Water and soil conservation and carbon sequestration and sink increase improvement method for Nanling mountain degraded agriculture and forestry compound system

Abstract

The invention relates to the field related to ecology and environment, and provides a water and soil conservation and carbon sequestration and sink increase improvement method for a Nanling mountain degraded agriculture and forestry composite system, which comprises the following steps: aiming at Nanling mountain degraded agriculture and forestry composite system treatment, fully considering the combination of engineering and vegetation measures, comprehensively planning ecological benefits and economic benefits, and improving the water and soil conservation and carbon sequestration and sink increase. Through the technical methods of'farmland rice straw square and slope melastoma dodecandrum vegetation covering ', 'fungus planting in pine forest land under forest and application of solid waste such as farmland rice hulls and straws to construction of fungus culture media' and the like, on one hand, land surface covering is increased, runoff is regulated and controlled, erosion is reduced, and the water and soil conservation function is enhanced; meanwhile, the treatment cost is reduced, the COemission is reduced, the carbon sink function of the system is enhanced, and the ecological benefits are improved. On the other hand, the resource utilization efficiency in the degeneration system is also improved, the product output of vegetation treatment measures is enhanced, the economic benefit is further improved, and finally the stability of the Nanling mountain degeneration agriculture and forestry composite ecological system is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ecology and environment, in particular to a method for improving soil conservation and carbon sequestration of a degraded agroforestry system in Nanling mountainous area. BACKGROUND

[0002] The red soil slope in Nanling mountainous area is seriously degraded and eroded due to long-term unreasonable agricultural and forestry activities. Traditional management measures are costly and have limited ecological benefits. Meanwhile, the mode of straw burning and returning to field aggravates carbon emissions. The existing technology fails to effectively balance ecological and economic benefits, and there is an urgent need for a low-cost, high-adaptability and carbon sink function-considered restoration method. SUMMARY

[0003] Therefore, the present application provides a method for improving soil conservation and carbon sequestration of a degraded agroforestry system in Nanling mountainous area to solve the above technical problems.

[0004] In order to achieve the above purpose, the present application adopts the following technical solution: a method for improving soil conservation and carbon sequestration of a degraded red soil slope in Nanling mountainous area, comprising the following steps: Step one: through the cooperation of engineering and vegetation measures, the combination of arbor-shrub-grass composite vegetation, the composite consideration of agroforestry ecosystem, and the comprehensive balance of ecological and economic benefits; Step two: developing under-forest economy by planting fungi under pine forest, and fully utilizing solid waste such as rice hulls and straws in farmland to construct culture medium for fungi, so as to construct a resource recycling system; Preferably, a arbor-shrub-grass composite vegetation structure is constructed, which significantly increases the ground coverage, including: By planting shade-tolerant and water-soil conservation strong native herbaceous plants between fruit tree rows and under forest, the developed root network effectively intercepts surface runoff and reduces soil erosion.

[0005] Preferably, the native herbaceous plants are specifically Geum aleppicum and Ampelopsis grossve-nidia.

[0006] Preferably, the composite consideration of agroforestry ecosystem and the comprehensive balance of ecological and economic benefits in step one are specifically: by changing the traditional mode of straw burning and returning to field in Nanling mountainous area farmland system, exploratory use of rice field straw to construct grass lattice and slope Geum aleppicum vegetation coverage, increase ground coverage, enhance water and soil conservation function, and improve ecological benefits.

[0007] Preferably, the use of rice field straw to construct grass lattice in step one is specifically: collecting rice field straw in Nanling mountainous area, drying and bundling, and then weaving into grass lattice according to 1.25m x 1.50m specifications, with a grass lattice width range of 0.10m-0.20m, and fixed on the degraded slope.

[0008] Preferably, the slope mulberry vegetation cover in step one specifically involves sowing mulberry in the gaps between the grass squares to form a composite cover layer of grass square framework and mulberry vegetation.

[0009] Preferably, in step two, solid waste such as rice husks and straw from the degraded system is used to construct a culture medium for fungi, taking advantage of the shaded environment under the forest to reduce cultivation costs, and fungi are planted under the degraded pine forest.

[0010] The beneficial effects of this invention are: This invention utilizes a technique combining paddy field straw checkerboard grids with slope mulch, which significantly reduces the construction cost of traditional slope management methods using concrete grids and vegetation cover, while simultaneously enhancing the slope's resistance to water erosion. Furthermore, this technique also reduces the need for straw burning and returning to the fields in the Nanling Mountains agricultural system, thereby decreasing direct CO2 emissions into the atmosphere.

