Efficient cultivation method of clumping bamboo based on clump cutting

Abstract

The present application provides a kind of clump bamboo efficient cultivation method based on clump harvesting, with the bamboo clump of natural growth as basic unit, bamboo clump is divided into two grades of health good clump and severe rejuvenation clump, in winter dormancy period, severe rejuvenation clump is harvested, the sprout of reserved shoot is treated with fungicide, after preservation, sprout agent is applied, is injected in the inside of shoot, the deep ploughing of clump harvesting trace is carried out, organic improved substrate is applied, and the layer of keeping warm and moist is covered, the new sprout germination dynamics is monitored, and new generation bamboo clump is cultivated by fixed plant selection, disease and insect pest control and water and fertilizer regulation.The present application significantly improves the sprouting rate of degraded clump bamboo and the quality of new bamboo through the synergistic effect of physical removal, chemical stimulation and ecological reconstruction, shortens the recovery period to 2 years, while maintaining the ecological stability of forest land, and is suitable for the rejuvenation cultivation of Dendrocalamus latiflorus, Dendrocalamus giganteus, Dendrocalamus strictus and Dendrocalamus strictus.

Description

Technical Field

[0001] This invention relates to the field of forestry cultivation and ecological restoration technology, and in particular to a method for the efficient cultivation of clump-forming bamboo based on clump harvesting. Background Technology

[0002] Bamboo, a general term for plants in the Bambusoideae subfamily of the Poaceae family, is a perennial woody plant. Bamboo is characterized by its hollow heart, firm joints, evergreen nature, and resilience to cold. With numerous varieties and wide-ranging uses, bamboo provides various forestry products and services to humankind. Its strong vitality and the ability to generate benefits for many years after a single planting make it a popular choice. Based on the distribution of its above-ground parts and the growth habits of its rhizomes, bamboo species are mainly classified into three types: scattered, clumping, and mixed. Generally, clumping bamboo is more suitable for tropical and subtropical regions, while scattered bamboo is more suitable for temperate and northern subtropical regions. Scattered bamboo, such as Moso bamboo and Square bamboo, has densely packed rhizomes underground, while the culms grow dispersedly above ground after the shoots emerge. Clumping bamboo, such as Bambusa textilis, Green bamboo, and Moso bamboo, has unique biological characteristics: its underground rhizomes (pseudonyms) are short, with densely packed internodes, and the culms grow in clusters, forming a relatively independent physiological and ecological unit—the bamboo clump. The bamboo grove utilizes a symbiotic root network to regulate nutrients and water.

[0003] In traditional bamboo forest management, bamboo farmers often adopt a uniform management model for different types of bamboo forests due to a lack of professional knowledge. They generally adopt a single-tree selective felling model of "harvesting old trees and keeping young ones, harvesting weak trees and keeping strong ones". This model is highly effective during the prime of bamboo forests, but as the management period lengthens (usually after 5-8 years), it gradually reveals serious problems of clump degradation: First, there is a physiological inhibition effect. The density of old bamboo clumps is too high, resulting in poor ventilation and light penetration. The vitality of the old stump roots declines, and a large amount of autotoxic substances (such as phenolic acid compounds) accumulate, inhibiting the germination and growth of new shoots, leading to a sharp decline in the shoot emergence rate. Second, there is insufficient regeneration momentum. Selective felling of individual clumps preserves the main body of the old stumps, which cannot completely break the apical dominance and physiological balance of the old clumps. New bamboo shoots are often thin and short, forming a vicious cycle of "small old bamboo" stands. Third, there are limitations in operation. For severely degraded bamboo clumps, it is difficult to select individual clumps, and frequent entry into the clump for operation can easily damage the shallow root system of the preserved bamboo. Although the existing large-scale clear-cutting can completely regenerate, it has obvious drawbacks such as high ecological risks, damage to surface vegetation, and easy to cause soil erosion.

