A method for planting grass and green manure to reduce water and soil loss of economic forest on sloping land

Abstract

The application provides a grass green manure planting method for reducing water and soil loss of economic forest on slope farmland, and belongs to the technical field of water and soil conservation. According to the fruit tree type, regional characteristics and climate conditions, the application selects suitable grass varieties according to the soil characteristics, selects suitable green manure varieties according to the nutrient requirements of the fruit tree growth, and further adjusts the planting scale of the grass and green manure according to the slope change of the slope farmland. With the increase of 1 degree of the slope of the slope farmland, the planting row spacing of the grass and green manure is reduced by 0.08-0.2 m, the planting density is increased by 3-15%, and the planting proportion of the green manure is reduced by 4-10%. The planting scale of the grass and green manure is adjusted according to the slope change, the high investment-strong competition adverse effect brought by the grass coverage is reduced or eliminated under the condition of guaranteeing the reduction of the water and soil loss of the economic forest, the soil environment is improved, the water and soil loss of the economic forest is reduced, and the green and sustainable development of the industry is promoted.

Description

Technical Field

[0001] This invention belongs to the field of soil and water conservation technology, and in particular relates to a method for planting green manure to reduce soil and water loss in economic forests on sloping farmland. Background Technology

[0002] Sloping farmland is one of the main types of arable land. However, due to its steep slope and frequent disturbance during cultivation, sloping farmland faces a high risk of soil erosion. Economic forests (orchards, camellia oleifera forests, etc.) suffer from further exacerbated soil erosion due to long-term exposed soil surfaces caused by intensive planting. Reports indicate that the soil erosion modulus of typical economic forests can reach 5000-8000 t / km². 2 This has led to a rapid thinning of the topsoil in economic forests, severe loss of soil nutrients, seriously affecting sustainable agricultural development, and also easily causing siltation in downstream river channels, seriously threatening the safety of rivers and aquatic ecosystems.

[0003] Grass mulch is a biological control technique that involves planting adapted herbaceous plants between rows of economic forests on sloping farmland or on bare ground to form a continuous or strip-shaped vegetation layer. It mitigates soil erosion through root fixation and canopy interception, offering eco-friendly benefits and significant long-term advantages. It also controls the impact of undesirable weeds on fruit trees and is convenient and economical. Currently, related technologies for grass mulch mainly focus on efficient cultivation and planting methods. CN 110476735 A discloses a method for planting grass in orchards, which involves setting up circular trenches around fruit trees for fertilization and grass planting. While this can suppress weeds around the tree base and reduce local runoff, its coverage area is limited, and there is a lack of a regulatory mechanism for nutrient competition between understory grass and crops. CN 116918628A discloses a method for efficient cultivation of orchard cover grass. By preparing the land before spring rains and planting *Ipomoea aquatica*, the seedlings are collected by the cutting method and transplanted with a row spacing of 50cm to achieve a high survival rate of *Ipomoea aquatica* in the orchard. Although this method can improve the survival rate and coverage efficiency of cover grass, it still has problems such as increased competition for nitrogen from the main crop and insufficient ecological stability due to the monoculture of grass species.

[0004] Although the ecological benefits of orchard mulch are widely recognized, its technological promotion is difficult, and its large-scale application is subject to multiple constraints. This is mainly because it conflicts with growers' traditional understanding of "clean cultivation to retain fertilizer," while also increasing production costs. Therefore, understanding the role of slope differences in regulating grass seed selection and developing an optimized "low-cost, high-efficiency, and nutrient-enhancing" mulch formulation model is of great significance for orchard soil and water conservation and agricultural ecological production safety. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method for planting grass and green manure to reduce soil erosion in economic forests on sloping farmland. By adjusting the planting scale of grass and green manure according to the slope, the adverse effects of "high input-strong competition" brought about by grass cover are reduced or eliminated while ensuring the reduction of soil erosion in economic forests. This improves the soil environment, saves production costs, reduces soil erosion in economic forests, and promotes the green and sustainable development of the industry.

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

[0007] A method for planting grass and green manure to reduce soil erosion in economic forests on sloping farmland, wherein the planting scale of grass and green manure is adjusted according to the slope variation of the sloping farmland; wherein:

[0008] For sloping farmland with gentle slopes, for every 1° increase in slope, the planting row spacing for grass and green manure decreases by 0.08–0.12 m, the planting density increases by 3%–5%, and the planting proportion of green manure decreases by 10%.

