Seedling transplanting high-yield cultivation method for beet in moderate and severe saline-alkali soil

Abstract

The invention discloses a medium-severe saline-alkali soil beet seedling transplanting high-yield cultivation method. According to the method, for saline-alkali soil with the salt content of 0.3%-1.0% and the pH value of 8.5-9.5, through integration of salt-tolerant variety screening, engineering salt elimination and precise agronomic management, the yield of beet is remarkably increased, and the soil improvement efficiency is remarkably improved. The method comprises the following steps: (1) screening saline-alkaline tolerant beet varieties, and adopting a paper tube seedling raising method to improve the seedling rate; (2) an inverted trapezoidal empty pond and an impermeable membrane drainage system are constructed, salt is induced to migrate to a salt collecting pond in combination with small-flow drip irrigation, and the annual salt discharge amount is larger than or equal to 10 tons / mu; (3) dynamically regulating and controlling the planting density, and matching salt and alkali gradients; water and fertilizer are integrally managed, water is saved by 40% through drip irrigation, and the nitrogen fertilizer utilization rate is increased to 50%; and (5) foliar topdressing to increase the sugar content to be greater than or equal to 16%. According to the method, the root tuber yield reaches 4.8-5.2 tons / mu, the annual salinity reduction amplitude of a plough layer is 15%-20%, the organic matter content is increased, the problems that saline-alkali soil beet planting is high in cost and low in efficiency are solved, and a feasible scheme is provided for resource utilization of saline-alkali soil in northwest arid regions.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural planting, in particular to a high-yield cultivation method for sugar beet seedlings, transplanting, and so on in moderate to severe saline-alkali land. Background Art

[0002] The salt content of moderately and severely saline-alkali soil is 0.3%-1.0%, pH 8.5-9.5, and sodium ion Na + The proportion of exchangeable cations exceeds 15%, resulting in the disintegration of soil aggregate structure, the permeability coefficient drops to 0.1-0.3cm / d, and a 20-40cm compacted layer is formed; the concentrations of basic ions Na⁺, Cl⁻, and HCO3⁻ exceed the standard, resulting in an effective phosphorus fixation rate of 60%-80%, and a 40%-50% decrease in the effectiveness of trace elements such as iron and zinc; the osmotic pressure of the soil solution is as high as 0.5-1.2 MPa, which exceeds the tolerance threshold of ordinary crop cells. In saline-alkali environments, soil microbial biomass carbon (MBC) drops to 30%-50% of normal soil, and the abundance of functional bacteria such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria decreases by 2-3 orders of magnitude, resulting in a 40%-60% reduction in the decomposition rate of organic matter.

[0003] The acclimatization of moderately to severely saline-alkali land requires a combination of measures, tailored to local conditions. Choosing the appropriate acclimatization method based on factors such as soil type, salinity, and climatic conditions is crucial for achieving good results. Conventional techniques employ a concealed drainage system, coupled with salt irrigation, to reduce salinity in the cultivated layer by 0.1%-0.2% per season. However, the construction cost of this system is as high as 12,000-18,000 yuan per mu, and maintenance costs account for 15%-20% of the output value. Chemical amendments, with annual investment exceeding 3,000 yuan per mu, only last for one to two seasons, posing the risk of secondary soil contamination.

[0004] Traditional planting methods are difficult to achieve high-yield and stable planting results on this type of land. Therefore, an effective cultivation method is urgently needed to improve the domestication level of moderate to severe saline-alkali land. Summary of the Invention

[0005] One object of the present invention is to provide a high-yield cultivation method for sugar beet seedlings and transplanting in moderately to severely saline-alkali soil, which simultaneously achieves efficient domestication of the saline-alkali soil and high-yield cultivation of sugar beets.

[0006] To achieve the above-mentioned object, the present invention provides a method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil, comprising the following steps:

[0007] S1. Select salt- and alkali-tolerant sugar beet varieties and grow seedlings in early March;

[0008] S2. Establish a ridge-pond structure and incorporate low-flow drip irrigation technology to channel some of the soil salt along with water into the empty ponds between planting strips. Acidic fertilizers and soil conditioners are also used to improve the soil in the growing zone.

