A method of repairing a degraded sward by overseeding

Abstract

The application discloses a method for repairing and restoring a degraded mowing grassland to its original state, and comprises the following steps: step 1, deep cutting, a deep cutting seam with a length of not less than 10 cm is vertically cut on the surface of the degraded mowing grassland by using a disc cutter; step 2, vertical trenching, a soil and root system in the deep cutting seam is crushed by using a corrugated disc along the deep cutting seam, and the crushing depth is 6 cm to 8 cm; step 3, middle layer seedbed preparation, a T-shaped seedbed is prepared in the vertical trench by using a T-shaped seedbed preparation device in the vertical trench direction, and the seedbed depth is 4 cm to 6 cm; and step 4, blowing and pressing, blowing and fertilizing is firstly carried out along the vertical trench, and then a presser is used to press the seedbed. In the method, the cutting seam depth is increased, the soil and root system in the cutting seam is disturbed, the similar 'upper virtual lower actual' plough layer condition and the T-shaped seedbed for increasing temperature and preserving soil moisture are created, and the damage to the grassland is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of forage cultivation, and particularly relates to a method for repairing a degraded mowing and grazing grassland. BACKGROUND

[0002] In China, there are about 660 million mu of grasslands with rainfall greater than 300 mm, an altitude lower than 4000 m and a slope less than 10 degrees suitable for mechanized operation, and these grasslands are basically mowing and grazing lands (hereinafter referred to as mowing and grazing grasslands) with high productivity, which are the food fields of grass-eating livestock in pastoral areas and provide nearly 1 / 3 of beef and mutton and 1 / 4 of milk products in China. However, the mowing and grazing grasslands have been in a state of “low investment and strong utilization” for a long time, and more than 90% of the mowing and grazing grasslands are seriously degraded at present, the soil fertility declines, and the yield and quality of the forage grasses decrease, which seriously threatens the ecological safety and livestock product production of the region.

[0003] The soil of the degraded mowing and grazing grassland is compacted, high-quality forage grasses are reduced or even disappeared, and the vegetative reproduction or soil seed bank driven vegetation regeneration process of the forage grasses is hindered, so that natural repair may take hundreds of years to achieve the purpose of improving soil fertility and restoring vegetation. Using agricultural measures to loosen the soil and improve the soil fertility and using the no-tillage supplemental seeding method to reintroduce high-quality forage grasses to the degraded grassland and increase the proportion of high-quality forage grasses are basic measures to promote the repair of the degraded mowing and grazing grassland. Although the no-tillage supplemental seeding technology commonly used in ploughing can achieve the supplemental seeding and reintroduction of high-quality forage grass seeds to a certain extent, the following shortcomings exist.

[0004] Firstly, the soil of the degraded grassland is compacted, and the ordinary no-tillage supplemental seeding method has insufficient ditch depth, which is not conducive to the development of the roots of the supplemental seeding forage grasses; meanwhile, the ordinary no-tillage supplemental seeding machine uses a cutter to directly form a V-shaped seeding ditch, which not only causes the ditching component to be easily worn but also has poor soil conservation capacity.

[0005] Secondly, the forage grass seeds are small and irregular in shape, and the seed arrangement and feeding are difficult.

[0006] Thirdly, the ditch depth is uneven, resulting in poor uniformity of seedling emergence.

[0007] Meanwhile, the competition of the original plants of the degraded grassland causes the supplemental seeding forage grasses to grow weakly in the seedling stage and difficult to store enough nutrients to guarantee overwintering.

[0008] Therefore, there is an urgent need for a new method to effectively solve the problems of uneven ground surface, high soil compactness, poor seeding uniformity and low survival rate of the supplemental seeding forage grasses in the degraded mowing and grazing grassland. SUMMARY

[0009] In view of the problems in the background art, the application provides a method for repairing a degraded mowing and grazing grassland, and the technical scheme comprises:

[0010] Step 1, deep slitting, using a disc cutter to vertically cut a deep slit no less than 10 cm on the surface of the degraded pasture without ridge; the slit width is less than 1.5 cm;

[0011] Step 2, medium-deep vertical trenching along the slit, using a corrugated disc to cut the soil and roots on the inner wall of the deep slit, with a cutting depth of 6-8 cm;

[0012] Step 3, medium-level seedbed preparation along the vertical trench, using a reverse T-shaped seedbed preparation device to prepare a reverse T-shaped seedbed in the lower part of the vertical trench along the vertical trench direction, with a seedbed depth of 4-6 cm; the seedbed preparation device extrudes the loose soil cut by the corrugated disc and forms a reverse T-shaped seedbed;

[0013] Step 4, blowing seeds and fertilizers along the vertical trench, followed by using a compactor to compact the seedbed.

[0014] The disc cutter surface is smooth without corrugation, and the disc cutter edge thickness gradually decreases from the center to the edge and forms a blade at the outermost edge.

