A dual-micro salt-driven root-promoting technology using original soil and water in saline-alkali land

Abstract

This invention discloses a dual-micro salt-removal and root-promoting technology using original soil and water in saline-alkali land. The method involves adding 150-1500 kg of soil conditioner, 30-150 kg of soil remediation agent, and 450-1500 kg of soil biological conditioning fertilizer per hectare to the original soil, tailored to the actual salinity of the farmland soil. Depending on the actual crop cultivation conditions, furrows are dug and ridges are made, drip irrigation tape is laid, water is applied, and seeds are sown. A halophilic microbial agent is applied, mixed evenly, and then delivered through the drip irrigation tape. This invention improves the rhizosphere microenvironment of crops by synergistically promoting the metabolism of halophilic microorganisms, thus promoting strong root growth and enhancing crop salt tolerance, resulting in high yield and quality. This technology requires no imported soil and consumes large amounts of freshwater resources, eliminating complex remediation projects and saving costs. While enabling crops to freely achieve yields and economic benefits in saline-alkali land, it gradually and effectively improves saline-alkali land, making a groundbreaking and positive contribution to solving the problem of crop cultivation on saline-alkali land.

Description

Technical Field

[0001] This invention belongs to the field of environmental remediation and relates to a dual micro-salt-expelling and root-promoting technology for original soil and water in saline-alkali land. Specifically, it relates to a method for improving planting in original soil and water on saline-alkali land by utilizing water resources such as fresh water, saline water, or brackish water. Background Technology

[0002] Soil salinization, as a global ecological problem, triggers a chain reaction of agricultural production decline, soil structure deterioration, reduced water resource efficiency, and biodiversity loss, causing serious environmental risks and ecological damage.

[0003] Currently, research institutions are actively exploring various soil improvement technologies. Sand-covered topsoil can rapidly improve soil physical structure, promote the formation of soil aggregates, enhance permeability, and effectively inhibit groundwater from carrying salt to the surface through capillary action. A research team conducted sand-covered dryland farming experiments in the Songnen Plain, showing that sand cover has a significant impact on crop growth and yield; within a certain range, the greater the sand cover thickness, the better the yield increase, and soil indicators are also significantly improved. At the engineering technology level, a research team, based on the water-salt transport law of "salt comes with water, salt goes with water," proposed a winter saline water freezing irrigation technology system. This technology effectively utilizes regional cold energy and groundwater resources, combined with field experiments in typical areas such as the coastal plain of Hebei Province. Based on the difference between salt and water during the freezing process of saline water, it utilizes the water-salt separation characteristics during the ice melting stage to achieve efficient leaching of soil salts. Simultaneously, it combines this with the abundant summer rainfall in monsoon climate zones to form a multi-technology synergistic mechanism for saline-alkali land improvement.

[0004] Chemical remediation measures primarily achieve soil restoration through the addition of soil conditioners and the application of novel fertilizers. Their mechanisms of action mainly include: regulating soil physicochemical properties based on the principle of acid-base neutralization to enhance salt leaching efficiency, and controlling the composition of soil basic ions through processes such as ion exchange. For example, applying a composite conditioner of desulfurized gypsum-furfural residue-cow manure combined with a subsurface drainage system effectively inhibits secondary soil salinization; others promote soil aggregate formation by applying aluminum sulfate, significantly improving soil permeability and hydraulic conductivity. A silicon-calcium-iron-potassium magnetic fertilizer system, composed of silicate minerals, fly ash, pyrite ash, and humic acid-microbial agents, can optimize the soil colloidal double-layer structure, regulate soil solution ion activity, and increase yields of crops such as rice and wheat by 8.1%–10.2%.

[0005] Biological management measures include planting salt-tolerant crops and using microbial fertilizers. Halophytes have significant economic value; cultivating them in arid western regions, combined with water-saving drip irrigation technology, can create a low-salt environment for seedling establishment. Microbial fertilizers are beneficial for improving soil salinity. Research teams have used halophilic microbial fertilizers and scientific planting methods to improve saline-alkali land in Lanzhou New Area, enhancing soil permeability and aeration. The combined application of bio-fertilizers and chemical fertilizers has significantly increased winter wheat yields.

