time is 4 to 6 hours; when the flowering control threshold reaches -8 to -12 kPa, the irrigation water volume is 100-130m 3 / hm 3 , the time is 5-7h; when the maturity control threshold reaches -18~-22kPa, the irrigation water volume is 50-70m 3 / hm 3 The soil matrix potential of the present invention is preferably monitored at a depth of 20 cm below the dripper. When the control threshold reaches -10 kPa during the seedling stage, the irrigation water volume is 110 m 3 / hm 3 , the time is 5h; when the flowering control threshold reaches -10kPa, the irrigation water volume is 120m 3 / hm 3 , the time is 6h; when the maturity control threshold reaches -20kPa, the irrigation water volume is 60m 3 / hm 3 , time is 2.5h.

[0025] In the present invention, the stubble height of sesbania returned to the field is 2-8 cm, preferably 3-7 cm, and more preferably 5 cm. The sesbania is chopped and spread on the saline-alkali land of the photovoltaic power station. The present invention harvests sesbania when it reaches the early to peak flowering stage. The purpose of returning sesbania to the field is to provide nutrients through green manure decomposition and to reduce saline-alkali toxicity through biological action.

[0026] In the present invention, the setting of the mobile water storage device has the following advantages: first, its mobility can match the spacing between photovoltaic panels, realize precise fixed-point irrigation, and avoid construction conflicts caused by fixed pipes passing through the bracket; second, it is easy to adjust the position to follow the crops. For example, there is a spatial difference between the growing period of field sesbania and the water-requiring area of ​​forage, which can be adjusted appropriately; third, it is easy to replenish water sources due to its mobility.

[0027] The present invention also provides the application of the ecological restoration method in improving saline-alkali grasslands in photovoltaic power plants. This invention combines photovoltaic technology with saline-alkali grassland ecosystems, aiming to fully utilize saline-alkali land resources, improve the soil environment, promote vegetation recovery, and achieve comprehensive improvements in ecological, economic, and social benefits.

[0028] In the present invention, unless otherwise specified, the raw materials or reagents used are commercially available products well known to those skilled in the art.

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Example 1

[0031] 1. Land preparation before sowing

[0032] Before sowing, the saline-alkali grassland between the photovoltaic panels was carefully prepared, including deep plowing, harrowing, weeding, and compacting. Autumn preparation is preferred, with a deep plowing depth of 18-20 cm. In conjunction with soil preparation, 2500 kg / hm2 of soil amendment (containing silicate minerals, organic acids, and microbial agents, sourced from Beijing Bennong Technology Development Co., Ltd.) was applied. 2 , while applying 5t / hm 2 Composted cow dung (fermented and decomposed carbon-containing organic fertilizer N+P2O5+K2O≥4.0%, sourced from livestock farms).

[0033] Drip irrigation pipes were laid in the saline-alkali grassland test area between the photovoltaic panels, and the mobile water storage tanks were connected to the drip irrigation pipes. See the schematic diagram. Figure 1 The mobile water reservoir is on the main pipe of the drip irrigation pipe, the spacing between the mobile water reservoirs is 48 cm, the row spacing between the branches of the drip irrigation pipe is 40 cm, and the spacing between the drippers of the branch drip irrigation pipe is 50 cm.

[0034] 2. Sowing Sesbania

[0035] Sesbania seed selection: Choose a sesbania variety suitable for local conditions (Qingtian Sesbania, exclusively distributed by Huafeng Grass Company). Seed quality should meet the requirements of GB6141-2008. Soak sesbania seeds in 50°C hot water for 24 hours before sowing to facilitate germination.

[0036] Sowing is done from early May to early July, with a sowing rate of 60kg / hm2 2 The row sowing method is adopted, with a row spacing of 40cm, a sowing depth of 1-2cm, and a plant spacing of 50cm. After sowing, the corn stalks are cut into 2-3cm lengths, with a thickness of 5-8cm and a covering amount of 45t / hm. 2 . Then irrigate in time with drip irrigation to keep the soil moist and promote seed germination.

[0037] 3. Mobile water storage arrangement

[0038] Water storage tank selection: Custom steel capacity is 1m 3The portable water storage device, measuring 1m x 1m x 1m in length, width, and height, features a rust-resistant coating, an internal filter to trap impurities, and a water outlet valve at the bottom connected to a drip irrigation system. A retractable top cover facilitates cleaning and maintenance, while water level markings on the side allow for real-time water level monitoring. The overall structure is durable and easy to move.

