Annual intercropping green manure planting method suitable for orchards in plateau regions

Abstract

The invention provides an annual intercropping green manure planting method suitable for orchards in plateau areas. According to the method, tartary buckwheat and vicia villosa are mainly adopted as green manure plants, and a plurality of key steps of land parcel selection, soil preparation before sowing, variety selection, seed treatment, green manure sowing, plant management, cutting and covering and the like are clearly stipulated. The method can improve the utilization rate of nutrients in the soil, increase the content of organic matters in the soil, improve the soil quality, effectively inhibit growth of weeds between rows and on ridges of the organic apple orchard, reduce the weeding cost, and solve the problem of high labor cost caused by long-term ploughing and weeding of the organic apple orchard in the plateau mountain area of Yunnan province. Excessive dependence on organic fertilizer is effectively relieved, and the method is an annual intercropping mode for comprehensively improving ecological benefits and economic benefits of the orchard.

Description

Technical Field

[0001] The invention relates to the field of green manure planting, and in particular to a planting method of year-round intercropping green manure suitable for orchards in plateau areas. Background Art

[0002] Apples are considered a leading agricultural product both globally and in China. In particular, in the central, northwestern, northeastern and eastern regions of Yunnan, the apple planting area in Yunnan Province has expanded to about 56,000 hectares as of 2021. Although China ranks first in the world in both apple cultivation area and output, the apple industry still faces many challenges. Because of these problems, organic apple production has begun to receive widespread attention. Organic apples can not only ensure the quality and safety of fruits and protect the health of consumers and fruit farmers, but also have a positive role in promoting the ecological environment and the long-term sustainable development of orchards. Although organic orchards around the world have a history of more than a hundred years, organic orchards in China began in the 1990s, and this field has developed rapidly after the 21st century. According to data from 2020, China's organic apple planting area has accounted for 19.2% of the world, but its proportion in China is still 0.85%. The key issues behind this are high labor costs, especially those related to weeding, as well as the high price of organic fertilizers and the production challenges brought about by the special soil characteristics of the Yunnan plateau and mountainous areas.

[0003] In the management of organic orchards, intercropping green manure between rows has been proven to be an effective soil management strategy. Its main advantages are: increasing the organic matter content of the soil and enhancing the soil's buffering capacity; reducing dependence on organic fertilizers and farmyard manure, effectively improving soil structure, promoting the reproduction of beneficial microorganisms and earthworms, and further forming a good soil aggregate structure. In addition, the cultivation of green manure can also effectively suppress weeds, thereby reducing the labor and cost of weeding, which is particularly critical in organic production because chemical herbicides are prohibited in organic agriculture. Green manure can also stabilize soil temperature, reduce temperature fluctuations, promote the healthy growth and nutrient absorption of fruit tree roots, and reduce the risk of frost damage. In addition, green manure can help soil water infiltration and improve soil drainage capacity through its root system. At the same time, it can also reduce water evaporation in the dry season, thereby enhancing the drought resistance of the orchard. The production mode of planting green manure between rows in organic orchards is of great significance to the establishment of a healthy and stable orchard ecological environment. At the same time, it can effectively reduce production costs and improve the economic benefits of orchards.

[0004] In the mountainous areas of Yunnan Plateau, many organic orchards still tend to use the traditional whole-garden clear-tilling method to manage the soil, which leads to a decrease in soil organic matter content, resulting in low soil fertility in the orchard. This means that the yield and benefits of the orchard mainly rely on the supply of organic fertilizers. At the same time, organic orchards that have adopted inter-row green manure still face limitations in planting patterns, mainly because the current planting strategies have not been deeply studied and promoted for different grass species and the unique geographical and climatic characteristics of the Yunnan Plateau Mountainous Area. Therefore, it is necessary to study and promote the green manure planting model of organic orchards adapted to the Yunnan Plateau Mountainous Area. Summary of the invention

[0005] The purpose of the invention is to provide a planting method of green manure intercropping suitable for orchards in plateau areas throughout the year.

[0006] In order to achieve the purpose of the present invention, a method for planting green manure in year-round intercropping in orchards in plateau areas is provided. The year-round intercropping mode is adopted to carry out rotary tillage and alternate planting of buckwheat and glossy vetch between rows in orchards in plateau areas to realize green manure covering and returning the fields.

[0007] Specifically, the model is to sow glossy vetch in autumn, mow and cover the crops before the following spring, and sow bitter buckwheat, mow and cover the crops before the following autumn, thereby achieving year-round green coverage of the orchard.

[0008] Furthermore, before planting buckwheat and vetch, the soil between the orchard rows should be loosened by rotary tillage to a depth of 20cm-30cm, and then properly leveled and debris in the soil should be removed.

[0009] Furthermore, before sowing, remove shriveled seeds, immature light-colored seeds, and damaged, moldy or germinated seeds; select mature and full-grained glossy vetch and buckwheat seeds of the current year, and expose them to the sun for 2-3 days; the day before sowing, soak the seeds in 40-50℃ warm water for 20 minutes to help promote seed germination.

