A High-Efficiency and Stable-Yield Cultivation Method for Tropical Camellia oleifera in Hainan

Abstract

This invention belongs to the field of camellia oleifera cultivation technology and discloses a high-efficiency and stable-yield cultivation method for tropical camellia oleifera in Hainan, aiming to solve problems such as soil erosion, nutrient leaching, high incidence of pests and diseases, and low pollination efficiency in the cultivation of tropical camellia oleifera in Hainan. The method is characterized by: constructing a micro-water-conserving and soil-retaining system; creating a multiclonal spatiotemporal coupled pollination matrix and pollination habitat; implementing precise nutrient management; constructing a dynamic ventilation and photosynthetic framework; and implementing integrated pest management. By adopting the above technical solutions, this invention effectively improves soil and water conservation, nutrient utilization, physiological resistance, pollination efficiency, and yield stability of camellia oleifera.

Description

Technical Field

[0001] This invention belongs to the field of camellia oleifera planting technology, specifically relating to a high-efficiency and stable-yield planting method for tropical camellia oleifera in Hainan. Background Technology

[0002] Camellia oleifera ( Camellia oleifera Camellia oleifera, a unique woody oilseed tree species in my country with significant economic value, plays a crucial role in not only improving regional economic benefits but also ensuring national food and oil security and optimizing the edible oil supply structure. For a long time, my country has developed a relatively mature technical system for the cultivation and management of Camellia oleifera. This system is primarily based on the ecological environment characteristics of my country's traditional Camellia oleifera producing areas, namely subtropical or temperate monsoon climate zones. In these regions, technicians have developed clear procedures for forest land management, water and fertilizer management, tree pruning, and pest and disease control through decades of practical exploration. The core objective is to address the low yield problem under traditional extensive management models by optimizing the utilization efficiency of light, water, and nutrients. Specifically, in water and fertilizer management, this system typically applies fertilizer in stages according to the growth cycles of spring, summer, and autumn shoots to match the mild seasonal growth rhythm. In pruning, conventional methods aimed at improving canopy ventilation and light penetration are mostly adopted to promote fruiting in the inner canopy and reduce the occurrence of common diseases. This technology system has effectively improved the yield of camellia oleifera in specific climate zones, laying a solid foundation for the stable development of the camellia oleifera industry.

[0003] However, with the development of agricultural technology and the diversification of market demand, the suitable growing areas and cultivated varieties of Camellia oleifera are constantly expanding, including Vietnamese Camellia oleifera (Camellia oleifera). Camellia vietnamensisThe introduction of tropical endemic species such as [names of species] into Hainan for large-scale cultivation has become an important direction for exploring new growth points in the camellia oil industry. However, when this technical system, effective in specific climatic zones, is directly applied to the tropical maritime climate of Hainan, a fundamental mismatch arises between its design premises and actual ecological conditions. This exposes its inherent limitations at the theoretical level and gives rise to a more profound technical contradiction. This contradiction is not simply a mismatch in technical aspects, but a chain reaction of negative effects caused by ecological niche mismatch, leading to the failure of synergy among various production and management links. The reason lies in the complex climatic characteristics of Hainan: high temperature and humidity, strong sunlight throughout the year, distinct dry and rainy seasons, and highly concentrated rainfall. This completely overturns the mild environmental basis upon which the traditional technical system relies. For example, conventional slope management methods aimed at water and soil conservation are not only ineffective in curbing soil erosion under the impact of short-duration heavy rainfall during Hainan's rainy season, but may also exacerbate slope erosion due to poor drainage, leading to rapid loss of soil fertility. Furthermore, the traditional phased fertilization model, whose timing and dosage settings are intended to match the mild seasonal growth rhythm, has created a sharp contradiction in tropical regions where the plant's almost year-round continuous nutritional needs and the concentrated nutrient leaching during the rainy season result in extremely low fertilizer utilization. This not only increases production costs but also fails to meet the nutritional needs of camellia trees during critical growth periods (such as flower bud differentiation and fruit enlargement).

[0004] Even more serious is the fact that this chain reaction of negative effects is particularly pronounced at the level of tree management and physiological regulation. While traditional pruning methods aim to allow light penetration, in Hainan's environment of strong sunlight and high humidity, they often lead to a contradictory situation where canopy closure coexists with leaf and branch scorching. On the one hand, the high temperature and humidity easily create a miniature "humidity greenhouse" within the canopy, providing an ideal breeding ground for fungal diseases such as anthracnose and soft rot. The closed canopy created by traditional pruning methods results in a disease incidence and spread rate far exceeding that of subtropical regions. On the other hand, an overemphasis on an open tree shape exposes the outer branches and leaves directly to the tropical sun, making them highly susceptible to sunscald and affecting photosynthetic efficiency. Simultaneously, the sustained high temperatures directly impact the pollination process of camellia oleifera, reducing fruit set. The considerations regarding variety selection and pollination environment in traditional planting techniques have clearly failed to provide effective solutions to this heat stress problem. Therefore, while existing technologies can solve the yield problem in one region, their technological paradigm, when transplanted to a new ecological environment, has instead given rise to a series of new problems that are interconnected and exacerbate each other, such as increased soil erosion, low fertilizer efficiency, high incidence of pests and diseases, and severe physiological stress.

