Cultivation method for improving germination rate of wild soybeans by interplanting oil sunflowers in saline-alkali soil

Abstract

The invention belongs to the technical field of agricultural ecological improvement and cultivation of saline-alkali soil, and particularly relates to a cultivation method for improving the germination rate of wild soybeans by interplanting oil sunflowers in saline-alkali soil. Through an ecological interplanting mode of the wild soybeans and the oil sunflowers and by combining innovative seed treatment, soil improvement and green management technologies, the problems that the germination rate of the wild soybeans in the saline-alkali soil is low and seedlings are difficult to grow are effectively solved, and the method has remarkable advantages in the aspects of improving soil quality, enhancing biological diversity, optimizing ecological system service and the like; compared with the prior art, the method is more systematic, ecological and sustainable, and a replicable and generalizable efficient cultivation method is provided for agricultural ecological restoration of the saline-alkali soil.

Description

Technical Field

[0001] This invention belongs to the field of agricultural ecological improvement and cultivation technology of saline-alkali land, specifically involving a cultivation method for intercropping wild soybeans with sunflowers in saline-alkali land to improve the germination rate of wild soybeans. Background Technology

[0002] Wild soybean is an important wild legume germplasm resource with strong adaptability and nitrogen-fixing ability, showing great potential in the improvement of saline-alkali land. However, the high salinity, high pH, ​​and compaction of saline-alkali land severely inhibit the germination of wild soybean seeds and seedling growth, resulting in low emergence rate, sparse plants, and insufficient cover, thus limiting its improvement effect and application. Oil sunflower (oil-producing sunflower) has strong salt and alkali tolerance and a well-developed root system, which can improve soil structure and regulate the microenvironment through water absorption and root activity, and is often used as a pioneer crop for improving saline-alkali land. However, current planting methods mostly focus on monoculture or simple crop rotation, lacking systematic biological interaction and ecological regulation mechanisms, and have the following obvious defects:

[0003] 1) Low seed germination rate: Conventional wild soybean cultivation lacks seed pretreatment technology for saline-alkali stress, and ordinary germination agents are difficult to effectively break dormancy and enhance stress resistance, resulting in seed germination being hindered in saline-alkali environments.

[0004] 2) The soil environment has not been fundamentally improved. Simply applying ordinary chemical fertilizers or organic fertilizers is not enough to alleviate the compaction and alkalinity of saline-alkali soil. There is a lack of targeted soil conditioning substances (such as desulfurized gypsum, citric acid, etc.), and the effect of soil structure improvement is limited.

[0005] 3) The lack of ecological interaction design means that existing intercropping patterns are mostly limited to spatial matching. As an "ecological crop", sunflower has not fully utilized its functions such as shading, humidity regulation and improvement of rhizosphere microecology. Wild soybean seedlings face stresses such as high temperature, high transpiration and salt accumulation.

[0006] 4) Nutrient management is extensive. Conventional fertilizers are easily fixed or lost in saline-alkali soil, resulting in low utilization. There is a lack of slow-release and micronutrient synergistic replenishment mechanisms, leading to widespread nutrient imbalance in wild soybeans.

[0007] 5) Pest and disease control relies on chemical pesticides. The saline-alkali land ecosystem is fragile, and frequent use of chemical pesticides further inhibits soil microbial activity and disrupts the ecological balance.

[0008] 6) The ecosystem service function is weak. Monoculture or simple intercropping patterns result in low biodiversity, short vegetation cover duration, slow accumulation of soil organic matter, weak carbon sequestration capacity, monotonous landscape, and difficulty in providing sustainable ecosystem services. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a cultivation method for intercropping wild soybean with sunflower in saline-alkali land to improve the germination rate of wild soybean. Intercropping wild soybean with oilseed crops such as sunflower increases population density and vegetation cover, reduces soil salinity, improves soil structure (e.g., reduced soil bulk density, increased soil porosity) and soil ecological environment (significantly enhanced microbial diversity), effectively optimizing the saline-alkali farmland environment. It also enhances ecosystem service functions, such as provision services (biological habitats, genetic resources, ornamental plant resources), regulatory services (carbon sequestration, erosion control), support services (nutrient cycling, primary production, biodiversity maintenance), and cultural services (recreation and ecotourism).

