Foeniculum vulgare ecological planting method for selenium sand melons in land with reduced tillage and pressed sand and application thereof

Abstract

The invention belongs to the field of fennel planting, and particularly relates to an ecological fennel planting method for selenium sand melons in a ploughing-reducing and sand-pressing land and application of the ecological fennel planting method. The method comprises the following steps: carrying out soil preparation treatment of deeply ploughing soil, applying a base fertilizer and spraying a weed sealing agent on the selenium sand melon reduced-tillage sand pressing land; secondly, sowing in spring through mechanical drilling, and synchronously applying a compound fertilizer and a bacterial fertilizer mixture containing specific microorganisms; in the field management, irrigation is only needed for 2-3 times in the whole growth period; monopotassium phosphate is sprayed on leaf surfaces in the early flowering stage and the filling stage; weeds are dynamically prevented and controlled according to different periods; and implementing threshold response type medicament control on powdery mildew, fennel, papilionella and the like. According to the method, the day and night temperature difference environment of the pressure sand land is fully utilized, the problems of soil hardening, fertility decline and desertification risks caused by continuous cropping of the selenium sand melons are solved, the physical and chemical properties of the soil are remarkably improved, the medicinal component content of the fennel is increased, and high-economic-value crops are synchronously produced; and a win-win planting scheme of ecological and economic benefits is provided for the sand-pressed and abandoned cultivated land in the arid region.

Description

Technical Field

[0001] This invention belongs to the field of fennel cultivation, specifically relating to an ecological cultivation method for fennel on sandy land converted from cultivated land and its application. Background Technology

[0002] Fennel (Foeniculum vulgare Mill.) is an annual or perennial herb belonging to the genus Fennel in the family Umbelliferae of the class Dicotyledonous plants. Commonly known as fennel, its leaves and seeds have a strong, distinctive aroma. As a versatile aromatic plant, its stems, leaves, and seeds all possess a potent fragrance. The tender stems and leaves can be eaten as vegetables, while the fruits (seeds) are widely used in seasonings, spices, and essential oil extraction. Simultaneously, its roots, leaves, fruits, and even the entire plant are important traditional Chinese medicinal materials, possessing warm properties and a pungent taste, primarily used to treat symptoms such as abdominal pain due to cold, abdominal distension and pain, poor appetite, vomiting, and diarrhea. Fennel essential oil is widely used in the pharmaceutical, cosmetic, and food industries. This crop also exhibits strong drought resistance. Therefore, fennel, with its dual nature of being both food and medicine, possesses outstanding edible, medicinal, economic, and ecological value. In recent years, with increasing attention to its medicinal and edible value, market demand has continued to grow.

[0003] Since 2021, large-scale cultivation of selenium-rich sand melons has been phased out in Zhongwei, Ningxia. A significant amount of land previously used for selenium-rich sand melon production is now idle, urgently requiring new industrial solutions for transformation. These sand-covered lands, previously used for selenium-rich sand melon cultivation, have become sandy and soil-mixed after years of melon planting. The topsoil layer is predominantly sandy with little soil, and soil organic matter has gradually decreased. Most sand-covered lands rely on groundwater irrigation, leading to a drop in the water table and a thickening of the dry soil layer. Long-term irrigation with brackish water has caused soil salinization, resulting in increasingly poor soil structure and gradual desertification, making the land unsuitable for crop growth. Summary of the Invention

[0004] This invention aims to provide a new model for specialty planting in sandy land by constructing a gravel-vegetation-microbe ecological barrier to improve soil quality and reduce the rate of sand and gravel weathering, thereby providing a replicable solution for agricultural transformation in arid regions.