[0011] This invention combines paddy field straw grids with local native plant *Gnaphalium affine* vegetation cover, which can not only fully utilize the efficiency of farmland straw resources and enhance economic and ecological benefits, but also allow the *Gnaphalium affine* vegetation covering the slopes to play its economic and ecological role.

[0012] The *Gnaphalium affine* in this invention is an indicator plant for acidic soils and has excellent value for soil and water conservation. The red soil slopes of the Nanling Mountains are mostly acidic or slightly acidic, making *Gnaphalium affine* a very suitable native species for the area. *Gnaphalium affine* blooms with purplish-red flowers from May to July and bears fruit from July to September. The fruit and the whole plant can be used medicinally. It has good ornamental value and is a good source of nectar for bees. At the same time, the fruit and the whole plant have high medicinal value, which can fully realize its economic value in this method.

[0013] This invention utilizes techniques such as "farmland rice straw checkerboard + slope mulch" and "understory fungi cultivation in pine forests + using rice husks and other solid waste from farmland as a culture medium for fungi." These methods regulate surface runoff, reduce soil erosion, and significantly improve soil and water conservation efficiency. Simultaneously, they reduce the cost of ecological governance measures and decrease CO2 emissions directly into the atmosphere from traditional straw burning and returning to the field, significantly enhancing the carbon sequestration function of the ecosystem. Ultimately, this leads to improved stability of the degraded agroforestry ecosystem in the Nanling Mountains. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process structure of the present invention. Detailed Implementation

[0015] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0016] like Figure 1 As shown, this invention provides a method for soil and water conservation and carbon sequestration enhancement in degraded agroforestry systems in the Nanling Mountains, comprising the following steps: Step 1: By combining engineering and vegetation measures, integrating tree-shrub-grass composite vegetation, and taking into account the comprehensive agricultural and forestry ecosystem, ecological and economic benefits are fully considered. Step 2: By cultivating fungi under the pine forest, we can develop the understory economy, make full use of solid waste such as rice husks and straw from farmland to construct a culture medium for fungi, build a resource recycling system, increase the utilization efficiency of resources within the system, give full play to its economic value and ecological benefits such as soil and water conservation and carbon sequestration, and thus enhance the stability of the entire agroforestry system. Constructing a tree-shrub-grass composite vegetation structure significantly increases ground cover, including: Planting shade-tolerant, water-retaining, and soil-stabilizing native herbaceous plants between fruit tree rows and under forest can effectively intercept surface runoff and reduce soil erosion through their extensive root networks.

[0017] The native herbaceous plants are specifically *Gnaphalium affine* and Virginia creeper.

[0018] The plant residues specifically include green manure crops, weeds, and harvested crop straw.

[0019] refer to Figure 1 As shown, the comprehensive consideration of the forest ecosystem in step one, and the overall planning of ecological and economic benefits, specifically involves: changing the traditional straw burning and returning to the field model of farmland system in the Nanling Mountains, exploring the use of paddy field straw to construct grass grids + slope mulberry vegetation cover, increasing surface coverage, enhancing soil and water conservation function, and improving ecological benefits. The agroforestry system takes into account resource allocation, and the technical method of paddy field straw grid + slope vegetation cover has greatly reduced the construction cost of the traditional slope treatment method of concrete grid + slope vegetation cover, while significantly improving the ability of slope treatment measures to resist water erosion. The use of rice paddy straw checkerboard + slope mulching with ground ivy vegetation not only reduces the traditional practice of burning and returning straw to the field in the Nanling Mountain area, but also reduces CO2 emissions directly into the atmosphere. The combination of rice paddy straw checkerboard and local native ground ivy vegetation mulching can fully utilize the efficiency of farmland straw resources, improve economic value and ecological benefits, while the ground ivy vegetation covering the slope can also play its economic and ecological role.

[0020] The specific steps of constructing straw grids using paddy field straw in step one involve collecting paddy field straw from the Nanling Mountains, drying and bundling it, and then weaving it into straw grids with a size of 1.25m × 1.50m. The width of the straw grids ranges from 0.10m to 0.20m, and they are then fixed to the degraded slope.

[0021] The specific steps are as follows: After rice harvesting, collect rice straw from the field and spread it out evenly to dry until the moisture content is below 15%; bundle the dried straw into bundles with a diameter of about 5-8cm, and weave them into a grid of 1.25m × 1.50m straw squares along the contour lines of the slope; the width of the straw squares should be between 0.10m and 0.20m, and the anchoring depth should be no less than 20cm to ensure that the straw squares are close to the ground surface; the density of the straw squares can be adjusted according to the slope.