[0005] In summary, the core deficiency of existing camellia oleifera cultivation techniques lies not in technical oversights in a single step, but in a systemic mismatch between its overall technical logic and the unique tropical ecological environment. This mismatch prevents key production factors such as water, soil, fertilizer, light, and heat from achieving efficient synergy, instead causing them to mutually restrict each other and collectively constitute the fundamental technical bottleneck limiting the yield and quality improvement of camellia oleifera in Hainan. Therefore, how to break through the framework of traditional cultivation models and construct a new method for high-efficiency and stable-yield camellia oleifera cultivation that can systematically cope with the complex environmental stresses of high temperature, high humidity, strong sunlight, and seasonal heavy rainfall in Hainan, and achieve multiple objectives such as soil and water conservation, efficient nutrient utilization, tree structure optimization, and improved pollination efficiency, has become a key challenge and an urgent technical problem for those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to overcome the systemic mismatch between existing camellia oleifera cultivation techniques and the tropical marine climate of Hainan, and to provide a multi-objective synergistic method for efficient and stable yield cultivation of tropical camellia oleifera in Hainan that can systematically cope with the complex environmental stresses such as high temperature, high humidity, strong light and seasonal heavy rainfall, and achieve efficient soil and water conservation, precise nutrient supply, optimization of tree structure and photosynthetic efficiency, and synergistic improvement of pollination efficiency and physiological resistance.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0008] A highly efficient and stable-yield cultivation method for tropical camellia oleifera in Hainan includes the following steps:

[0009] S1. Construct a micro-water collection system: On the sloping land, excavate terraced working surfaces with an inward slope of 1 to 3 degrees along the contour lines, and excavate bioretention and interception ditches at the outer edge of the terraced working surfaces. Permeable control dams are set in the bioretention and interception ditches.

[0010] S2. Creating a pollination matrix and habitat for pollinating insects: Select at least nine Camellia oleifera clones with synchronized flowering periods, and adopt a nine-square grid unit layout with the central main variety and surrounding pollinating varieties for staggered planting in a checkerboard pattern to ensure that any plant in the unit is surrounded by at least three different pollinating clones, and plant nectar-source ground cover plants in the biological retention and interception trenches.

[0011] S3. Implement precise nutrient management: Apply base fertilizer containing rhizosphere growth-promoting bacteria at the time of planting, and apply a double-layered controlled-release fertilizer with a water-responsive inner membrane and a temperature and water-responsive outer membrane during the growing season.

[0012] S4. Construct a dynamic ventilation-type three-dimensional photosynthetic framework: Through shaping and pruning, the canopy of the camellia tree is constructed into a three-layer structure from top to bottom, consisting of a top sparse layer, a middle fruiting layer, and a lower ventilation layer.

[0013] S5. Implement integrated pest management: combine physical control, biological control, and precise chemical intervention based on disease incidence or insect population density monitoring thresholds.

[0014] Furthermore, the specific method for constructing the micro-water collection system in S1 is as follows:

[0015] (1) On a selected sunny or semi-sunny slope with an altitude of less than 600 meters, a slope of less than 25 degrees, and a soil pH value between 5.0 and 6.0, the terrace working surface is excavated along the contour line so that the terrace working surface has an inward slope of 1 to 3 degrees.

[0016] (2) At the outer edge of each terrace working surface, the biological retention and interception ditch is excavated along the contour line. The cross-section of the ditch is trapezoidal, with an upper base width of 50 cm, a lower base width of 30 cm, and a depth of 40 cm.

[0017] (3) In the bioretention and interception ditch, a permeable control dam is set every 4 meters along its length, and the topsoil dug out when excavating the planting hole is backfilled in the middle section of the bioretention and interception ditch between two adjacent permeable control dams to form a water retaining wall structure with a height of 20 cm.

[0018] Furthermore, the permeable control dam has a height of 25 centimeters, and its construction material is selected from gravel with a particle size of 5 to 10 centimeters or high-density bamboo.

[0019] Furthermore, the specific method for creating the pollination matrix and pollinating insect habitat in S2 is as follows:

[0020] (1) The flowering synchronization rate among the nine selected Camellia oleifera clonal varieties is greater than or equal to 90%;

[0021] (2) The nine-square grid unit layout is a 3x3 planting unit, with the core main variety planted in the center and eight other pollinating varieties planted in the eight surrounding positions to ensure that any plant in the unit is surrounded by at least three different pollinating clones.

[0022] (3) Arrange the multiple planting units in a checkerboard pattern on the slope.

[0023] Furthermore, among the nine Camellia oleifera clonal varieties, Wanhai Camellia oleifera No. 3 is the core main cultivated variety.

[0024] Furthermore, the nectar source ground cover plant planted in the bioretention and interception ditch is peanut, with a sowing density of 20 grams per square meter. The peanut has the characteristics of being shade-tolerant, tolerant of poor soil, nitrogen-fixing, and having a flowering period that overlaps with that of camellia oleifera.

[0025] Furthermore, the specific methods for implementing precision nutrient management in S3 are as follows:

[0026] (1) At the planting point with a spacing of 4 meters × 3 meters, dig a planting hole with a top diameter of 70 cm, a bottom diameter of 50 cm and a depth of 50 cm;

[0027] (2) When planting, apply 15 kg of fully decomposed farmyard manure, 0.5 kg of superphosphate and 50 g of the rhizosphere growth-promoting bacteria agent as base fertilizer to each hole; the rhizosphere growth-promoting bacteria agent is a compound bacteria agent containing nitrogen-fixing bacteria, phosphorus-solubilizing bacteria and potassium-solubilizing bacteria, and its effective live bacteria count is not less than 2×10^9 CFU / g.