[0009] S3. When the beet seedlings grow to 3-4 true leaves, transplant them with soil in late April to mid-May, controlling the planting density to 4000-6000 plants per acre;

[0010] S4. Immediately after transplanting, water the plants to help them grow. During the growing season, irrigate with a small flow rate according to soil moisture conditions, with each irrigation volume ≤ 30 m³.

[0011] S5. Combine basal fertilizer with topdressing, primarily nitrogen fertilizer with phosphorus and potassium fertilizers, and apply foliar topdressing in the middle and late growing season.

[0012] S6. Regularly cultivate and weed after transplanting to control the increase of soil salinity;

[0013] S7. Use integrated biological, physical and chemical control measures to prevent and control pests and diseases.

[0014] The salt-alkali tolerant sugar beet variety is an early maturing and high-yielding variety screened through salt-alkali stress, and the salt-alkali stress screening method is: germination rate ≥85% under 0.3%-0.5% soil salt content; seedling survival rate ≥75% under pH8.5-9.0 environment; full growth period ≤110 days; and more than 3,000 kg per mu.

[0015] The ridge-pond structure is to form ridges on the soil of the plant growth zone, the ridges are planting zones, and empty ponds are opened between adjacent planting zones. The empty pond structure is:

[0016] (a) The empty pond is located between adjacent planting zones and has an inverted trapezoidal cross-section, with an upper width of 40-60 cm, a bottom width of 20-30 cm, and a depth of 5-40 cm;

[0017] (b) A 1-15 cm gravel layer is laid at the bottom of the empty pond, the surface is covered with an impermeable membrane, and a drainage pipe is connected to lead the saline water to the salt collection pond.

[0018] The small flow drip irrigation technology specifically includes:

[0019] (a) Lay drip irrigation pipes parallel to the plant planting belt, with a dripper spacing of 20-30 cm, a single dripper flow rate of 1.0-2.0 L / h, and irrigation water salinity ≤ 0.3%;

[0020] (b) Irrigation is carried out every 3-5 days, with each irrigation lasting 2-4 hours, so that water carrying salts migrates to the empty pond (3).

[0021] The dripper is arranged at the top of the ridge, and the flow deviation is ≤5%.

[0022] The anti-seepage membrane is made of HDPE material with a thickness of ≥0.5mm, and the membrane surface is tilted 3°-5° toward the center of the empty pond to prevent salt from seeping in.

[0023] The diameter of the drainage pipe is 10-15 cm, and the slope is ≥0.5%.

[0024] The steps of improving the soil in the plant growth zone are as follows:

[0025] First, apply 5m³ of high-quality farmyard manure and soil conditioners per mu to increase soil organic matter content and change soil properties;

[0026] Then, use acidic fertilizers such as mineral potassium humate at a rate of 15-25 kg / mu to improve the soil in the plant planting area.

[0027] The foliar topdressing method is as follows: after the beet seedlings are transplanted and survive, 40 kg / mu of nitrogen fertilizer is applied in combination with drip irrigation, and appropriate amounts of phosphorus and potassium fertilizers are added, including 30 kg / mu of phosphorus fertilizer and 15 kg / mu of potassium fertilizer;

[0028] In the middle and late growth stages, apply 1 kg of potassium dihydrogen phosphate, 2.5 kg of urea or their mixed solution per mu every 7-10 days for foliar topdressing, and spray continuously for 3-5 times; the spraying mass concentration should be 0.2%-0.5% potassium dihydrogen phosphate and 0.5%-1.0% urea.

[0029] In the above-mentioned transplanting with soil clumps, the planting density is reduced to 4,000 plants per mu in areas where the salinity is higher than pH 9.5; and the planting density is increased to 6,000 plants per mu in areas where the salinity is lower than pH 8.5 and the organic matter content is higher than 1%.

[0030] The soil conditioner comprises humus and silicon-calcium based materials.

[0031] The soil ball transplanting adopts the paper tube seedling raising method, and during transplanting, the paper tube is cut and the soil ball is kept intact and implanted into the seedling hole.

[0032] The irrigation amount of the seedling-growing water is 0.5-1.0 L per plant, and after irrigation, ensure that the wet zone is separated from the dry pond.

[0033] The foliar topdressing is spraying a mixture of 0.2%-0.5% potassium dihydrogen phosphate and 0.5%-1.0% urea.

[0034] The tillage depth is 5-10 cm, and is combined with straw or mulch covering to reduce water evaporation.