[0009] For sloping farmland with a medium slope, for every 1° increase in slope, the planting row spacing for grass and green manure decreases by 0.12–0.15 m, the planting density increases by 5%–8%, and the planting proportion of green manure decreases by 6%.

[0010] Sloping farmland is steep. For every 1° increase in slope, the planting row spacing for grass and green manure decreases by 0.15 to 0.2 meters, the planting density increases by 10% to 15%, and the planting proportion of green manure decreases by 4%.

[0011] Preferably, the slope of the gentle slope is 2 to 6°; the slope of the medium slope is 6 to 15°; and the slope of the steep slope is 15 to 25°.

[0012] More preferably, the planting row spacing for the grass and green manure on the gentle slope is 2-3m, and the planting density is 20-30 plants / m². 2 The planting ratio of grass and green manure is 10%–40% and 60%–90%, respectively.

[0013] More preferably, the planting row spacing for the medium-slope grass and green manure is 1.5–2 m, and the planting density is 30–40 plants / m². 2 The planting ratio of grass and green manure is 40%–60%.

[0014] More preferably, the planting row spacing for the grass and green manure on steep slopes is 0.5–1.5 m, and the planting density is 40–50 plants / m². 2 The planting ratio of grass and green manure is 70%–90%: 10%–30%.

[0015] Preferably, the variety of the cover grass is determined according to the climatic characteristics of the sloping farmland, including: heat-resistant cover grass varieties are selected for areas with annual precipitation ≥800mm and annual accumulated temperature above 10℃ ≥5000℃; cold-resistant and drought-resistant cover grass varieties are selected for areas with annual precipitation 400~800mm and annual accumulated temperature above 10℃ ≥2000~5000℃; and high-altitude cover grass varieties are selected for areas with altitude ≥1500m.

[0016] More preferably, the variety of the cover grass is determined according to the type of economic forest, including: evergreen economic forests select shade-tolerant cover grass varieties; deciduous economic forests select fast-growing cover grass varieties; and vine economic forests select shallow-rooted cover grass varieties.

[0017] Preferably, the variety of green manure is determined according to the nutrient requirements of the economic forest, including: nitrogen-fixing green manure varieties for nitrogen-requiring economic forests; phosphorus-solubilizing green manure varieties for phosphorus-requiring economic forests; and potassium-solubilizing green manure varieties for potassium-requiring economic forests.

[0018] Preferably, the sloping farmland is a gentle slope, with grass planted at the bottom; the sloping farmland is a medium slope, with grass and green manure mixed or intercropped in rows; the sloping farmland is a steep slope, with grass and green manure mixed.

[0019] Preferably, the economic forest is defined as a no-grass zone with a radius of 0.5 to 0.7 meters centered on the trees, where no grass or green manure is planted.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention divides the grass cover density according to the slope of economic forest, which can not only save costs, but also effectively control soil and water loss.

[0022] (2) This invention combines grass and green manure, and optimizes the combination according to the slope gradient. While preventing soil erosion, it can also provide nutrients for economic forests, enrich and improve the soil of economic forests, and improve the ecological and economic benefits of economic forests.

[0023] (3) The present invention selects suitable grass varieties based on regional climate characteristics and soil properties to further improve the effect of soil and water conservation;

[0024] (4) The present invention selects appropriate green manure varieties according to the fruit tree type and nutrient requirements, which is conducive to improving the economic benefits of economic forests. Attached Figure Description

[0025] Figure 1 This invention relates to a method for planting green manure on sloping farmland with different slopes for economic forests. Detailed Implementation

[0026] This invention provides a method for planting grass and green manure to reduce soil and water loss in economic forests on sloping farmland, adjusting the planting scale of grass and green manure according to the slope of the sloping farmland.