[0028] (3) After backfilling the soil, a mound of soil 15 cm higher than the working surface of the terrace is formed at the planting hole.

[0029] Furthermore, the structure of the double-coated controlled-release fertilizer includes a nutrient core matrix, which is sequentially coated with a moisture-responsive controlled-release inner membrane and a temperature- and moisture-responsive slow-release outer membrane.

[0030] Furthermore, the controlled-release fertilizer is applied once a year before the rainy season in a trench. The fertilizer is applied inside the drip line of the tree canopy, in a circular trench with a depth of 20 cm and a width of 15 cm. 70% of the total annual fertilizer required is applied to the bottom of the trench, and the remaining 30% is applied to the top 10 cm of soil. In addition, different formulations of the controlled-release fertilizer are used for the young tree stage and the fruiting stage: the controlled-release fertilizer applied during the young tree stage has a nitrogen-phosphorus-potassium ratio of 20-10-15; the controlled-release fertilizer applied during the fruiting stage has a nitrogen-phosphorus-potassium ratio of 15-10-20.

[0031] Furthermore, the specific method for constructing the dynamic ventilation-type three-dimensional photosynthesis framework in S4 is as follows:

[0032] (1) Starting from the second year after planting, the main stem height should be maintained at 40 to 50 cm;

[0033] (2) Select 3 to 4 strong branches that are evenly distributed and have an angle of 45 to 55 degrees with the main trunk as primary branches. The primary branches are distributed in a 120-degree spiral staggered upward distribution in space.

[0034] (3) The amount of branches and leaves in each functional layer is precisely controlled so that the top sparse layer retains 30% of the total amount of branches and leaves in the canopy, the middle fruiting layer retains 55% of the total amount of branches and leaves in the canopy, and the lower ventilation layer retains 15% of the total amount of branches and leaves in the canopy.

[0035] Furthermore, the further operations of the shaping and trimming include:

[0036] (1) Pruning should be carried out from November to February of the following year after the harvest. This includes thoroughly removing diseased and insect-infested branches, dead branches, crossing branches, overlapping branches, and drooping overgrown branches.

[0037] (2) Prune the middle fruiting layer to ensure that the distance between adjacent fruiting branches is maintained at more than 30 cm, and retain 8 to 10 strong fruiting branches per square meter of canopy projection area;

[0038] (3) Prune the extension branches of each main branch appropriately to promote the development of lateral fruiting branches.

[0039] Furthermore, the specific methods of integrated pest management in S5 are as follows:

[0040] (1) The physical control measures include: during the peak emergence period of adult tea oil pests, installing and activating solar insecticidal lamps with a wavelength of 365 nanometers at a density of one lamp per 3 hectares at night;

[0041] (2) The biological control includes: for the Camellia tussock moth, hanging pheromone slow-release traps to lure and kill male moths;

[0042] (3) The precise chemical intervention includes: establishing a regular monitoring system, and starting chemical control when the disease incidence rate reaches 5% or the insect population density reaches 5 insects per 100 shoots; for anthracnose, alternately spray with 800 times dilution of 50% carbendazim wettable powder or 1500 times dilution of 10% pyraclostrobin water-dispersible granules; for tea tussock moth larvae, spray with 2500 times dilution of 0.2% abamectin EC or 1500 times dilution of 50% fenitrothion EC; all chemical spraying operations are carried out in the evening or on cloudy days.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) This invention systematically solves the problem of water, soil and fertilizer loss in tropical environments using existing technologies. By constructing a micro-water collection system, short-term heavy rainfall is converted into usable slow-release water resources, and recycled soil nutrients are intercepted in situ. Compared with traditional slope planting methods, the technical method provided by this invention can reduce the slope runoff coefficient by more than 70% and reduce the annual loss of soil nitrogen and phosphorus by more than 65%, providing a solid water and soil foundation for the stable growth of camellia trees.

[0045] (2) Significantly improved nutrient utilization efficiency and input-output ratio. By applying precision nutrient management technology based on root zone environmental regulation, the fertilizer release rate is precisely matched with the tropical climate rhythm and the growth needs of camellia trees, and nutrient absorption is enhanced by utilizing rhizosphere microorganisms. Compared with traditional staged broadcasting or hole application fertilization methods, the nitrogen utilization rate of fertilizers in this invention can be increased from less than 30% under traditional methods to more than 60%, while reducing the amount of chemical fertilizer input by 30% and achieving a significant improvement in the nutritional level of the tree.

[0046] (3) It synergistically alleviates the dual pressure of disease and physiological stress. By constructing a dynamic ventilation-type three-dimensional photosynthetic framework, this invention ensures that the middle of the canopy receives sufficient photosynthetic radiation while effectively reducing the relative humidity inside the canopy, thus reducing the natural incidence of diseases dependent on high humidity environments, such as anthracnose and soft rot, by more than 50%. At the same time, the filtering effect of the top drainage layer on strong light completely avoids sunburn on fruits and leaves, ensuring the health and function of photosynthetic organs.

