A soil improvement method and a corn seeding method based on vertical cultivation principle

Abstract

The application provides a soil improvement method and a corn seeding method based on the vertical tillage principle, wherein straw is crushed, all the straw is returned to the field and uniformly scattered on the ground surface; combined soil preparation is carried out, and deep scarification and harrowing are sequentially carried out, the deep scarification depth reaches the plough pan, and the harrowing operation rakes part of the straw into the soil; two vertical tillage operations are carried out, part of the straw is mixed into the soil after the operation, and part of the straw is left to cover the ground surface. The soil water holding capacity can be significantly improved, the formation of large aggregates is promoted, the soil penetration resistance is reduced, the soil compaction is reduced, and the soil water erosion is reduced; and the corn seeding method provided by the application can promote the growth of the above-ground part and the root system of crops and significantly improve the crop yield.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a soil improvement method and a corn planting method based on the principle of vertical tillage. Background Technology

[0002] Black soil is a highly scarce and valuable arable land resource, often referred to as the "giant panda of arable land." It plays a fundamental supporting role in ensuring my country's food security system and is a core element for maintaining stable grain production capacity. Currently, due to long-term extensive farming practices and intensive planting, my country's black soil is experiencing widespread reductions in arable land area and soil degradation, leading to a continuous decline in overall soil productivity. Conservation tillage, centered on straw mulching, reduced tillage, and no-tillage, is the mainstream technology for conserving black soil and promoting sustainable arable land use. Because of the significant differences in natural resources, climate conditions, and soil properties across different regions of Northeast my country's black soil, conservation tillage techniques cannot be applied uniformly. They must be adapted and optimized based on regional characteristics to coordinate and manage core soil resources such as water, heat, and nutrients, achieving the dual goals of improving soil fertility and ensuring stable and increased crop yields.

[0003] The cold and humid region of Northeast my country is the core distribution area of ​​black soil, geographically encompassing Heilongjiang Province, Jilin Province, and eastern Inner Mongolia. Located between 40° and 50° north latitude, this region has a temperate humid and semi-humid continental monsoon climate. The regional climate is characterized by cold, long winters with an average annual temperature range of -5°C to 5°C, well-developed permafrost with a maximum thickness of 2.5 meters, and concentrated summer rainfall with low soil evaporation, resulting in the cultivated land maintaining a consistently low-temperature, high-humidity physical and chemical state. The soils in this region are mainly black soil, chernozem, and meadow soil, possessing abundant organic matter and excellent basic fertility, but generally exhibiting poor soil structural stability. Meanwhile, the region's arable land is mostly sloping farmland with rolling hills and valleys. Long-term heavy machinery operation and unreasonable farming methods have led to multiple soil problems, including soil structure deterioration, weakened aeration and water permeability, poor water retention, slow soil warming in spring, reduced fertility and wind erosion resistance, and restricted crop growth and reduced yield.

[0004] Currently, the most widely used tillage techniques in agricultural production in the cold and humid region of Northeast China mainly include three categories: straw removal rotary tillage, straw deep plowing, and straw full return to the field no-till technology. Each technology is suitable for different production scenarios and has its own inherent advantages. However, due to the special cold and humid environment of the region, they all have significant technical defects and cannot simultaneously meet the production needs of black soil conservation and high-quality, high-yield crops. The specific application status and drawbacks of each technology are as follows: Firstly, there is the straw removal and rotary tillage technology. This technology mainly removes crop straw from the field through burning or mechanical baling, and then uses rotary tillage equipment to till and break up the soil in the 0-15cm shallow topsoil layer. This technology is simple to operate and consumes relatively low energy for agricultural machinery operations, and can alleviate the problem of soil compaction to a certain extent. Therefore, it has a high application rate in small-scale farming in some areas. However, long-term continuous use of this tillage method will cause continuous loss of soil organic carbon, exacerbating the problem of organic matter depletion and soil fertility decline in black soil. At the same time, the shallow rotary tillage operation mode will solidify the plow pan structure, causing subsurface soil compaction and hardening, and damaging the soil profile structure.