[0004] Patent CN202410731427.2 discloses a method for rejuvenating square bamboo forests. This method adjusts the age structure of the standing bamboo, retaining young and mature bamboo while harvesting damaged, fallen, or diseased mature bamboo, gradually removing older, mature bamboo to achieve a reasonable age structure ratio in the bamboo forest. This changes the traditional single-mode approach of one-time harvesting and replanting. This patented technology targets square bamboo, which is a clump-forming bamboo, not a cluster-forming bamboo. The physiological characteristics of clump-forming and cluster-forming bamboo differ significantly. In particular, large-scale clear-cutting of old bamboo forests, as described in this patent, can easily lead to severe physiological inhibition and high ecological risks for cluster-forming bamboo forests. Therefore, the rejuvenation problems faced by clump-forming and clump-forming bamboo are different. Furthermore, this patented technology uses a thinning strategy based on bamboo age. While thinning can produce new bamboo, the diameter at breast height (DBH) of these new bamboo is significantly reduced, resulting in a long recovery period and thus failing to generate economic benefits in the short term. Summary of the Invention

[0005] This invention proposes a clump-growing method for bamboo that falls between selective felling of individual plants and clear-cutting of large areas, based on the growth characteristics of clump-forming bamboo. This method can not only increase the growth volume of bamboo forests but also improve the quality of bamboo forest growth and shorten the recovery period.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] A highly efficient cultivation method for clump-forming bamboo based on clump harvesting is proposed. Using naturally growing bamboo clumps as the basic unit, the clumps are divided into two levels: healthy clumps and severely rejuvenated clumps. During the winter dormancy period, the severely rejuvenated clumps are harvested in their entirety. The remaining bamboo shoot stumps are sterilized and preserved, then a sprouting agent is applied and injected into the stumps. The harvested area is then deeply tilled and loosened, organic improved substrate is applied, and a heat-insulating and moisture-retaining layer is added. The sprouting dynamics of new bamboo shoots are monitored, and the selection of individual plants, pest and disease control, and water and fertilizer regulation are implemented to cultivate a new generation of bamboo clumps.

[0008] The main steps include:

[0009] (1) Diagnosis and grading: Using naturally growing bamboo clumps as the basic unit, we investigated and observed their age structure, shoot growth potential and pest and disease status, and divided the bamboo clumps into two levels: healthy clumps and severely rejuvenated clumps.

[0010] (2) Clump harvesting: During the winter dormancy period, the entire clump of severely rejuvenated clumps is harvested to form an independent clump harvesting site; during harvesting, the entire above-ground bamboo plants of severely rejuvenated clumps are removed, and old bamboo stumps older than 3 years are selectively dug up, while bamboo stumps ≤ 2 years old are retained.

[0011] (3) Rhizosphere sprouting: After sterilizing and preserving the bamboo shoots retained in step (2), a sprouting agent is applied and injected into the bamboo shoots to induce the latent buds to sprout.

[0012] (4) Soil improvement: Deeply till and loosen the soil in the clump-like logging area, apply organic improvement substrate, and cover with a heat-insulating and moisture-retaining layer;

[0013] (5) Targeted bamboo cultivation: Monitor the sprouting dynamics of new bamboo shoots, select and retain plants, control pests and diseases, and regulate water and fertilizer to cultivate a new generation of bamboo clumps.

[0014] Preferably, the grading criteria for step (1) above are as follows: a bush is considered severely rejuvenated if it meets any of the following conditions, and the rest are considered healthy bushes:

[0015] a. The average age of the bamboo clump is ≥5 years, and the proportion of old bamboo (3 years or older) exceeds 60%;

[0016] b. The average number of bamboo shoots per mu (unit of land area) is less than 40% of the normal level for two consecutive years, or the diameter at breast height (DBH) of new bamboo is less than 70% of that of old bamboo;

[0017] c. Bamboo clumps that are flowering or have more than 30% dead bamboo stalks, or that have been severely infected by pests and diseases and are difficult to recover through individual plant treatment.

[0018] Preferably, the whole-clump harvesting described in step (2) above involves cutting all the above-ground bamboo culms of the heavily rejuvenated clump from the base and removing them from the forest. When cutting, the stump height should be less than 5cm, the cut section should be flat, and the angle of inclination with the horizontal plane should be 10°-15° to facilitate drainage. The surface debris and residual bamboo stumps should be cleared to expose the underground stem system of the bamboo clump. For old bamboo stumps that are older than 3 years, they should be dug up and removed by mechanical or manual means, and the removal depth should not exceed 40cm below the ground surface to avoid excessive damage to the root network.

