A deep layer induction method of orchard water and fertilizer based on root system complementation

Abstract

The present application relates to orchard water and fertilizer management technical field, the present application provides a kind of orchard water and fertilizer deep layer induction method based on root system complement, comprising the following steps: (1) by analyzing orchard root niche, delimit shallow ecological niche compensation area and deep ecological niche development area;(2) in shallow ecological niche compensation area sowing fibrous root system small grass, in deep ecological niche development area planting straight root system large grass;(3) after grass grows, carry out partition differentiation stimulation management;(4) after grass death decomposes, form stable and connected three-dimensional pore network in soil.The core of the present application is to accelerate the construction of structure and function complementary rotten root pore network by partition grass management, wherein shallow horizontal pore network optimizes fruit tree root zone water and fertilizer microcirculation, and deep vertical pore channel opens up water and fertilizer deep storage and drought compensation path, and cooperatively solves orchard soil hardening, low water and fertilizer utilization efficiency and seasonal drought and other problems.

Description

Technical Field

[0001] This invention relates to the field of orchard water and fertilizer management technology, and in particular to a deep induction method for orchard water and fertilizer based on root complementarity. Background Technology

[0002] Orchard soil is the foundation for fruit tree growth and development; its physical structure and ecological function directly determine water and fertilizer utilization efficiency and the tree's resilience. However, current orchard soil management generally faces structural bottlenecks, hindering the high-quality development of the industry.

[0003] First, the root system of fruit trees has a natural niche defect. The vast majority of fruit trees have taproot systems, with the main roots growing vertically downwards. This results in a lack of dense fibrous root networks in the shallow soil (0-30cm), which reduces the fruit trees' efficiency in capturing surface water and fertilizer. As a result, a large amount of water and nutrients are left on the surface and lost without being effectively utilized.

[0004] Secondly, traditional soil management practices have further deteriorated the root zone environment. Clean cultivation leads to soil exposure and structural damage, while mechanical operations cause severe soil compaction between rows, forming a physical barrier that hinders the root system of fruit trees from penetrating and water and fertilizer from seeping into the soil. Coupled with unreasonable fertilization and irrigation systems, soil properties continue to deteriorate.

[0005] To improve soil conditions, sod cultivation has been widely promoted as an alternative to clean cultivation. However, existing sod cultivation techniques have significant limitations: the selection of grass species and spatial layout lack precise design, and most orchards use a single grass species. If fibrous-rooted grasses are used, although they can improve the surface structure, they are difficult to penetrate the plow pan and cannot solve the problem of deep water and fertilizer transport and storage; if taprooted grasses are used, they easily compete with fruit trees for deep water and fertilizer and cannot form an effective shallow absorption network in the root zone of fruit trees.

[0006] Crucially, existing technologies have fundamental flaws in constructing stable, interconnected porous networks. The pores formed by grass roots rely on natural growth and decomposition, presenting three major technical bottlenecks: an excessively long formation cycle, making it unable to respond promptly to seasonal droughts; poor pore stability, as naturally decomposed pores are mostly temporary and prone to collapse and blockage, losing their water and fertilizer conduction functions; and insufficient network connectivity, making it difficult for a single grass species to form an effective interconnected network spanning upper and lower soil layers and linking vertical and horizontal directions, thus hindering the directional and efficient transport of water and fertilizer.

[0007] In summary, existing technologies fail to be scientifically designed based on the principle of complementary functions between fruit tree and grass root systems, and lack effective means to rapidly construct a stable and interconnected pore system. There is an urgent need to develop an innovative grass-planting method that, through scientific and precise spatial configuration and functional division, combined with proactive intervention measures, accelerates the construction of a stable, interconnected, and functionally complementary three-dimensional soil pore network, fundamentally breaking through the technical bottlenecks of existing orchard soil management. Summary of the Invention

[0008] The purpose of this invention is to provide a deep induction method for orchard water and fertilizer based on root complementarity. Through scientific zoning and precise management, a stable and interconnected three-dimensional pore network can be quickly constructed, thereby synergistically improving the water and fertilizer retention capacity of orchard soil and the drought resistance of fruit trees.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for deep induction of water and fertilizer in orchards based on root complementarity, comprising the following steps: (1) Based on the spatial distribution characteristics of fruit tree roots, the orchard is divided into a shallow niche compensation zone and a deep niche development zone with complementary functions. The shallow niche compensation zone is usually located within the projection range of the fruit tree canopy, while the deep niche development zone is located between the rows of fruit trees.