[0010] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a comprehensive method integrating biological intercropping, physical improvement, chemical regulation, and nutrient management. The core of this method lies in the precise physiological regulation of wild soybean seeds using a novel environmentally friendly germination promoter to break dormancy and enhance their stress-resistant germination ability. Then, sunflowers are used as an "ecological nurse crop" to provide shade for the wild soybean seedlings, improving the rhizosphere microecological environment. Furthermore, specialized cultivation substrates and slow-release fertilizers are applied to rapidly optimize the physical structure and chemical properties of the sowing holes, creating the optimal environment for seed germination and seedling growth. Ultimately, this achieves the goal of short-term benefits supporting long-term growth, promoting improvement through planting, and simultaneously realizing ecological and economic benefits.

[0011] Specifically, the following steps are included:

[0012] Step 1: Select plump, disease-free wild soybean seeds, rinse them with clean water to remove impurities, take out the seeds and mix them with disinfectant at a mass ratio of 1:(2-4), soak them at 20-30℃ for 8-12 minutes for disinfection, then rinse the seeds with clean water to remove any residual liquid on the surface and drain them for later use.

[0013] Preferably, the disinfectant is a potassium permanganate solution with a mass fraction of 0.2-0.4%, a sodium hypochlorite solution with a mass fraction of 0.1-0.3%, or an ethanol solution with a volume fraction of 70-75%.

[0014] Step 2: Mix the seeds and germination agent at a mass ratio of 1:(3-4) and soak at 25-28℃ for 7-9 hours. After soaking, wash off the residual liquid on the seed surface with clean water. Mix the seeds and water at a mass ratio of 1:(3-4) and soak at 25-28℃ for 36-48 hours. Take out the seeds and store them at ≤-20℃ for more than 3 days. Take out the seeds before sowing.

[0015] Preferably, the germination agent, based on water, comprises 4-6 g / L of seaweed extract, 1-2 g / L of chitosan, 2-4 g / L of humic acid, 0.3-0.7 g / L of amino acids, 0.04-0.06 g / L of salicylic acid, and 0.08-0.12 g / L of ammonium molybdate.

[0016] Preferably, the seaweed extract contains ≥95% seaweed polysaccharide, which effectively stimulates seed vitality and provides non-specific stress resistance; the chitosan has a degree of deacetylation ≥90%, which induces seeds to produce resistance proteins, enhancing resistance to salt and pathogens, and simultaneously forming a breathable, water-retaining film on the seed surface; the humic acid contains ≥50% fulvic acid, an excellent natural organic acid that can chelate harmful ions, regulate osmotic pressure, and promote seed enzyme activity; the amino acids include one or more of proline, glutamic acid, aspartic acid, arginine, alanine, lysine, and methionine, which help seeds maintain cell water balance and resist salt stress in the early stages of germination.

[0017] Step 3: Before sowing, water the soil to a moisture content of 40-50% and till the soil to a depth of 15-25cm. Dig planting furrows. The row spacing for sunflowers is 45-55cm, and the plant spacing is 20-30cm. Sow wild soybeans between two rows of sunflowers. After sowing, apply the special cultivation substrate and special slow-release fertilizer in the planting furrows in sequence, and then cover with 2-3cm of soil. The seed rate for sunflowers is 0.4-0.6kg / mu, the seed rate for wild soybeans is 2.5-3.5kg / mu, the amount of special cultivation substrate is 150-200kg / mu, and the amount of special slow-release fertilizer is 60-70kg / mu.