[0047] (4) Significantly improved pollination success rate and yield stability. By creating a multiclonal spatiotemporally coupled pollination matrix and integrating pollinating insect habitats, this invention effectively addresses the adverse effects of tropical high temperatures on the pollination process. Compared to traditional single or random mixed planting models, this invention can increase the average fruit set rate of Camellia oleifera by 40% to 55%, and the yield fluctuation is less than 10% during periods of continuous high temperatures, demonstrating extremely high yield stability. Finally, considering all the above synergistic effects, Camellia oleifera gardens planted using the method of this invention can enter the peak production period in the 5th year after planting, with a stable annual yield of 2,500 kg to 3,000 kg of fresh fruit per hectare. Compared to directly applying traditional technology to Hainan, the yield increase reaches 80% to 120%, with extremely significant economic and ecological benefits. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating a method for efficient and stable-yield cultivation of tropical camellia oleifera in Hainan according to the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0050] A highly efficient and stable-yield cultivation method for tropical camellia oleifera in Hainan includes the following steps:

[0051] S1. Site selection: Preferably, sites with an altitude between 300 and 600 meters, a slope of less than 25 degrees, well-drained lateritic red soil or brick-red soil, and a soil pH between 5.0 and 6.0, preferably on sunny or semi-sunny slopes. After selecting the site, use a total station or laser level to accurately measure and mark the contour lines as the baseline for the terraced field operation. Then, use a small excavator to excavate the terraces along the marked contour lines. The constructed terraced field operation surface is not horizontal, but has a precise inward slope of 1 to 3 degrees. This inward slope design makes the terraced field operation surface itself a broad-spectrum catchment area, effectively intercepting and collecting rainfall, promoting in-situ infiltration rather than forming destructive slope runoff.

[0052] S2. Building upon the construction of reverse-slope terraces, a bioretention and interception ditch is further excavated along the contour lines at the outer edge of each terrace's working surface, adjacent to the top of the slope embankment of the next terrace. This ditch has a precisely designed trapezoidal cross-section, with an upper base width of 50 cm, a lower base width of 30 cm, and a depth of 40 cm. The trapezoidal structure provides the ditch walls with higher physical stability. To effectively regulate the water flow within the ditch and prevent the formation of high-speed water flows and new erosion, a permeable control dam is installed every 4 meters along the length of the ditch. These control dams are constructed using clean gravel with a uniform particle size distribution between 5 and 10 cm, piled to a height of 25 cm. These control dams divide the long, narrow interception ditch into a series of independent, bamboo-joint-shaped water storage units, significantly extending the retention time of runoff within the system and achieving a shift from "drainage" to "storage." When excavating planting holes, the topsoil (0-20 cm deep) and subsoil (below 20 cm) are piled separately. Then, the organic-rich topsoil is backfilled into the middle section of the bioretention and interception ditch between two adjacent permeable control dams, forming a soil retaining wall structure approximately 20 cm high and 50 cm wide. This structure further slows the water flow within the unit and physically intercepts fine soil particles and organic matter transported by runoff, achieving in-situ enrichment and recycling of nutrients.

[0053] S3. Following land engineering improvements, a multiclonal spatiotemporally coupled pollination matrix is ​​created, and a friendly habitat for pollinating insects is simultaneously constructed. The aim is to systematically address the negative impacts of sustained tropical high temperatures on camellia pollen viability, stigma receptivity, and the pollination process through sophisticated planting layout and ecological configuration, ensuring a stable high fruit set rate even under adverse climatic conditions. Specifically, nine superior camellia clones with a flowering synchronization rate of ≥90% and significant gradient differences in tolerance to high-temperature stress are selected. As a preferred implementation method, this invention selects Haiyou No. 3, Reyan No. 2, Qiongzhong No. 4, Haida No. 1, Wanhai Camellia No. 3, Qiongdong No. 2, Qiongkeyou No. 1, Houchen No. 3, and Haikeda No. 3. Among them, Wanhai Camellia No. 3 is selected as the core main cultivated variety due to its high yield, high oil content, and wide adaptability, while the other eight varieties are used as pollinating varieties. When faced with high temperatures exceeding 32 degrees Celsius for several consecutive days, these varieties exhibit subtle but crucial differences in the rate of decline in pollen viability and the duration of stigma viability maintenance. These differences constitute a "time insurance" for pollination.

[0054] S4. Using a 3x3 grid as a repeating planting unit, each point represents a camellia oleifera tree. At the center of this unit, position 5, plant the core main variety (e.g., Haiyou No. 3). Around it, plant eight other pollinating varieties in eight surrounding positions, ensuring that every plant within the unit, whether the main or pollinating variety, is surrounded by at least three different pollinating clones. For example, the central main variety is surrounded by eight neighbors from eight different plants of different varieties. This extreme spatial interweaving maximizes the probability of cross-pollination in terms of physical distance. Across the entire slope, these 3x3 planting units are arranged in a checkerboard pattern, further breaking down any potential pollination barriers. This layout not only maximizes the pollination probability spatially but, more importantly, creates a "relay" effect of pollination over time due to the different responses of each variety to high-temperature stress. When a brief, extreme heat event may cause a variety to lose its pollination ability instantly, other more tolerant varieties can still pollinate effectively, thus greatly reducing the systemic risk of complete pollination failure due to a single climate event.