[0010] (2) Sow small grasses with fibrous roots (such as golden ear grass, motherwort and mouse grass) in the shallow ecological niche compensation zone to form a dense surface root network; plant large grasses with taproots (such as mugwort, hairy vetch and bamboo bean) in the deep ecological niche development zone to construct deep vertical root channels.

[0011] When sowing small grasses with fibrous roots, the seed sowing density should be controlled at 8~10g / m². 2 When planting large taproot grasses, the row spacing should be controlled at 15-30cm and the plant spacing at 10-20cm.

[0012] (3) After the grasses grow up, implement differentiated management strategies for the two functional zones. The management method is to cut and cover or cut and remove, with a frequency of 20 to 30 days / time; cut the shallow ecological niche compensation zone with low stubble (3 to 5 cm) to stimulate the density of fibrous roots; cut the deep ecological niche development zone with high stubble (5 to 10 cm) to cover or cut and remove to promote the deep rooting of the taproot.

[0013] (4) By allowing grasses to die and decompose naturally or through artificial means (such as mowing and covering the ground), a three-dimensional pore system is formed in the soil, consisting of a shallow horizontal pore network and a deep vertical pore channel. The shallow fibrous root system forms a dense horizontal interconnected pore network, which is used to store and laterally channel water and fertilizer for the fruit trees to absorb and utilize. The deep taproot system forms a vertical flow channel extending from the surface to the deep soil, which is used to quickly introduce excess water and fertilizer into the deep soil for storage, and to replenish the fruit trees upward according to the water potential gradient during drought periods.

[0014] (5) The natural death refers to the natural withering of grass; the time for artificially promoting death is before the arrival of the dry season or at the end of the grass growth period. The method for artificially promoting death is to cut all the grass stems and leaves above the soil surface in the grass planting area and use the cut grass stems and leaves to cover or remove the grass planting area.

[0015] (6) The method of artificially promoting death is: spraying a compound microbial agent before the grass dies, wherein the compound microbial agent contains Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum.

[0016] The amount of the compound microbial agent used is 60-80g / mu. Before spraying, the compound microbial agent is diluted with water 15-20 times to obtain a compound microbial agent solution, and then sprayed. The effective viable count of Bacillus subtilis in the compound microbial agent is 2.5~3.5×10⁻⁶. 10 cfu / g; The effective viable count of Trichoderma harzianum in the compound microbial agent is 1.0~1.4×10⁻⁶. 10 cfu / g; The effective viable count of *Lactobacillus plantarum* in the compound microbial agent is 1.8~2.2×10⁻⁶. 10 cfu / g.

[0017] Compared with the prior art, the present invention has the following significant advantages: (1) From experience to science, precise design was achieved: Through root ecological niche analysis, the grass covering technology was upgraded from vague experience operation to precise design based on data diagnosis, ensuring that the grass species configuration was accurately matched with the orchard site conditions and fruit tree needs.

[0018] (2) From single to system, a pore network with complementary structure and function was constructed: by planting grasses with different root configurations in different areas and implementing differentiated stimulation management, a three-dimensional pore system of "shallow optimization circulation and deep flow and storage" was actively constructed, which solved the problem of the limitation of pore function of single grass species.

[0019] (3) From passive to active, the formation of ideal pore structure is accelerated: by regulating root growth through stimuli such as mowing and guiding directional decomposition through measures to promote withering, the formation of stable and connected pore networks is significantly accelerated, enabling them to cope with seasonal drought in a timely and effective manner.

[0020] (4) Synergistic improvement of ecological and economic benefits: This method improves soil structure, increases water and fertilizer utilization, and enhances drought resistance, while reducing dependence on external irrigation and fertilizers, thus achieving synergistic growth of orchard ecological health and production economic benefits. Attached Figure Description

[0021] Figure 1To illustrate the differences in soil infiltration performance in orchards under different experimental treatments; Figure 2 To investigate the differences in soil water replenishment characteristics after water infiltration in orchards under different experimental treatments. Detailed Implementation

[0022] 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.

[0023] Example 1

[0024] A deep-layer induction method for orchard water and fertilizer based on root complementarity includes the following steps: (1) Clean the soil surface of the orchard, remove soil intrusions such as stones on the soil surface, delineate the area within the projection range of the fruit tree canopy as the shallow ecological niche compensation zone, and divide the area between the fruit tree rows into the deep ecological niche development zone. (2) In the shallow ecological niche compensation zone, according to 8g / m 2 The standard seeding of Golden Ear Grass was carried out, and Bamboo Bean was planted in the deep ecological niche development area according to the standard of 30cm row spacing and 10cm plant spacing. (3) After the grass grows up, the grass is cut every 20 days. When cutting, leave a 3cm stubble for small grasses with fibrous roots and a 5cm stubble for large grasses with taproots. Cover the cut grass stems in the original area. (4) Prepare compound microbial agent according to the standard of 60g / mu, and set aside; (5) Dilute the compound microbial agent with water 15 times to obtain a compound microbial agent solution. Spray it before the grass dies. After the grass dies and decomposes, a stable and interconnected three-dimensional pore network is formed in the soil. The shallow ecological niche compensation zone forms a horizontal pore network, and the deep ecological niche development zone forms a vertical pore channel.