[0006] There are also various comprehensive management measures. Chitosan-containing soil conditioners can improve the properties of low-lying saline soils and achieve original soil greening; in shallow water level areas with heavily saline soils, original soil planting can be achieved by constructing isolation zones, controlling microcirculation systems, and leaching salt with fresh water; coastal areas with heavily saline soils can be improved by mixing materials, through steps such as spreading coarse sand and other materials, deep plowing, fertilization, ridging and planting, and drip irrigation; soil conditioner fertilizers containing zeolite powder can be used for original soil greening in low-lying saline soils, as well as for planting cherry blossoms and controlling pests and diseases.

[0007] In summary, the current ecological restoration technology system for saline-alkali land is becoming increasingly diversified, forming a multi-dimensional technical path encompassing physical improvement, chemical conditioning, biological restoration, and comprehensive regulation. However, the existing technology system still has significant limitations. Although the dominance of water washing as the core method for controlling salinity is weakening, it remains the primary approach at present. These technologies generally rely on the supply of high-quality freshwater resources, and their application is severely constrained in arid and semi-arid regions and coastal saline areas where freshwater resources are scarce. Therefore, developing innovative agricultural governance models for saline-alkali land that break through traditional freshwater dependence, and developing in-soil and in-water planting technology systems based on the synergistic utilization of freshwater resources and brackish / brackish water resources, is of significant scientific value and practical guiding significance for expanding the agricultural development and utilization of saline-alkali land. Summary of the Invention

[0008] The purpose of this invention is to address the aforementioned shortcomings of existing technologies by providing a dual-micro salt-dissipation and root-promoting technology for saline-alkali land using both soil and water. This technology is based on halophilic / salt-tolerant microbial agents, developing a soil conditioner for targeted treatment of severely saline-alkali land. It improves the rhizosphere microenvironment by synergistically promoting the metabolic salt-dissipation of halophilic / salt-tolerant microorganisms, thus promoting robust root growth, enhancing crop salt tolerance, and achieving high yields and quality. Using this method, crops can be irrigated on saline-alkali land using flowing freshwater, brackish water, or bitter water, and a certain amount of agricultural products can be harvested.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] A method for improving planting in saline-alkali land using original soil and water, characterized by comprising the following steps:

[0011] Step 1: Level the land to ensure smooth irrigation and drainage and prevent waterlogging;

[0012] Step 2: Based on the actual crop cultivation conditions, dig furrows and ridges or make beds. Apply 150-1500 kg of mineral conditioner, 30-150 kg of soil repair agent and 450-1500 kg of soil biological conditioner per hectare, according to the degree of soil salinity and its salt composition. Then rake the soil level.

[0013] Step 3: Lay drip irrigation tape, irrigate, and sow seeds. The water used for irrigation should be fresh water, slightly brackish water, or bitter water.

[0014] Step 4: Apply 15-45 kg / hm² of undiluted halophilic / salt-tolerant bacterial agent stock solution each time. 2 For the first application, dilute the bacterial agent stock solution to water at a ratio of 1:100 to 300. For subsequent applications, dilute the stock solution to water at a ratio of 1:200 to 600. Stir well and apply the diluted solution through a drip irrigation belt.

[0015] Preferably, the salinity and salt content of farmland soil are obtained by conducting on-site investigations before land preparation and collecting soil samples according to the technical requirements of HJ / T 166-2004. The collected soil samples are then tested and analyzed according to conventional soil physicochemical property indicators.

[0016] Preferably, the mineral conditioning and improving agent in step 2 is composed of organic matter and calcined mineral powder in a weight ratio of 1-5:1. The mineral powder includes the following components by weight fraction: 20-35 parts volcanic ash, 5-15 parts potassium feldspar, 20-30 parts maifanite, 8-12 parts zeolite, 5-15 parts diatomaceous earth, 5-10 parts Bianstone, 3-7 parts calcite, and 1-5 parts basalt. The soil remediation agent includes 20-40 g / L organic complexing agent, 0.3-0.8 g / L metalloproteinase, 1.0-3.0 g / L glutamic acid, 0.3-1.0 g / L biological coenzyme, and 150 million-300 million CFU / g of effective viable bacteria, namely Bacillus laterosporus (Shandong Yihao Biotechnology Co., Ltd.).

[0017] Preferably, the correspondence between the application amount of the mineral conditioner and soil remediation agent in step 2 and the degree of soil salinity and soil salinity content is shown in the following table:

[0018] Ⅰ <1.0 — — Ⅱ 1.0～3.0 150～300 30 Ⅲ 3.0～5.0 300～600 60 Ⅳ 5.0～10.0 600～1050 90 Ⅴ ＞10.0 1050～1500 150 .