[0005] Secondly, there is the deep plowing technique using straw. This technique involves burying shredded straw to a depth of 30cm in the soil using deep-plowing machinery after the corn harvest, and is primarily used in large-scale farms. This technique improves the compaction of the 0-30cm soil layer and properly disposes of corn straw waste, achieving basic utilization of straw by returning it to the field. However, due to the cold and humid climate of the region, the decomposition rate of the straw buried in the soil is slow, making it difficult for the straw organic matter to be effectively converted into soil nutrients, and the soil-improving effect of organic carbon cannot be fully realized. Furthermore, after deep plowing, the surface is left uncovered, resulting in a large exposed soil area that is highly susceptible to water and wind erosion, exacerbating the loss of black soil.

[0006] Thirdly, there is the no-till technology of returning all straw to the field. This technology falls under the category of conservation tillage. During the operation, crushed straw is completely covered on the surface of the cultivated land without any soil tillage. This technology can effectively resist the damage of cultivated land caused by water and wind erosion, continuously replenish the soil's organic carbon source, and achieve long-term maintenance of soil fertility. However, in the cold and humid regions of Northeast China, the soil temperature rises slowly in spring. Covering the field with straw will further block the soil from absorbing heat, and the low temperature environment is not conducive to the germination of corn seeds and the growth of seedlings. At the same time, the straw left on the surface will increase the surface roughness, interfere with the sowing operation of agricultural machinery, and make it difficult to ensure the uniformity and rate of seedling emergence in the field, which will have an adverse impact on the orderly planting in the field.

[0007] In summary, current farming techniques in the cold and humid Northeast region all have shortcomings in adaptability, failing to meet the regional characteristics of cold and humid conditions, thick permafrost, and abundant sloping farmland. This makes it difficult to simultaneously achieve the production goals of black soil improvement, soil moisture retention and fertilization, and stable and uniform corn yields. Therefore, developing a black soil conservation tillage technique adapted to the characteristics of the cold and humid Northeast region, while simultaneously considering soil conservation and corn growth, has become a pressing technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0008] This invention provides a soil improvement method and a corn planting method based on the principle of vertical tillage. By crushing and mixing straw into the field and using three-dimensional deep tillage, the ratio of straw surface cover to straw mixed into the soil is adjusted to balance the contradiction between spring warming and water erosion control. This method can effectively break up the plow pan without damaging the soil structure of the topsoil, and effectively solves the regional suitability problem of conservation tillage in the cold and humid Northeast region.

[0009] This invention provides a soil improvement method based on the principle of vertical tillage, which involves crushing straw, returning it in full to the field, and spreading it evenly on the surface. Combined land preparation operations are carried out, including deep tillage and harrowing. The deep tillage reaches the plow pan, and the harrowing removes some of the straw from the soil. Two vertical tillage operations are carried out. After the operation, some of the straw is mixed into the soil, while some straw is left to cover the surface.

[0010] This invention defines a process flow of fully crushing and returning straw to the field, followed by combined tillage and two vertical tillage operations. Firstly, fully returning straw to the field continuously replenishes soil organic carbon, improving the low organic matter content and soil degradation problems of black soil. The deep tillage operation during combined tillage breaks up the solidified plow pan, reduces the compaction of the subsoil, and improves soil aeration and water permeability. Combined with two vertical tillage operations, straw is layered and mixed into the soil, with some straw remaining as surface cover. On the one hand, this optimizes soil profile structure, improves soil water retention capacity, and alleviates the problems of cold and waterlogged soils in the cold and humid Northeast region. On the other hand, surface straw cover inhibits soil water and wind erosion, reducing black soil loss. Simultaneously, the multi-stage tillage method ensures appropriate soil compaction, avoiding the defects of traditional deep plowing that result in disordered soil structure and high penetration resistance, creating an excellent soil environment for crop root development, and achieving simultaneous improvement in soil genomics and crop yield.

[0011] According to a soil improvement method provided by the present invention, in two vertical tillage operations, the direction of the first vertical tillage operation is at a 60° angle to the direction of the second vertical tillage operation; further, the direction of the first vertical tillage operation is at a 30° angle to the ridge direction and at a 75° angle to the combined tillage direction; the direction of the second vertical tillage operation is at a 30° angle to the ridge direction and at a 15° angle to the combined tillage direction.