[0005] To achieve the above objectives, this invention provides a method for ecological cultivation of fennel on land converted from cultivated land to sandy soil, comprising the following steps: S1. Site selection and land preparation: Select a plot of land that has been converted from selenium-rich sandy melon cultivation and covered with sand. After the selenium-rich sandy melon is harvested, plow the sandy plot to a depth of 30-40cm, apply base fertilizer, and after the soil thaws in the following spring, harrow and hoe before sowing, and spray weed sealant. The amount of base fertilizer applied is 1000~1500 kg / mu; S2. Sowing: Spring sowing is carried out using a fertilizer-seeding integrated machine for mechanical row sowing, where seeds and mixed fertilizer are sown simultaneously. The seeds are local Ningxia varieties or Minqin fennel varieties; the row spacing for row sowing is 20-30cm, the seed sowing rate is 1.0-1.5kg / mu, the sowing depth is 4-6cm, and the fertilizer application rate is 15-30kg / mu; the fertilizer is a compound fertilizer and microbial fertilizer. S3. Field management, including: Water management: Irrigate 2-3 times throughout the growing season, with each irrigation amount being 10-14 m³. 3 / mu; During the seedling stage of the entire growth period, when the soil moisture content is 7%~10%, water should be added in time to bring the soil moisture content to a level greater than 10%; Nutrient management: During the pre-flowering and grain-filling stages, spray with a 0.3% (w / w) solution of potassium dihydrogen phosphate; Weed management: Weeds should be completely removed as early as possible during their seedling stage; During the vegetative growth period and critical reproductive growth period of fennel, when the height of weeds is higher than that of fennel and / or the weed coverage reaches 10% to 15%, apply a low-toxicity herbicide to the stems and leaves of the weeds; the application frequency of the low-toxicity herbicide is 1 to 2 times per year. S4. Pest and disease control: To combat powdery mildew, spray 15% triadimefon at a dilution of 1000 times or 40% flusilazole emulsifiable concentrate at a dilution of 8000 times at the early stage of the disease in fennel. Spray once every 7 to 10 days, and spray 2 to 3 times each time the disease occurs, with 20L / mu each time. For the control of fennel swallowtail butterfly pests, when the larvae of fennel swallowtail butterfly infestation rate in the field reaches 10%~15%, spray with 2.5% deltamethrin at 3000 times dilution or 20% cypermethrin at 2000 times dilution. Aphid control: When the aphid rate in the field reaches 30% to 50% and the number of aphids per plant continues to rise, pesticide spraying should be used for control. The pesticide spraying includes 1000 times diluted imidacloprid or pymetrozine, with each spraying being 20L / acre.

[0006] In the above method, the sand-pressing thickness of the sand-pressing plot in S1 is 10~20cm.

[0007] The method described above is characterized in that the base fertilizer in S1 is farmyard manure.

[0008] In the above method, S1 refers to 5-9 days before sowing.

[0009] In the above method, the weed pre-emergence agent in S1 is 48% trifluralin EC, and the application rate of 48% trifluralin EC is 100~150mL / mu.

[0010] In the above method, the compound fertilizer in S2 is a pure potassium sulfate type compound fertilizer with a mass ratio of N:P2O5:K2O of 14:16:15 and an application rate of 10~20 kg / mu; the effective strains in the microbial fertilizer are Bacillus subtilis and Bacillus spp., with a beneficial live bacteria count ≥1 billion / gram and organic matter ≥60%, and an application rate of 5~10 kg / mu.

[0011] In the above method, the application rate of potassium dihydrogen phosphate in S3 nutrient management is 200g / mu.

[0012] In the above method, the low-toxicity herbicide in S3 weed management is a 5% quizalofop-P-ethyl aqueous solution. The preparation method of the 5% quizalofop-P-ethyl aqueous solution is as follows: mix 100~150mL of 5% quizalofop-P-ethyl with 40~50kg of water.

[0013] On the other hand, this application provides the application of any of the above planting methods in improving the physical and chemical properties of soil.

[0014] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: 1. The planting method provided in this application is compatible with the ecological environment of sandy soil, improving the physical and chemical properties of the soil while increasing the content of medicinal components in fennel. By limiting the sowing depth and sowing time, the water-retaining barrier formed by the 10-15cm thick gravel cover layer of the sandy soil can be used to ensure that the fennel roots can maintain a certain soil moisture content under drought conditions, enabling cultivation under drought conditions with an annual precipitation of 200mm. At the same time, the special environment of 15℃ diurnal temperature difference in the sandy layer promotes the accumulation of fennel essential oil, significantly increasing its medicinal component content.

[0015] 2. The planting method provided in this application can simultaneously restore soil microecology and biological activity; this application uses fennel to plant in sandy land after the return of selenium-rich watermelon, which can alleviate the problems of soil fertility decline and increased pests and diseases caused by long-term continuous watermelon planting. The organic acids secreted by its roots can effectively activate the fixed nutrients in the soil and significantly reverse the soil compaction, fertility decline and high incidence of soil-borne pests and diseases caused by continuous watermelon planting.

[0016] 3. The planting method provided in this application can construct an ecological protection system and carbon sequestration function; the well-developed root network of fennel and the sand-stabilizing layer work together to form a three-layer sand-fixing structure of "gravel-vegetation-soil", which reduces the weathering rate of surface sand and gravel and reduces the amount of surface erosion; at the same time, planting fennel can also achieve the effect of carbon sequestration and oxygen release, and solve the risk of land desertification and ecological degradation caused by watermelon planting.