[0019] Preferably, the soil biological conditioning fertilizer in step 2 includes organic matter and effective live bacteria, wherein diatomaceous earth accounts for 25%, organic matter accounts for more than 40%, and the number of effective live bacteria is not less than 0.2 billion CFU / g; wherein the effective live bacteria are commercially available Bacillus subtilis (Shandong Yihao Biotechnology Co., Ltd.) and Bacillus spp. (Kunming Zichen Agricultural Biotechnology Co., Ltd.).

[0020] More preferably, the correspondence between the application of soil biological conditioning fertilizer and soil remediation agent in step 2 and the degree of soil salinity and soil salinity content is shown in the following table:

[0021] Ⅰ <1.0 — Ⅱ 1.0～3.0 450～600 Ⅲ 3.0～5.0 600～750 Ⅳ 5.0～10.0 750～1050 Ⅴ ＞10.0 1050～1500 .

[0022] Preferably, the crops planted in step 2 are selected from food crops, cash crops, and vegetables.

[0023] Preferably, the relationship between the application rate of the halophilic bacteria agent, the dilution ratio for each application, and the degree of soil salinity and soil salinity content in step 4 is shown in the table below:

[0024]

[0025] More preferably, the application time points in step 5 are as follows: the first application is after the seedlings have emerged from the dripping water; the second application is on the 2nd to 3rd day after sowing; the third application is on the 7th to 10th day after sowing; the fourth application is on the 20th to 22nd day after sowing; and the fifth application is on the 35th to 37th day after sowing.

[0026] Preferably, the halophilic bacterial agent in step 4 is a halophilic / salt-tolerant microbial agent purchased from Fengda Saltwater Technology Development (Shandong) Co., Ltd.

[0027] Field management should follow the local routine operating procedures for this crop, and attention should be paid to timely prevention and control of diseases, pests and weeds.

[0028] Beneficial effects:

[0029] This invention utilizes a planting technique in saline-alkali land with its original soil and water, eliminating the need for imported soil and large amounts of freshwater resources. It also avoids complex remediation projects, thus saving on costs. While enabling farmers to freely obtain yields and economic benefits, it gradually and effectively improves saline-alkali land, making a positive contribution to solving the problems of crop cultivation on such land. Detailed Implementation

[0030] Example 1:

[0031] In July 2024, a 0.67-hectare saline-alkali land base in a certain industrial park in Kashgar City was planted with sunflowers (seeds were purchased from the local market). The implementation steps were as follows:

[0032] 1) Level the saline-alkali land where sunflowers need to be planted. No soil needs to be added. Just dig drainage ditches to ensure smooth irrigation and drainage and prevent water accumulation.

[0033] 2) Mixed soil samples were collected on-site according to the technical requirements of HJ / T 166-2004, and the soil salinity was measured to be 14.15 g / kg after air drying, grinding, and sieving, with a salt damage level of V and a pH value of 8.11.

[0034] 3) Dig trenches, 15cm deep and 15cm wide at the bottom, with row spacing of 100cm and 40cm respectively;

[0035] 4) Based on the results, apply 1425 kg of soil conditioner, 150 kg of soil remediation agent, and 1425 kg of soil conditioning fertilizer evenly per hectare. The soil conditioner consists of 70% organic matter and 30% mineral powder, with the mineral powder comprising the following components by weight: 30 parts volcanic ash, 15 parts potassium feldspar, 20 parts maifanite, 10 parts zeolite, 10 parts diatomaceous earth, 5 parts Bianstone, 7 parts calcite, and 3 parts basalt. The soil remediation agent consists of the following components: 30 g / L humic acid, 0.5 g / L cellulase, 200 million CFU / g of viable bacteria, Bacillus laterosporus (Shandong Yihao Biotechnology Co., Ltd.), 2.0 g / L glutamic acid, and 0.5 g / L coenzyme A. The soil conditioner contains 25% diatomaceous earth, 40% organic matter, with an effective live bacteria count of no less than 0.2 billion / g, a moisture content of no more than 30%, and all heavy metals in the soil are within normal standards. It also contains Bacillus subtilis (Shandong Yihao Biotechnology Co., Ltd.) and Bacillus spp. (Kunming Zichen Agricultural Biotechnology Co., Ltd.).