[0010] Furthermore, sow glossy vetch in late July to early August, and mow for the first time when the grass layer reaches 40-50cm in height and has not yet bloomed. The second mowing is done in March of the following year. After mowing, cover the fruit tree tray and around the drip line with green manure, with a thickness of 20-30cm. To prevent rodent damage in autumn, winter and early spring, it is necessary to ensure that there is at least a 10cm gap between the cover and the tree trunk.

[0011] Furthermore, sow buckwheat in mid-to-late April of the following year. Before sowing, crush and turn over the stubble of glossy vetch with a rotary tiller at a depth of 20-30cm. Sow buckwheat in rows or by broadcasting at a depth of 2-3cm. Cover with 1-2cm of soil after sowing and compact it to maintain soil moisture. Mow when more than 70% of the buckwheat grains turn from green to light brown. After mowing, cover the fruit tree with green manure around the tree tray and the drip line of the fruit tree with a covering thickness of 20-30cm, and ensure that there is at least a 10cm gap between the covering and the tree trunk.

[0012] Furthermore, for glossy vetch: the first mowing is carried out when the glossy vetch is 40-50 cm tall and has not yet bloomed, leaving 8-10 cm of stubble; in March of the following year, mowing is carried out again when the glossy vetch has bloomed 90%.

[0013] Furthermore, the sowing rates of Vetch and Buckwheat are as follows: Broadcasting of glossy vetch: about 4 kg per mu; Buckwheat sowing: about 3.5kg per mu.

[0014] Furthermore, the distance between the edge of the rotary tillage belt and the drip line of the fruit tree is as follows: A. For young or dwarfed orchards, the value is 10-20 cm. B. For mature orchards, the distance should be at least 20 cm or more.

[0015] Preferably, the plateau area is the Yunnan plateau area.

[0016] Preferably, the orchard is an organic apple orchard.

[0017] Preferably, the glossy-leaf vetch is glossy-leaf purple vetch.

[0018] In a specific embodiment of the present invention, the present invention provides a method for cultivating green manure for year-round intercropping in organic apple orchards in the Yunnan plateau region, comprising the following steps: (1) Site selection: Choose a flat site with a small slope, loose soil and good air permeability; avoid choosing a steep, low-lying site prone to waterlogging or with compacted soil; (2) Land preparation before sowing: Use rotary tillers and other equipment to loosen the soil between rows in the orchard. The soil should be 20-30 cm deep. Then, level the soil appropriately and remove debris from the soil. (3) Variety selection: The varieties of glossy-leafed purple vetch that match the climatic conditions of Yunnan Province are selected, including glossy-leafed vetch 74-2, 75-13, and 79-13; the medium-short-stemmed buckwheat varieties that are resistant to lodging, with a plant height not exceeding 120 cm and adapted to the local climate are selected, including Zhaoku No. 1 and Yunqiao No. 2; (4) Seed treatment: Before sowing, first remove shriveled seeds, immature light-colored seeds, and seeds that are damaged, moldy, or have already germinated; select mature, plump, and smooth-leaved vetch and buckwheat seeds of the current year, and expose them to the sun for 2-3 days; soak the seeds in 40-50℃ warm water for 20 minutes the day before sowing to help promote seed germination; (5) Autumn sowing of glossy purple vetch: sowing in late July to early August. Use a rotary tiller to crush and press the stubble of the previous crop before sowing. The rotary tillage depth is 20-30 cm and the sowing depth is 1-2 cm. (6) Management of glossy purple vetch: within 7-10 days after sowing, check the seedlings and replant according to the lack of seedlings. 10-15 days after the emergence of seedlings, carry out inter-row cultivation and weeding according to the growth of weeds until the vetch completely covers the surface. During the management period, no fertilizer is applied. (7) Mowing of glossy purple vetch: The first mowing is done when the grass layer reaches 40cm-50cm in height and it has not yet bloomed; the second mowing is done in March of the following year. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree with a thickness of 20-30cm. To prevent rodent damage in autumn, winter and early spring, it is necessary to ensure that there is at least a 10cm gap between the cover and the tree trunk to prevent rodents from building nests under the cover and causing damage to the tree trunk. (8) Spring sowing of buckwheat: In mid-to-late April, use a rotary tiller to crush and press the stubble of glossy purple vetch before sowing. The rotary tillage depth is 20-30 cm. Use row sowing or broadcast sowing methods. The sowing depth is 2-3 cm. After sowing, cover the soil with 1-2 cm and compact it to maintain soil moisture. (9) Management of buckwheat: Check the emergence of seedlings within 7-10 days after sowing, and replant any missing seedlings in time. During the seedling stage, irrigate appropriately according to the soil moisture conditions. During the management period, do not apply any fertilizers. (10) Buckwheat mowing: Mowing should be carried out when more than 70% of the buckwheat grains turn from green to light brown. After mowing, the green manure should be evenly covered around the tree circle and the drip line of the fruit tree with a thickness of 20-30 cm. To prevent the lower part of the tree trunk from being buried by the green manure, thereby providing shade for diseases, insects and rodents, it is necessary to ensure that there is at least a 10 cm gap between the covering material and the tree trunk.