[0017] 4. The planting method provided in this application has created significant economic and social value in practice; the yield of fennel in sandy soil is 88 kg per mu, and the output value per mu is 1320 yuan based on the market price of 15 yuan / kg; compared with watermelon planting, it saves irrigation costs, provides farmers in arid areas with new income channels, and absorbs surplus rural labor to participate in the harvesting and processing process, resulting in significant social benefits. Detailed Implementation

[0018] The technical solution of the present invention will be described below with reference to embodiments. However, the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental and detection methods described in each embodiment are conventional methods; the reagents and materials described are commercially available unless otherwise specified. Unless otherwise specified, all percentages in the following embodiments refer to mass percentages. Unless otherwise specified, all proportions in the following embodiments refer to mass ratios.

[0019] Planting Site: The experimental site is located in Xiongshui Village, Changle Town, Shapotou District, Zhongwei City, Ningxia (37.36°N ~ 105.14°E). This region has a temperate continental arid climate, exhibiting characteristics of both the northwestern inland and desert fringe climates. It is dry with little rainfall, abundant sunshine, and significant diurnal temperature variations. The average annual effective precipitation is approximately 200 mm, the average annual evaporation is approximately 2200 mm, and the average annual sunshine duration is 2800 hours. 70% of the precipitation is concentrated between July and September. The soil in the experimental site is thin and has low fertility, with a sandy loam soil type. The previous crop in the experimental site was watermelon.

[0020] Planting time: Land preparation time: Autumn land preparation, from late September to late October.

[0021] Sowing time: Except for sowing period trials, the general sowing time is 3 to 5 days before or after the Qingming Festival in April.

[0022] Example 1 This embodiment provides a method for ecological cultivation of fennel in sandy soil, including the following steps: S1. Site selection and land preparation: Select a sandy soil plot with a sandy soil thickness of 10-20cm that has been converted from selenium-rich sandy soil for melon cultivation. After the melon harvest, deeply plow the sandy soil plot to a depth of 35cm and apply 1250kg / mu of farmyard manure. After the soil thaws in the following spring, harrow and hoe the soil 8 days before sowing, and spray 125mL / mu of 48% trifluralin EC to seal the soil against weeds and form a uniform film to prevent weed damage during the seedling stage. S2. Sowing: Spring sowing is carried out using a fertilizer-planting machine for mechanical row sowing. Seeds and mixed fertilizer are sown at the same time, with a row spacing of 25cm, a seed sowing rate of 1.25kg / mu, and a sowing depth of 5cm. The seeds are local Ningxia varieties or Minqin fennel varieties; the application rate of the mixed fertilizer is 25 kg / mu; the mixed fertilizer is a compound fertilizer and a microbial fertilizer; the compound fertilizer is a pure potassium sulfate type compound fertilizer with a N:P2O5:K2O mass ratio of 14:16:15 and an application rate of 18 kg / mu; the effective strains in the microbial fertilizer are Bacillus subtilis and Bacillus mucilaginosa, with a beneficial live bacteria count ≥1 billion / gram and organic matter ≥60%, and an application rate of 7 kg / mu.

[0023] S3. Field management, including: Water management: Irrigate 3 times during the entire growth period, with each irrigation amount being 12m³. 3 / mu; During the seedling stage of the entire growth period, when the soil moisture content is 7%~10%, water should be added in time to bring the soil moisture content to a level greater than 10%; Nutrient management: During the pre-flowering and grain-filling stages, spray with a 0.3% potassium dihydrogen phosphate solution at a concentration of 200g / mu. Weed management: Weeds should be completely removed as early as possible during their seedling stage; During the vegetative growth period and critical reproductive growth period of fennel, when the height of the weeds is higher than that of fennel and / or the weed coverage reaches 10% to 15%, a low-toxicity herbicide is applied to the stems and leaves of the weeds; the application frequency of the low-toxicity herbicide is 2 times / year; the low-toxicity herbicide is a 5% aqueous solution of quizalofop-P-ethyl, and the 5% aqueous solution of quizalofop-P-ethyl is prepared by mixing 125 mL of 5% quizalofop-P-ethyl with 40 to 50 kg of water.

[0024] S4. Pest and disease control: To combat powdery mildew, spray 15% triadimefon at a dilution of 1000 times or 40% flusilazole emulsifiable concentrate at a dilution of 8000 times at the early stage of the disease in fennel. The spraying frequency is once every 7 to 10 days, and 2 to 3 times for each disease outbreak, with 20L / mu per spray each time. For the control of fennel swallowtail butterfly pests, when the larvae of fennel swallowtail butterfly infestation rate in the field reaches 10%~15%, spray with 2.5% deltamethrin at 3000 times dilution or 20% cypermethrin at 2000 times dilution. Aphid control: When the aphid rate in the field reaches 30% to 50% and the number of aphids per plant continues to rise, pesticide spraying should be used for control; the pesticide spraying includes 1000 times diluted imidacloprid or pymetrozine, with each spraying being 20L / acre.