[0035] The chemical control uses low-toxic pesticides, including a combination of chlorantraniliprole and thiamethoxam, with an application rate of 70%-80% of the recommended dose.

[0036] The method for screening salt-alkali tolerant sugar beet varieties is characterized by comprising the following steps:

[0037] (a) selecting multiple sugar beet varieties as candidate populations and planting them in a simulated moderate to severe saline-alkali soil environment, wherein the soil salinity is 0.6%-1.0% and the pH is 8.5-9.0;

[0038] (b) Apply saline-alkali stress in stages: control the soil salinity to 0.3%-0.5% during the seedling stage (1-3 true leaves), and gradually increase it to 0.6%-1.0% during the growth stage (4-8 true leaves);

[0039] (c) Monitoring the growth indicators of each variety, including seedling emergence rate, survival rate, true leaf growth rate, and root development;

[0040] (d) Measure the root weight, sugar content, and number of days of the full growth period of each plant at maturity, and select early-maturing, high-yield varieties with a growth period of ≤120 days and a yield of ≥4 tons per mu;

[0041] (e) Determine the salt-alkali stability of the target variety through multiple rounds of repeated screening and field verification.

[0042] The simulated saline-alkali environment is controlled by adding a mixed salt solution of NaCl, Na2SO4 and NaHCO3, with the ion ratio of Cl⁻:SO4²⁻:HCO3⁻=5:3:2.

[0043] In step (b), saline-alkali stress is precisely regulated by a drip irrigation system, and the salinity of the irrigation water increases gradually with the growth stage, with each increase being ≤0.1%.

[0044] The screening parameters for the root development degree in step (c) are root length ≥ 25 cm and number of lateral roots ≥ 15.

[0045] The full growth period of the early-maturing variety is 100-120 days, the yield per mu is ≥4.5 tons and the sugar content is ≥16%.

[0046] The field verification in step (e) requires repeated planting in at least three experimental fields with different salinity gradients (salinity content of 0.6%, 0.8%, and 1.0%), and the survival rate of the target variety must be ≥85%.

[0047] The method for raising and transplanting sugar beets in medium-to-severe saline-alkali land and achieving high yields is described in the present invention. Its beneficial effects are: significant enhancement of salt-alkali resistance, and improvement of seedling rate and survival rate. The inverted trapezoidal hollow pond structure of the present invention forms a salt drainage channel with the HDPE anti-seepage membrane, and cooperates with the gravel layer 8 to achieve capillary isolation, thereby increasing the efficiency of horizontal salt migration by 50%; small-flow drip irrigation technology (1.0-2.0L / h dripper) induces salt to accumulate in the hollow pond through high-frequency (3-5 days / time) and low-water volume (≤30m³ / time) irrigation, and the EC value of the cultivated layer decreases at a rate of 0.1-0.15 mS / cm·d; the drainage concealed pipe (slope ≥0.5%) is linked to the salt collection pool to achieve an annual salt discharge of ≥12t / ha, which is 3 times more efficient than the traditional open ditch salt discharge; the ridge structure forms a local lifting area, and cooperates with the precise positioning of the dripper to reduce the salt concentration gradient in the root zone to 0.8-1.2 g / kg; acidic fertilizer stabilizes the rhizosphere pH value at 7.8-8.2 and increases the available phosphorus activation rate to 45%-55%; soil conditioners (humus + silicon-calcium-based materials) promote the formation of aggregate structure and reduce soil bulk density to 1.25-1.35 g / cm³;

[0048] The drip irrigation system achieves an irrigation water utilization rate of ≥85% (conventional flood irrigation ≤50%), saving 40%-50% of water throughout the entire growing period. Nitrogen fertilizer topdressing combined with foliar spraying increases nitrogen utilization to 45%-50%, and increases root sugar content by 1.2-1.5 percentage points. A combination of slow-release basal fertilizer and precision topdressing reduces nutrient loss by ≥30%. After three consecutive years of implementation, the salt content of the tillage layer has dropped from an initial 0.6%-0.8% to 0.3%-0.4%, and the organic matter content has increased from 0.6%-0.8% to 1.2%-1.5%. Microbial communities have recovered: the number of nitrogen-fixing bacteria has reached 1×10 6 CFU / g (before improvement ≤1×10 4 CFU / g), soil enzyme activity increased 2-3 times;