[0019] The present invention selects glossy purple flower vetch as autumn sowing green manure, and bitter buckwheat is selected as spring sowing green manure to achieve year-round green coverage between rows of apple trees. First, these two green manure crops have no symbiotic diseases and pests with apple trees during their entire growth period, which provides basic conditions for implementing year-round green coverage between rows of apple orchards. Secondly, the basis of the green manure selected by the present invention is their respective growth characteristics. Glossy purple flower vetch likes cold, cool and moist, is suitable for planting in mountainous areas, and is resistant to barrenness, drought, shade, cold, and has good wintering properties. Glossy purple flower vetch not only has good covering effect, large biomass, rich nutrients, but also can be mowed multiple times. As a leguminous nectar plant, it can enhance the diversity of the organic orchard ecosystem, form a relatively stable ecosystem, and thus reduce the risk of diseases and pests in the organic orchard. Relatively speaking, bitter buckwheat is a thermophilic crop, and its seeds can germinate rapidly within 4-5 days at a suitable temperature of 16-20°C. The optimum temperature for flowering is 24-26℃. Buckwheat has the characteristics of short emergence time, fast seedling growth, large biomass, moderate growth period, drought resistance, barrenness resistance, and dense planting resistance, and can achieve excellent inter-row weed control. The climate characteristics of the Yunnan plateau in spring are highly consistent with the climate and temperature requirements of buckwheat during its growth period.

[0020] By means of the above technical solution, the present invention has at least the following advantages and beneficial effects: (I) Improvement of soil nutrients and structure: Using Vetch and Tartary Buckwheat as green manure can effectively improve the utilization rate of soil nutrients, increase the content of soil organic matter, and enhance its buffering capacity. At the same time, the increased input of soil organic matter can reduce the external input of organic fertilizer and farmyard manure, reduce production costs, and is conducive to the reproduction of beneficial microorganisms such as earthworms, further promoting the formation of soil aggregate structure.

[0021] (ii) Inhibition of weed growth: In organic orchards, the use of chemical herbicides is prohibited. Covering the rows with green manure throughout the year can effectively inhibit weed growth, and covering the apple tree tray after mowing can not only further inhibit weeds on the ridges, but also reduce water evaporation from the apple trees, playing a role in heat preservation and moisture retention. This method can not only reduce the labor cost of weeding between rows, but also effectively reduce the damage to the orchard's integrated water and fertilizer fertilization pipeline caused by misoperation when manually using a backpack weeder to weed on the ridges.

[0022] (III) Regulation of soil temperature and moisture: Planting and covering green manure can stabilize soil temperature, reduce the temperature difference between day and night, and is beneficial to the growth of fruit tree roots and nutrient absorption. In addition, green manure vegetation can promote water infiltration through its root channels, improve the soil's drainage capacity, and reduce water evaporation during droughts, thereby enhancing the orchard's drought resistance.

[0023] (IV) Other functional characteristics of green manure: After buckwheat seeds are formed, not only are the plants rich in nutrients, but they can also attract birds to peck at them, reducing the frequency of birds pecking at apples in the orchard, which provides an additional ecological protection measure for organic orchards. DETAILED DESCRIPTION

[0024] The present invention optimizes and innovates the existing green manure planting technology for organic apple orchards in the mountainous areas of the Yunnan Plateau, aiming to provide an annual intercropping model that integrates ecological and economic benefits for organic orchards. This model increases the amount of green manure crops returned to the field throughout the year, improves the organic matter content in the soil, and reduces the input of organic fertilizer by sowing glossy purple flower vetch in autumn and sowing tartary buckwheat in spring. At the same time, the orchard is covered with green throughout the year, thereby effectively controlling the growth of weeds in the organic orchard, and solving the problem of high manual weeding costs caused by long-term clearing and weeding in existing organic apple orchards in the mountainous areas of the Yunnan Plateau.

[0025] The present invention adopts the following technical solution: The present invention provides a method for cultivating green manure by intercropping in an organic apple orchard in the Yunnan plateau region throughout the year, comprising the following steps: 1. Site selection: Choose a flat site with a small slope, loose soil and good air permeability. Avoid choosing steep, low-lying sites that are prone to waterlogging or have compacted soil.

[0026] 2. Land preparation before sowing: Use mechanical equipment such as rotary tillers to loosen the soil between rows in the orchard. For orchards that are in the young stage or use dwarfing and dense planting technology, the total root system is small, shallowly distributed, and mainly composed of fibrous roots, and the root absorption capacity is relatively weak. Therefore, the distance between the edge of the rotary tillage belt and the drip line of the fruit tree should be controlled at 10-20cm. As the fruit trees transition from the young stage to the mature stage, their root systems gradually expand and the total root volume increases. The distance between the rotary tillage belt and the drip line of the fruit tree should be adjusted in time to 20cm or more to avoid competition between the green manure between the rows and the fruit trees for water and fertilizer. The depth of rotary tillage is controlled at 20cm to 30cm. After rotary tillage, the land should be properly leveled, and large stones, branches and other debris in the soil should be manually removed.