[0036] 5) Lay drip irrigation tape; irrigate with local well water, sow seeds in furrows at a spacing of 20cm, and thin out seedlings to maintain a plant spacing of 40cm when seedlings reach 25cm in height. When sowing, ensure the pointed end of the seed is facing down into the soil. The well water should have a salt content of 0.3%. Sunflower seeds should be sun-dried for 1-2 days before sowing to improve germination rate.

[0037] 6) Subsequently, apply a diluted solution of salt-tolerant / halophilic bacteria agent by drip irrigation. Dilute 45 kg of the stock solution of salt-tolerant / halophilic bacteria agent with well water 100 times per hectare each time and apply by drip irrigation. On the 3rd, 9th, 20th and 36th days, apply a diluted solution of salt-tolerant / halophilic bacteria agent 200 times. Keep the soil in the furrow moist during the sunflower growing season, and pay attention to timely weeding and prevention and control of diseases and pests.

[0038] The sunflower seed yield was 2610 kg / hm² 2 The soil salinity was measured to be 4.36 g / kg, and the pH value was 7.66.

[0039] Example 2:

[0040] In 2021, a rice planting experiment was conducted on 0.167 hectares of land at the Dongying District base in Dongying City, Shandong Province, with sowing in mid-April.

[0041] 1) Level the land on-site and ensure proper drainage and irrigation ditches to prevent waterlogging. Collect mixed soil samples on-site according to the technical requirements of HJ / T 166-2004. The local soil salinity was measured to be 5.46 g / kg, the salinity level was IV, and the pH value was 8.2. Irrigate with brackish water from local ditches, with a salinity between 0.3% and 1.5%.

[0042] 2) Make furrows and ridges, with furrows 30cm wide and 30cm deep, and ridges 120cm wide. Plant 4 rows of rice, with row spacing of 30cm and plant spacing of 18cm.

[0043] 3) Apply 645 kg of soil conditioner, 90 kg of soil remediation agent, and 780 kg of soil conditioning fertilizer evenly per hectare. The soil conditioner consists of 70% organic matter and 30% mineral powder, with the mineral powder comprising the following components by weight: 20 parts volcanic ash, 15 parts potassium feldspar, 30 parts maifanite, 10 parts zeolite, 5 parts diatomaceous earth, 10 parts Bianstone, 7 parts calcite, and 3 parts basalt. The soil remediation agent includes 30 g / L humic acid, 0.5 g / L cellulase, 200 million CFU / g of viable bacteria, Bacillus laterosporus (Shandong Yihao Biotechnology Co., Ltd.), 2.0 g / L glutamic acid, and 0.5 g / L coenzyme A. The soil conditioner contains 25% diatomaceous earth, 40% organic matter, with an effective live bacteria count of no less than 0.2 billion CFU / g, a moisture content of no more than 30%, and all soil heavy metals are within normal standards. It also contains Bacillus subtilis (Shandong Yihao Biotechnology Co., Ltd.) and Bacillus spp. (Kunming Zichen Agricultural Biotechnology Co., Ltd.).

[0044] 4) Lay out drip irrigation tape, irrigate, and then sow 2-3 seeds per hole at a depth of about 1cm, and then cover with a thin layer of soil;

[0045] 5) Subsequently, take 30 kg of salt-tolerant / halophilic bacteria agent and 4500 kg of brackish water per hectare, mix and dilute them, and apply them by drip. Similarly, on the 3rd, 10th, 20th and 36th days, take 30 kg of salt-tolerant / halophilic bacteria agent and 9000 kg of brackish water, mix and dilute them, and apply them by drip. During this period, follow the principle of alternating between dry and wet conditions for rice, ensure water supply during the water-sensitive period, and pay attention to timely weeding and prevention and control of diseases and pests.

[0046] Harvested on September 18th, yielding a yield of 4677 kg / hm². 2 The soil salinity was measured to be 1.75 g / kg, and the pH value was 7.7.

[0047] Example 3:

[0048] In November 2023, the rapeseed planting cooperative base in Potou District, Zhanjiang City, Guangdong Province, planted 5.33 hectares of rapeseed.