[0019] Preferably, the bamboo shoot stump mentioned in step (2) above refers to the residual tissue at the base of 1-2 year old bamboo culms, which is plump, non-lignified or slightly lignified.

[0020] Preferably, the content of each raw material of the sprouting agent mentioned in step (3) above is: 50-100mg / L 6-BA + 10-20mg / L NAA + 10mg / L boric acid + 10mg / L zinc sulfate + 20mg / L 5-ALA, pH adjustment: 5.8-6.2.

[0021] Preferably, the organic improved substrate in step (4) above is made by mixing decomposed bamboo chips, fungal residue and wood ash in a weight ratio of 4:3:1, and adding a small amount of superphosphate; the thickness of the heat preservation and moisture retention layer is 8-12cm, and the material is black degradable mulch film combined with straw or pure organic covering (such as rice husks, crushed coconut coir), so that the root zone soil temperature is increased by 2-4℃ in early spring and the soil moisture content is maintained at 75%-85% of field water holding capacity.

[0022] Preferably, the selection and retention of bamboo shoots in step (5) above follows the principle of "removing the weak and retaining the strong, and evenly distributing them". Specifically, among the new bamboo shoots that sprout in the current year, 2-3 strong mother bamboo shoots / clumps are retained, and the remaining weak and diseased bamboo shoots are removed as soon as possible. The retained new bamboo shoots should be evenly distributed radially around the center of the original bamboo clump to avoid uneven growth.

[0023] Preferably, after the diagnosis and classification in step (1), only 20%-30% of the severely rejuvenated thickets in the basic unit are harvested in clump form each year, and the management is carried out on an annual rotation basis; to ensure that the entire forest stand maintains a canopy closure of more than 70% at any time, maintain the stability of the forest microclimate, and prevent soil erosion.

[0024] Preferably, the above-mentioned clump-forming bamboo is any one of the following varieties: Bambusa textilis, Bambusa spp., Bambusa cirrhosa, Bambusa spp. var. spp., or Bambusa spp. var. spp.

[0025] The advantages and beneficial effects of this invention are as follows:

[0026] 1. This invention completely removes the above-ground and aged parts (old bamboo clumps older than 3 years) and selectively retains young and vigorous bamboo shoots (bamboo age ≤ 2 years), eliminating above-ground competition and completely removing the source of phenolic allelochemicals, thus relieving the inhibitory signal to the underground buds. At the same time, the retained bamboo shoots are directly injected with a sprouting agent to break dormancy and induce shoot growth, thereby ensuring that the underground buds can respond and sprout quickly after the old clumps are removed, significantly improving the bamboo clump sprouting ability and the survival rate of new shoots.

[0027] 2. The sprouting agent used in this invention contains 6-BA, which can break the dormancy of bamboo shoots and induce the germination of dormant buds; NAA, which can stimulate the differentiation of root primordia at the base of the bamboo shoot and surrounding areas, and rapidly establish a new root network; boron and zinc, as trace elements, can improve the quality of bamboo shoot differentiation and enhance photosynthesis; 5-ALA, as a plant growth regulator, provides the energy required for rooting, enhances stress resistance, and can also promote the cell division signal transduction of 6-BA; the components of the sprouting agent work synergistically to rejuvenate the bamboo shoots by breaking dormancy, inducing shoot growth, promoting root development, and enhancing stress resistance. The slightly acidic environment ensures that the sprouting agent can be rapidly absorbed and transported after being injected into the bamboo shoot. Experimental data show that this sprouting agent combination can advance the shoot growth time by at least 15 days, increase the number of shoots, and produce straighter new bamboo culms with increased wall thickness, thereby increasing the proportion of first-grade commercial bamboo.

[0028] 3. This invention creates a warm and humid soil environment by improving the organic substrate and covering it with a heat-insulating and moisture-retaining layer, which raises the rhizosphere soil temperature by 2-4°C in early spring and maintains the water content at 75%-85% of field capacity. This provides the best temperature and humidity conditions for the sprouting agent to exert its maximum effect, and further supports the realization of the goal of rapid and efficient rejuvenation of clump-shaped rejuvenating cuttings.