[0027] 3. Variety selection: Choose varieties that match the climate conditions of the province, such as Guangye Tiao 74-2, 75-13, and 79-13. Considering that the suitable apple planting areas in Yunnan Province are all high-altitude mountainous areas, with an altitude of 1900-2300m and strong winds, choose medium-short-stemmed buckwheat varieties that are resistant to lodging, with a plant height of no more than 120cm, and can adapt to local climatic conditions to reduce lodging during the filling period, such as Zhaoku No. 1 and Yunqiao No. 2.

[0028] 4. Seed treatment: Before sowing, first remove the shriveled seeds, immature light-colored seeds, and damaged, moldy or germinated seeds. Select the mature and full-grained glossy vetch and bitter buckwheat seeds of the current year, and expose them to the sun for 2-3 days. Soak the seeds in 40-50℃ warm water for 20 minutes the day before sowing to help improve the germination rate of the seeds.

[0029] 5. Autumn sowing of glossy-leaved purple vetch: Sowing should be carried out from late July to early August. Before sowing, the residues of the previous crop should be crushed and pressed with a rotary tiller. Sowing should be carried out while the moisture is moist after the rain. The sowing method is broadcasting. The sowing depth is controlled at 1cm-2cm. After sowing, cover with 1-2cm of soil. The suitable sowing amount per mu is about 4kg.

[0030] 6. Management of glossy purple vetch: The Yunnan Plateau is still in the rainy season from July to August. When there is heavy rain or high soil moisture after sowing, the soil is prone to compaction. The topsoil needs to be loosened to facilitate emergence. 7-10 days after sowing, check and replant according to the seedling conditions to avoid block seedling shortages. Vetch grows slowly in the seedling stage and is easily harmed by weeds. When the seedlings emerge 10-15 days later, the first intertillage and weeding are carried out, and then intertillage and weeding are carried out again according to the growth of weeds until the vetch covers the surface. Vetch is drought-tolerant and afraid of waterlogging. In case of heavy rain, drainage ditches need to be dug outside the drip line of the fruit trees. The depth of the ditch should be lower than the main distribution layer of the fruit tree root system. No fertilizer is applied during the management period.

[0031] 7. Autumn sowing green manure mowing: When the natural height of the grass layer reaches 40cm-50cm and it has not yet bloomed, the first mowing is carried out, leaving a stubble height of about 8cm-10cm. At this time, the sweet potato is in the budding stage and has a strong regeneration ability. The first mowing should be completed before the arrival of frost in early November to ensure that its regeneration and wintering are not affected. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree, with a covering thickness of 20-30cm. In March of the following year, when 90% of the sweet potato blooms and begins to pod, it can be mowed again. At this time, the sweet potato is in full bloom and the biomass reaches its maximum. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree again, with the same covering thickness of 20-30cm, which can effectively inhibit the growth of weeds on the apple tree ridges. To prevent rodent infestations in autumn, winter and early spring, ensure that there is at least a 10cm gap between the mulch and the tree trunk to prevent rodents from building nests under the mulch and causing damage to the tree trunk.

[0032] 8. Spring sowing of buckwheat: In mid-to-late April, use a rotary tiller to crush and turn over the residues of glossy purple vetch before sowing. The tillage depth is 20-30cm. Sow in moist soil after rainfall. Use row sowing or broadcast sowing. The row spacing is 25cm-30cm and the sowing depth is 2cm-3cm. Cover with 1-2cm of soil after sowing and compact it to maintain soil moisture. The sowing amount per mu is about 3kg. The sowing amount should be appropriately increased for broadcast sowing, about 3.5kg per mu.

[0033] 9. Buckwheat management: 7-10 days after sowing, check the emergence of seedlings. If there are any seedling shortages, replant them in time to avoid block shortages. During the seedling stage of buckwheat, irrigate appropriately according to the soil moisture to keep the soil moist and ensure the normal growth of the crop. During other periods, irrigate normally according to the actual water requirement of the apple tree. From the seedling stage of buckwheat to mowing and returning to the field, there is no need to apply fertilizer separately or to cultivate and weed. For plots with too many weeds, especially perennial and malignant weeds, the sowing density of buckwheat can be appropriately increased, but the planting density should not exceed 80,000 plants / mu. No fertilizer should be applied during the management period.

[0034] 10. Spring sowing green manure mowing: When more than 70% of the bitter buckwheat grains turn from green to light brown, the bitter buckwheat is in the late stage of filling and the biomass reaches the maximum, and it can be mowed. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree, with a thickness of 20-30cm. In order to prevent the lower part of the tree trunk from being buried by the green manure, thereby providing shade conditions for pests and diseases, it is necessary to ensure that there is at least a 10cm gap between the covering and the tree trunk.

[0035] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0036] Example 1 A method for growing green manure as an intercrop for organic apple orchards in the Yunnan plateau The operation site of this embodiment is: Heshi Lanmao Apple Manor in Shilin Yi Autonomous County, Yunnan Province, which has obtained organic certification. The specific steps are as follows: (1) Plot selection: On July 10, 2022, a plot survey was conducted at Lanmao Apple Farm. Taking into account the terrain, soil quality and other factors, we selected a plot with a small slope, loose soil and good air permeability. The apple variety planted on this plot is "Qincui", using dwarfing and dense planting technology, the rootstock is M26, the tree shape is free spindle, the tree age is 5 years at the beginning of the experiment, the row spacing is 5 meters, the plant spacing is 1.2 meters, and the tree vigor is similar.