[0049] The "empty pond salt collection" system, combined with localized underground pipework, reduces pipe network size and lowers maintenance costs for the underground salt drainage system. In moderately saline-alkali land with a salinity of 0.6%, root yields are consistently 4.5-5.5 tons / mu (compared to ≤3.5 tons / mu with conventional technology), with a sugar content ≥16% (compared to ≤14% for conventional varieties). Salt-alkali land is being utilized as a resource, with annual salt recovery in the salt collection ponds exceeding 8 t / ha, which can be reused as industrial raw materials. A three-stage sedimentation treatment system in empty ponds reduces the COD level of drainage water to ≤50 mg / L (discharge standard ≤100 mg / L), achieving water recycling. A modular design (variety-engineering-agronomy) adapts to varying salinity gradients: in salinity zones of 0.6%-0.8%, a planting density of 6,000 plants / mu achieves a yield of 4.8-5.2 tons per mu; in pH zones of 9.0-9.5, a combination of silica-calcium conditioners and a planting density of 4,000 plants / mu still maintains a yield of 3.5-4.0 tons per mu. Field verification has shown that this method has good adaptability in typical areas such as the soda saline-alkali land in Northeast China and the sulfate saline-alkali land in Northwest China, increasing yields by 25%-40% compared with traditional planting models, providing a replicable technical paradigm for saline-alkali land agricultural development. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the structure of an embodiment of the present invention Figure 1 ;

[0051] Figure 2 A schematic diagram of the structure of an embodiment of the present invention Figure 2 ;

[0052] Figure 3 A schematic diagram of the structure of an embodiment of the present invention Figure 3 ;

[0053] Figure 4 Schematic diagram of the diffusion direction of salt with water in an embodiment of the present invention Figure 1 ;

[0054] Figure 5 This is a schematic diagram of the planting belt structure according to an embodiment of the present invention;

[0055] Figure 6 Schematic diagram of the diffusion direction of salt with water in an embodiment of the present invention Figure 2 ;

[0056] In the figure: 1- planting belt, 2- ridge, 3- empty pond, 4- drainage pipe, 5- soil in the plant growth zone, 6- salt collection pond, 7- anti-seepage membrane, 8- gravel layer, 9- dripper, 10- direction of salt diffusion with water. DETAILED DESCRIPTION

[0057] Example 1:

[0058] Overview of the test site.

[0059] Location: Bianwan Farm Improvement Demonstration Area, Suzhou District, Jiuquan City, Gansu Province.

[0060] Soil parameters: initial salt content 0.7%, pH 8.8, sodium adsorption ratio (SAR) ≥12, organic matter content 0.6%.

[0061] Climate conditions: annual precipitation ≤80mm, evaporation ≥2500mm, frost-free period 160-180 days.

[0062] like Figure 1-6 As shown, the present invention provides a method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil, and the implementation steps are as follows:

[0063] 1. Variety screening and seedling cultivation:

[0064] (a) Selecting salt-tolerant sugar beet varieties as candidate populations, and planting them in a simulated moderate to severe saline-alkali soil environment, wherein the simulated saline-alkali soil environment is controlled by adding a mixed salt solution of NaCl, Na2SO4, and NaHCO3, with an ion ratio of Cl⁻:SO4²⁻:HCO3⁻=5:3:2; the soil salinity is 0.6%-1.0%, and the pH is 8.5-9.0;

[0065] (b) applying saline-alkali stress in stages: controlling the soil salinity to 0.3%-0.5% during the seedling stage (1-3 true leaves), and gradually increasing it to 0.6%-1.0% during the growth stage (4-8 true leaves); the salinity stress is precisely controlled through a drip irrigation system, with the salinity of the irrigation water increasing gradually with the growth stage, with each increase being ≤0.1%;

[0066] (c) Monitoring the growth indicators of each variety. The root development screening parameters are root length ≥ 25 cm, number of lateral roots ≥ 15, full growth period of the variety of 100-120 days, yield per mu ≥ 4.5 tons, and sugar content ≥ 16%;

[0067] (d) Measure the root weight, sugar content, and number of days of the full growth period of each plant at maturity, and select early-maturing, high-yield varieties with a growth period of ≤120 days and a yield of ≥4 tons per mu;

[0068] (e) determining the salt-alkali stability of the target variety through multiple rounds of repeated screening and field verification, wherein the field verification requires repeated planting in three test fields with different salinity gradients (salt content of 0.6%, 0.8%, and 1.0%), and the survival rate of the target variety is ≥88%; thereby obtaining the salt-tolerant sugar beet variety of the present invention;

[0069] (f) Seedlings were raised from March 5 to March 15 in a medium consisting of peat:vermiculite:decomposed cow dung (3:2:1) with a pH of 7.8-8.0. Sowing was done in paper tubes 5 cm in diameter and 10 cm in height at a depth of 1.5 cm, with two seeds per tube covered with non-woven fabric for insulation. Daytime temperatures were maintained at 25-28°C and nighttime temperatures at 15-18°C. The medium humidity was maintained at 18%-20%.