[0039] Arrangement plan: Connect the mobile water tank to the drip irrigation system. According to the growth stage and water demand of the sesbania, the soil matrix potential at a depth of 20 cm below the dripper is monitored by a vacuum pressure gauge to set the irrigation time. The control threshold for the seedling stage is -10 kPa, and the irrigation water volume is 110 m 3 / hm 3 , the time is 5h; when the flowering control threshold is reached, -10kPa, the irrigation water volume is 120m 3 / hm 3 , the time is 6h; when the maturity control threshold is reached -20kPa, the irrigation water volume is 60m 3 / hm 3 , time is 2.5h.

[0040] Water source replenishment: Use rainwater and cleaning water collected between photovoltaic panels to replenish the water source of the mobile water storage tank to keep the water level in the water storage tank sufficient.

[0041] 4. Post-maintenance

[0042] Pest and disease control: Strengthen the monitoring of pests and diseases of Sesbania sesbania and take timely prevention and control measures.

[0043] Mobile water storage tank management: Regularly check mobile water storage tanks to prevent leakage, damage, etc. Regularly replace the water source in the mobile water storage tank according to water quality to prevent water quality deterioration.

[0044] Harvest and return to the field in time: Harvest the Sesbania when it reaches the early to peak flowering stage, leaving a stubble height of 5 cm, chop it and spread it evenly on the photovoltaic saline-alkali grassland.

[0045] 5. On September 30th, soil samples were collected at a depth of 0-10 cm at each test site using a soil sampler for analysis of soil physical and chemical parameters. The CK group refers to the untreated saline-alkali soil from the photovoltaic power station. The results are shown in Table 1.

[0046] The pH value was determined by potentiometric method; the electrical conductivity (EC) was determined by conductivity meter; the total soluble salt content was determined by residue drying-mass method; the organic carbon (SOC) content was determined by potassium dichromate oxidation-external heating method; NH4 was determined by continuous flow analyzer method + -N, NO3 --N; the content of available phosphorus (AP) was determined by sodium bicarbonate extraction-molybdenum antimony colorimetry; the content of available potassium (AK) was determined by ammonium acetate extraction-atomic absorption spectrophotometry; and the soil moisture was determined by drying method.

[0047] Table 10-10cm soil physical and chemical properties changes

[0048]

[0049] The results of the field test show that the "Sesbania planting-precision irrigation" synergistic improvement model has a significant restoration effect on photovoltaic saline-alkali grassland. The overall performance is that the salinity of the surface soil (0-10cm) decreased and the nutrient content increased (Table 1). The pH value and electrical conductivity of the test points both decreased, with a decrease of 9.33% and 18.69% respectively. The soluble salt content of the surface soil decreased from 5.03g / kg to 4.72g / kg, a decrease of more than 6.00%. At the same time, soil fertility indicators were significantly improved, with organic carbon content increasing by 3.21%, ammonium nitrogen and nitrate nitrogen contents increasing by 6.39% and 3.42% respectively, and available phosphorus and available potassium contents increasing by 21.92% and 5.15% respectively. This improvement effect is mainly due to the biological nitrogen fixation of Sesbania and the nutrient cycle brought about by its straw return to the field, as well as the replacement of sodium ions by calcium-based components in the amendment. In terms of resource utilization, this technology system is more water-efficient than traditional drip irrigation, thanks to multiple benefits: mobile water storage devices reduce water transmission losses, sesbania shading reduces evaporation, and improved soil structure increases infiltration. Furthermore, while improving soil quality, the efficiency of photovoltaic modules remains stable, fully demonstrating the technical advantages of the "on-panel power generation, off-panel improvement" model. This technology is particularly suitable for photovoltaic power stations in areas with rainfall of 400-600 mm, providing a reliable solution for the coordinated development of new energy and ecological agriculture.

[0050] Example 2

[0051] 1. Land preparation before sowing

[0052] Before sowing, the saline-alkali grassland between the photovoltaic panels was carefully prepared, including deep plowing, harrowing, weeding, and compacting. Autumn preparation is preferred, with a deep plowing depth of 18-20 cm. In conjunction with soil preparation, 2000 kg / hm2 of soil amendment (containing silicate minerals, organic acids, and microbial agents, sourced from Beijing Bennong Technology Development Co., Ltd.) was applied. 2 , while applying 2t / hm 2 Composted cow dung (fermented and decomposed carbon-containing organic fertilizer N+P2O5+K2O≥4.0%, sourced from livestock farms).

[0053] Drip irrigation pipes were laid in the saline-alkali grassland test area between the photovoltaic panels, and the mobile water storage tanks were connected to the drip irrigation pipes. See the schematic diagram. Figure 1The mobile water storage device is on the main pipe of the drip irrigation pipe. The spacing between the mobile water storage devices is 40 cm. The spacing between the branches of the drip irrigation pipe is 35 cm. The spacing between the drippers of the branch drip irrigation pipe is 45 cm.