[0025] Note 1: The death of grasses mentioned includes natural death and death caused by human intervention; The natural death referred to is the natural withering of grasses; The artificially induced death occurs before the dry season or at the end of the grass growth period. The method for artificially induced death is to cut all the grass stems and leaves above the soil surface in the grass planting area and remove them after cutting.

[0026] Note 2: The compound microbial agent contains Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum; The effective viable count of Bacillus subtilis in the compound microbial agent is 3.5 × 10⁻⁶. 10 cfu / g; The effective viable count of Trichoderma harzianum in the compound microbial agent is 1.4 × 10⁻⁶. 10 cfu / g; The effective viable count of *Lactobacillus plantarum* in the compound microbial agent is 1.8 × 10⁻⁶. 10 cfu / g.

[0027] Example 2

[0028] A deep-layer induction method for orchard water and fertilizer based on root complementarity includes the following steps: (1) Clean the soil surface of the orchard, remove soil intrusions such as stones on the soil surface, delineate the area within the projection range of the fruit tree canopy as the shallow ecological niche compensation zone, and divide the area between the fruit tree rows into the deep ecological niche development zone. (2) In the shallow ecological niche compensation zone, according to 10g / m 2 The standard for sowing motherwort is to plant hairy vetch in the deep ecological niche development area according to the standard of row spacing of 15cm and plant spacing of 20cm. (3) After the grass grows up, the grass is cut every 30 days. When cutting, leave a 5cm stubble for small grasses with fibrous roots and a 10cm stubble for large grasses with taproots. Remove the cut grass stems. (4) Prepare compound microbial agent according to the standard of 80g / mu, and set aside; (5) Dilute the compound microbial agent with water 20 times to obtain a compound microbial agent solution. Spray it before the grass dies. After the grass dies and decomposes, a stable and interconnected three-dimensional pore network is formed in the soil. The shallow ecological niche compensation zone forms a horizontal pore network, and the deep ecological niche development zone forms a vertical pore channel.

[0029] Note 1: The death of grasses mentioned includes natural death and death caused by human intervention; The natural death referred to is the natural withering of grasses; The artificially induced death occurs before the dry season or at the end of the grass growth period. The method for artificially induced death is to cut all the grass stems and leaves above the soil surface in the grass planting area and use the cut grass stems and leaves to cover the grass planting area.

[0030] Note 2: The compound microbial agent contains Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum; The effective viable count of Bacillus subtilis in the compound microbial agent is 2.5 × 10⁻⁶. 10 cfu / g; The effective viable count of Trichoderma harzianum in the compound microbial agent is 1.0 × 10⁻⁶. 10 cfu / g; The effective viable count of *Lactobacillus plantarum* in the compound microbial agent is 2.2 × 10⁻⁶. 10 cfu / g.

[0031] Example 3

[0032] A deep-layer induction method for orchard water and fertilizer based on root complementarity includes the following steps: (1) Clean the soil surface of the orchard, remove soil intrusions such as stones on the soil surface, delineate the area within the projection range of the fruit tree canopy as the shallow ecological niche compensation zone, and divide the area between the fruit tree rows into the deep ecological niche development zone. (2) In the shallow ecological niche compensation zone, according to 9g / m 2 Standard sowing of *Gnaphalium affine* was carried out, and *Artemisia argyi* was planted in the deep ecological niche development area according to the standard of 20cm row spacing and 15cm plant spacing. (3) After the grass grows up, the grass is cut every 25 days. When cutting, leave a 4cm stubble for small grasses with fibrous roots and an 8cm stubble for large grasses with taproots. Cover the cut grass stems in the original area. (4) Prepare compound microbial agent according to the standard of 70g / mu, and set aside; (5) Dilute the compound microbial agent with water 18 times to obtain a compound microbial agent solution. Spray it before the grass dies. After the grass dies and decomposes, a stable and interconnected three-dimensional pore network is formed in the soil. The shallow ecological niche compensation zone forms a horizontal pore network, and the deep ecological niche development zone forms a vertical pore channel.