[0018] Preferably, the special cultivation substrate comprises decomposed straw, humus, vermiculite, desulfurized gypsum powder, compound microbial powder, and citric acid, in a mass ratio of (20-25):(10-15):(5-10):(4-6):(2-3):(2-3). Decomposed straw provides organic matter and loosens the soil; humus is rich in organic matter and beneficial microorganisms; vermiculite retains water and fertilizer and improves porosity; desulfurized gypsum powder provides calcium ions, replacing sodium ions on soil colloids, and is a core substance for improving alkaline soil; compound microbial powder activates soil nutrients, secretes growth-promoting substances, and inhibits soil-borne diseases; citric acid powder can locally lower the pH value of the rhizosphere microenvironment.

[0019] Most preferably, the decomposed straw is one or more of decomposed corn straw, decomposed wheat straw, and decomposed rice straw. The compound microbial powder includes Bacillus subtilis powder, Bacillus mucilaginosus powder, and Bacillus brevis pylori powder in a mass ratio of 2:1:1.

[0020] Preferably, the special slow-release fertilizer comprises organic fertilizer, diammonium phosphate, potassium sulfate, sulfur powder, polyaspartic acid, and micronutrient fertilizer in a mass ratio of (55-65):(10-20):(8-12):(7-9):(4-6):(1-2). The organic fertilizer provides basic nutrients and organic matter; diammonium phosphate provides nitrogen and phosphorus; potassium sulfate provides potassium, enhancing stress resistance; sulfur powder is slowly oxidized to sulfuric acid, continuously neutralizing soil alkalinity; polyaspartic acid has extremely strong chelating and enrichment capabilities, activating micronutrients in the soil, reducing nutrient fixation, and improving fertilizer utilization; the micronutrient fertilizer supplements the micronutrients often lacking in saline-alkali land.

[0021] Most preferably, the organic fertilizer is well-rotted sheep manure with an organic matter content of ≥45%. The micronutrient fertilizer includes zinc sulfate heptahydrate, manganese sulfate, borax, ferrous sulfate, and ammonium molybdate in a mass ratio of (30-40):(20-30):(15-25):(8-12):(8-10).

[0022] Step 4: Immediately after sowing and fertilizing, irrigate to a soil moisture content of 75-85%. During the growing season of wild soybeans and sunflowers, maintain a soil moisture content of 60-75%. If pests occur, immediately spray with a 1000-fold dilution of 0.5% matrine aqueous solution. If fungal diseases occur, spray once with an 800-fold dilution of 100 billion CFU / g Bacillus subtilis wettable powder. After harvesting sunflowers, crush their stalks on the spot and return them directly to the field for plowing to further increase soil organic matter and consolidate the improvement effect.

[0023] The present invention has the following advantages:

[0024] (1) This invention uses a composite environmentally friendly germination agent containing a variety of bioactive components such as seaweed extract, chitosan, humic acid, amino acids, salicylic acid, and ammonium molybdate, which synergistically enhance seed stress resistance, break dormancy, and promote germination. Combined with low-temperature storage treatment, seed vitality is further stimulated. Compared with existing technologies, this invention significantly improves the uniformity of emergence and seedling survival rate of wild soybean in saline-alkali land, laying the foundation for subsequent vegetation restoration.

[0025] (2) This invention utilizes a specialized cultivation substrate and slow-release fertilizer. Desulfurized gypsum provides calcium ions to replace sodium ions, citric acid locally lowers the rhizosphere pH, compound microbial powder promotes nutrient activation and disease inhibition, and the slow-release fertilizer reduces nutrient fixation by chelating trace elements with polyaspartic acid. Returning sunflower straw to the field further increases organic matter and improves soil aggregate structure. This integrated "physical-chemical-biological" improvement strategy effectively alleviates the problems of saline-alkali soil compaction and alkalization, creating a suitable rhizosphere environment for wild soybeans.