[0027] In this invention, economic forests refer to forests and trees cultivated and managed primarily for the production of non-timber forest products, preferably fruit orchards, including but not limited to apple orchards, citrus orchards, vineyards, pear orchards, peach orchards, walnut forests, etc.; ground cover refers to grass species used for continuous mulching to play a role in soil and water conservation, without being turned over or cut; green manure refers to grass species whose tender green plants are directly turned over or cut and used as ground cover / shallowly buried in soil for decomposition and utilization when they reach a certain stage of growth (peak flowering period or vigorous vegetative growth period).

[0028] In this invention, for gentle slopes (2-6°) with less soil erosion, it is determined that green manure is used to improve soil quality and supplement it with grass to stabilize the soil. The relationship between slope change and planting scale is as follows: for every 1° increase in slope, the planting row spacing of grass and green manure is reduced by 0.08-0.12m, the planting density is increased by 3%-5%, and the planting ratio of green manure is reduced by 10%.

[0029] In this invention, the planting row spacing for grass and green manure is preferably set to be 2-3m, and the planting density is 20-30 plants / m². 2 The planting ratio of grass and green manure is 10%–40%: 60%–90%. The planting ratio in this invention refers to the planting density (number of plants) ratio. As one possible implementation, a planting density of 30 plants / m² is used. 2 When the planting ratio of grass and green manure is 10%:90%, the planting density of grass is 3 plants / m². 2 The planting density of green manure is 27 plants / m². 2 The same principle applies to medium and steep slopes.

[0030] In this invention, for medium slopes (6-15°) with a focus on both soil improvement and soil conservation, the relationship between slope change and planting scale is as follows: for every 1° increase in slope, the planting row spacing of grass and green manure decreases by 0.12-0.15m, the planting density increases by 5%-8%, and the planting proportion of green manure decreases by 6%.

[0031] In this invention, the planting row spacing for both grass and green manure is preferably set at 1.5–2 m, and the planting density at 30–40 plants / m². 2 The planting ratio of grass and green manure is 40%–60%.

[0032] In this invention, for situations where soil erosion is severe on steep slopes (15-25°), the main focus is on soil erosion control. The relationship between slope change and planting scale is as follows: for every 1° increase in slope, the planting row spacing of grass and green manure decreases by 0.15-0.2m, the planting density increases by 10%-15%, and the planting proportion of green manure decreases by 4%.

[0033] In this invention, the planting row spacing for both grass and green manure is preferably set at 0.5–1.5 m, and the planting density at 40–50 plants / m². 2 The planting ratio of grass and green manure is 70%–90%: 10%–30%.

[0034] In this invention, the preferred varieties of cover grass are determined based on the climatic characteristics of sloping farmland and the type of economic forest; further, heat-resistant cover grass varieties are selected for areas with annual precipitation ≥800mm and annual accumulated temperature above 10℃ ≥5000℃, including but not limited to Bahia grass, orchardgrass, stylosus, and winged bean; cold-resistant and drought-resistant cover grass varieties are selected for areas with annual precipitation 400-800mm and annual accumulated temperature above 10℃ ≥2000-5000℃, including but not limited to ice grass, alfalfa, crested wheatgrass, and white clover; and high-altitude cover grass varieties are selected for areas with altitude ≥1500m, including but not limited to ryegrass, red clover, old awned wheatgrass, and Chinese sheep fescue. Further optimization should be made for evergreen economic forests (such as citrus and lychee), selecting shade-tolerant grass varieties, including but not limited to white clover, orchardgrass, carpet grass, and violet; for deciduous economic forests (such as apple trees and pear trees), selecting fast-growing grass varieties, including but not limited to ryegrass, arrowhead pea, Sudan grass, and sorghum; and for vine-type economic forests (such as grapes and kiwifruit), selecting shallow-rooted grass varieties, including but not limited to milkvetch, ryegrass, and zoysia grass.

[0035] In this invention, the preferred green manure varieties are determined based on the nutrient requirements of economic forests; further preferred varieties are nitrogen-fixing green manure varieties for nitrogen-demanding economic forests, including but not limited to milkvetch, vetch, and mung bean; phosphorus-demanding green manure varieties are selected for phosphorus-solubilizing economic forests, including but not limited to white clover, Chinese violet cress, and rapeseed; and potassium-demanding green manure varieties are selected for potassium-solubilizing economic forests, including but not limited to roton bean, sesbania, and sunflower.