[0033] Note 1: The death of grasses mentioned includes natural death and death caused by human intervention; The natural death referred to is the natural withering of grasses; The artificially induced death occurs before the dry season or at the end of the grass growth period. The method for artificially induced death is to cut all the grass stems and leaves above the soil surface in the grass planting area and use the cut grass stems and leaves to cover the grass planting area.

[0034] Note 2: The compound microbial agent contains Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum; The effective viable count of Bacillus subtilis in the compound microbial agent is 3.0 × 10⁻⁶. 10 cfu / g; The effective viable count of Trichoderma harzianum in the compound microbial agent is 1.2 × 10⁻⁶. 10 cfu / g; The effective viable count of *Lactobacillus plantarum* in the compound microbial agent is 2.0 × 10⁻⁶. 10 cfu / g.

[0035] Test case

[0036] The experiment was conducted from 2023 to 2024 in the Yangou watershed (N29°16' to N29°17', E115°42' to E115°43') of De'an County, Jiangxi Province. The study area has a typical subtropical humid monsoon climate with distinct rainy and dry seasons. The average annual precipitation is 1469 mm, with approximately 70% or more of the total precipitation occurring from March to August. The average annual temperature is approximately 16.7℃. The main soil type in the area is red clay, formed by the decomposition of Quaternary sediments, with a depth exceeding 100 cm. Slope agriculture is widespread in this area, and citrus orchards are the main land use type in the red soil region.

[0037] Before the experiment, a 20-mu (approximately 3.3 hectares) citrus orchard was selected, with a planting spacing of 2 m × 3 m. The orchard was then divided into three plots, each with an area of ​​2000 m². 2 The three test sites were designated as experimental groups 1 and 2, and a control group. The three test sites were adjacent, with a maximum distance of 1 kilometer, to ensure similar site conditions between the different test sites. Detailed information about the three test sites is shown in Table 1.

[0038] Table 1. Basic information of sample plots for different experimental treatments (n=5)

[0039] Experimental group 1 used the traditional orchard cover cropping method, that is, all orchards used the same cover cropping method, with bermudagrass as the grass seed and a sowing density of 10 g / m². 2 Experimental group 2 was treated using the method described in Example 3, while the control group received no treatment and was planted and managed using the clean cultivation method. Apart from the experimental treatments, other agronomic practices in the orchard, such as pruning, pest and disease control, frost protection, and fruit harvesting, remained consistent.

[0040] From July to August 2024, the infiltration performance of orchard soil was measured using a field double-ring infiltrator. After the infiltration test, vertical and horizontal soil profiles were excavated, and soil moisture content, bulk density, porosity, and organic matter content at different soil layers (0-20 cm, 20-40 cm, and 40-100 cm) were measured. Differences in soil infiltration performance, soil recharge, and physicochemical properties among different experimental treatments were systematically compared. Results are as follows: Figure 1 , Figure 2 As shown in Table 2.

[0041] Compared with the control group, both experimental groups 1 and 2 significantly improved the soil infiltration performance of the orchard (p<0.05), with initial infiltration rate, steady-state infiltration rate, and average infiltration rate increasing by 61.4%~134.9%, 17.4%~102.2%, and 47.4%~120.1%, respectively. Figure 1Furthermore, there were significant differences in the effectiveness of the two experimental groups in improving the soil infiltration performance of the orchard (p<0.05), with the order being that experimental group 2 was higher than that of experimental group 1. The initial infiltration rate, steady-state infiltration rate, and average infiltration rate of experimental group 2 were 1.46 times, 1.72 times, and 1.49 times that of experimental group 1, respectively. Figure 1 ).

[0042] Compared with the control group, both experimental groups showed higher soil recharge throughout the entire vertical profile (p<0.05), increasing by 38.2% and 107.2%, respectively. In the topsoil (0-20 cm), the difference in soil recharge between the two experimental groups was small. With increasing soil depth, the difference between the two experimental groups gradually increased. Figure 2 The control group showed lower deep soil water recharge (40-100 cm), while experimental groups 1 and 2 resulted in a greater distribution of soil water recharge in the deep soil layer (40-100 cm), which was 1.17 times and 4.00 times that of the control group, respectively. Furthermore, in terms of the proportion of soil water recharge in each soil layer, experimental group 2 was more effective in increasing deep soil water recharge (40-100 cm), with a proportion (39.1%) that was 2.25 times that of the control group and 2.44 times that of experimental group 1, respectively. Notably, experimental group 2 achieved the highest soil water recharge depth, reaching a deeper soil layer (60-100 cm).