[0022] refer to Figure 1 As shown, the specific steps of slope vegetation cover in step one are as follows: Sowing *Rhizophora stylosa* in the gaps between the grass squares to form a composite cover layer of grass square framework and *Rhizophora stylosa* vegetation; *Rhizophora stylosa* is an indicator plant for acidic soils and has good water and soil conservation value, while the soils of the Nanling red soil slopes are mostly acidic or weakly acidic, making *Rhizophora stylosa* a very suitable native species for the area; *Rhizophora stylosa* plants bloom with purplish-red flowers from May to July and bear fruit from July to September. The fruit and the whole plant can be used medicinally, making it not only a good ornamental plant and a good source of nectar, but also a plant with high medicinal value, thus fully leveraging its economic value in this method. Ground ivy is a wild herb or shrub widely distributed in southern China. It has many interesting aliases, such as ground ivy, ground pomegranate, ground red flower, and mountain ivy. It prefers warm and humid environments, is tolerant of poor soil and drought, and is often found growing wild on grassy slopes, hillside thickets, roadsides, and field ridges. It is an indicator plant for acidic soils.

[0023] Planting *Gnaphalium affine*: Dig planting holes 10-15cm deep in the center and edge gaps of each grid of the grass checkerboard; apply 100-200g of well-rotted organic fertilizer to each hole and mix it evenly with the topsoil; plant using *Gnaphalium affine* cuttings or seeds. If using cuttings: Select healthy, disease-free, semi-lignified branches, cut them into 10-15cm long cuttings, plant 3-5 cuttings per hole, cover with soil, compact, and water thoroughly to settle the roots. If using seeds: Mix the seeds of *Gnaphalium affine* with fine sand in a 1:3 ratio and sow them evenly in the hole, covering them with 0.5-1cm of soil.

[0024] The best time to plant is in spring (March-April) or autumn (September-October). The soil should be kept moist for the first two months after planting.

[0025] refer to Figure 1As shown, step two involves cultivating fungi under the pine forest to develop the understory economy. This fully utilizes solid waste such as rice husks and straw from farmland to construct a culture medium for fungi, thereby building a resource recycling system, increasing the efficiency of resource utilization within the system, and fully leveraging its economic value and ecological benefits such as soil and water conservation and carbon sequestration, ultimately enhancing the stability of the entire agroforestry system.

[0026] refer to Figure 1 As shown, in step two, the fungi are planted under degraded pine forests, taking advantage of the shaded environment under the forest to reduce cultivation costs; agricultural waste rice husks and straw (70%), pine sawdust (20%) and humus (10%) are used as raw materials, which are fermented and used as substrate for the fungi bags to realize the resource utilization of agricultural waste. After mixing the raw materials, adjust the moisture content to 60-65%, and add 1-2% lime to adjust the pH to 6.5-7.0.

[0027] Ferment in piles for 20-30 days, turning the pile over every 5-7 days during this period. It can be used when the pile temperature drops to room temperature and there is no ammonia smell. Understory planting management: Select a clearing under a pine forest with a canopy density of 0.6-0.7, clear the surface weeds, and dig a planting trench 15-20cm deep. Fill the fermented culture medium into mushroom bags (20×40cm) and inoculate with suitable spawn such as oyster mushrooms or shiitake mushrooms; place the mushroom bags in a triangular pattern in the planting trench and cover the surface with 1-2cm of soil; maintain the air humidity under the forest at 70-85% during the planting period and check the growth of the mushroom bags regularly.

[0028] This invention provides a method for improving soil and water conservation and carbon sequestration in degraded agroforestry systems in the Nanling Mountains. Focusing on the restoration of degraded agroforestry ecosystems in the southern mountainous region, this technical method fully considers the coordination of engineering and vegetation measures, the integration of tree-shrub-grass composite vegetation, and the comprehensive consideration of the agroforestry ecosystem, integrating ecological and economic benefits. Through techniques such as "farmland rice straw checkerboard + slope mulch" and "understory fungi cultivation in pine forests + using rice husks and other solid waste from farmland as a culture medium for fungi," this method regulates surface runoff, reduces soil erosion, and significantly improves soil and water conservation efficiency. It also reduces the cost of ecological restoration measures and decreases direct CO2 emissions into the atmosphere from traditional straw burning and returning to the field, significantly enhancing the ecosystem's carbon sequestration function and ultimately improving the stability of degraded agroforestry ecosystems in the Nanling Mountains.