[0037] (2) Land preparation before sowing: On August 8, 2022, use mechanical equipment such as rotary tillers to loosen the soil between the rows of the orchard, ensuring that the tillage depth is within the range of 20cm-30cm. At the same time, pay attention to the fact that the tillage area must be more than 20cm away from the drip line of the fruit trees. After rotary tillage, the land should be properly leveled and large stones, branches and other debris in the soil should be manually removed.

[0038] (3) Variety selection: The medium-short-stemmed buckwheat variety from Guishan Town, Shilin, is selected. It has strong resistance to lodging and a plant height of no more than 120 cm. The light-leaf vetch is selected from the excellent variety bred by the Yunnan Academy of Agricultural Sciences: Light-leaf vetch 79-13.

[0039] (4) Seed treatment: To ensure seed quality and growth effect, before sowing, initially screen out shriveled seeds, immature light-colored seeds, and damaged, moldy or germinated seeds. Select glossy vetch and bitter buckwheat seeds with high maturity and full grains of the year, and expose them to the sun for 2-3 days. Soaking the seeds in 40-50℃ warm water for 20 minutes the day before sowing will help improve the germination rate of the seeds.

[0040] (5) Autumn sowing of glossy-leaved purple vetch: On August 17, 2022, wait for rainfall at the base and sow according to the soil moisture conditions. The sowing method is broadcasting with a sowing depth of 1cm-2cm. Cover with 1-2cm of soil after sowing. The sowing amount per mu is about 4 kg.

[0041] (6) Management of Vetch: On August 20, 2022, the base was in the rainy season. The weather was sunny during the day, but it rained occasionally at night, which made the soil easy to become compacted. In order to promote the smooth emergence of the vetch seedlings, the topsoil was loosened manually with a hoe. On August 26, a careful inspection was carried out based on the seedling conditions, and the plots without seedlings were replanted. The number of replants was within 10% of the total sowing amount. The first intertillage and weeding was carried out on August 31, and some tall grasses and other malignant weeds were manually removed. Another intertillage and weeding was carried out on September 15. The Vetch had formed runners that could effectively cover the surface. No fertilizer was applied during the entire management period.

[0042] The maximum fresh weight yield of glossy purple vetch after two mowings is 765kg / mu, the average fresh grass yield is 752kg / mu, the average hay yield is 113kg / mu, and the nutrient content of hay plants is N 5.63%, P2O50.51%, and K2O 3.86%. 113kg of glossy purple vetch hay can provide N 6.36kg, P2O50.6kg, and K2O 4.35kg.

[0043] (7) Autumn-sown green manure mowing: On November 13, 2022, when the natural height of the grass layer reaches 40cm-50cm and it has not yet bloomed, the first mowing is carried out, leaving a stubble height of 8cm-10cm. At this time, the glossy purple flower vetch is in the budding stage, its biomass is relatively rich, and it has strong regeneration ability. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree, with a covering thickness of 20-30cm. On March 22, 2023, when it is observed that about 90% of the vetch has entered the flowering stage and started to pod, mow again. At this time, the vetch is in full bloom and the biomass reaches the maximum. Similarly, after mowing, the obtained fresh grass is evenly covered around the tree tray and the drip line of the fruit tree, with a covering thickness of 20-30cm, which can effectively inhibit the growth of weeds on the apple tree ridges. To prevent rodent infestations in autumn, winter and early spring, ensure that there is at least a 10cm gap between the mulch and the tree trunk to prevent rodents from building nests under the mulch and causing damage to the tree trunk.

[0044] (8) Spring sowing of buckwheat: Due to the drought in Shilin area, the spring sowing time of green manure is postponed to May 10, 2023. Before sowing, the stubble of glossy purple vetch should be crushed and turned with a rotary tiller to ensure that the tillage depth is between 20-30 cm. Sowing should be done after rainfall while the soil is moist. The sowing method is broadcast sowing with a sowing depth of 2 cm-3 cm. After sowing, the soil should be covered with soil with a thickness of about 1-2 cm and then compacted to maintain soil moisture. The sowing amount per mu is about 3.5 kg.

[0045] (9) Buckwheat management: On May 20, 2023, the emergence of seedlings was checked. Due to the low rainfall in the entire Shilin area and the lack of irrigation conditions, the emergence of seedlings was uneven. On May 26, targeted seedling replenishment was carried out on the plots lacking seedlings. The amount of seedling replenishment was about 30% of the original sowing amount. No fertilizer was applied during the entire management period.