[0026] (3) Sunflowers not only provide shade for wild soybeans, reducing surface temperature and water evaporation, but also regulate the rhizosphere microenvironment by secreting organic matter and absorbing salt through their roots, thus alleviating salt stress on wild soybean seedlings. This invention achieves resource complementarity and ecological synergy between the two crops through reasonable row and plant spacing configuration, significantly improving the survival rate and growth vigor of wild soybeans.

[0027] (4) The combined use of special slow-release fertilizers and micronutrient fertilizers improves fertilizer utilization efficiency and avoids nutrient loss and environmental pollution. Pest and disease control uses biological agents such as matrine and Bacillus subtilis to reduce the use of chemical pesticides, protect soil microbial diversity, and conform to the development direction of ecological agriculture.

[0028] (5) This invention not only improves crop yield and land utilization, but also enhances the service functions of saline-alkali land ecosystems in multiple dimensions:

[0029] Supply services: Wild soybeans, as a high-quality wild germplasm resource, provide materials for genetic breeding; sunflower seeds can be pressed for oil, increasing economic benefits; and intercropping systems also provide habitats for insects, birds, and other organisms, enhancing biodiversity.

[0030] Regulation services: Increased vegetation cover effectively inhibits wind and water erosion, enhances soil carbon sequestration capacity, and responds to the "dual carbon" target through carbon sequestration and emission reduction; the root systems of sunflower and wild soybean enhance soil water holding capacity and regulate regional water cycle.

[0031] Support services: Intercropping of leguminous and non-leguminous crops promotes nutrient cycling (e.g., nitrogen fixation by wild soybean); complex microbial communities enhance soil enzyme activity and nutrient conversion capacity; increased vegetation diversity helps maintain ecosystem stability and resilience.

[0032] Cultural services: After vegetation restoration, the landscape of saline-alkali land is beautified, which has ecotourism and science education value, provides people with places for leisure and cultural experience, and enhances the dual ecological and cultural value of the land. Detailed Implementation

[0033] The technical solutions in the embodiments of the invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] Raw material preparation:

[0036] Germination promoter: Based on water, it includes 5 g / L of seaweed extract (purchased from Hebei Pengyu Biotechnology Co., Ltd., with seaweed polysaccharide content ≥95%), 1.5 g / L of chitosan (degree of deacetylation ≥90%), 3 g / L of humic acid (fulvic acid content ≥50%), 0.5 g / L of proline, 0.05 g / L of salicylic acid, and 0.1 g / L of ammonium molybdate.

[0037] Specialized cultivation substrate: well-rotted rice straw, humus, vermiculite, desulfurized gypsum powder, compound bacterial powder and citric acid, in a mass ratio of 23:12:8:5:2:3.

[0038] The compound bacterial powder consists of Bacillus subtilis powder, Bacillus mucilaginosus powder, and Bacillus brevis pylori powder, in a mass ratio of 2:1:1. The Bacillus subtilis powder and Bacillus mucilaginosus powder were purchased from Shandong Yihao Biotechnology Co., Ltd., and the Bacillus brevis pylori powder was purchased from Shandong Qilu Chemical Technology Co., Ltd.

[0039] Special slow-release fertilizer: well-rotted sheep manure (organic matter content ≥45%), diammonium phosphate, potassium sulfate, sulfur powder, polyaspartic acid and trace element fertilizer, in a mass ratio of 60:15:10:8:5:2.

[0040] Micronutrient fertilizer: zinc sulfate heptahydrate, manganese sulfate, borax, ferrous sulfate and ammonium molybdate, in a mass ratio of 35:25:20:10:9.

[0041] Specific implementation methods:

[0042] Step 1: Select plump, disease-free wild soybean seeds, rinse them with clean water to remove impurities, take out the seeds and mix them with a 0.3% potassium permanganate solution at a mass ratio of 1:3, soak them at 28℃ for 10 minutes to disinfect, then rinse the seeds with clean water to remove any residual liquid on the surface and drain them for later use.