[0054] 2. Sowing Sesbania

[0055] Sesbania seed selection: Choose a sesbania variety suitable for local conditions (Qingtian Sesbania, exclusively distributed by Huafeng Grass Company). Seed quality should meet the requirements of GB6141-2008. Soak sesbania seeds in 48°C hot water for 20 hours before sowing to facilitate germination.

[0056] Sowing is done from early May to early July, with a sowing rate of 45kg / hm2 2 The seeding method is adopted, with a row spacing of 35cm, a sowing depth of 1-2cm, and a plant spacing of 45cm. After sowing, the corn stalks are cut into 2-3cm lengths, with a thickness of 5-8cm and a covering amount of 40t / hm. 2 . Then irrigate in time with drip irrigation to keep the soil moist and promote seed germination.

[0057] 3. Mobile water storage arrangement

[0058] Water storage tank selection: Custom steel capacity is 1m 3 The portable water storage device, measuring 1m x 1m x 1m in length, width, and height, features a rust-resistant coating, an internal filter to trap impurities, and a water outlet valve at the bottom connected to a drip irrigation system. A retractable top cover facilitates cleaning and maintenance, while water level markings on the side allow for real-time water level monitoring. The overall structure is durable and easy to move.

[0059] Arrangement plan: Connect the mobile water tank to the drip irrigation system. According to the growth stage and water demand of the sesbania, the soil matrix potential at a depth of 18 cm below the dripper is monitored by a vacuum pressure gauge to set the irrigation time. The control threshold for the seedling stage is -8 kPa, and the irrigation water volume is 90 m3. 3 / hm 3 , time is 5h; when the flowering control threshold is reached, -8kPa, the irrigation water volume is 100m 3 / hm 3 , the time is 5h; when the maturity control threshold is reached -18kPa, the irrigation water volume is 50m 3 / hm 3 , time is 2h.

[0060] Water source replenishment: Use rainwater and cleaning water collected between photovoltaic panels to replenish the water source of the mobile water storage tank to keep the water level in the water storage tank sufficient.

[0061] 4. Post-maintenance

[0062] Pest and disease control: Strengthen the monitoring of pests and diseases of Sesbania sesbania and take timely prevention and control measures.

[0063] Mobile water storage tank management: Regularly check mobile water storage tanks to prevent leakage, damage, etc. Regularly replace the water source in the mobile water storage tank according to water quality to prevent water quality deterioration.

[0064] Harvest and return to the field in time: Harvest the Sesbania when it reaches the early to peak flowering stage, leaving a stubble height of 3 cm, chop it and spread it evenly on the photovoltaic saline-alkali grassland.

[0065] Example 3

[0066] 1. Land preparation before sowing

[0067] Before sowing, the saline-alkali grassland between the photovoltaic panels was carefully prepared, including deep plowing, harrowing, weeding, and compacting. Autumn preparation is preferred, with a deep plowing depth of 18-20 cm. In conjunction with soil preparation, 3000 kg / hm2 of soil conditioner (containing silicate minerals, organic acids, and microbial agents, sourced from Beijing Bennong Technology Development Co., Ltd.) was applied. 2 , while applying 8t / hm 2 Composted cow dung (fermented and decomposed carbon-containing organic fertilizer N+P2O5+K2O≥4.0%, sourced from livestock farms).

[0068] Drip irrigation pipes were laid in the saline-alkali grassland test area between the photovoltaic panels, and mobile water reservoirs were connected to the drip irrigation pipes. The mobile water reservoirs were placed on the main drip irrigation pipes, with a spacing of 52 cm between each mobile water reservoir. The spacing between the branches of the drip irrigation pipes was 45 cm, and the distance between the emitters of the branch drip irrigation pipes was 55 cm.

[0069] 2. Sowing Sesbania

[0070] Sesbania seed selection: Choose a sesbania variety suitable for local conditions (Qingtian Sesbania, exclusively distributed by Huafeng Grass Industry Company), whose seed quality meets the requirements of GB6141-2008. Soak the sesbania seeds in 52°C hot water for 28 hours before sowing to facilitate germination.

[0071] Sow in early May to early July at a sowing rate of 75kg / hm2 2 The seeding method is adopted, with a row spacing of 45cm, a sowing depth of 1-2cm, and a plant spacing of 55cm. After sowing, the corn straw is cut into 2-3cm lengths, with a thickness of 5-8cm and a covering amount of 50t / hm. 2 . Then irrigate in time with drip irrigation to keep the soil moist and promote seed germination.