[0046] (10) Spring sowing and mowing of green manure: Due to drought, the grain filling period of buckwheat was delayed. On August 18, 2023, when more than 70% of the grains turned from green to light brown, that is, buckwheat was in the late grain filling period and the biomass reached the maximum, mowing was carried out. After mowing, the green manure was evenly covered around the tree circle and the drip line of the fruit tree, with a thickness of 20-30 cm. In order to prevent the lower part of the tree trunk from being buried by the green manure, thereby providing shade conditions for pests and diseases, it is necessary to ensure that there is at least a 10 cm gap between the covering and the tree trunk. This time, the maximum fresh weight yield of bitter buckwheat was 1067kg / mu, the average fresh grass yield was 1045kg / mu, the average hay yield was 295kg / mu, and the plant nutrient content in the hay was N 2.17%, P2O50.32%, K2O 2.30%, 295kg, bitter buckwheat hay can provide N 7kg, P2O50.93kg, K2O 6.9kg. In summary, the annual intercropping pattern of apple intercropping with glossy purple vetch (autumn sowing)-buckwheat (spring sowing) can return about 13.36kg / mu of nitrogen nutrients, 1.53kg / mu of phosphorus nutrients, and 11.25kg / mu of potassium nutrients to the field throughout the year.

[0047] Test example At present, most organic apple orchards in the mountainous areas of Yunnan Plateau are generally faced with problems such as low soil organic matter, high cost of organic fertilizer input, and insufficient soil nutrient supply. In addition, the continuous application of traditional tillage management methods has further aggravated the reduction of soil organic matter and nutrient loss. Green manure intercropping, as an effective soil management measure, can not only increase soil nutrients, but also reduce the use of organic fertilizers and the cost of manual weeding. In view of the unique natural conditions and rich biodiversity in the mountainous areas of Yunnan Plateau, there are many kinds of weeds with strong growth competitiveness, such as Bidens pilosa, Imperata cylindrica, and Digitaria sanguinea. In this experiment, nine green manure crops, including buckwheat, arrow pea, glossy vetch, soybean, green rye, astragalus, motherwort, February orchid, and bahia grass, were selected for adaptability screening. Through trial sowing and screening, it was found that the coverage of buckwheat, arrow pea, glossy vetch, and soybean exceeded 50%, and they showed strong competitiveness compared with natural grass and malignant weeds. Therefore, this experiment selected these four green manure crops for intercropping with apples. The specific plan is as follows: 1. Apple intercropping with glossy vetch (autumn sowing) and bitter buckwheat (spring sowing) is Example 1; 2. Apple intercropping with pea (autumn sowing) and buckwheat (spring sowing); 3. Apple intercropping with buckwheat (autumn sowing) - buckwheat (spring sowing); 4. Apple intercropping with soybeans (autumn sowing) - soybeans (spring sowing); 5. Natural grass growth between rows and clear tillage management were both used as control groups.

[0048] Among them, natural weed treatment: fine wild weeds are allowed to grow naturally between rows, and malignant weeds are removed manually. Clear tillage management: there is no cover between rows, and weeds in the orchard are completely removed manually. All intercropping treatments are sown manually. Among them, buckwheat, glossy vetch, and arrow pea are sown by broadcasting. The sowing rate of buckwheat per mu is 3.5kg, glossy vetch is 4kg, and arrow pea is 5kg. The sowing depth is 1-2cm. Soybeans are sown in holes, with a row spacing of 30cm and a plant spacing of 25cm. 3-4 seeds are sown in each hole, and the sowing depth is 5cm. The autumn green manure was sown on August 17, 2022. After the emergence of glossy vetch, arrow pea and soybean, manual weeding was carried out once to remove malignant weeds to establish the advantage of the seedling stage. On November 13, 2022, the autumn green manure and natural grass were mowed before wintering and covered in tree trays. The glossy vetch and arrow pea were left with a stubble of about 8-10 cm to ensure their regeneration ability. On March 22 of the following year, the glossy vetch and arrow pea were mowed for the second time and covered in tree trays. The sowing time of spring green manure was May 10, 2023. On August 18, the spring green manure and natural grass were mowed and covered in tree trays. No irrigation and fertilization measures were taken for each treatment during the experiment. Intercropping and grass treatment: The mowed plants should be evenly covered around the drip line of the fruit trees, more than 10 cm away from the trunk, with a covering thickness of 20-30 cm.

[0049] Example 1 was tested with other intercropping patterns and a control pattern. The results are shown in Tables 1 to 4.

[0050] The soil fertility index data of 0-20cm soil in tree trays of annual intercropping of Vetch and Tartary Buckwheat with other model fruit trees are shown in Table 1, and the data of apple yield and quality indexes are shown in Table 2.

[0051] Table 1 Soil fertility index Note: T1: before returning green manure to the field; T2: apple flowering period; T3: apple ripening period.

[0052] Table 2 Apple yield and quality indicators

[0053] In this experimental case, the annual intercropping of Vetch glabra and Tartary buckwheat had a significant positive effect on soil fertility and apple quality compared with other patterns. First, in terms of soil fertility, the intercropping treatment significantly increased the content of organic matter, total nitrogen, available phosphorus and available potassium in the surface soil of the tree circle during the apple flowering period (T2 period), indicating that the green manure return to the field can effectively improve soil fertility through this planting method. As the apple fruit expands and matures, the demand for nutrients by the fruit tree increases significantly, resulting in a large amount of nutrients being consumed. This explains why some soil fertility indicators decline during the maturity period (T3 period). Even during the apple maturity period (T3 period), the consumption of soil available nutrients in the 0-20cm soil layer was significantly reduced by returning the green manure to the field compared with the clear tillage treatment. This shows that returning green manure to the field has a positive effect on supplementing the nutrient consumption during the apple growth period.