[0029] 4. This invention preserves some bamboo clumps to maintain ecological functions through scientific planting and rotational harvesting, providing shade and seed sources for the treatment area, while continuously producing bamboo shoots and bamboo materials. It balances ecological stability and economic output, avoids the risks of a sudden drop in canopy density, exposed forest land, and nutrient loss caused by large-scale clear-cutting, and achieves optimized bamboo forest structure and continuous biomass growth.

[0030] 5. This invention significantly improves the sprouting rate and new bamboo quality of degraded clump bamboo through the synergistic effect of physical removal, chemical stimulation and ecological reconstruction, shortens the recovery cycle to 2 years, and maintains the ecological stability of forest land. It is suitable for the rejuvenation and cultivation of clump bamboo such as Phyllostachys edulis, Phyllostachys aurea, Phyllostachys nigra, and Phyllostachys pubescens. Attached Figure Description

[0031] Figure 1 This is a forest stand diagram of the rejuvenated bamboo forest according to Embodiment 1 of the present invention;

[0032] Figure 2 This is a forest stand diagram of the rejuvenated *Bamboo stalks* forest according to Embodiment 5 of the present invention;

[0033] Figure 3 This is a comparison image of the bamboo clump before and after rejuvenation according to the present invention;

[0034] Figure 4 This is a photograph of bamboo shoots sprouting from a bamboo clump after rejuvenation according to Embodiment 1 of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments. However, the scope of protection of the present invention is not limited to the following embodiments. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the concept of the present invention should be included within the scope of protection of the present invention.

[0036] Example 1:

[0037] This embodiment uses a degraded bamboo forest in a bamboo planting base in Nanning City, Guangxi Zhuang Autonomous Region as the experimental subject, and the implementation period is from November 2022 to May 2024. The base has a planting history of about 10 years, and the bamboo shoot rate and quality of new bamboo have declined significantly in the past 3 years.

[0038] A highly efficient cultivation method for clump-forming bamboo based on clump harvesting mainly includes the following steps:

[0039] (1) Diagnostic grading: Using naturally growing bamboo clumps as the basic unit, the age structure, shoot growth potential, and pest and disease status of the bamboo clumps were investigated and observed. The bamboo clumps were divided into two levels: healthy clumps and severely rejuvenated clumps;

[0040] The grading criteria are as follows: A bush is considered severely rejuvenated if it meets any of the following conditions; otherwise, it is considered healthy.

[0041] a. The average age of the bamboo clump is ≥5 years, and the proportion of old bamboo (3 years or older) exceeds 60%;

[0042] b. The average number of bamboo shoots per mu (unit of land area) is less than 40% of the normal level for two consecutive years, or the diameter at breast height (DBH) of new bamboo is less than 70% of that of old bamboo;

[0043] c. Bamboo clumps that are flowering or have more than 30% dead bamboo stalks, or that have been severely infected by pests and diseases and are difficult to recover through individual plant treatment.

[0044] (2) Clump harvesting: In December 2022, during the winter dormancy period, the selected heavily rejuvenated clumps were harvested in their entirety to form independent clump harvesting sites; during harvesting, the above-ground bamboo plants of the heavily rejuvenated clumps were completely removed, and the old bamboo stumps with a bamboo age of more than 3 years were selectively dug up, while the bamboo stumps with a bamboo age of ≤2 years were retained. The bamboo stumps refer to the residual tissue at the base of 1-2 year old bamboo culms, with plump shoots that are not lignified or slightly lignified.

[0045] Specifically, whole-clump harvesting involves cutting all above-ground bamboo stalks from the base of severely rejuvenated clumps and removing them from the forest. During felling, the stump height should be less than 5cm, the cut surface should be flat, and the cut should be at a 10°-15° angle to the horizontal to facilitate drainage. The surface debris and remaining bamboo stumps should be cleared to expose the underground stem system of the bamboo clump. For aging bamboo stumps older than 3 years, mechanical or manual methods should be used to dig and remove them, with the removal depth not exceeding 40cm below the surface to avoid excessive damage to the root network.