[0012] Limiting the two vertical tillage operations to a 60° angle alters the regular compaction patterns formed by unidirectional tillage, avoiding blind spots and directional soil compaction. This cross-angle tillage achieves comprehensive loosening of the topsoil, resulting in a more uniform spatial distribution of soil hardness and eliminating localized high-resistance, dense soil layers beneath the ridges. Simultaneously, angled tillage disrupts existing soil compaction layers, improves the uniformity of straw mixing across different soil layers, enhances water and soil transport channels, further optimizes soil pore structure, reduces root penetration resistance, and promotes uniform lateral and longitudinal root growth within the topsoil. Further defining the angle parameters between the two vertical tillage operations relative to the ridge direction and the combined tillage direction allows for precise matching to the terrain characteristics of rolling hills and slopes. This angle combination method can specifically disturb the dense soil layer in the ridge and furrow transition area, eliminating the drawbacks of concentrated resistance and uneven soil looseness under the ridge in traditional farming. At the same time, the differentiated angle operation can optimize the surface micro-topography, slow down the slope runoff velocity, strengthen the soil and water conservation capacity of farmland, and the multi-angle disturbance can improve the aeration and permeability of deep soil, improve the cold and waterlogged conditions of deep soil in cold and humid areas, and ensure the balanced distribution of water and heat resources in the topsoil.

[0013] According to a soil improvement method provided by the present invention, after two vertical tillage operations, 60% to 70% of the straw is mixed into the soil, and 30% to 40% of the straw is left to cover the surface.

[0014] The ratio of straw mixed into the soil to surface cover is limited to 60%–70% and 30%–40%, respectively, balancing the dual functions of straw decomposition and fertilization with surface insulation and moisture retention. Straw mixed into the soil continuously decomposes, replenishing organic matter, promoting the formation of large soil aggregates, and improving soil structure stability and fertility. The appropriate amount of straw left on the surface avoids the problems of slow spring temperature rise and uneven seedling emergence caused by full mulching, and also shields the topsoil layer, inhibiting rainwater erosion and wind erosion, reducing surface runoff and soil loss. This ratio is suitable for the climate characteristics of the cold and humid Northeast region, balancing soil warming, water retention, and fertilization, and avoiding the adaptability defects of traditional straw return methods.

[0015] According to a soil improvement method provided by the present invention, in the combined tillage operation, the operation direction is at a 45° angle to the ridge direction.

[0016] By limiting the direction of combined tillage operations to a 45° angle with the ridge direction, compared to parallel or perpendicular ridge tillage, oblique tillage can better adapt to the terrain of sloping farmland and reduce the erosion force of slope runoff. At the same time, oblique deep loosening and harrowing can break up the compacted hard layer formed along the ridge, expand the loose soil area, improve the uniformity of the topsoil, lay a flat and loose soil foundation for subsequent vertical tillage operations, reduce the energy consumption of mechanical operations, further optimize the soil moisture infiltration capacity, reduce surface water accumulation, and alleviate the cold water stress of soils in cold and humid areas.

[0017] According to a soil improvement method provided by the present invention, the deep loosening operation depth reaches 35cm and the harrowing depth reaches 25cm.

[0018] The deep tillage depth is limited to 35 cm, and the harrowing depth to 25 cm, creating a gradient tillage structure. Deep tillage penetrates the plow pan, thoroughly breaking up subsurface compaction and opening up water and air exchange channels in the deeper soil layers, thus improving the saturated hydraulic conductivity of the deeper soils. Harrowing breaks up and levels the middle and shallow soil layers, ensuring even mixing of straw and optimizing the looseness of the topsoil. This combination of deep and shallow tillage creates a continuous soil profile with a loose topsoil and a gentler bottoms, avoiding soil hardening caused by single-depth tillage and providing ample space for deep root extension.

[0019] According to a soil improvement method provided by the present invention, straw is crushed to 8-12cm.

[0020] The optimal length for straw crushing is 8-12 cm. Straw within this length range avoids the problem of excessive length leading to poor adhesion and gaps after being returned to the field, while also preventing excessively rapid decomposition and short organic matter retention due to excessively short lengths. Straw of this moderate length, when mixed into the soil, forms a stable porous structure, improving soil permeability. Simultaneously, the neatly arranged straw cover evenly blocks direct sunlight and rainwater erosion, providing insulation, moisture retention, and erosion prevention. This approach is well-suited to the slow decomposition of straw in the cold and humid Northeast region, extending the soil-improving effect of straw.

[0021] The present invention also provides a corn planting method, which first improves the soil of farmland using the above-mentioned soil improvement method, and then carries out ridging and planting operations.