[0055] S5. To ensure sufficient and active pollinators, the habitat construction of pollinating insects is integrated into the micro-water collection system established in the first step. Ground cover plants are sown within the bioretention and interception trenches. The selected ground cover plants must meet several conditions: shade tolerance (able to adapt to the light environment under the Camellia oleifera canopy), tolerance to poor soil, non-vine (will not twine around the main trunk of the Camellia oleifera), nitrogen-fixing ability, and a flowering period that highly overlaps with the main flowering period of Camellia oleifera (usually October to December in Hainan) or can provide supplementary nectar sources. As a preferred embodiment of the invention, *Peanuta pintoides* (a type of peanut) is used. Arachis pintoi Peanut seeds were selected as an ideal ground cover plant. At the beginning of the rainy season, peanut seeds were evenly sown in bioretention and interception trenches at a sowing density of 20 grams per square meter. Peanut seeds not only effectively cover the soil in the trenches with their dense creeping stems and leaves, preventing rainwater erosion and weed growth, but their nitrogen-fixing root system also provides a continuous and slow-release nitrogen source for the camellia trees. More importantly, their small yellow flowers bloom almost year-round, providing a stable and abundant nectar and pollen source for key pollinators such as honeybees and bumblebees, thus attracting these insects to "settle" in the camellia garden, forming a stable and efficient pollination service system.

[0056] S6. Implement precision nutrient management based on precise control of the root zone environment, applying a customized double-layer coated controlled-release fertilizer, combined with the colonization of beneficial rhizosphere microorganisms, to address the dual challenges of highly leached nutrients during the tropical rainy season and soil moisture stress during the dry season, achieving precise matching between the nutrient supply curve and the annual growth rhythm curve of the camellia oleifera tree. In the planting stage, planting points are planned according to a spacing of 4 meters × 3 meters, and planting holes with a top diameter of 70 cm, a bottom diameter of 50 cm, and a depth of 50 cm are dug at each point. Each hole is filled with 15 kg of fully decomposed and harmless farmyard manure (e.g., chicken or pig manure compost with a C / N ratio of 25:1), 0.5 kg of superphosphate, and 50 g of rhizosphere growth-promoting bacteria as base fertilizer. The rhizosphere growth-promoting bacteria is a compound microbial preparation containing nitrogen-fixing bacteria with a total effective viable count of not less than 2 × 10^9 CFU / g. Azotobacter chroococcum ), Phosphate-solubilizing bacteria ( Bacillus megaterium ) and potassium-solubilizing bacteria ( Bacillus mucilaginosus The above-mentioned base fertilizer and microbial agent are thoroughly mixed with the excavated core soil (soil layer below 20 cm) outside the planting hole, and then backfilled into the hole. Finally, the top 0-20 cm of soil is backfilled, forming a mound-shaped micro-topographic mound 15 cm higher than the terrace working surface at the planting hole. This is intended to effectively prevent water accumulation at the root collar during the rainy season and prevent the occurrence of root rot.

[0057] S7. After the plants have established themselves, they enter the topdressing management stage. The core of topdressing management is the use of a specially designed double-layered controlled-release fertilizer. The structure of this fertilizer, from the inside out, consists of: a nutrient core substrate, a water-responsive controlled-release inner membrane, and a temperature- and water-responsive slow-release outer membrane. The nutrient core substrate is formulated according to the needs of different growth stages of the camellia oleifera. In the young tree stage (1-3 years after planting), to promote the rapid growth of vegetative organs, a high-nitrogen formula with a nitrogen-phosphorus-potassium (N-P2O5-K2O) ratio of 20-10-15 is used; after entering the fruiting stage (4 years and above), to meet the nutrient requirements for flowering, fruiting, and oil synthesis, a high-potassium formula with a nitrogen-phosphorus-potassium (N-P2O5-K2O) ratio of 15-10-20 is used. The fertilizer is applied once a year in trenches, in late April before the rainy season in Hainan. The specific operation is as follows: with the trunk as the center, dig a circular fertilization trench with a depth of 20 cm and a width of 15 cm inside the drip line of the vertical projection of the canopy. 70% of the total annual fertilizer requirement is evenly spread at a depth of 20 cm at the bottom of the trench, and the remaining 30% is applied to the top 10 cm of soil. The area is then covered with soil and compacted appropriately. This double-layered coating structure and stratified fertilization technique work synergistically to create a precise nutrient release mechanism. During the dry season, when soil moisture content is low, even a small amount of soil water vapor can trigger the inner water-responsive controlled-release membrane, causing it to swell slightly and release a small amount of nutrients to maintain the tree's basic physiological activities and root vitality. When the rainy season arrives, soil temperature and humidity rise simultaneously, activating the outer temperature- and water-responsive slow-release membrane. Its polymer structure micropores expand, significantly increasing permeability, thus releasing a large amount of nutrients at a controlled and stable rate that matches the vigorous growth rate of the camellia during the rainy season. This mechanism ensures efficient nutrient supply while minimizing economic and environmental losses caused by nutrient leaching during heavy rainfall events.

[0058] In a preferred embodiment, the moisture-responsive controlled-release inner membrane can be made by mixing polyvinyl alcohol (PVA) and sodium alginate in a certain proportion, with its thickness controlled at 10-20 micrometers; the temperature- and moisture-responsive slow-release outer membrane can be made by blending modified thermoplastic resin (such as ethylene-vinyl acetate copolymer EVA) and water-sensitive polymer (such as polyacrylic acid). By adjusting the blending ratio and the amount of crosslinking agent, it can achieve the optimal nutrient release rate under the average soil temperature (such as 25-30°C) and high soil moisture conditions during the rainy season in Hainan. Those skilled in the art can also use other polymer materials with similar functional properties according to the principles disclosed in this invention.