[0046] (3) Rhizosphere budding: After sterilizing and preserving the bamboo shoots retained in step (2), apply a budding agent and inject it into the bamboo shoots to induce the latent buds to sprout; the sterilization and preservation treatment can be carried out by conventional bactericides in this field, such as 0.5% potassium permanganate solution or 50% carbendazim wettable powder at 500 times dilution, which are evenly sprayed on the surface of the bamboo shoots and the cut, and then dried before the subsequent budding agent is injected;

[0047] The content of each raw material in the sprouting agent is: 50mg / L 6-BA + 20mg / L NAA + 10mg / L boric acid + 10mg / L zinc sulfate + 20mg / L 5-ALA, pH adjustment: 5.8-6.0;

[0048] (4) Soil improvement: Deeply till and loosen the soil in the clump-like logging area, apply organic improvement substrate, and cover with a heat-insulating and moisture-retaining layer;

[0049] The organic improved substrate was composed of well-rotted bamboo chips, mushroom residue, and wood ash mixed in a weight ratio of 4:3:1, with a small amount of superphosphate added. The heat-insulating and moisture-retaining layer was 8 cm thick, and the material used was black biodegradable mulch film combined with straw. Measurements after treatment showed that the rhizosphere soil temperature in early spring (February-March) was 2-4℃ higher than the control area, and the soil moisture content remained at 75%-85% of field capacity.

[0050] (5) Targeted bamboo cultivation: Monitor the sprouting dynamics of new bamboo shoots, select and retain healthy shoots, control pests and diseases, and regulate water and fertilizer to cultivate a new generation of bamboo clumps. The selection and retention of shoots follows the principle of "removing weak shoots and retaining strong shoots, and even distribution". Specifically, among the new shoots that sprout in the current year, retain 2-3 healthy mother shoots / clumps, and remove the remaining weak and diseased shoots as early as possible. The retained new bamboo should be evenly distributed radially around the center of the original bamboo clump to avoid lopsided growth. During the growth period, carry out pest and disease control and water and fertilizer regulation according to routine management.

[0051] According to the annual plan, only 20% of the severely rejuvenated bamboo clumps in the basic unit will be subject to the above-mentioned clump harvesting each year, while the remaining bamboo clumps will be maintained under normal management; to ensure that the entire forest stand maintains a canopy closure of more than 70% at any time, maintain the stability of the forest microclimate, and prevent soil erosion.

[0052] Example 2:

[0053] This embodiment uses a degraded bamboo forest at a bamboo planting base in Liuzhou City, Guangxi Zhuang Autonomous Region as the experimental subject, and the implementation period is from November 2022 to May 2024. The base has a planting history of about 8 years, and the rate of bamboo shoots and the quality of new bamboo have declined significantly in the past 3 years.

[0054] The efficient cultivation method for clump-forming bamboo based on clump harvesting used in this embodiment is basically the same as that in Example 1, with the only difference being:

[0055] The sprouting agent formulation in step (3) is: 60 mg / L 6-BA + 20 mg / L NAA + 10 mg / L boric acid + 10 mg / L zinc sulfate + 20 mg / L 5-ALA, pH adjustment: 5.8-6.0;

[0056] The moisture-retaining and heat-insulating layer described in step (4) is covered with rice husks and crushed coconut coir, with a thickness of 10cm;

[0057] Rotation ratio: According to the annual plan, only 25% of the severely rejuvenated thickets in the basic unit will be harvested in clumps each year.

[0058] Example 3:

[0059] This embodiment uses a degraded bamboo forest at a bamboo planting base in Guilin City, Guangxi Zhuang Autonomous Region as the experimental subject, and the implementation period is from November 2022 to May 2024. The base has a planting history of about 8 years, and the rate of bamboo shoots and the quality of new bamboo shoots have declined significantly in the past 3 years.

[0060] The efficient cultivation method for clump-forming bamboo based on clump harvesting used in this embodiment is basically the same as that in Example 1, with the only difference being:

[0061] The sprouting agent formulation in step (3) is: 80 mg / L 6-BA + 15 mg / L NAA + 10 mg / L boric acid + 10 mg / L zinc sulfate + 20 mg / L 5-ALA, pH adjustment: 6.0-6.2;

[0062] The moisture-retaining and heat-insulating layer mentioned in step (4) is made of black degradable mulch film combined with straw, with a thickness of 12cm;

[0063] Rotation ratio: According to the annual plan, only 25% of the severely rejuvenated thickets in the basic unit will be harvested in clumps each year.