[0029] This invention combines paddy field straw grids with local native plant *Gnaphalium affine* vegetation cover, which can not only fully utilize the efficiency of farmland straw resources and enhance economic and ecological benefits, but also allow the *Gnaphalium affine* vegetation covering the slopes to play its economic and ecological role.

[0030] The *Gnaphalium affine* in this invention is an indicator plant for acidic soils and has excellent value for soil and water conservation. The red soil slopes of the Nanling Mountains are mostly acidic or slightly acidic, making *Gnaphalium affine* a very suitable native species for the area. *Gnaphalium affine* blooms with purplish-red flowers from May to July and bears fruit from July to September. The fruit and the whole plant can be used medicinally. It has good ornamental value and is a good source of nectar for bees. At the same time, the fruit and the whole plant have high medicinal value, which can fully realize its economic value in this method.

[0031] This invention utilizes techniques such as "farmland rice straw checkerboard + slope mulch" and "understory fungi cultivation in pine forests + using rice husks and other solid waste from farmland as a culture medium for fungi." These methods regulate surface runoff, reduce soil erosion, and significantly improve soil and water conservation efficiency. Simultaneously, they reduce the cost of ecological governance measures and decrease CO2 emissions directly into the atmosphere from traditional straw burning and returning to the field, significantly enhancing the carbon sequestration function of the ecosystem. Ultimately, this leads to improved stability of the degraded agroforestry ecosystem in the Nanling Mountains.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for soil and water conservation and carbon sequestration enhancement in degraded agroforestry systems in the Nanling Mountains, characterized by: Includes the following steps: Step 1: By combining engineering and vegetation measures, integrating tree-shrub-grass composite vegetation, and taking into account the comprehensive agricultural and forestry ecosystem, ecological and economic benefits are integrated. The technical method of paddy field straw grid + slope vegetation cover reduces the construction cost of the traditional concrete grid + slope vegetation cover method in slope management, significantly improves the slope's ability to resist water erosion, and also reduces the traditional burning and returning of straw to the field in the farmland system of Nanling Mountain area, thus reducing the direct emission of CO2 into the atmosphere. Step 2: By cultivating fungi under the pine forest, we can make full use of solid waste such as rice husks and straw from farmland to construct a culture medium for fungi and build a resource recycling system. Step 3: Focusing on the overall restoration of the degraded agroforestry ecosystem in the adjacent mountainous area, this step utilizes techniques such as "farmland rice straw checkerboard + slope mulch" and "understory fungi cultivation in pine forests + using solid waste such as rice husks and straw from farmland to construct fungi culture media." These methods aim to regulate runoff, reduce erosion, decrease CO2 emissions, and enhance soil and water conservation benefits. Simultaneously, they reduce the cost of ecological restoration measures, improve resource utilization efficiency within the system, increase economic benefits, and ultimately enhance system stability.

2. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 1, characterized in that: Constructing a tree-shrub-grass composite vegetation structure significantly increases ground cover, including: By planting shade-tolerant, water-retaining, and soil-stabilizing native herbaceous plants between fruit tree rows and under forest canopies, their extensive root networks can effectively intercept surface runoff and reduce soil erosion.

3. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 2, characterized in that: The native herbaceous plants are specifically *Gnaphalium affine* and Virginia creeper.

4. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 1, characterized in that: In step one, the forest ecosystem is considered in a comprehensive manner, and ecological and economic benefits are integrated. By changing the traditional straw burning and returning to the field model of farmland system in the Nanling Mountains, the use of paddy field straw to construct grass grids and slope mulberry vegetation cover is explored.

5. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 1, characterized in that: The specific steps of constructing straw grids using paddy field straw in step one involve collecting paddy field straw from the Nanling Mountains, drying and bundling it, and then weaving it into straw grids with a size of 1.25m × 1.50m. The width of the straw grids ranges from 0.10m to 0.20m, and they are then fixed to degraded slopes.

6. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 4, characterized in that: The specific steps of slope mulberry vegetation cover in step one are as follows: sowing mulberry in the gaps between the grass squares to form a composite cover layer of grass square framework and mulberry vegetation.

7. The method for soil and water conservation and carbon sequestration enhancement in the degraded agroforestry system of the Nanling Mountains according to claim 1, characterized in that: In step two, solid waste such as rice husks and straw from the degraded system's farmland is used to construct a culture medium for fungi. By leveraging the shade environment under the forest, the cultivation cost is reduced. Planting fungi under degraded pine forests can improve the soil and water conservation capacity of the slopes under the forest and also develop understory planting, thereby increasing economic benefits.

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