[0049] 1) After leveling the land, the mixed soil was taken. According to the standard, the soil salt content was measured in the laboratory to be 8.64 g / kg, the salt damage level was IV, the pH value was 3.8, and the water source was general farmland irrigation water.

[0050] 2) Create raised beds, 90cm wide and 20cm high, planting 4 rows per bed with wide rows 40cm apart and narrow rows 22cm apart, with a plant spacing of 18-20cm. 3) Apply 930kg of soil conditioner, 90kg of soil remediation agent, and 1120kg of soil conditioning fertilizer per hectare. The soil conditioner consists of 70% organic matter and 30% mineral powder, with the following weight percentages: 25 parts volcanic ash, 15 parts potassium feldspar, 30 parts maifanite, 10 parts zeolite, 5 parts diatomaceous earth, 5 parts Bianstone, 5 parts calcite, and 5 parts basalt. The soil remediation agent includes 30g / L humic acid, 0.5g / L cellulase, 200 million CFU / g of viable bacteria, Bacillus laterosporus (Shandong Yihao Biotechnology Co., Ltd.), 2.0g / L glutamic acid, and 0.5g / L coenzyme A. The soil conditioner contains 25% diatomaceous earth, 40% organic matter, with an effective live bacteria count of no less than 0.2 billion CFU / g, a moisture content of no more than 30%, and all soil heavy metals are within normal standards. It also contains Bacillus subtilis (Shandong Yihao Biotechnology Co., Ltd.) and Bacillus spp. (Kunming Zichen Agricultural Biotechnology Co., Ltd.).

[0051] 4) Lay drip irrigation tape between two narrow rows, irrigate, make shallow furrows about 2cm deep at the sowing site, mix the seeds and fine sand evenly and sow them, and cover with a thin layer of soil after sowing.

[0052] 5) Subsequently, mix and dilute 30 kg of salt-tolerant / halophilic bacteria agent and 4500 kg of irrigation water per hectare and apply by drip irrigation. Similarly, on days 3, 10, 20 and 36, apply 30 kg of salt-tolerant / halophilic bacteria agent and 9000 kg of irrigation water by drip irrigation. Keep the soil moist during this period and ensure the necessary water supply during the water-sensitive period. At the same time, pay attention to thinning, timely weeding and prevention and control of diseases and pests.

[0053] At harvest, the rapeseed yield was 2742 kg / hm². 2 The soil salinity is 2.89 g / kg, and the pH value is 5.46.

[0054] Example 4:

[0055] On October 12, 2024, 0.467 hectares of winter wheat variety "Jimai 22" were sown at the Binzhou National High-tech Agricultural Science and Technology Park in Shandong Province.

[0056] 1) After leveling the land, ensure proper drainage and irrigation ditches to prevent waterlogging. According to the technical requirements of HJ / T 166-2004, mixed soil samples were collected on-site. The local soil salinity was measured to be 5.6–8.2 g / kg, with a salinity level of IV, and a pH of 8.0. The irrigation water was a mixture of local river and canal water, with a salinity of 0.65%–0.89%.

[0057] 2) Make flat beds, 1.5m wide, and sow in rows with a row spacing of 15cm.

[0058] 3) Apply 930 kg of soil conditioner, 90 kg of soil remediation agent, and 1120 kg of soil conditioning fertilizer per hectare. The soil conditioner consists of 70% organic matter and 30% mineral powder, with the following weight percentages of mineral powder: 25 parts volcanic ash, 15 parts potassium feldspar, 30 parts maifanite, 10 parts zeolite, 5 parts diatomaceous earth, 5 parts Bianstone, 5 parts calcite, and 5 parts basalt. The soil remediation agent includes 30 g / L humic acid, 0.5 g / L cellulase, 200 million CFU / g of viable bacteria, Bacillus laterosporus (Shandong Yihao Biotechnology Co., Ltd.), 2.0 g / L glutamic acid, and 0.5 g / L coenzyme A. The soil conditioner contains 25% diatomaceous earth, 40% organic matter, with an effective live bacteria count of no less than 0.2 billion CFU / g, a moisture content of no more than 30%, and all soil heavy metals are within normal standards. It also contains Bacillus subtilis (Shandong Yihao Biotechnology Co., Ltd.) and Bacillus spp. (Kunming Zichen Agricultural Biotechnology Co., Ltd.).