[0064] Example 4:

[0065] This embodiment uses a degraded *Phyllostachys edulis* forest at a *Phyllostachys edulis* planting base in Baise City, Guangxi Zhuang Autonomous Region as the experimental subject, and the implementation period is from November 2022 to May 2024. The base has a planting history of about 8 years, and the rate of bamboo shoots and the quality of new bamboo shoots have declined significantly in the past 3 years.

[0066] The efficient cultivation method for clump-forming bamboo based on clump harvesting used in this embodiment is basically the same as that in Example 1, with the only difference being:

[0067] The sprouting agent formulation in step (3) is: 100 mg / L 6-BA + 10 mg / L NAA + 10 mg / L boric acid + 10 mg / L zinc sulfate + 20 mg / L 5-ALA, pH adjustment: 6.0-6.2;

[0068] The moisture-retaining and heat-insulating layer described in step (4) is made of pure organic covering material rice husk and crushed coconut coir, with a thickness of 12cm;

[0069] Rotation ratio: According to the annual plan, only 30% of the severely rejuvenated thickets in the basic unit will be felled in clumps each year.

[0070] Example 5:

[0071] This embodiment uses a degraded *Phyllostachys edulis* (dragon bamboo) forest at a *Phyllostachys edulis* planting base in Nanning City, Guangxi Zhuang Autonomous Region, as the experimental subject, and the implementation period is from November 2022 to May 2024. The base has a planting history of about 8 years, and the rate of bamboo shoots and the quality of new bamboo shoots have declined significantly in the past 3 years.

[0072] The efficient cultivation method for clump-forming bamboo based on clump harvesting used in this embodiment is basically the same as that in Example 1, except that the variety is different. The variety in this embodiment is *Phyllostachys edulis*.

[0073] Comparative Example 1:

[0074] The experiment was conducted at the same bamboo plantation as in Example 1, and bamboo clumps with a similar degree of degradation to those in Example 1 were selected as controls.

[0075] Treatment method: The traditional single-plant selective felling model of "harvesting old and keeping young, harvesting weak and keeping strong" was adopted. In December 2022, old bamboos over 3 years old and diseased and weak bamboos were felled, and 1-2 year old young bamboos and some 2-3 year old strong bamboos were retained. Old stumps were not dug up, root zone sprouting was not promoted, and soil improvement was not carried out. The following year, pest and disease control and water and fertilizer regulation were carried out according to routine management.

[0076] Comparative Example 2:

[0077] The experiment was conducted at the same bamboo plantation as in Example 1, and bamboo clumps with a similar degree of degradation to those in Example 1 were selected as controls.

[0078] Treatment method: Steps (1) and (2) are the same as in Example 1, but without the rhizosphere sprouting and soil improvement steps. Only after harvesting, pest and disease control and water and fertilizer regulation are carried out according to routine management.

[0079] Comparative Example 3:

[0080] The experiment was conducted at the same bamboo plantation as in Example 1, and bamboo clumps with a similar degree of degradation to those in Example 1 were selected as controls.

[0081] Treatment method: Steps (1), (2) and (3) are the same as in Example 1, but without the soil improvement step. In the following year, pest and disease control and water and fertilizer regulation are carried out according to routine management.

[0082] Comparative Example 4:

[0083] The experiment was conducted at the same bamboo plantation as in Example 1, and bamboo clumps with a similar degree of degradation to those in Example 1 were selected as controls.

[0084] Processing method: The only difference from Example 1 is that the content of each raw material of the sprouting agent in step (3) is: 50-100mg / L 6-BA + 10-20mg / L NAA + 10mg / L boric acid + 10mg / L zinc sulfate, pH adjustment: 5.8-6.2; no 5-ALA component. The remaining steps are the same as in Example 1.

[0085] Comparative Example 5:

[0086] The experiment was conducted at the same bamboo plantation as in Example 1, and bamboo clumps with a similar degree of degradation to those in Example 1 were selected as controls.

[0087] Processing method: The only difference from Example 1 is that the content of each raw material of the sprouting agent in step (3) is: 50-100mg / L 6-BA + 10-20mg / L NAA + 20mg / L 5-ALA, pH adjustment: 5.8-6.2; without boric acid and zinc sulfate. The remaining steps are the same as in Example 1.