[0025] Finally, the quality and yield of the fennel produced in this embodiment were statistically analyzed, and the results showed that the germination rate was 90.3%, the plant height was 117.08 cm, the ground diameter was 9.72 mm, the number of branches was 14, the number of inflorescences was 75, and the yield was 103.94 kg / mu.

[0026] Example 2 This embodiment provides a method for ecological cultivation of fennel in sandy soil, including the following steps: S1. Site selection and land preparation: Select a sandy soil plot with a sandy soil thickness of 10-20cm that has been converted from selenium-rich sandy soil for melon cultivation. After the melon harvest, deeply plow the sandy soil plot to a depth of 30cm and apply 1000kg / mu of farmyard manure. After the soil thaws in the following spring, harrow and hoe the soil 5 days before sowing, and spray 100mL / mu of 48% trifluralin EC to seal the soil against weeds and form a uniform film to prevent weed damage during the seedling stage. S2. Sowing: Spring sowing is carried out using a fertilizer-planting machine for mechanical row sowing. Seeds and mixed fertilizer are sown at the same time, with a row spacing of 20cm, a seed sowing rate of 1.0kg / mu, and a sowing depth of 4cm. The seeds are local Ningxia varieties or Minqin fennel varieties; the application rate of the mixed fertilizer is 15 kg / mu; the mixed fertilizer is a compound fertilizer and a microbial fertilizer; the compound fertilizer is a pure potassium sulfate type compound fertilizer with a N:P2O5:K2O mass ratio of 14:16:15 and an application rate of 10 kg / mu; the effective strains in the microbial fertilizer are Bacillus subtilis and Bacillus mucilaginosa, with a beneficial live bacteria count ≥1 billion / gram and organic matter ≥60%, and an application rate of 5 kg / mu.

[0027] S3. Field management, including: Water management: Irrigate twice during the entire growth period, with each irrigation amount being 10m³. 3 / mu; During the seedling stage of the entire growth period, when the soil moisture content is 7%~10%, water should be added in time to bring the soil moisture content to a level greater than 10%; Nutrient management: During the pre-flowering and grain-filling stages, spray with a 0.3% potassium dihydrogen phosphate solution at a concentration of 200g / mu. Weed management: Weeds should be completely removed as early as possible during their seedling stage; During the vegetative growth period and critical reproductive growth period of fennel, when the height of the weeds is higher than that of fennel and / or the weed coverage reaches 10% to 15%, a low-toxicity herbicide is applied to the stems and leaves of the weeds; the application frequency of the low-toxicity herbicide is once per year; the low-toxicity herbicide is an aqueous solution of 5% quizalofop-P-ethyl, and the preparation method of the 5% quizalofop-P-ethyl aqueous solution is as follows: mix 100 mL of 5% quizalofop-P-ethyl with 40 to 50 kg of water.

[0028] S4. Pest and disease control: To combat powdery mildew, spray 15% triadimefon at a dilution of 1000 times or 40% flusilazole emulsifiable concentrate at a dilution of 8000 times at the early stage of the disease in fennel. The spraying frequency is once every 7 to 10 days, and 2 to 3 times for each disease outbreak, with 20L / mu per spray each time. For the control of fennel swallowtail butterfly pests, when the larvae of fennel swallowtail butterfly infestation rate in the field reaches 10%~15%, spray with 2.5% deltamethrin at 3000 times dilution or 20% cypermethrin at 2000 times dilution. Aphid control: When the aphid rate in the field reaches 30% to 50% and the number of aphids per plant continues to rise, pesticide spraying should be used for control; the pesticide spraying includes 1000 times diluted imidacloprid or pymetrozine, with each spraying being 20L / acre.

[0029] Finally, the quality and yield of the fennel produced in this embodiment were statistically analyzed, and the results showed that the germination rate was 88.01%, the plant height was 115.64 cm, the ground diameter was 7.08 mm, the number of branches was 13, the number of inflorescences was 68, and the yield was 99.48 kg / mu.