[0059] 4) Drip irrigation tape should be laid simultaneously with sowing. One tape should be laid for every four rows of wheat, with a spacing of 60cm between tapes. Irrigate promptly after sowing.

[0060] 5) Subsequently, mix and dilute 30 kg of halophilic / salt-tolerant bacteria agent with 4500 kg of irrigation water per hectare and apply by drip irrigation. Similarly, apply 30 kg of halophilic / salt-tolerant bacteria agent and 9000 kg of irrigation water by drip irrigation on days 3, 10, 22, and 37, respectively. During the water-sensitive stages of crop growth, ensure the necessary amount of irrigation water is provided, while avoiding irrigation when the temperature is below zero to prevent damage to seedlings from ground freezing. Except for irrigation during overwintering, each irrigation should follow the principle of ensuring complete infiltration of water on the same day and preventing surface runoff. At the same time, timely weeding should be carried out, and measures should be taken to control pests and diseases.

[0061] Yield measurement and acceptance were conducted, yielding an equivalent dry weight of 5806.5 kg / hm² for wheat. 2 The soil salinity is 3.83 g / kg, and the pH value is 7.78.

Claims

1. A method for improving planting in saline-alkali land using original soil and water, characterized in that, Includes the following steps: Step 1: Collect soil samples according to the technical requirements of HJ / T 166-2004. Test and analyze the collected soil samples according to conventional soil physicochemical property indicators to obtain the degree of farmland soil salinity and its salt content. Level the land to ensure smooth irrigation and drainage and prevent waterlogging. Step 2: Based on the actual crop cultivation conditions, dig furrows and create ridges or furrows. Apply 150-1500 kg of mineral conditioner, 30-150 kg of soil remediation agent, and 450-1500 kg of soil biological conditioner per hectare, evenly according to the degree of soil salinity and its salt content. Then rake the soil level. The mineral conditioner consists of organic matter and mineral powder in a weight ratio of 1-5:

1. The mineral powder includes the following components by weight: 20-35 parts volcanic ash, potassium... The soil remediation agent comprises 5-15 parts feldspar, 20-30 parts maifanite, 8-12 parts zeolite, 5-15 parts diatomaceous earth, 5-10 parts Bianstone, 3-7 parts calcite, and 1-5 parts basalt; the soil remediation agent includes 20-40 g / L organic complexing agent, 0.3-0.8 g / L metalloproteinase, 1.0-3.0 g / L glutamic acid, 0.3-1.0 g / L biological coenzyme, and 150 million-300 million CFU / g of effective live bacteria, wherein the effective live bacteria are commercially available Bacillus laterosporus. The corresponding relationship between the application rate of the mineral conditioner and soil remediation agent and the degree of soil salinity and soil salinity content is shown in the table below: ； The soil bio-conditioning fertilizer comprises organic matter and effective live bacteria, including 25% diatomaceous earth, more than 40% organic matter, and an effective live bacteria count of no less than 0.2 billion CFU / g. The effective live bacteria are commercially available Bacillus subtilis and Bacillus mucilaginosa. The correspondence between the application of the soil bio-conditioning fertilizer and the degree of soil salinity and soil salinity is shown in the table below: ； The organic complexing agent in the soil remediation agent is selected from humic acid, the metalloproteinase is selected from cellulase, and the biological coenzyme is selected from coenzyme A. Step 3: Lay drip irrigation tape, irrigate, and sow seeds. The water used for irrigation should be fresh water, slightly brackish water, or bitter water. Step 4: Apply 15-45 kg / hm² of undiluted halophilic / salt-tolerant bacterial agent stock solution each time. 2 For the first application, the inoculant solution was diluted with water at a ratio of 1:100-300. Subsequent applications were diluted at a ratio of 1:200-600. The solutions were stirred thoroughly and then applied via drip irrigation. The table below shows the correlation between the application rate of the salt-tolerant / halophilic inoculant, the dilution ratio for each application, and the degree of soil salinity and soil salt content. ， The application times are as follows: the first application is after the seedlings have emerged from the drip irrigation; the second application is on the 2nd to 3rd day after sowing; the third application is on the 7th to 10th day after sowing; the fourth application is on the 20th to 22nd day after sowing; and the fifth application is on the 35th to 37th day after sowing.

2. The method for improving and planting in saline-alkali land with original soil and water according to claim 1, characterized in that, The crops mentioned are selected from rice, wheat, sunflower, or rapeseed.

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