[0072] 3. Mobile water storage arrangement

[0073] Water storage tank selection: Custom steel capacity is 1m 3The portable water storage device, measuring 1m x 1m x 1m in length, width, and height, features a rust-resistant coating, an internal filter to trap impurities, and a water outlet valve at the bottom connected to a drip irrigation system. A retractable top cover facilitates cleaning and maintenance, while water level markings on the side allow for real-time water level monitoring. The overall structure is durable and easy to move.

[0074] Arrangement plan: Connect the mobile water tank to the drip irrigation system. According to the growth stage and water demand of the sesbania, the soil matrix potential at a depth of 22 cm below the dripper is monitored by a vacuum pressure gauge to set the irrigation time. The control threshold for the seedling stage is -12 kPa, and the irrigation water volume is 120 m3. 3 / hm 3 , the time is 2h; when the flowering control threshold is reached, -10kPa, the irrigation water volume is 130m 3 / hm 3 , the time is 7h; when the maturity control threshold is reached -22kPa, the irrigation water volume is 70m 3 / hm 3 , time is 3h.

[0075] Water source replenishment: Use rainwater and cleaning water collected between photovoltaic panels to replenish the water source of the mobile water storage tank to keep the water level in the water storage tank sufficient.

[0076] 4. Post-maintenance

[0077] Pest and disease control: Strengthen the monitoring of pests and diseases of Sesbania sesbania and take timely prevention and control measures.

[0078] Mobile water storage tank management: Regularly check mobile water storage tanks to prevent leakage, damage, etc. Regularly replace the water source in the mobile water storage tank according to water quality to prevent water quality deterioration.

[0079] Harvest and return to the field in time: Harvest the Sesbania when it grows to the early to peak flowering stage, leaving a stubble height of 8 cm, chop it and spread it evenly on the photovoltaic saline-alkali grassland.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for ecological restoration of saline-alkali grassland in a photovoltaic power station, characterized in that: The method comprises the following steps: applying soil conditioner and organic fertilizer, laying drip irrigation pipes and connecting them to mobile water storage devices; covering with straw after sowing sesbania, and irrigating; crushing the sesbania and returning it to the field; The soil conditioner contains silicate minerals and organic acids; the organic fertilizer is a fermented and decomposed carbon-containing organic fertilizer.

2. The ecological restoration method according to claim 1, characterized in that: The application amount of the soil conditioner is 2000-3000kg / hm 2 ; The amount of organic fertilizer applied is 2-8t / hm 2 .

3. The ecological restoration method according to claim 1, characterized in that: The organic fertilizer includes decomposed cow dung, decomposed sheep dung or decomposed pig dung; and the N+P2O5+K2O content of the organic fertilizer is ≥4.0%.

4. The ecological restoration method according to claim 1, wherein: The sesbania is soaked in 48-52°C water for 20-28 hours before sowing; the sowing method of the sesbania is drill sowing or broadcast sowing, and the sowing rate is 45-75kg / hm 2 , row spacing is 35-45cm, plant spacing is 45-55cm, and sowing depth is 1-2cm.

5. The ecological restoration method according to claim 1, characterized in that: The straw includes one or more of corn straw, wheat straw, rice straw, cotton straw, and soybean straw; and the straw is processed to 2-3 cm.

6. The ecological restoration method according to claim 1, characterized in that: The thickness of the covering is 5-8 cm, and the amount of the covering is 40-50 t / hm 2 .

7. The ecological restoration method according to claim 1, characterized in that: According to the growth stage and water requirement of Sesbania sesbania, the irrigation time and amount are set based on the soil matrix potential.

8. The ecological restoration method according to claim 7, characterized in that: The soil matrix potential is monitored at a depth of 18-22 cm below the dripper; when the control threshold of the sesbania seedlings reaches -8 to -12 kPa, the irrigation water volume is 90-120 m 3 / hm 3 , the time is 4 to 6 hours; when the flowering control threshold reaches -8 to -12 kPa, the irrigation water volume is 100-130m 3 / hm 3 , the time is 5-7h; when the maturity control threshold reaches -18~-22kPa, the irrigation water volume is 50-70m 3 / hm 3 , time is 2-3h.

9. The ecological restoration method according to claim 1, characterized in that: The stubble height of Sesbania sesbania when returning to the field is 2-8cm; the Sesbania sesbania is chopped and spread on the saline-alkali land of the photovoltaic power station.

10. Use of the ecological restoration method according to any one of claims 1 to 9 in improving saline-alkali grassland in photovoltaic power stations.

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