[0036] In this invention, when the sloping farmland is a gentle slope, the grass is planted at the bottom of the sloping farmland; when the sloping farmland is a medium slope, the grass and green manure are mixed or intercropped in rows; when the sloping farmland is a steep slope, the grass and green manure are mixed.

[0037] In this invention, a no-grass zone is preferably defined as an area within a radius of 0.5 to 0.7 m centered on the trees in the economic forest. More preferably, an area within a radius of 0.6 m is not planted with grass or green manure to avoid competition between the fruit trees and the horizontal root systems of grass and green manure.

[0038] In this invention, it is preferable to loosen the soil and apply fertilizer in other areas of the economic forest that are not covered by grass or green manure. This invention does not have specific limitations on soil loosening and fertilizer application; conventional techniques in the field can be used depending on the specific tree species of the economic forest.

[0039] In this invention, taking into account the rapid growth rate of weeds in the early stages of planting, it is preferable to strengthen the weed clearing in the areas where grass and green manure have not been sown in the first two weeks after the sowing of grass and green manure.

[0040] Unless otherwise specified, the varieties of grass and green manure planted in this invention are all conventional materials in the field and can be purchased through commercial channels.

[0041] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0042] Example 1

[0043] A method for planting green manure to reduce soil erosion in economic forests (citrus orchards) on sloping farmland includes the following steps:

[0044] (1) Citrus is an evergreen fruit tree. The planting area is mainly distributed in the subtropical and tropical regions between 20° and 33° north latitude. The climate is mainly subtropical monsoon, with rain and heat occurring at the same time. Therefore, heat-resistant and shade-tolerant grass variety - Bahia grass - is selected for grass planting.

[0045] (2) Citrus trees have a high demand for nutrients during their growth, with nitrogen being the most important. This demand usually peaks in summer. Therefore, we choose white clover as a nitrogen-fixing green manure variety for green manure planting and turn it over in summer.

[0046] (3) On a 6° medium slope, sow Bahia grass and white clover at the same height according to the slope aspect, with a spacing of 2m and a planting density of 30 plants / m². 2 Bahia grass accounted for 40%, at 12 plants / m². 2 White clover accounts for 60%, at 18 plants / m². 2 The two are intercropped in rows; when the slope increases to 15°, the spacing is 1.5m, and the planting density is 40 plants / m². 2 Bahia grass accounted for 60%, at 24 plants / m². 2 White clover accounts for 40%, at 16 plants / m². 2 ;

[0047] (4) A no-weed zone is defined as an area within a radius of 0.6m centered on the citrus trees to avoid competition between the horizontal root systems of the trees and the grass; fertilizer is applied within the no-weed zone, either by hole application or trench application.

[0048] (5) Loosen the soil and apply base fertilizer to other areas in the orchard that are not covered by grass or green manure;

[0049] (6) In the early stage of grass seed sowing, weeds grow rapidly, so it is necessary to strengthen the weed clearing in areas where grass and green manure have not been sown.

[0050] Example 2

[0051] A method for planting green manure to reduce soil erosion in economic forests (vineyards) on sloping farmland includes the following steps:

[0052] (1) Grapes are vine fruit trees, and the planting area is mainly distributed in the southern hilly area with an annual precipitation of ≥800mm and an annual accumulated temperature of 5500℃ above 10℃. Therefore, heat-resistant, shallow-rooted grass variety - Bahia grass is selected for grass planting.

[0053] (2) Grapes have a high demand for nutrients during their growth, especially potassium, which usually reaches its peak in summer. Therefore, we choose the potassium-relieving green manure variety, sesbania, for green manure planting and turn it over in summer.

[0054] (3) On a 15° steep slope, sow Zoysia japonica and Sesbania serratifolia at the same height according to the slope aspect, with a spacing of 1.5m and a planting density of 40 plants / m². 2 Zoysia japonica accounted for 70%, with 28 plants / m². 2 Sesbania accounts for 30%, with 12 plants / m². 2 The two species are sown together; when the slope increases to 25°, the spacing is 0.5m and the planting density is 50 plants / m². 2 Zoysia japonica accounted for 90% of the total, at 45 plants / m². 2 Sesbania accounts for 10%, consisting of 5 plants per m 2 ;

[0055] (4)~(6) Same as Example 1.