[0022] This invention defines a sequential process of first improving the soil and then ridging and sowing. Farmland treated by the aforementioned improvement method possesses reasonable soil compaction, excellent water and air permeability, and a balanced distribution of water, fertilizer, and heat resources, resulting in significantly superior soil physical and chemical properties compared to traditional cultivated land. Ridging and sowing on this basis avoids the defects of traditional cultivation, such as soil compaction, low temperatures, and severe erosion, providing a stable and suitable soil environment for corn seedling germination and mid-to-late-stage growth, optimizing the root conditions for crop growth, ensuring uniform corn growth, and achieving stable and increased yields.

[0023] According to a corn planting method provided by the present invention, during the ridging operation, the ridge spacing is 100-120cm, the ridge height is 18-22cm, and the ridge width is 65-75cm.

[0024] The parameters for ridge spacing, ridge height, and ridge width are limited to suit maize planting patterns in the cold and humid regions of Northeast China. The wide ridge structure increases the soil's surface area exposed to sunlight, accelerating soil warming in spring and addressing the issue of low soil temperature during spring sowing in cold and humid areas. The regular ridge structure optimizes field ventilation and light penetration, reduces field humidity, and minimizes the occurrence of waterlogging-related diseases. Simultaneously, the wide ridge structure increases soil water storage capacity, enhancing water and fertilizer retention, meeting the spatial needs of maize root growth and development, and promoting the growth of the above-ground canopy.

[0025] According to a corn planting method provided by the present invention, the planting operation is carried out when the temperature of the 5cm tillage layer in the cornfield reaches 5℃ for 5 consecutive days in spring. Two rows are planted on each ridge, with a row spacing of 35~45cm.

[0026] By limiting the sowing temperature threshold and row spacing, the planting method precisely matches the climate of the cold and humid Northeast region and the growth habits of maize. Sowing when the temperature in the 5cm tillage layer is consistently 5℃ for five consecutive days can avoid low-temperature freezing damage and ensure seed germination rate and uniform emergence. The single-row, double-row sowing method with controllable row spacing can reasonably regulate the planting density in the field, optimize the competition for light, ventilation, and nutrients among plants, promote the healthy development of maize plant height, stem diameter, and leaf area index, increase dry matter accumulation, and optimize root spatial distribution, ultimately achieving increased maize yield and improved quality.

[0027] This invention provides a soil improvement method based on the principle of vertical tillage. This method involves crushing straw, returning it entirely to the field, and spreading it evenly on the surface; performing combined tillage operations, including deep tillage and harrowing. Deep tillage reaches the plow pan, while harrowing incorporates some straw into the soil. These two vertical tillage operations, with some straw mixed into the soil and some remaining on the surface, significantly improve soil water retention capacity, promote the formation of large aggregates, reduce soil penetration resistance, decrease soil compaction, and reduce soil water erosion. This invention also provides a corn planting method that promotes the growth of the above-ground parts and roots of the crop and significantly increases crop yield. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 The diagram shows the dynamic soil moisture throughout the crop growing season in Application Examples 1 and 2.

[0030] Figure 2 The temperature dynamics are shown in Application Examples 1 and 2 for the entire crop growing season.

[0031] Figure 3 The diagram shows the bulk density of farmland soil in Application Example 1 and Application Example 2.

[0032] Figure 4 The diagram shows the soil penetration resistance in Application Example 1 and Application Example 2.

[0033] Figure 5 The spatial distribution characteristics of soil penetration resistance in Application Example 1 and Application Example 2 (0 cm is the middle of the ridge).

[0034] Figure 6 The content of water-stable aggregates in soil in Application Example 1 and Application Example 2.

[0035] Figure 7 The diagram shows the saturated hydraulic conductivity of the soil in Application Example 1 and Application Example 2.

[0036] Figure 8 The diagram shows the total surface runoff during the maize growing season in Application Examples 1 and 2.

[0037] Figure 9 The aboveground growth indicators of maize are shown in Application Example 1 and Application Example 2.

[0038] Figure 10 The graph shows the dry matter content of corn in Application Example 1 and Application Example 2.

[0039] Figure 11 The diagram shows the corn leaf area index in Application Example 1 and Application Example 2.

[0040] Figure 12 The diagram shows the root system structure of corn in Application Example 1 and Application Example 2.

[0041] Figure 13 The figures show the corn yield in Application Example 1 and Application Example 2. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] This invention provides a soil improvement method based on the principle of vertical tillage. The straw is crushed, returned to the field in full, and evenly spread on the ground. Combined land preparation operations are carried out, including deep tillage and harrowing. The deep tillage reaches the plow pan, and the harrowing removes some of the straw from the soil. Two vertical tillage operations are carried out. After the operation, some of the straw is mixed into the soil, while some straw is left to cover the surface.