[0059] S8. This invention constructs and maintains a dynamic, ventilated, three-dimensional photosynthetic framework. The aim is to address the contradiction arising from the coexistence of strong sunlight and high humidity in Hainan through a refined pruning technique. Traditional closed tree shapes easily lead to diseases induced by high humidity within the canopy, while the outer branches and leaves are easily scorched by strong sunlight. The canopy structure constructed in this invention is vertically divided into three distinct layers: a top channeling layer, a middle fruiting layer, and a lower ventilation layer. Pruning begins in the winter of the second year after planting. First, the trunk height is controlled to between 40 and 50 cm through pruning, a height suitable for future harvesting and management. On the trunk, 3 to 4 branches with evenly distributed, vigorous growth, and an ideal angle of 45 to 55 degrees with the trunk are selected as primary main branches. To ensure the three-dimensionality of the canopy and uniform light exposure, the selected main branches are arranged in a spiral staggered pattern at approximately 120 degrees, avoiding structural weaknesses caused by branches growing on the same horizontal plane.

[0060] S9. In subsequent management, the amount of branches and leaves in each functional layer is continuously and dynamically regulated. The top thinning layer, mainly composed of the extension branches of the main branches and upper branches, is pruned appropriately to retain 30% of the total branches and leaves of the entire canopy. Its core function is not to maximize photosynthesis, but to act as a "biological light filter," converting the intense direct sunlight of the tropics into more efficient and gentle diffused light for the lower leaves, while providing sufficient light energy for itself. The middle fruiting layer is the main nutrient production center and fruiting area of ​​the tree, distributed in the central area of ​​the canopy, retaining 55% of the total branches and leaves of the entire canopy. The core of pruning this layer is to ensure its internal permeability. By thinning out overly dense branches, a distance of at least 30 cm is maintained between adjacent fruiting branch groups, ensuring that each fruiting branch group receives sufficient light. The lower ventilation layer, located below 40 cm from the canopy, involves thoroughly pruning all drooping, overly vigorous, and inward-growing branches, retaining only 15% sparse foliage. Its main task is to ensure free airflow at the bottom of the canopy, effectively reducing relative humidity and disrupting the microenvironment for pathogen growth. Pruning can be carried out year-round as needed, but the main concentrated pruning period is set after fruit harvest and before spring shoot emergence (November to February of the following year). Specific pruning includes: systematically removing all diseased, insect-infested, dead, crossing, overlapping, and inward-growing overly vigorous branches; finely thinning overly dense fruiting branch groups in the middle fruiting layer to achieve an optimized density of 8 to 10 robust fruiting branch groups per square meter of canopy projection area; and moderately shortening the extension branches of each main branch to encourage more lateral fruiting mother branches. The resulting canopy structure creates a top-down light intensity gradient and a bottom-up air humidity gradient within the canopy, systematically optimizing the ecological balance of light, temperature, air, and water within the canopy.

[0061] S10. Implement a comprehensive pest and disease management system based on ecological prevention and precise intervention. This system aims to maximize the inherent resistance of the healthy ecosystem built through the aforementioned steps, minimizing the frequency and amount of chemical pesticide use as a last resort to address the high incidence of pests and diseases in tropical regions, characterized by year-round occurrence and overlapping generations. This management system is divided into three defense levels:

[0062] The first level is prevention at the ecosystem level. This level is the cornerstone of the entire system, and its effectiveness stems from the synergistic effect of the first four technical steps. For example, by constructing a dynamic, ventilated, three-dimensional photosynthetic framework, the canopy microclimate is physically altered, significantly reducing the natural incidence of fungal diseases that thrive in high-humidity environments, such as anthracnose and soft rot. Applying rhizosphere growth-promoting agents at planting and increasing organic fertilizer application during the growing season enhances the diversity of rhizosphere soil microorganisms and the abundance of beneficial bacteria, thereby effectively suppressing the proliferation of soil-borne diseases through occupancy and antagonistic effects. Planting peanuts, a nectar-producing ground cover plant, in interception trenches provides a continuous food source and shelter for natural enemies of pests and diseases, such as parasitic wasps and predatory spiders, strengthening the natural basis of biological control.

[0063] The second level involves physical and biological control. During the peak emergence periods of major pests of camellia oleifera, such as the camellia oleifera tussock moth (usually April to May and September to October), solar-powered insecticidal lamps are installed and activated at a density of one lamp per 3 hectares within the park. These lamps emit ultraviolet light with a wavelength of 365 nanometers, which has the strongest attraction effect on nocturnal lepidopteran pests. They automatically activate at night (e.g., 7:00 PM to 5:00 AM the following day) to trap and kill the pests. Simultaneously, for the camellia oleifera tussock moth, pheromone slow-release traps are hung within the park. These traps utilize artificially synthesized sex pheromones to efficiently trap male adult moths, thereby disrupting their mating process and reducing the population size of the next generation. The traps are hung at a density of 2 to 3 per hectare in the lower part of the tree canopy, at a height of approximately 1.5 meters.