[0056] Example 3

[0057] A method for planting green manure to reduce soil erosion in economic forests (peach orchards) on sloping farmland includes the following steps:

[0058] (1) Peach trees are deciduous fruit trees, and the planting area is mainly distributed in the southern subtropical region with an annual rainfall of 850 mm and an annual accumulated temperature of 5200℃ above 10℃. Therefore, heat-resistant and fast-growing grass variety - Sudan grass is selected for grass planting.

[0059] (2) Peach trees have a high demand for nutrients during their growth, with nitrogen being the most important. Therefore, we chose vetch as a nitrogen-fixing green manure variety for green manure planting.

[0060] (3) On a gentle 2° slope, Sudan grass and vetch are sown at the same height according to the slope aspect, with a spacing of 3m and a planting density of 20 plants / m². 2 Sudan grass accounted for 10%, with 2 plants / m². 2 Vetch accounts for 90%, with 18 plants / m². 2 Sudan grass is planted at the bottom of sloping farmland, with vetch sown in rows; when the slope increases to 6°, the spacing is 2.6m, and the planting density is 23 plants / m². 2 Sudan grass accounted for 50%, at 11.5 plants / m².2 Vetch plants accounted for 50%, totaling 11.5 plants / m². 2 ;

[0061] (4)~(6) Same as Example 1.

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for planting green manure to reduce soil erosion in economic forests on sloping farmland, characterized in that, Sloping farmland is divided into gentle slopes, medium slopes, and steep slopes based on its gradient, and the planting scale of cover crop and green manure is adjusted according to the slope variation; among which: The slope of the gentle slope is 2-6°, and the planting row spacing for grass and green manure on the gentle slope is 2-3m, with a planting density of 20-30 plants / m². 2 The planting ratio of grass and green manure is 10%~40%: 60%~90%; grass is planted at the bottom of sloping farmland; for every 1° increase in slope, the planting row spacing of grass and green manure decreases by 0.08~0.12m, the planting density increases by 3%~5%, and the planting ratio of green manure decreases by 10%. The slope of the medium-slope is 6-15°, and the planting row spacing for grass and green manure on the medium-slope is 1.5-2m, with a planting density of 30-40 plants / m². 2 The planting ratio of grass and green manure is 40%~60%:40%~60%; grass and green manure are mixed or intercropped in rows; for every 1° increase in slope, the planting row spacing of grass and green manure is reduced by 0.12~0.15m, the planting density is increased by 5%~8%, and the planting ratio of green manure is reduced by 6%; The steep slope has a gradient of 15-25°. The planting row spacing for grass and green manure on the steep slope is 0.5-1.5m, and the planting density is 40-50 plants / m². 2 The planting ratio of grass and green manure is 70%~90%: 10%~30%; grass and green manure are mixed; for every 1° increase in slope, the planting row spacing of grass and green manure is reduced by 0.15~0.2m, the planting density is increased by 10%~15%, and the planting ratio of green manure is reduced by 4%. The varieties of cover grass are determined according to the type of economic forest, including: evergreen economic forests should select shade-tolerant cover grass varieties; deciduous economic forests should select fast-growing cover grass varieties; and vine economic forests should select shallow-rooted cover grass varieties. The varieties of green manure are determined according to the nutrient requirements of economic forests, including: nitrogen-fixing green manure varieties for nitrogen-requiring economic forests; phosphorus-solubilizing green manure varieties for phosphorus-requiring economic forests; and potassium-solubilizing green manure varieties for potassium-requiring economic forests.

2. The method for planting green manure according to claim 1, characterized in that, The varieties of cover grass are determined based on the climatic characteristics of sloping farmland, including: heat-resistant cover grass varieties are selected for areas with annual precipitation ≥800mm and annual accumulated temperature above 10℃ ≥5000℃; cold-resistant and drought-resistant cover grass varieties are selected for areas with annual precipitation 400~800mm and annual accumulated temperature above 10℃ ≥2000~5000℃; and high-altitude cover grass varieties are selected for areas with altitude ≥1500m.

3. The method for planting green manure according to claim 1, characterized in that, The economic forest is defined as a no-grass zone with a radius of 0.5 to 0.7 meters centered on the trees, where no grass or green manure will be planted.

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