[0044] According to a soil improvement method provided by the present invention, in two vertical tillage operations, the direction of the first vertical tillage operation is at a 60° angle to the direction of the second vertical tillage operation; further, the direction of the first vertical tillage operation is at a 30° angle to the ridge direction and at a 75° angle to the combined tillage direction; the direction of the second vertical tillage operation is at a 30° angle to the ridge direction and at a 15° angle to the combined tillage direction.

[0045] According to a soil improvement method provided by the present invention, after two vertical tillage operations, 60% to 70% of the straw is mixed into the soil, and 30% to 40% of the straw is left to cover the surface.

[0046] According to a soil improvement method provided by the present invention, in the combined tillage operation, the operation direction is at a 45° angle to the ridge direction.

[0047] According to a soil improvement method provided by the present invention, the deep loosening operation depth reaches 35cm and the harrowing depth reaches 25cm.

[0048] According to a soil improvement method provided by the present invention, straw is crushed to 8-12cm.

[0049] The present invention also provides a corn planting method, which first improves the soil of farmland using the above-mentioned soil improvement method, and then carries out ridging and planting operations.

[0050] According to a corn planting method provided by the present invention, during the ridging operation, the ridge spacing is 100-120cm, the ridge height is 18-22cm, and the ridge width is 65-75cm.

[0051] According to a corn planting method provided by the present invention, the planting operation is carried out when the temperature of the 5cm tillage layer in the cornfield reaches 5℃ for 5 consecutive days in spring. Two rows are planted on each ridge, with a row spacing of 35~45cm.

[0052] The following is combined with Figures 1 to 13 This invention is described.

[0053] A comparative experiment on different farming methods was conducted on sloping farmland (4° slope) in Zhaoguang Farm, Bei'an City, Heilongjiang Province, to compare the effects of different farming methods on soil temperature, moisture, soil structure, crop growth and soil erosion.

[0054] The experiment included two methods: the experiential method used was the vertical tillage treatment technology (VT) provided by this invention, and the comparative method was the straw deep tillage technology (CK). Each treatment was replicated three times. Temperature and moisture sensors were installed at depths of 5, 15, 30, and 50 cm from the soil surface in each treatment plot to monitor water temperature dynamics. Simultaneously, three micro-root tubes were installed in each plot to monitor root growth dynamics. Application Examples 1 and 2 were used to sow corn in farmland treated with the two methods described above.

[0055] Example This embodiment provides a soil improvement method based on the principle of vertical tillage.

[0056] In autumn, corn is harvested using a combine harvester. The harvester is equipped with a straw crushing and spreading device, which crushes the straw to about 10cm and spreads it evenly on the ground, returning all of it to the field.

[0057] When soil moisture is suitable, a combined tillage machine is used for combined tillage operations, with the working direction at a 45° angle to the ridge direction. The deep tillage depth reaches 35cm, breaking up the plow pan, and the harrowing depth reaches 25cm, while simultaneously harrowing some straw into the soil.

[0058] Two vertical tillage operations are performed using a vertical disc harrow. The first vertical tillage operation is at a 30° angle to the ridge direction and a 75° angle to the combined tillage direction; the second vertical tillage operation is at a 30° angle to the ridge direction and a 15° angle to the combined tillage direction, with the two harrowing operations occurring at a 60° angle. After the operations, 60%–70% of the straw is mixed into the soil, while 30%–40% of the straw remains on the surface to reduce wind and water erosion.

[0059] Comparative Example This comparative example uses straw deep tillage (CK) technology to prepare farmland.

[0060] Application Example 1: Sowing operations are carried out on farmland prepared using the technical solution in the embodiments of this application. A ridging machine is used for ridging operations, with a ridge spacing of 110cm, a ridge height of approximately 20cm, and a ridge width of approximately 70cm. In spring, when the temperature in the 0-5cm tillage layer of the cornfield has remained stable at 5℃ for 5 consecutive days, a no-till seeder is used for sowing operations, with two rows sown per ridge and a row spacing of 40cm on the ridge.