[0030] Example 3 This embodiment provides a method for ecological cultivation of fennel in sandy soil, including the following steps: S1. Site selection and land preparation: Select a sandy soil plot with a sandy soil thickness of 10-20cm that has been converted from selenium-rich sandy soil for melon cultivation. After the melon harvest, deeply plow the sandy soil plot to a depth of 40cm and apply 1500kg / mu of farmyard manure. After the soil thaws in the following spring, harrow and hoe the soil 9 days before sowing, and spray 150mL / mu of 48% trifluralin EC to seal the soil against weeds and form a uniform film to prevent weed damage during the seedling stage. S2. Sowing: Spring sowing is carried out using a fertilizer-planting machine for mechanical row sowing. Seeds and mixed fertilizer are sown at the same time, with a row spacing of 30cm, a seed sowing rate of 1.5kg / mu, and a sowing depth of 6cm. The seeds are local Ningxia varieties or Minqin fennel varieties; the application rate of the mixed fertilizer is 30 kg / mu; the mixed fertilizer is a compound fertilizer and a microbial fertilizer; the compound fertilizer is a pure potassium sulfate type compound fertilizer with a N:P2O5:K2O mass ratio of 14:16:15 and an application rate of 20 kg / mu; the effective strains in the microbial fertilizer are Bacillus subtilis and Bacillus mucilaginosa, with a beneficial live bacteria count ≥1 billion / gram and organic matter ≥60%, and an application rate of 10 kg / mu.

[0031] S3. Field management, including: Water management: Irrigate 3 times during the entire growth period, with each irrigation volume being 14m³. 3 / mu; During the seedling stage of the entire growth period, when the soil moisture content is 7%~10%, water should be added in time to bring the soil moisture content to a level greater than 10%; Nutrient management: During the pre-flowering and grain-filling stages, spray with a 0.3% potassium dihydrogen phosphate solution at a concentration of 200g / mu. Weed management: Weeds should be completely removed as early as possible during their seedling stage; During the vegetative growth period and critical reproductive growth period of fennel, when the height of the weeds is higher than that of fennel and / or the weed coverage reaches 10%~15%, a low-toxicity herbicide is applied to the stems and leaves of the weeds; the application frequency of the low-toxicity herbicide is 2 times / year; the low-toxicity herbicide is a 5% aqueous solution of quizalofop-P-ethyl, and the 5% aqueous solution of quizalofop-P-ethyl is prepared by mixing 150mL of 5% quizalofop-P-ethyl with 40~50kg of water.

[0032] S4. Pest and disease control: To combat powdery mildew, spray 15% triadimefon at a dilution of 1000 times or 40% flusilazole emulsifiable concentrate at a dilution of 8000 times at the early stage of the disease in fennel. The spraying frequency is once every 7 to 10 days, and 2 to 3 times for each disease outbreak, with 20L / mu per spray each time. For the control of fennel swallowtail butterfly pests, when the larvae of fennel swallowtail butterfly infestation rate in the field reaches 10%~15%, spray with 2.5% deltamethrin at 3000 times dilution or 20% cypermethrin at 2000 times dilution. Aphid control: When the aphid rate in the field reaches 30% to 50% and the number of aphids per plant continues to rise, pesticide spraying should be used for control; the pesticide spraying includes 1000 times diluted imidacloprid or pymetrozine, with each spraying being 20L / acre.

[0033] Finally, the quality and yield of the fennel produced in this embodiment were statistically analyzed, and the results showed that the germination rate was 89.01%, the plant height was 113.58 cm, the ground diameter was 8.13 mm, the number of branches was 12, the number of inflorescences was 71, and the yield was 100.14 kg / mu.

[0034] Example 4 To illustrate the superiority of the planting method of this application, this embodiment adopts the planting method in Example 2, wherein all parameters are consistent except for the sowing depth. Specifically, a comparative study was conducted on the sowing depth. By setting sowing depths of 2cm, 4cm, 6cm, and 8cm, the effects on plant emergence rate, plant height, ground diameter, number of branches, number of inflorescences, and yield were studied to clarify the optimal sowing depth for planting fennel in sandy soil, providing scientific support for the standardized planting of fennel in sandy soil. See Table 1 for details. Table 1: Effects of different sowing depths on plant growth and yield of fennel in sandy soil Table 1 shows that the sowing depth of fennel in sandy soil has different effects on plant growth and yield. The emergence rate of fennel seedlings in different treatments showed the following order: 4cm > 6cm > 2cm > 8cm. The emergence rate was highest at a sowing depth of 4cm, followed by 6cm, with values ​​of 89.67% and 86% respectively, and the difference between the two was not significant (P>0.05). The differences between the 2cm and 8cm sowing depth treatments were also not significant (P>0.05), but the differences between the 2cm and 8cm treatments and the 4cm and 6cm treatments were significant (P<0.05). There were no significant differences in plant height and diameter at ground level among the different treatments (P>0.05). The 4cm and 6cm sowing depth treatments had higher numbers of branches and inflorescences, with no significant differences between the two treatments (P>0.05), but significant differences compared to the other treatments (P<0.05). The yield of fennel under different treatments was as follows: 4cm > 6cm > 2cm > 8cm, consistent with the trend of emergence rate. The yield was highest at a sowing depth of 4cm, followed by 6cm, with values ​​of 101.90 kg / mu and 99.91 kg / mu, respectively. The difference between the two was not significant (P>0.05), but the differences with the others were significant (P>0.05).