[0088] In April 2023, the survey results for Example-5 and Comparative Examples 1-5 are shown in Table 1.

[0089] variety Mazhu Green bamboo Cizhu Bamboo pole Diao Si Zhu Mazhu Mazhu Mazhu Mazhu Mazhu Bamboo shoot sprouting rate (%) 94 92 92 90 93 41 52 78 65 70 Average number of shoots produced (per clump) 8-12 7-10 9-11 7-10 9-11 2-4 3-5 6-8 6-8 6-9 Average diameter at breast height (DBH) in Hsinchu (cm) 5.8 4.2 4.8 5.6 5.7 3.2 4.1 5.0 4.9 4.6 Chest diameter recovery rate (vs. Lao Zhu) 93.5% 93.3% 96.0% 93.3% 95.0% 51.6% 66.1% 80.6% 79.0% 74.2% Average culm height in Hsinchu (m) 7.5 6.1 7.2 8.5 7.8 4.1 5.0 6.2 6.0 5.8 High culm recovery rate (vs. old bamboo) 96.2% 96.8% 96.0% 94.4% 95.1% 52.6% 64.1% 79.5% 76.9% 74.4% Percentage of Grade A Bamboo (%) 85 83 90 86 88 35 50 68 65 62 Bamboo shoot emergence time (vs. Comparative Example 1: number of days in advance) 21 days —— —— —— —— —— 6 days 15 days 8 days 7 days Bamboo shoot withdrawal rate (%) 3 3 5 5 3 30 30 18 20 15 Recovery period to pre-degradation level (in years) 2 2 2 2 2 ＞4 4 3.5 3 3

[0090] Note: (1) Diameter at breast height recovery rate = average diameter at breast height of new bamboo / average diameter at breast height of old bamboo × 100%; culm height recovery rate = average culm height of new bamboo / average culm height of old bamboo × 100%;

[0091] The average diameter at breast height (DBH) / culm height of the original old bamboo was taken as the level before degradation: Example 1 and Comparative Examples 1-5 were 6.2cm / 7.8m; Example 2 was 4.5cm / 6.3m; Example 3 was 5.0cm / 7.5m; Example 4 was 6.0cm / 9.0m; Example 5 was 6.0cm / 8.2cm.

[0092] (2) Bamboo shoot withdrawal rate = number of non-grown bamboo shoots / total number of bamboo shoots that have emerged from the ground × 100%.

[0093] As can be seen from the data in Table 1, especially from the comparison between Example 1 and Comparative Examples 1-5,

[0094] (1) The sprouting rate of the present invention can reach 94%, indicating that the present invention has a significant synergistic effect on relieving sprouting inhibition and inducing sprouting, and the sprouting rate is significantly improved;

[0095] (2) The diameter at breast height and culm height of the new bamboo in Example 1 recovered to 93.5% and 96.2% of the pre-degeneration level, respectively, which is far better than the data of Comparative Examples 1-5, indicating that the dual influence of sprouting promoter and soil improvement has an irreplaceable role in the continuous healthy growth of new bamboo;

[0096] (3) The bud drop rate of Example 1 was only 3%, which was much lower than that of Comparative Example 1, Comparative Example 2 and Comparative Example 4, indicating that the bud-promoting agent of the present invention, especially the stress-inducing effect of 5-ALA, can significantly enhance the stress resistance of new bamboo under the synergistic effect of soil improvement.

[0097] In summary, this invention achieves rapid rejuvenation and efficient cultivation of degenerated clump-forming bamboo through diagnostic grading, clump harvesting, rhizosphere sprouting promotion, soil improvement, targeted bamboo tending, and rotational management.