[0054] In terms of apple yield and quality, the year-round intercropping of glossy purple vetch and bitter buckwheat showed significant growth in 2023 compared to 2022. The yield increased from 564.58kg / mu to 621.24kg / mu, far exceeding the slight increase in the clean-till orchard during the same period. In addition, the quality indicators of intercropped apples, such as soluble solids, soluble sugars and titratable acid, were improved, showing the positive effect of intercropping on improving apple quality. This implementation case shows that the intercropping pattern of glossy purple vetch and bitter buckwheat not only significantly increased the yield of the orchard, but also improved the overall quality of apples. This finding provides strong evidence for the practical value of the present invention in improving agricultural production efficiency and fruit quality.

[0055] The planting cost data of Example 1 and other intercropping patterns and controls are shown in Table 3.

[0056] Table 3 Cost accounting table

[0057] The planting costs of each intercropping pattern are calculated, including: 1. Seed cost: According to the local market pricing, the unit price of seeds is as follows: 8 yuan / kg for buckwheat, 14 yuan / kg for glossy vetch, 24 yuan / kg for peas, and 8 yuan / kg for soybeans. The seed cost of each treatment was calculated based on the sowing amount of each crop (3.5 kg of sowing per mu for buckwheat, 4 kg of sowing per mu for glossy vetch, 5 kg of peas, and 4 kg of sowing per mu for soybeans).

[0058] 2. Pre-sowing land preparation cost: A rotary tiller is used for pre-sowing land preparation. The daily operating costs of the machine include depreciation, fuel costs and labor wages. Depreciation: The purchase cost of the rotary tiller is 50,000 yuan, which is amortized over a 10-year service life, about 13.7 yuan / day; Fuel costs: The rotary tiller can cultivate 40 mu of orchard every day. Considering that only the inter-row strips are rotary tilled, the actual cultivated area is 20 mu. Each mu of rotary tillage requires 3 liters of fuel. The fuel cost is calculated at 7.6 yuan / liter. 20 mu is cultivated every day, so the daily fuel cost is 456 yuan; Labor costs: A worker who is skilled in operating a rotary tiller has a daily wage of 150 yuan. Therefore, the daily cost of rotary tillage is 456+150+13.7=619.7 yuan, which is about 619.7 / 40=15.49 yuan per mu of orchard on average.

[0059] 3. Cost of sowing, weeding and mowing: Manual sowing costs 120 yuan / day, calculated based on 6 mu per day, that is, 20 yuan / mu, and manual weeding costs are calculated based on 1 mu per day, 120 yuan / mu. The purchase price of the mowing machine is 2,000 yuan, with an expected service life of 5 years and a daily depreciation of 1.10 yuan. A worker can handle 2 mu of land per day, mowing for 5 hours and returning to the field for 3 hours, fuel costs 60.8 yuan, labor costs 120 yuan, and the total cost is 181.9 yuan, averaging 90.95 yuan per mu.

[0060] The economic benefits of year-round intercropping of Vetch and Tartary Buckwheat compared with other patterns are shown in Table 4.

[0061] Table 4 Economic Benefit Analysis

[0062] Year-round intercropping of Vetch and Tartary Buckwheat has a significant benefit in increasing income compared to traditional clear-till orchards. As the number of years of intercropping green manure crops increases, the coverage of green manure crops and their competitive relationship with weeds can effectively inhibit the germination and growth of weeds, gradually reduce the number of weed seed banks in the soil, and control the growth and spread of malignant weeds from the source. In addition, as the number of years of green manure planting increases, the cost of planting can be reduced by collecting seeds by oneself or using existing seed resources in the soil. Long-term green manure return to the field can provide a continuous supply of nutrients to the soil, which has a potential positive impact on increasing apple yields and improving fruit quality, thus further demonstrating the economic benefits of intercropping green manure crops.

[0063] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for planting green manures in year-round intercropping in orchards in plateau areas, characterized in that: Adopting the year-round intercropping model, rotary tillage is carried out between the rows of orchards in the plateau area to alternately plant buckwheat and glossy vetch, so as to realize the green manure mulching and returning to the fields; Specifically, the model is to sow glossy vetch in autumn, mow and cover the crops before the following spring, and sow bitter buckwheat, mow and cover the crops before the following autumn, thereby achieving year-round green coverage of the orchard.

2. The method according to claim 1, characterized in that: Before planting buckwheat and vetch, loosen the soil between the orchard rows by rotary tillage to a depth of 20-30cm, then level the soil appropriately and remove debris from the soil.