[0064] The third level is data-driven precision chemical intervention. A grid-based, regular pest and disease monitoring system is established and strictly implemented. The entire camellia oleifera plantation is divided into several 1-hectare management units. Each week, technicians randomly select 5 sampling points within each unit, examining 10 new shoots or fruits at each point, and meticulously recording symptoms and pest populations. Chemical control is only initiated when the monitoring data reaches the preset control threshold. For example, application of pesticides is only permitted when the anthracnose incidence rate reaches 5%, or when the density of camellia oleifera tussock moth larvae reaches an average of 5 larvae per 100 shoots. For anthracnose, in the early stages of disease occurrence, foliar spraying with 50% carbendazim wettable powder at an 800-fold dilution or 10% pyraclostrobin water-dispersible granules at a 1500-fold dilution can be used. To delay the development of resistance, the two pesticides must be used alternately, spraying once every 10 days, and applied continuously for 2 to 3 times depending on the disease progression. For the camellia tussock moth, spraying should be carried out when the larvae are in their low resistance stage before the third instar. Use a 2500-fold dilution of 0.2% abamectin EC or a 1500-fold dilution of 50% fenitrothion EC. All chemical spraying operations must be carried out after 5 pm or on windless, cloudy days to avoid rapid evaporation and photodegradation of the pesticide solution under high temperature and strong sunlight, and to minimize damage to daytime pollinators and natural enemies. Example 1

[0065] This example was conducted at an experimental site in Qiongzhong Li and Miao Autonomous County, Hainan Province. The site has an altitude of 450 meters, an average slope of 18 degrees, and a soil type of red soil. The soil pH value was 5.5 before planting. The site area is 5 hectares.

[0066] The operation was carried out strictly according to the above steps. First, a terraced working surface with an inward slope of 2 degrees was constructed along the contour lines. At the outer edge of each terrace, a biological retention and interception ditch, 50 cm wide at the top, 30 cm wide at the bottom, and 40 cm deep, was excavated. A gravel control dam with a particle size of 5-10 cm was installed every 4 meters within the ditch. When excavating the planting holes, topsoil was used to construct retaining walls within the interception ditches. Second, Haiyou No. 3 was selected as the main planted variety, with Reyan No. 2, Qiongzhong No. 4, Haida No. 1, Wanhai Youcha No. 3, Qiongdong No. 2, Qiongkeyou No. 1, and Houchen No. 3 as pollinating varieties. They were planted in a checkerboard pattern in 3x3 grid units, with a plant spacing of 4 meters × 3 meters. Peanut seeds were sown in the interception ditches at a density of 20 grams per square meter. At planting time, each hole was treated with 15 kg of well-rotted chicken manure, 0.5 kg of superphosphate, and 50 g of compound rhizosphere growth-promoting bacteria. From the second year onwards, in late April each year, double-layer coated controlled-release fertilizer is applied in furrows according to the described method. For the first three years, a formula with an N-P₂O₅-K₂O ratio of 20-10-15 is used; from the fourth year onwards, a formula of 15-10-20 is used. Starting in the winter of the second year, the camellia trees are pruned and shaped to construct the described three-dimensional photosynthetic framework. Simultaneously, a comprehensive system based on ecological prevention, physical and biological control, and precise chemical intervention is implemented.

[0067] Comparative Example 1

[0068] On a 5-hectare plot of land adjacent to Example 1 with identical area, altitude, slope, and soil conditions, a comparison was made using traditional Hainan camellia oleifera cultivation methods.

[0069] This method involves clearing land along contour lines, but without constructing reverse-slope terraces or bioretention ditches, and planting along the slope. Two varieties, Haiyou No. 3 and Qiongzhong No. 4, are randomly mixed in a 2:1 ratio, with a spacing of 4 meters × 3 meters. At planting time, each hole is fertilized with uncomposted farmyard manure and ordinary compound fertilizer. Topdressing uses commercially available general-purpose compound fertilizer (N-P2O5-K2O ratio of 15-15-15), applied three times a year in spring, summer, and autumn, near the drip line of the canopy, followed by shallow hoeing. Pruning follows the traditional open-center shape, without fine-grained stratification of the canopy structure. Pest and disease control relies mainly on regular, preventative chemical pesticide spraying, with broad-spectrum insecticides and fungicides sprayed 4-5 times annually.

[0070] Results and Analysis

[0071] Over seven years of observation and data collection, key indicators of Example 1 and Comparative Example 1 were compared, and the results are shown in the table below:

[0072] Table 1 Comparison of Core Benefit Indicators

[0073]

[0074] Data analysis shows that the complete set of technologies provided by this invention achieves significant beneficial effects through systematic synergistic effects. The micro-water collection system greatly reduces the loss of water, soil, and nutrients, providing a stable foundation for the growth of Camellia oleifera. Precision fertilization technology, while reducing fertilizer input by 30%, more than doubles nitrogen utilization. The combination of a three-dimensional photosynthetic framework and a polyclonal pollination matrix not only significantly reduces disease incidence and physiological stress but also elevates fruit set rate and yield stability to a new level. Ultimately, compared to traditional technologies, this invention achieved a doubling of Camellia oleifera yield in the specific environment of tropical Hainan, demonstrating its technological advancement, systematic nature, and immense application value.

[0075] In summary, this invention provides a highly systematic, engineered, and ecological method for the efficient and stable production of tropical camellia oleifera in Hainan. Its various technical steps are interconnected and mutually supportive, together forming a production system that can proactively adapt to and optimize the tropical adverse ecosystem.