[0043] Step 2: Mix the seeds and germination agent at a mass ratio of 1:4, soak at 27℃ for 8 hours. After soaking, wash off the residual liquid on the seed surface with clean water. Mix the seeds and water at a mass ratio of 1:3, soak at 27℃ for 42 hours, remove the seeds, and store at ≤-20℃ for more than 3 days. Remove the seeds before sowing.

[0044] Step 3: Before sowing, water the soil to a moisture content of 45% and till the soil to a depth of 20cm. Dig planting furrows. The row spacing for sunflowers is 50cm and the plant spacing is 25cm. Sow wild soybeans between two rows of sunflowers. After sowing, apply the special cultivation substrate and special slow-release fertilizer in the planting furrows in sequence, and then cover with 2-3cm of soil. The seed rate for sunflowers is 0.5kg / mu, the seed rate for wild soybeans is 3kg / mu, the amount of special cultivation substrate is 175kg / mu, and the amount of special slow-release fertilizer is 65kg / mu.

[0045] Step 4: Immediately after sowing and fertilizing, water the soil to 80% moisture content. During the growing season of wild soybeans and sunflowers, maintain the soil moisture content at 68%. If pests occur, immediately spray with a 1000-fold dilution of 0.5% matrine aqueous solution. If fungal diseases occur, spray once with an 800-fold dilution of 100 billion CFU / g Bacillus subtilis wettable powder. After harvesting sunflowers, crush their stalks on the spot.

[0046] Experimental Example 1

[0047] Experimental Design:

[0048] Set up 3 treatment groups, each with 3 replicates, using a randomized block design:

[0049] Experimental group: Following the method in Example 1, wild soybean and sunflower were intercropped, seed treated, and treated with a special substrate, slow-release fertilizer, and water and fertilizer management were carried out.

[0050] Control group 1: The difference from Example 1 is that wild soybean was monocultured with water and fertilizer management, that is, no seed treatment, no special substrate, and no slow-release fertilizer.

[0051] Control group 2: The difference from Example 1 is that wild soybean monoculture + seed treatment + special substrate + slow-release fertilizer + water and fertilizer management.

[0052] Soil type: moderately saline-alkali soil (pH 8.5, salt content 0.4%).

[0053] Data collection:

[0054] Germination rate: Statistics were collected on the 7th and 14th days after sowing.

[0055] Survival rate: Statistical analysis was conducted on the 30th day after sowing.

[0056] Soil samples: Soil layers of 0-20cm were collected before sowing and after harvest to measure pH, EC, organic matter, available phosphorus, available potassium, etc.

[0057] Biomass: The dry weight of the aboveground parts is measured at harvest.

[0058] Table 1 Comparison of Germination Rate and Survival Rate of Wild Soybean

[0059] Germination rate (%) on day 7 Germination rate (%) on day 14 Survival rate on day 30 (%) Control group 1 42.3±3.2 51.6±4.1 45.2±3.8 Control group 2 68.5±4.7 78.2±5.3 72.4±4.9 experimental group 82.6±5.1 90.4±4.8 86.7±5.2

[0060] Table 2 Changes in soil physicochemical properties (before sowing and after harvest)

[0061]

[0062]

[0063] Table 3 Plant growth indicators and yield

[0064] Wild soybean plant height (cm) <![CDATA[Wild soybean biomass (g / m 2 )]]> Sunflower seed yield (kg / mu) Control group 1 28.5±2.3 105.6±8.7 - Control group 2 36.8±3.1 158.4±10.2 - experimental group 45.2±3.8 192.3±12.5 185.6±15.4

[0065] As shown in Tables 1-3, the wild soybean-sunflower intercropping cultivation method of the present invention significantly improves the germination rate and survival rate of wild soybean in saline-alkali land through systematic seed treatment, soil improvement, ecological interaction and green management, effectively improves soil physical and chemical properties, and enhances crop yield and ecosystem service functions. It has significant ecological and economic benefits and is suitable for ecological restoration of saline-alkali land and sustainable agricultural development.