[0035] Example 5 This embodiment, to illustrate the superiority of the planting method of this application, specifically adopts the planting method in Embodiment 2, wherein all parameters are the same except for the sowing time. Specifically, by setting different sowing times of March 25th, April 3rd, April 8th, and April 24th, the effects of sowing date on plant emergence rate, plant height, ground diameter, number of branches, number of inflorescences, and yield were studied. The optimal sowing date for fennel in sandy soil was explored, providing scientific support for the standardized planting of fennel in sandy soil. The experimental results are shown in Table 2. Table 2: Effects of different sowing dates on plant growth and yield of fennel in sandy soil Table 2 shows that different sowing dates significantly affected the growth and yield of fennel in sandy soil. The emergence rate, plant height, diameter at root, and yield of fennel under different treatments showed a trend of: April 3rd > April 8th > March 25th > April 24th. Sowing on April 3rd resulted in the highest emergence rate, plant height, diameter at root, and yield, with values ​​of 88.67%, 110.67 cm, 12.33 mm, and 97.11 kg / mu, respectively. These values ​​were 51.13%, 16.91%, 36.54%, and 76.47% higher than those of the April 24th treatment, and all differences were statistically significant (P<0.05). Therefore, fennel sown on April 3rd exhibited better growth and yield advantages, while fennel sown on April 24th showed poorer growth.

[0036] Example 6 This embodiment addresses the problem of insufficient rainfall and water scarcity in sandy soil planting areas of the arid central Ningxia region. Using the planting method described in Example 2, this experiment studies the effects of different irrigation quotas throughout the entire growth period of fennel on plant growth, photosynthetic physiology, and yield. It explores the optimal irrigation amount for fennel growth, providing theoretical support for cost-saving and efficiency-enhancing fennel cultivation in sandy soil. The irrigation quota refers to the total irrigation amount within one year. The experimental results are shown in Table 3. Table 3: Effects of different irrigation quotas on plant growth and yield of fennel in sandy soil Table 3 shows that different irrigation rates for fennel in sandy soil have a significant impact on plant growth and yield. The plant height, diameter at ground level, number of branches, number of inflorescences, and yield of fennel under different treatments all show the following trends: 30m... 3 / mu>40m 3 / mu>20m 3 / mu>0m 3 The trend is per mu (unit of land area). The irrigation quota is 30m³. 3 The highest plant height, ground diameter, number of branches, number of inflorescences, and yield were observed in the control group (107.33 cm, 10.74 mm, 15.00, 70.00, and 88.60 kg / mu), representing increases of 39.39%, 36.82%, 55.12%, 64.05%, and 29.99% respectively compared to the unirrigated treatment. All differences were statistically significant (P < 0.05). The irrigation quota was 40 m³ / mu. 3 / mu of ground diameter, number of inflorescences and yield and irrigation quota of 30m 3 The difference in the value per mu was not significant (P>0.05). Therefore, from the perspective of cost reduction and efficiency improvement, the irrigation quota throughout the entire growth period is 30m³. 3 The treatment method of [amount] / mu (unit of land area) is beneficial to promoting the growth and yield of fennel. Furthermore, to investigate the specific factors leading to the differences in plant growth and yield, the inventors studied the relationship between different irrigation quotas and the plant's photosynthetic physiological indicators. Specific results are shown in Table 4. Table 4: Effects of different irrigation quotas on photosynthetic physiological indicators of Fennel plants in sandy soil Table 4 shows that different irrigation rates for fennel in sandy soil have different effects on the photosynthetic physiological indicators of the plants. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and SPAD value of fennel leaves under different treatments all showed the following differences: 30m 3 / mu>40m 3 / mu>20m 3 / mu>0m 3 The trend is consistent with the trend in the impact on growth indicators and yield. The irrigation quota is 30m.3 The values ​​of Pn, Gs, Ci, and SPAD per mu were the highest, with values ​​of 14.07 μmol·m⁻¹. -2 ·s -1 422.67 μmol·m -2 ·s -1 426.33 μmol·mol -1 The transpiration rates (Tr) of fennel leaves under different treatments were 43.17, which were 50.16%, 95.68%, 36.35%, and 25.75% higher than those under the no-irrigation treatment (lowest value), respectively, and all differences were statistically significant (P<0.05). The transpiration rates (Tr) of fennel leaves under different treatments showed the following: 40m 3 / mu>30m 3 / mu>20m 3 / mu>0m 3 The trend is per mu, with an irrigation quota of 40m. 3 The highest Tr value was observed at 3.60 ± 2.41 mmol / m². -2 ·s -1 Compared with the non-irrigated treatment (2.41 mmol·m -2 ·s -1 The irrigation rate increased by 49.38%, and the difference was statistically significant (P<0.05); the irrigation quota was 30m. 3 The Tr value per mu was the second highest, and it was also consistent with the irrigation quota of 40m. 3 The difference in the value per mu was not significant (P>0.05). Therefore, the irrigation quota is 30m. 3 / mu and 40m 3 Treatment at a rate of / mu has a strong photosynthetic production capacity.