[0070] 2. Construction of field engineering system:

[0071] Establish a ridge-pond structure: planting strip 1 has a top width of 60 cm, a bottom width of 100 cm, a ridge height of 5 cm, and a longitudinal slope of 0.6%;

[0072] Empty pond design: The upper width of the inverted trapezoidal section is 50 cm, the bottom width is 25 cm, and the depth is 35 cm. The bottom is paved with a 1 cm gravel layer 8, covered with a HDPE anti-seepage membrane with a thickness of 0.6 mm and a slope of 4°;

[0073] Drip irrigation system: 9 drippers with a spacing of 25 cm, single dripper flow rate of 1.5 L / h, flow deviation ≤ 3%;

[0074] EC value of irrigation water ≤ 0.8 dS / m (salt content ≤ 0.3%);

[0075] 3. Transplanting and density control:

[0076] Transplanting time: April 25-May 10 (ground temperature ≥ 12℃);

[0077] Planting density:

[0078]

[0079] Transplanting method: Cut three 5cm incisions at the bottom of the paper tube, leaving a soil ball with a diameter of 8-10cm, and plant at a depth of 12-15cm. Cover with soil to form a "concave" water collection hole.

[0080] 4. Integrated water and fertilizer management:

[0081]

[0082] Fertilization plan:

[0083] Base fertilizer: 5m³ / mu of decomposed sheep manure + 200kg / mu of silicon-calcium conditioner (containing SiO2≥25%, CaO≥30%);

[0084] top dressing:

[0085] 10 days after transplanting: drip irrigation of urea 40kg / mu;

[0086] Root enlargement period: drip irrigation of potassium sulfate 15kg / mu;

[0087] Foliar fertilizer: 0.3% potassium dihydrogen phosphate + 0.8% urea, spray every 10 days, for a total of 4 times.

[0088] Example 2:

[0089] Overview of the test site.

[0090] Location: Improvement Demonstration Area, Xinhu Village, Huangnibao Township, Suzhou District, Jiuquan City, Gansu Province.

[0091] Soil parameters: initial salt content 1.0%, pH 9.3, sodium adsorption ratio (SAR) ≥12, organic matter content 0.8%.

[0092] Climate conditions: annual precipitation ≤80mm, evaporation ≥2500mm, frost-free period 160-180 days.

[0093] like Figure 1-6 As shown, the present invention provides a method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil, and the implementation steps are as follows:

[0094] 1. Variety screening and seedling cultivation:

[0095] (a) Selecting salt-tolerant sugar beet varieties as candidate populations, and planting them in a simulated moderate to severe saline-alkali soil environment. The simulated saline-alkali soil environment was controlled by adding a mixed salt solution of NaCl, Na2SO4, and NaHCO3, with an ion ratio of Cl⁻:SO4²⁻:HCO3⁻=5:3:2; the soil salinity was 1.0% and the pH was 9.0;

[0096] (b) applying saline-alkali stress in stages: controlling the soil salinity to 0.3%-0.5% during the seedling stage (1-3 true leaves), and gradually increasing it to 0.6%-1.0% during the growth stage (4-8 true leaves); the salinity stress is precisely controlled through a drip irrigation system, with the salinity of the irrigation water increasing gradually with the growth stage, with each increase being ≤0.1%;

[0097] (c) Monitoring the growth indicators of each variety. The root development screening parameters are root length ≥ 25 cm, number of lateral roots ≥ 15, full growth period of the variety of 100-120 days, yield per mu ≥ 4.5 tons, and sugar content ≥ 16%;

[0098] (d) Measure the root weight, sugar content, and number of days of the full growth period of each plant at maturity, and select early-maturing, high-yield varieties with a growth period of ≤120 days and a yield of ≥4 tons per mu;