[0061] Application Example 2 uses the tilled farmland prepared according to the technical scheme in the comparative example for sowing. A ridging machine is used for ridging, with a ridge spacing of 110cm, a ridge height of approximately 20cm, and a ridge width of approximately 70cm. In spring, when the temperature in the 0-5cm tillage layer of the cornfield has remained stable at 5℃ for 5 consecutive days, a no-till seeder is used for sowing, planting two rows per ridge with a row spacing of 40cm.

[0062] During the critical growth stages of maize, aboveground growth indicators such as plant height, stem diameter, leaf area index, and dry matter weight were monitored regularly. Root systems were monitored using the US-made CI-602 root system monitoring system (CID Bio-Science, Camas, WA, USA). Yield was measured after harvest. Additionally, soil samples were collected after harvest for laboratory analysis of soil bulk density, penetration resistance, and water-stable aggregates.

[0063] Figure 1 The diagram shows the dynamic soil moisture throughout the crop growing season in Application Examples 1 and 2.

[0064] from Figure 1 It can be seen that throughout the crop growing season, the soil moisture content at different depths in Application Example 1 was higher than that in Application Example 2 at the same depth.

[0065] Figure 2 The temperature dynamics are shown in Application Examples 1 and 2 for the entire crop growing season.

[0066] from Figure 2 It can be seen that the tillage methods used in the examples or comparative examples do not significantly affect soil temperature at different depths. At depths of 5 and 15 cm, the soil temperature from deep tillage is slightly higher than that from vertical tillage, but the difference is not significant. At depths of 30 cm and 50 cm, the soil temperatures are essentially the same. This indicates that surface soil temperature is affected to some extent by tillage methods and straw return to the field, while deep soil temperature is largely unaffected and exhibits relatively stable changes.

[0067] Figure 3 The diagram shows the bulk density of farmland soil in Application Example 1 and Application Example 2.

[0068] from Figure 3 It can be seen that the soil bulk density of the vertical tillage treatment (VT) in Application Example 1 is generally greater than that of the deep plowing treatment (CK) in Application Example 2, and the differences are significant in the 10-20 cm and 20-40 cm soil layers (P<0.05).

[0069] Figure 4 The diagram shows the soil penetration resistance in Application Example 1 and Application Example 2. Figure 5 The spatial distribution characteristics of soil penetration resistance in Application Example 1 and Application Example 2 (0 cm is the middle of the ridge).

[0070] from Figure 4 It can be seen that, regardless of whether it is a furrow or a raised platform, the penetration resistance of the 0-45 cm soil layer in the deep plowing treatment (CK) of Example 2 was generally greater than that in the vertical tillage treatment (VT) of Example 1 in both periods. Considering that the bulk density shows opposite trends under different tillage methods ( Figure 3This indicates that the moisture content distribution significantly affects the penetration resistance under different treatments. From Figure 5 In terms of spatial distribution, the high value area of ​​penetration resistance (red area) of CK treatment in Application Example 2 is concentrated at a depth of 15-30 cm in the middle of the ridge, while the soil penetration resistance distribution after VT treatment in Application Example 1 is more uniform.

[0071] Figure 6 Table 1 shows the content of water-stable aggregates in soil in Application Example 1 and Application Example 2; Table 1 shows the average weight diameter of soil.

[0072] Table 1. Average weight diameter of soil under different treatments

[0073] Depend on Figure 6 It can be seen that, compared with the CK treatment in Application Example 2, the VT treatment in Application Example 1 increased the proportion of aggregates >2 mm in each soil layer and decreased the proportion of aggregates <0.25 mm, and this effect was more significant in the 0–20 cm soil layer. Table 1 shows that the average weight diameter of the VT treatment in Application Example 1 was significantly higher than that of the CK treatment in Application Example 2 for each soil layer. This result indicates that the soil amendment method used in the embodiments of the present invention is conducive to the formation of large aggregates.

[0074] Figure 7 The diagram shows the saturated hydraulic conductivity of the soil in Application Example 1 and Application Example 2.

[0075] from Figure 7 It can be seen that, except for the 0-10cm soil layer, the saturated hydraulic conductivity of the soil in the vertical tillage treatment (VT) in Application Example 1 and the deep plowing treatment (CK) in Application Example 2 in the other two soil layers of 10-20cm and 20-40cm is significantly higher (P<0.05).

[0076] Figure 8 The diagram shows the total surface runoff during the maize growing season in Application Examples 1 and 2.