[0037] Example 7 This example evaluates whether planting fennel on sandy soil can improve soil quality degradation caused by long-term cultivation of selenium-rich watermelon. Field samples were taken in August 2025, and the physicochemical properties of the 0-20cm soil layer were tested in both the selenium-rich watermelon cultivation area and the fennel cultivation area. The comparison results are shown in Table 5. Table 5: Effects of Fennel Planting on Soil Physicochemical Properties in Areas Where Selenium-Rich Watermelon Planting Has Been Removed Note: The areas where selenium-rich watermelon cultivation was phased out are those that had been growing selenium-rich watermelon before 2024 and did not plant any crops in 2025; the areas where fennel was grown were those that had been growing selenium-rich watermelon before 2024 and have been growing fennel since 2024.

[0038] Table 5 shows that there are significant differences in the physicochemical properties between the selenium-rich watermelon-exited area and the fennel-growing area (P<0.05). The pH of the selenium-rich watermelon-exited area was 9.00, while the pH decreased slightly after planting fennel, by 0.89%. For the remaining physicochemical properties, the values ​​of the fennel-growing area were higher than those of the selenium-rich watermelon-exited area. The values ​​of soil organic matter, total nitrogen, total phosphorus, total potassium, hydrolyzable nitrogen, available phosphorus, and available potassium increased by 25.66%, 16.67%, 4.55%, 23.54%, 7.85%, 21.73%, and 12.55%, respectively. Therefore, the planting of fennel can improve the physicochemical properties of the soil.

[0039] In addition, to evaluate the quality of fennel from sandy soil in the arid central region of Ningxia, this experiment used distillation extraction and combined gas chromatography-mass spectrometry to detect the essential oil content and the content of the main chemical components of the essential oil in fennel from different origins. The comparison results are shown in Table 6: Table 6: Comparison of main active ingredients in fennel from different origins Table 6 shows that the contents of fennel essential oil and trans-anetinoside in the three producing areas were significantly higher than the contents specified in the pharmacopoeia (essential oil content ≥1.5%, trans-anetinoside content ≥1.4%). The fennel from the sandy soil of Zhongwei had higher contents of both essential oil and trans-anetinoside, at 3.02% (mL / g) and 10.24% respectively, which were 19.37% and 6.89% higher than those from the uncovered fennel of Minqin, respectively, with statistically significant differences (P<0.05). The effective components of uncovered fennel from Haiyuan and Minqin were basically the same, with no significant differences (P>0.05). Therefore, planting fennel in sandy soil can moderately increase its medicinal component content.

[0040] Table 7: Fennel Yield and Economic Benefits in Sandy Soil Note: This data is the yield data of fennel obtained in 2023 using the planting method of Example 2. The economic benefits are calculated based on the market price of fennel of 15 yuan / kg in 2023.

[0041] Table 7 shows that the average yield of fennel in sandy soil can reach 88.35 kg / mu, and the economic benefit can reach 1325.20 yuan / mu.

[0042] It is evident that fennel grown on sandy soil exhibits significant economic and ecological adaptability in the arid central region of Ningxia. From an agricultural production perspective, its average yield reaches 88.35 kg / mu (approximately 11.33 kg / hectare), a particularly valuable figure given the harsh environment of drought, low rainfall, and poor soil. This is primarily due to fennel's status as a drought-resistant and barren-tolerant spice crop. Its well-developed root system and significantly lower water requirements during its growth period compared to conventional crops allow for efficient utilization of limited rainfall and soil nutrients. This, combined with sandy soil cultivation (a unique farming method that uses gravel to reduce water evaporation and inhibit salinity rise), creates an excellent ecological synergy.

[0043] From an economic perspective, based on current market conditions, the average economic benefit per mu (a Chinese unit of area, approximately 0.165 acres) could reach 1325.20 yuan. For the arid central region of Ningxia, a region with a harsh ecological environment, traditional agricultural output is extremely unstable. This level of income constitutes a significant source of cash income for local farmers, making the economic benefits substantial. It not only directly increases land productivity and farmers' income but also promotes the optimization of the planting structure.