Claims

1. A highly efficient and stable-yield cultivation method for Hainan tropical camellia, characterized in that, Includes the following steps: S1. Constructing a micro-water collection system: (1) On a selected sunny or semi-sunny slope with an altitude of less than 600 meters, a slope of less than 25 degrees, and a soil pH value between 5.0 and 6.0, a terraced working surface is excavated along the contour line so that the terraced working surface has an inward slope of 1 to 3 degrees. (2) At the outer edge of each terrace working surface, a biological retention and interception ditch is excavated along the contour line. The cross-section of the biological retention and interception ditch is trapezoidal, with an upper base width of 50 cm, a lower base width of 30 cm, and a depth of 40 cm. (3) In the bioretention and interception ditch, a permeable control dam is set every 4 meters along its length; the height of the permeable control dam is 25 cm, and its construction material is selected from gravel with a particle size of 5 to 10 cm or high-density bamboo; and the topsoil dug out when excavating the planting hole is backfilled in the middle section of the bioretention and interception ditch between two adjacent permeable control dams to form a water retaining wall structure with a height of 20 cm. S2. Creating a pollination matrix and habitat for pollinating insects: (1) Nine Camellia oleifera clonal varieties were selected, and the synchronization rate of their flowering periods was greater than or equal to 90%. (2) A 3x3 grid unit layout is adopted for chessboard-style staggered planting. The core main planted variety, Wanhai Camellia No. 3, is planted in the center, and eight other pollinating varieties are planted in the eight positions around it to ensure that any plant in the unit is surrounded by at least three different pollinating clones; and the honey source ground cover plant, Peanut sylvestris, is planted in the bioretention and interception trench with a planting density of 20 grams per square meter. S3. Implement precise nutrient management: (1) At the planting point with a spacing of 4 meters × 3 meters, dig a planting hole with a top diameter of 70 cm, a bottom diameter of 50 cm and a depth of 50 cm; (2) At the time of planting, apply 15 kg of fully decomposed farmyard manure, 0.5 kg of superphosphate, and 50 g of rhizosphere growth-promoting bacteria per hole as base fertilizer; the rhizosphere growth-promoting bacteria is a compound bacteria agent containing nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and potassium-solubilizing bacteria, with an effective viable count of not less than 2 × 10⁻⁶. 9 CFU / gram; (3) After backfilling the soil, a mound-shaped soil pile 15 cm higher than the terrace working surface is formed at the planting hole; and a double-layered controlled-release fertilizer with a water-responsive inner membrane and a temperature and water-responsive outer membrane is applied during the growing season; the double-layered controlled-release fertilizer is applied once in trenches before the rainy season each year, with the fertilizer applied inside the drip line of the tree canopy. A circular trench with a depth of 20 cm and a width of 15 cm is dug, and 70% of the total fertilizer required for the whole year is applied to the bottom of the trench, and the remaining 30% is applied to the top 10 cm. Within a 1 cm soil layer; and, for the young tree stage and the fruiting stage, different formulations of the double-layered coated controlled-release fertilizer are used: the double-layered coated controlled-release fertilizer applied during the young tree stage has a nitrogen-phosphorus-potassium ratio of 20-10-15; the double-layered coated controlled-release fertilizer applied during the fruiting stage has a nitrogen-phosphorus-potassium ratio of 15-10-20; wherein, the structure of the double-layered coated controlled-release fertilizer includes a nutrient core matrix, and the core matrix is ​​sequentially coated with a water-responsive controlled-release inner membrane and a temperature and water dual-responsive slow-release outer membrane; S4. Construct a dynamic, ventilated, three-dimensional photosynthetic framework: (1) Starting from the second year after planting, the main stem height should be maintained at 40 to 50 cm; (2) Select 3 to 4 strong branches that are evenly distributed and have an angle of 45 to 55 degrees with the main trunk as primary branches. The primary branches are distributed in a 120-degree spiral staggered upward distribution in space. (3) The amount of branches and leaves in each functional layer is precisely controlled so that the top sparse layer retains 30% of the total amount of branches and leaves in the canopy, the middle fruiting layer retains 55% of the total amount of branches and leaves in the canopy, and the lower ventilation layer retains 15% of the total amount of branches and leaves in the canopy. S5. Implement integrated pest management: combine physical control, biological control, and precise chemical intervention based on disease incidence or insect population density monitoring thresholds.

2. The method according to claim 1, characterized in that, Step S4 also includes the following operations: (1) Pruning should be carried out from November to February of the following year after the harvest. This includes thoroughly removing diseased and insect-infested branches, dead branches, crossing branches, overlapping branches and drooping overgrown branches. (2) Prune the middle fruiting layer to ensure that the distance between adjacent fruiting branches is maintained at more than 30 cm, and retain 8 to 10 strong fruiting branches per square meter of canopy projection area; (3) Prune the extension branches of each main branch appropriately to promote the development of lateral fruiting branches.

3. The method according to claim 1, characterized in that, The specific method of integrated pest management in step S5 is as follows: (1) The physical control measures include: during the peak emergence period of adult tea oil pests, installing and activating solar insecticidal lamps with a wavelength of 365 nanometers at a density of one lamp per 3 hectares at night; (2) The biological control includes: for the Camellia tussock moth, hanging pheromone slow-release traps to lure and kill male moths; (3) The precise chemical intervention includes: establishing a regular monitoring system, and starting chemical control when the disease incidence rate reaches 5% or the insect population density reaches 5 insects per 100 shoots; for anthracnose, alternately spray with 800 times dilution of 50% carbendazim wettable powder or 1500 times dilution of 10% pyraclostrobin water-dispersible granules; for tea tussock moth larvae, spray with 2500 times dilution of 0.2% abamectin EC or 1500 times dilution of 50% fenitrothion EC; all chemical spraying operations are carried out in the evening or on cloudy days.

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