[0077] from Figure 8 It can be seen that the total soil erosion (soil loss) of the vertical tillage treatment (VT) in Application Example 1 is only 0.2 t / hm2, which is only 1 / 3 of the deep plowing treatment (CK) in the comparative example used in Application Example 2. This indicates that the soil improvement method used in this invention is more conducive to reducing soil erosion.

[0078] Figure 9 The aboveground growth indicators of maize are shown in Application Example 1 and Application Example 2.

[0079] from Figure 9It can be seen that throughout the growing season, the plant height and stem diameter of maize in the vertical tillage treatment (VT) of Application Example 1 were significantly higher than those in the comparative deep plowing treatment (CK) of Application Example 2.

[0080] Figure 10 The graph shows the dry matter content of corn in Application Example 1 and Application Example 2.

[0081] from Figure 10 As can be seen, similar to plant height and stem diameter, different soil treatments show similar trends in dry matter. In the example of Application Example 1, the aboveground and underground dry matter of maize treated by vertical tillage (VT) was significantly greater than that of the comparative deep plowing treatment (CK) used in Application Example 2, and this difference became more pronounced as the growth period progressed.

[0082] Figure 11 The diagram shows the corn leaf area index in Application Example 1 and Application Example 2.

[0083] from Figure 11 It can be seen that the LAI of maize planted in both Application Example 1 and Application Example 2 showed a trend of first increasing and then decreasing as the growth period progressed. In the example of Application Example 1, the maize treated by vertical tillage (VT) was significantly higher than that of the maize treated by deep plowing (CK) in the comparative example of Application Example 2 at all stages.

[0084] Figure 12 The diagram shows the root system structure of corn in Application Example 1 and Application Example 2.

[0085] from Figure 12 It can be seen that, except for the jointing stage of maize, the vertical tillage treatment (VT) in the example of application example 1 significantly increased the root length density, average root diameter, root surface area and root volume of maize in the 0-60 cm soil layer compared with the comparative deep plowing treatment (CK) in application example 2 (P<0.05).

[0086] Figure 13 The figures show the corn yield in Application Example 1 and Application Example 2.

[0087] from Figure 13 The measured yields show that the maize yield of the vertical tillage (VT) treatment used in Example 1 is approximately 13 t / hm². 2 The maize yield increased by 13.2% compared to the comparative deep plowing treatment (CK) used in Application Example 2.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soil improvement method based on the principle of vertical tillage, characterized in that, The method includes: The straw is crushed, returned to the field in full, and evenly spread on the ground. Combined land preparation operations are carried out, including deep tillage and harrowing. The deep tillage reaches the plow pan, and the harrowing removes some of the straw from the soil. Two vertical tillage operations are carried out. After the operation, some of the straw is mixed into the soil, while some straw is left to cover the surface.

2. The soil improvement method according to claim 1, characterized in that, In the two vertical tillage operations, the direction of the first vertical tillage operation and the direction of the second vertical tillage operation form a 60° angle.

3. The soil improvement method according to claim 2, characterized in that, In the two vertical tillage operations, the direction of the first vertical tillage operation was at a 30° angle to the ridge direction and at a 75° angle to the combined tillage direction; the direction of the second vertical tillage operation was at a 30° angle to the ridge direction and at a 15° angle to the combined tillage direction.

4. The soil improvement method according to claim 1, characterized in that, After two vertical tillage operations, 60% to 70% of the straw is mixed into the soil, while 30% to 40% of the straw is left to cover the surface.

5. The soil improvement method according to any one of claims 1 to 4, characterized in that, In combined tillage operations, the working direction forms a 45° angle with the ridge direction.

6. The soil improvement method according to any one of claims 1 to 4, characterized in that, The deep tillage depth reaches 35cm, and the harrowing depth reaches 25cm.

7. The soil improvement method according to any one of claims 1 to 4, characterized in that, The straw is crushed to 8-12cm.

8. A method for planting corn, characterized in that, First, the soil in the farmland is improved using any of the soil improvement methods described in 1 to 7 above, and then ridging and sowing operations are carried out.

9. The sowing method according to claim 8, characterized in that, During ridging operations, the ridge spacing is 100-120cm, the ridge height is 18-22cm, and the ridge width is 65-75cm.

10. The sowing method according to claim 8, characterized in that, During sowing operations, the operation is carried out when the temperature in the 5cm tillage layer of the cornfield reaches a stable 5℃ for 5 consecutive days in spring. Two rows are sown on each ridge, with a row spacing of 35-45cm.

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