Claims

1. A method for efficient cultivation of clump-forming bamboo based on clump harvesting, characterized in that: Using naturally growing bamboo clumps as the basic unit, the bamboo clumps are divided into two levels: healthy clumps and severely rejuvenated clumps. During the winter dormancy period, the severely rejuvenated clumps are harvested in their entirety. The remaining bamboo shoot stumps are sterilized and preserved, and a sprouting agent is applied and injected into the stumps. The harvested clumps are then deeply tilled and the soil is loosened. Organic improved substrate is applied and covered with a heat-insulating and moisture-retaining layer. The sprouting dynamics of new bamboo shoots are monitored, and the selection and retention of individual plants, pest and disease control, and water and fertilizer regulation are carried out to cultivate a new generation of bamboo clumps. The main steps include: (1) Diagnosis and grading: Using naturally growing bamboo clumps as the basic unit, we investigated and observed their age structure, shoot growth potential and pest and disease status, and divided the bamboo clumps into two levels: healthy clumps and severely rejuvenated clumps. (2) Clump harvesting: During the winter dormancy period, the entire clump of severely rejuvenated clumps is harvested to form an independent clump harvesting site; during harvesting, the entire above-ground bamboo plants of severely rejuvenated clumps are removed, and old bamboo stumps older than 3 years are selectively dug up, while bamboo stumps ≤ 2 years old are retained. (3) Rhizosphere sprouting: After sterilizing and preserving the bamboo shoots retained in step (2), a sprouting agent is applied and injected into the bamboo shoots to induce the latent buds to sprout. (4) Soil improvement: Deeply till and loosen the soil in the clump-like logging area, apply organic improvement substrate, and cover with a heat-insulating and moisture-retaining layer; (5) Targeted bamboo cultivation: Monitor the sprouting dynamics of new bamboo shoots, select and retain plants, control pests and diseases, and regulate water and fertilizer to cultivate a new generation of bamboo clumps.

2. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The grading criteria for step (1) are as follows: a bush is considered severely rejuvenated if it meets any of the following conditions, and otherwise it is considered a healthy bush: a. The average age of the bamboo clump is ≥5 years, and the proportion of old bamboo (3 years or older) exceeds 60%; b. The average number of bamboo shoots per mu (unit of land area) is less than 40% of the normal level for two consecutive years, or the diameter at breast height (DBH) of new bamboo is less than 70% of that of old bamboo; c. Bamboo clumps that are flowering or have more than 30% dead bamboo stalks, or that have been severely infected by pests and diseases and are difficult to recover through individual plant treatment.

3. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: Step (2) involves harvesting the entire clump by cutting all the above-ground bamboo stalks of the severely rejuvenated clump from the base and removing them from the forest. When cutting, the stump height should be less than 5cm, the cut section should be flat, and the angle of inclination with the horizontal plane should be 10°-15° to facilitate drainage. The surface debris and residual bamboo stumps should be cleared to expose the underground stem system of the bamboo clump. For old bamboo stumps that are older than 3 years, they should be dug up and removed by mechanical or manual means, and the removal depth should not exceed 40cm below the ground surface to avoid excessive damage to the root network.

4. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The bamboo shoot stump mentioned in step (2) refers to the residual tissue at the base of 1-2 year old bamboo culms, which is plump, non-lignified or slightly lignified.

5. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The content of each raw material in the sprouting agent mentioned in step (3) is: 50-100mg / L 6-BA + 10-20mg / L NAA + 10mg / L boric acid + 10mg / L zinc sulfate + 20mg / L 5-ALA, pH adjustment: 5.8-6.

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6. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The organic improved substrate in step (4) is made by mixing decomposed bamboo chips, fungal residue and wood ash in a weight ratio of 4:3:1, and adding a small amount of superphosphate; the thickness of the heat preservation and moisture retention layer is 8-12cm, and the material is black degradable mulch film combined with straw or pure organic covering.

7. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The selection and retention of bamboo shoots in step (5) follows the principle of "removing the weak and retaining the strong, and evenly distributing them". Specifically, among the new bamboo shoots that sprout in the current year, 2-3 strong mother bamboo shoots / clumps should be retained, and the remaining weak and diseased bamboo shoots should be removed as soon as possible. The retained new bamboo shoots should be evenly distributed radially around the center of the original bamboo clump to avoid uneven growth.

8. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: After diagnosis and classification in step (1), only 20%-30% of the severely rejuvenated thickets in the basic unit are harvested in clump form each year, and managed on an annual rotation basis; to ensure that the entire forest stand maintains a canopy closure of more than 70% at any time.

9. The method for efficient cultivation of clump-forming bamboo based on clump harvesting according to claim 1, characterized in that: The clump-forming bamboo mentioned is any one of the following varieties: Bambusa textilis, Bambusa fasciata, Bambusa ventricosa, Bambusa textilis, or Bambusa ventricosa.

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