[0044] In summary, this planting method, by limiting three core parameters—sowing depth (4-6 cm), sowing time, and irrigation quota—and leveraging the characteristics of the gravel cover layer in sandy soil, has achieved a standardized production system with high germination rates and yields exceeding 88 kg per mu for fennel. This method simultaneously addresses three key technical challenges: efficient water use, restoration of soil physicochemical properties, and improvement of medicinal quality, providing a quantifiable and replicable solution for the ecological restoration and economic transformation of land converted from selenium-rich sandy soil for melon cultivation.

[0045] As described above, the basic principles, main features, and advantages of the present invention have been well described. The above embodiments and specifications are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A method for ecological cultivation of fennel on sandy land converted from cultivated land to sandy soil, characterized in that, Includes the following steps: S1. Site selection and land preparation: Select a plot of land that has been converted from farmland to sandy soil for selenium-rich watermelon cultivation. After the harvest of selenium-rich watermelon, deeply plow the sandy soil plot to a depth of 30-40cm, apply base fertilizer, and after the soil thaws in the following spring, harrow and hoe the soil before sowing, and spray weed sealant. The amount of base fertilizer applied is 1000~1500 kg / mu; S2. Sowing: Spring sowing is carried out using a fertilizer-seeding integrated machine for mechanical row sowing, where seeds and mixed fertilizer are sown simultaneously. The seeds are local Ningxia varieties or Minqin fennel varieties; the row spacing for the row sowing operation is 20-30cm, the seed sowing rate is 1.0-1.5kg / mu, the sowing depth is 4-6cm, and the fertilizer application rate is 15-30kg / mu; the fertilizer is a compound fertilizer and microbial fertilizer. S3. Field management, including: Water management: Irrigate 2-3 times throughout the growing season, with each irrigation amount being 10-14 m³. 3 / mu; During the seedling stage of the entire growth period, when the soil moisture content is 7%~10%, water should be added in time to bring the soil moisture content to a level greater than 10%; Nutrient management: During the pre-flowering and grain-filling stages, spray with a 0.3% (w / w) solution of potassium dihydrogen phosphate; Weed management: Weeds should be completely removed as early as possible during their seedling stage; During the vegetative growth period and critical reproductive growth period of fennel, when the height of the weeds is higher than that of fennel and / or the weed coverage reaches 10% to 15%, a low-toxicity herbicide is applied to the stems and leaves of the weeds; the application frequency of the low-toxicity herbicide is 1 to 2 times per year. S4. Pest and disease control: To combat powdery mildew, spray 15% triadimefon at a dilution of 1000 times or 40% flusilazole emulsifiable concentrate at a dilution of 8000 times at the early stage of the disease in fennel. The spraying frequency is once every 7 to 10 days, and 2 to 3 times for each disease outbreak, with 20L / mu per spray each time. For the control of fennel swallowtail butterfly pests, when the larvae of fennel swallowtail butterfly infestation rate in the field reaches 10%~15%, spray with 2.5% deltamethrin at 3000 times dilution or 20% cypermethrin at 2000 times dilution. Aphid control: When the aphid rate in the field reaches 30% to 50% and the number of aphids per plant continues to rise, pesticide spraying should be used for control; the pesticide spraying includes 1000 times diluted imidacloprid or pymetrozine, with each spraying being 20L / acre.

2. The method according to claim 1, characterized in that, The sand-stabilizing thickness of the sand-stabilized plots described in S1 is 10~20cm.

3. The method according to claim 1, characterized in that, The base fertilizer mentioned in S1 is farmyard manure.

4. The method according to claim 1, characterized in that, The "before sowing" mentioned in S1 refers to 5-9 days before sowing.

5. The method according to claim 1, characterized in that, The weed pre-emergence agent mentioned in S1 is 48% trifluralin EC, and the application rate of the 48% trifluralin EC is 100~150 mL / mu.

6. The method according to claim 1, characterized in that, The compound fertilizer described in S2 is a pure potassium sulfate type compound fertilizer with an N:P ratio of [missing information]. The mass ratio of 2O5 to K2O is 14:16:15, and the application rate is 10~20 kg / mu; the effective strains in the microbial fertilizer are Bacillus subtilis and Bacillus mucilaginosa, with a beneficial live bacteria count ≥1 billion / gram and organic matter ≥60%, and the application rate is 5~10 kg / mu.

7. The method according to claim 1, characterized in that, The application rate of potassium dihydrogen phosphate in S3 nutrient management is 200g / mu.

8. The method according to claim 1, characterized in that, The low-toxicity herbicide mentioned in S3 for weed management is a 5% aqueous solution of quizalofop-P-ethyl. The preparation method of the 5% quizalofop-P-ethyl aqueous solution is as follows: mix 100-150 mL of 5% quizalofop-P-ethyl with 40-50 kg of water.

9. The application of the planting method according to any one of claims 1 to 8 in improving the physical and chemical properties of soil.

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