3. The method according to claim 1, characterized in that Before sowing, remove shriveled seeds, immature light-colored seeds, and damaged, moldy or germinated seeds; select mature and full-grained glossy vetch and buckwheat seeds of the current year, and expose them to the sun for 2-3 days; the day before sowing, soak the seeds in 40-50℃ warm water for 20 minutes to help promote seed germination.

4. The method according to claim 1, characterized in that: Sow glossy vetch in late July to early August. Carry out the first mowing when the grass layer reaches 40-50cm in height and has not yet bloomed. The second mowing is in March of the following year. After mowing, cover the fruit tree tray and around the drip line of the fruit tree with green manure with a thickness of 20-30cm, and ensure that there is at least 10cm gap between the covering and the tree trunk.

5. The method according to claim 4, characterized in that Buckwheat is sown in mid-to-late April of the following year. Before sowing, the residues of glossy vetch are crushed and turned with a rotary tiller at a depth of 20-30cm. Buckwheat is sown by row sowing or broadcasting at a depth of 2-3cm. After sowing, 1-2cm of soil is covered and compacted to maintain soil moisture. When more than 70% of the buckwheat grains turn from green to light brown, they are mowed. After mowing, the green manure is covered on the tree tray and around the drip line of the fruit tree with a covering thickness of 20-30cm, and a gap of at least 10cm is ensured between the covering and the tree trunk.

6. The method according to claim 5, characterized in that For glossy vetch: the first mowing should be done when the glossy vetch is 40-50cm tall and has not yet bloomed, leaving 8-10cm of stubble; in March of the following year, mowing should be done again when 90% of the glossy vetch has bloomed.

7. The method according to claim 6, characterized in that The sowing rates of Vetch and Buckwheat are as follows: Broadcasting of glossy vetch: 4 kg per mu; Buckwheat sowing: 3.5kg per mu.

8. The method according to claim 1, characterized in that The distance between the edge of the rotary tillage belt and the drip line of the fruit tree is as follows: A. For young or dwarfed orchards, the value is 10-20cm; B. For mature orchards, the distance should be at least 20 cm or more.

9. The method according to any one of claims 1 to 8, characterized in that: The plateau area is the Yunnan plateau area; The orchard is an organic apple orchard; The glossy-leaf vetch is glossy-leaf purple vetch.

10. A method for cultivating green manure for year-round intercropping in organic apple orchards in the Yunnan plateau region, characterized in that: The following steps are involved: (1) Site selection: Choose a flat site with a small slope, loose soil and good air permeability; (2) Land preparation before sowing: Use a rotary tiller to loosen the soil between the rows of the orchard. The tillage depth should be 20-30 cm. Then, level the soil appropriately and remove debris from the soil. (3) Variety selection: The varieties of glossy-leafed purple vetch that match the climatic conditions of Yunnan Province are selected, including glossy-leafed vetch 74-2, 75-13, and 79-13; the medium-short-stemmed buckwheat varieties that are resistant to lodging, with a plant height not exceeding 120 cm and adapted to the local climate are selected, including Zhaoku No. 1 and Yunqiao No. 2; (4) Seed treatment: Before sowing, first remove shriveled seeds, immature light-colored seeds, and seeds that are damaged, moldy, or have already germinated; select mature, plump, and smooth-leaved vetch and buckwheat seeds of the current year, and expose them to the sun for 2-3 days; soak the seeds in 40-50℃ warm water for 20 minutes the day before sowing to help promote seed germination; (5) Autumn sowing of glossy purple vetch: sowing in late July to early August. Use a rotary tiller to crush and press the stubble of the previous crop before sowing. The rotary tillage depth is 20-30 cm and the sowing depth is 1-2 cm. (6) Management of glossy purple vetch: within 7-10 days after sowing, check the seedlings and replant according to the lack of seedlings. 10-15 days after the emergence of seedlings, carry out inter-row cultivation and weeding according to the growth of weeds until the vetch completely covers the surface. During the management period, no fertilizer is applied. (7) Mowing of glossy purple vetch: The first mowing is done when the grass layer reaches 40cm-50cm in height and it has not yet bloomed; the second mowing is done in March of the following year. After mowing, the green manure is evenly covered around the tree tray and the drip line of the fruit tree with a thickness of 20-30cm, and a gap of at least 10cm is ensured between the covering and the tree trunk. (8) Spring sowing of buckwheat: In mid-to-late April, use a rotary tiller to crush and press the stubble of glossy purple vetch before sowing. The rotary tillage depth is 20-30 cm. Use row sowing or broadcast sowing methods. The sowing depth is 2-3 cm. After sowing, cover the soil with 1-2 cm and compact it to maintain soil moisture. (9) Management of buckwheat: Check the emergence of seedlings within 7-10 days after sowing, and replant any missing seedlings in time. During the seedling stage, irrigate appropriately according to the soil moisture conditions. During the management period, do not apply any fertilizers. (10) Buckwheat mowing: Mowing should be carried out when more than 70% of the buckwheat grains turn from green to light brown. After mowing, the green manure should be evenly spread around the tree circle and the drip line of the fruit tree with a thickness of 20-30 cm, and ensure that there is at least 10 cm gap between the covering and the tree trunk.

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