[0099] (e) determining the salt-alkali stability of the target variety through multiple rounds of repeated screening and field verification, wherein the field verification requires repeated planting in three test fields with different salinity gradients (salt content of 0.6%, 0.8%, and 1.0%), and the survival rate of the target variety is 90%; thereby obtaining the salt-tolerant sugar beet variety of the present invention;

[0100] (f) Seedlings were raised from March 5 to March 15 in a medium consisting of peat:vermiculite:decomposed cow dung (3:2:1) with a pH of 8.0. Sowing was done in paper tubes 5 cm in diameter and 10 cm high at a depth of 1.5 cm, with two seeds per tube covered with non-woven fabric for insulation. Daytime temperatures were maintained at 25-28°C and nighttime temperatures at 15-18°C. The medium humidity was maintained at 18%-20%.

[0101] 2. Construction of field engineering system:

[0102] Establish a ridge-pond structure: planting strip 1 has a top width of 60 cm, a bottom width of 100 cm, a ridge height of 30 cm, and a longitudinal slope of 0.6%;

[0103] Empty pond design: The upper width of the inverted trapezoidal section is 50 cm, the bottom width is 25 cm, and the depth is 35 cm. The bottom is paved with a 12 cm gravel layer 8, covered with a HDPE anti-seepage membrane with a thickness of 0.6 mm and a slope of 4°;

[0104] Drip irrigation system: 9 drippers with a spacing of 25 cm, single dripper flow rate of 1.5 L / h, flow deviation ≤ 3%

[0105] Irrigation water EC value ≤ 0.8 dS / m (salt content ≤ 0.3%)

[0106] 3. Transplanting and density control:

[0107] Transplanting time: April 25-May 10 (ground temperature ≥ 12℃);

[0108] Planting density:

[0109]

[0110] Transplanting method: Cut three 5cm incisions at the bottom of the paper tube, leaving a soil ball with a diameter of 8-10cm, and plant at a depth of 12-15cm. Cover with soil to form a "concave" water collection hole.

[0111] 4. Integrated water and fertilizer management:

[0112]

[0113] Fertilization plan:

[0114] Base fertilizer: 5m³ / mu of decomposed sheep manure + 200kg / mu of silicon-calcium conditioner (containing SiO2≥25%, CaO≥30%);

[0115] top dressing:

[0116] 10 days after transplanting: drip irrigation of urea 40kg / mu;

[0117] Root enlargement period: drip irrigation of potassium sulfate 15kg / mu;

[0118] Foliar fertilizer: 0.3% potassium dihydrogen phosphate + 0.8% urea, spray every 10 days, for a total of 4 times.

[0119] Comparative experimental design:

[0120] Experimental group: using Example 1 and Example 2 of the method of the present invention;

[0121] Control group: traditional planting (conventional varieties + open ditch drainage + flood irrigation);

[0122]

[0123] Result analysis:

[0124] Yield and quality: The experimental group increased yield by 52%-73% compared with the control group, and the sugar content increased by 2.7-2.9 percentage points;

[0125] Salt control: The soil salt content in the experimental group was 0.42%, while that in the control group was 0.68%. The annual salt reduction in the cultivated layer of the experimental group was 15%-20%, while that in the control group was only 5%-8%.

[0126] Economic benefits: The experimental group had a net profit of 2,920 yuan / mu, while the control group suffered a loss (-500 yuan / mu).

[0127] Engineering-biological synergistic salt drainage: The inverted trapezoidal empty pond + concealed pipe system achieves an annual salt drainage capacity of ≥10 tons / mu, which is three times more efficient than open ditch;

[0128] Breakthrough in variety adaptability: The selected varieties can still maintain an acreage yield of ≥4.5 tons at a salt content of 0.9%;

[0129] Efficient resource utilization: drip irrigation saves 40% of water and increases nitrogen fertilizer utilization rate to 50%;

[0130] Ecological sustainability: Soil organic matter content increased to 1.5% in three years, and microbial activity recovered to 80% of normal soil fertility.

[0131] This plan provides a replicable technical path for sugar beet cultivation in saline-alkali lands in the arid northwest region, with significant economic and ecological benefits.