[0043] Compared with the control group, both experimental groups resulted in lower bulk density, higher total porosity, and higher organic matter content (Table 2). Experimental group 2 significantly increased the total porosity in the 0-20 cm and 20-40 cm layers, while experimental group 1 only increased the total porosity in the 0-20 cm layer. Experimental group 2 significantly increased the organic matter content in the 20-40 cm and 40-100 cm layers, while experimental group 1 only increased the organic matter content in the 0-20 cm layer. For the organic matter content in the 40-100 cm layer, experimental group 2 was 1.54 times that of experimental group 1 and 1.60 times that of the control group, respectively.

[0044] Table 2 Soil physicochemical properties under different experimental treatments

[0045] Note: Values ​​are mean ± standard deviation (n=5). p < 0.05; , p<0.01; ns, p>0.05.

[0046] Conclusion: The method provided by this invention can increase the water and fertilizer reservoirs in deep soil, thereby effectively coping with seasonal drought, reducing irrigation demand, and improving water and fertilizer utilization efficiency.

[0047] The root system complementary configuration method provided by this invention forms a shallow horizontal pore network to optimize the water and fertilizer microcirculation in the root zone of fruit trees, and constructs deep vertical pore channels to open up deep storage and drought-replenishment pathways for water and fertilizer. This collaboratively solves problems such as soil compaction, low water and fertilizer utilization efficiency, and seasonal drought in orchards. By adopting the root system complementary configuration method provided by this invention, soil structure can be effectively improved, water and fertilizer utilization can be increased, and drought resistance can be enhanced, while reducing dependence on external irrigation and fertilizers, thus achieving synergistic growth in orchard ecological health and economic benefits.

[0048] 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 deep induction of water and fertilizer in orchards based on root complementarity, characterized in that, Includes the following steps: (1) Based on the analysis of the spatial distribution of the ecological niche of fruit tree roots, the orchard is divided into a shallow ecological niche compensation zone and a deep ecological niche development zone with complementary functions. (2) Sow small grasses with fibrous roots in the shallow ecological niche compensation zone and plant large grasses with taproots in the deep ecological niche development zone; (3) After the grass grows up, implement differentiated stimulation management for the grass in the two areas; (4) After the grasses die and decompose, a stable and interconnected three-dimensional pore network is formed in the soil, wherein the shallow ecological niche compensation zone forms a horizontal pore network and the deep ecological niche development zone forms a vertical pore channel. The shallow niche compensation zone mentioned in step (1) is located within the projection range of the fruit tree canopy, and the deep niche development zone is located between the rows of fruit trees; The species of fibrous rooted small grasses mentioned in step (2) are one or more of the following: golden ear grass, motherwort and mouse grass; The types of large taproot grasses mentioned in step (2) are: one or more of Artemisia argyi, Vigna pubescens, and Leymus chinensis; The differentiated stimulation management of grasses mentioned in step (3) is to cut and cover or remove after cutting, with a frequency of 20 to 30 days / time; for small grasses with fibrous roots, leave a stubble of 3 to 5 cm, and for large grasses with taproots, leave a stubble of 5 to 10 cm.

2. The method according to claim 1, characterized in that, The seed sowing density of the small, fibrous-rooted grasses mentioned in step (2) is 8-10 g / m². 2 .

3. The method according to claim 2, characterized in that, The row spacing for planting large taproot grasses in step (2) is 15-30cm and the plant spacing is 10-20cm.

4. The method according to claim 1, characterized in that, The decomposition of grasses in step (4) includes natural decomposition and decomposition induced by human intervention; The natural death referred to is the natural withering of grasses; The artificially induced death occurs before the dry season or at the end of the grass growth period. The method for artificially induced death is to cut all the grass stems and leaves above the soil surface in the grass planting area, and then use the cut grass stems and leaves to cover or remove the grass planting area.

5. The method according to claim 4, characterized in that, The compound microbial agent is sprayed before the grass dies, and the compound microbial agent contains Bacillus subtilis, Trichoderma harzianum and Lactobacillus plantarum; The amount of the compound microbial agent used is 60-80g / mu. Before spraying, the compound microbial agent is diluted with water 15-20 times to obtain a compound microbial agent solution, and then sprayed. The effective viable count of Bacillus subtilis in the compound microbial agent is 2.5~3.5×10⁻⁶. 10 cfu / g; The effective viable count of Trichoderma harzianum in the compound microbial agent is 1.0~1.4×10⁻⁶. 10 cfu / g; The effective viable count of *Lactobacillus plantarum* in the compound microbial agent is 1.8~2.2×10⁻⁶. 10 cfu / g.

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