[0066] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cultivation method for increasing the germination rate of Glycine soja by interplanting oil sunflower in saline-alkali soil, characterized in that, The method comprises the following steps: Step one, select full, no disease and insect pests of wild soybean seeds, rinse with clean water, remove impurities, take out the seeds and mix with disinfectant for disinfection, then wash the seed surface with clean water, drain and reserve; Step two, soak the seeds with germination agent, after soaking, wash the seed surface with clean water, soak the seeds with clean water for 36-48h, take out the seeds, store at ≤-20℃ for more than 3 days, take out the seeds before sowing; Step three, before sowing, water the soil to 40-50% of water content and rotary till the soil, rotary tillage depth is 15-25cm, dig planting ditch, sunflower row spacing is 45-55cm, plant spacing is 20-30cm, wild soybean is sown between two rows of sunflower, then apply special cultivation substrate and special slow-release fertilizer in the planting ditch in turn, then cover 2-3cm of soil, the seed amount of sunflower is 0.4-0.6kg / mu, the seed amount of wild soybean is 2.5-3.5kg / mu, the amount of special cultivation substrate is 150-200kg / mu, the amount of special slow-release fertilizer is 60-70kg / mu; Step four, after sowing and fertilizing, immediately water the soil to 75-85% of water content, keep the soil water content of wild soybean and sunflower at 60-75% during the growth period, after harvesting sunflower, directly crush the straw in the field and turn it into the field.

2. The cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land according to claim 1, characterized in that, The disinfectant in step one is 0.2-0.4% potassium permanganate solution, 0.1-0.3% sodium hypochlorite solution or 70-75% ethanol solution.

3. The method according to claim 1, wherein the method is characterized by, The germination agent in step two comprises 4-6g / L seaweed extract, 1-2g / L chitosan, 2-4g / L humic acid, 0.3-0.7g / L amino acid, 0.04-0.06g / L salicylic acid and 0.08-0.12g / L ammonium molybdate, based on water.

4. The method according to claim 3, wherein the method is characterized by, The seaweed extract contains ≥95% seaweed polysaccharide, the deacetylation degree of chitosan is ≥90%, the content of fulvic acid in humic acid is ≥50%, and the amino acid comprises one or more of proline, glutamic acid, aspartic acid, arginine, alanine, lysine and methionine.

5. The cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land according to claim 1, characterized in that, The special cultivation substrate in step three comprises matured straw, humus soil, vermiculite, desulfurized gypsum powder, compound bacteria powder and citric acid, and the mass ratio is (20-25):(10-15):(5-10):(4-6):(2-3):(2-3).

6. The cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land according to claim 5, characterized in that, The matured straw is one or more of matured corn straw, matured wheat straw and matured rice straw.

7. The cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land according to claim 5, characterized in that, The compound bacteria powder comprises bacillus subtilis powder, bacillus mycoides powder and brevibacillus laterosporus powder, and the mass ratio is 2:1:

1.

8. The cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land according to claim 1, characterized in that, The special slow-release fertilizer in step three comprises organic fertilizer, diammonium phosphate, potassium sulfate, sulfur powder, polyaspartic acid and trace element fertilizer, and the mass ratio is (55-65):(10-20):(8-12):(7-9):(4-6):(1-2).

9. A cultivation method for improving the germination rate of wild soybean by intercropping with sunflower in saline-alkali land, as described in claim 8, is characterized in that... The organic fertilizer is mature sheep manure, and the organic matter content is greater than or equal to 45%; the trace element fertilizer comprises zinc sulfate heptahydrate, manganese sulfate, borax, ferrous sulfate and ammonium molybdate, and the mass ratio is (30-40):(20-30):(15-25):(8-12):(8-10).

10. The method according to claim 1, wherein the method is characterized by, In step four, 0.5% sophoramine water agent 1000 times liquid is also sprayed immediately when insect pests occur, and 100 billion CFU / g bacillus subtilis wettable powder 800 times liquid is sprayed once when fungal diseases occur.

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