Claims

1. A method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil, characterized in that: The following steps are involved: S1. Select salt- and alkali-tolerant sugar beet varieties and grow seedlings in early March; S2. Establish a ridge-pond structure and combine it with low-flow drip irrigation technology to introduce some of the salt in the soil along with the water into the empty pond (3) between the planting belts (1), and combine acidic fertilizers and soil conditioners to improve the soil in the plant growth zone (5); S3. When the beet seedlings grow to 3-4 true leaves, transplant them with soil in late April to mid-May, controlling the planting density to 4000-6000 plants per acre; S4. Immediately after transplanting, water the plants to help them grow. During the growing season, irrigate with a small flow rate according to soil moisture conditions, with each irrigation volume ≤ 30 m³. S5. Combine basal fertilizer with topdressing, primarily nitrogen fertilizer with phosphorus and potassium fertilizers, and apply foliar topdressing in the middle and late growing season. S6. Regularly cultivate and weed after transplanting to control the increase of soil salinity; S7. Use integrated biological, physical and chemical control measures to prevent and control pests and diseases.

2. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1, wherein: The salt-alkali tolerant sugar beet variety in S1 is an early-maturing, high-yielding variety screened under salt-alkali stress, wherein the salt-alkali stress screening method is: a germination rate of ≥85% under a soil salt content of 0.3%-0.5%; In the pH8.5-9.0 environment, the seedling survival rate is ≥75%, the whole growth period is ≤110 days, and the yield per mu is greater than 3000kg.

3. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1, wherein: The ridge-pond structure established in S2 is to form ridges on the soil (5) of the plant growth zone, the ridges are planting zones (1), and empty ponds (3) are opened between adjacent planting zones (1). The empty pond structure is: (a) The empty pond (3) is located between adjacent planting strips (1) and has an inverted trapezoidal cross section with an upper width of 40-60 cm, a bottom width of 20-30 cm, and a depth of 5-40 cm; (b) A 1-15 cm gravel layer (8) is laid on the bottom of the empty pond (3), and the surface is covered with an impermeable membrane (7). A drainage pipe (4) is connected to lead the saline water body to the salt collection pond (6).

4. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1 or 3, characterized in that: S2 small and medium flow drip irrigation technology, specifically including: (a) Drip irrigation pipes are laid parallel to the plant planting belt (1), with the drippers (9) spaced 20-30 cm apart, the flow rate of a single dripper being 1.0-2.0 L / h, and the salinity of the irrigation water being ≤0.3%; (b) Irrigation is carried out every 3-5 days, with each irrigation lasting 2-4 hours, so that water carrying salts migrates to the empty pond (3).

5. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 4, wherein: The dripper (9) is arranged at the top of the ridge (2), and the flow deviation is ≤5%.

6. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 4, wherein: The anti-seepage membrane (7) is made of HDPE material, with a thickness of ≥0.5 mm, and the membrane surface is inclined 3°-5° toward the center of the empty pond to prevent salt from seeping in; The diameter of the drainage pipe (4) is 10-15 cm, and the slope is ≥0.5%.

7. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1, wherein: Steps for improving the soil in the plant growth zone (5) as described in S2: First, apply 5m³ of high-quality farmyard manure and soil conditioners per mu to increase soil organic matter content and change soil properties; Then, use acidic fertilizers such as mineral potassium humate at a rate of 15-25 kg / mu to improve the soil in the plant planting area.

8. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1, wherein: The foliar topdressing method described in S5 is: after the beet seedlings are transplanted and survive, 40 kg / mu of nitrogen fertilizer is applied in combination with drip irrigation, and phosphorus and potassium fertilizers are applied in combination, of which 30 kg / mu of phosphorus fertilizer and 15 kg / mu of potassium fertilizer are applied; In the middle and late growth stages, apply 1 kg of potassium dihydrogen phosphate, 2.5 kg of urea or their mixed solution per mu every 7-10 days for foliar topdressing, and spray continuously for 3-5 times; the spraying mass concentration should be 0.2%-0.5% potassium dihydrogen phosphate and 0.5%-1.0% urea.

9. The method for raising and transplanting sugar beet seedlings and achieving high yield in moderate to severe saline-alkali soil according to claim 1, wherein: In S3, in the transplanting with soil lumps, the planting density is 4,000 plants per mu in areas where the salinity is higher than pH 9.5; for areas where the salinity is lower than pH 8.5 and the organic matter content is higher than 1%, the planting density is 6,000 plants per mu.

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