[0015] When mechanized operation is performed, multiple slits are arranged in parallel, the distance between two adjacent slits of severely degraded grassland is 15 cm, the distance between two adjacent slits of moderately degraded grassland is 20 cm, and the distance between two adjacent slits of lightly degraded or non-degraded grassland is 40 cm.

[0016] The width between the most protruding part and the most recessed part of the outer edge of the corrugated disc is 1.5-2.5 cm.

[0017] The reverse T-shaped seedbed preparation device includes a connecting rod part and a seedbed plow, wherein the connecting rod part is fixed above the top surface of the seedbed plow, the thickness of the connecting rod part is less than the width of the vertical trench, and the bottom surface of the seedbed plow forms an angle of 15°-30° with the ground; the seedbed plow extrudes the loose soil cut by the corrugated disc to the lower part of the seedbed plow, thereby forming a reverse T-shaped seedbed with a narrow upper part and a wide lower part in the lower part of the vertical trench, which has a warming and soil conservation effect, and is used to accommodate pasture seeds and seed fertilizers.

[0018] The seedbed plow is composed of a gradually expanding part in front and a rear stabilizing part, wherein the gradually expanding part is an isosceles trapezoid in plan view, and the rear stabilizing part is a rectangle in plan view, and the width of the rear stabilizing part in the left-right direction is not greater than the width of the rear part of the gradually expanding part.

[0019] The front end surface of the connecting rod part is located behind the front end surface;

[0020] The front end surface of the gradually expanding part is perpendicular to the forward direction to minimize wear; the length of the stabilizing part in the front-rear direction is 1-2 cm, and the thickness of the stabilizing part and the thickness of the gradually expanding part are both 0.5 cm to form a seedbed.

[0021] The upper end of the inverted T-shaped seedbed preparer is fixed with the single body profiling structure, and the seed guide tube is fixed at the rear of the inverted T-shaped seedbed preparer, thereby ensuring the consistency of the seeding depth; and the lowermost end of the inverted T-shaped seedbed preparer is kept horizontal with the lowermost end of the seed guide tube.

[0022] The process of blowing seeds and fertilizers into the prepared seedbed is that the seeds and the fertilizers are blown into the prepared seedbed, and are preliminarily mixed with the fine soil generated when the inverted T-shaped seedbed preparer prepares the seedbed, so that the virtual soil above the seedbed covers the surface of the seeds.

[0023] The process of using the presser to press the seedbed is that the presser is used to press the seedbed, so that the seeds in the seedbed are in close contact with the soil above and below the seeds, thereby facilitating the water absorption and germination of the seeds; the outer edge of the press wheel is in the shape of "U", and the thickness of the press wheel is consistent with the width of the connecting rod of the inverted T-shaped seedbed preparer.

[0024] The beneficial effects of the present application are that:

[0025] 1. In the case of no ridge ploughing on the grassland surface, the depth of the cutting slit is increased, the disturbance to the soil and the root system in the cutting slit is increased, the inverted T-shaped seedbed similar to the farmland soil is created, the uniformity of the cutting depth is improved, the grass seeds are precisely blown into the cutting slit, and then the favorable soil environment is created for the germination and growth of the grass seeds, so that the seedling emergence rate, the survival rate and the overwintering rate of the pasture grass are improved, and the success rate of repairing the degraded and mowed grassland is increased. The above cutting components are arranged in line, and the bottom end of the disc cutter is lower than the bottom end of the corrugated disc, and the bottom end of the corrugated disc is lower than the bottom end of the inverted T-shaped seedbed preparer + seed guide tube; the degraded and mowed grassland is not ploughed, and the damage to the grassland is reduced.

[0026] 2. The soil and the original plant root system in the cutting slit are cut again by the corrugated disc, so that the disturbance to the soil and the root system is increased as much as possible, and the similar "upper virtual and lower real" tillage layer condition to the farmland soil is prepared, which can effectively reduce the competition and exclusion of the original plants on the grassland to the supplemental sowing pasture, and promote the planting of the supplemental sowing pasture; at the same time, the cut soil can fill the gap in the deeper part of the cutting slit, prevent the seeds from falling into the bottom of the cutting slit, and cause the seeds to fail to germinate.

[0027] 3. The favorable soil environment is provided for the germination, rooting and aboveground growth of the supplemental sowing pasture, the competition with the original vegetation is avoided, the growth of the supplemental sowing pasture in the seedling stage is promoted, and the photosynthetic assimilation of the supplemental sowing pasture is accelerated; the problem that the pasture is difficult to absorb soil mineral elements due to slow root growth in the seedling stage is solved, the supplemental sowing pasture stores enough nutrients for overwintering, the planting success rate of the supplemental sowing pasture is improved, technical support is provided for the vegetation restoration and productivity improvement of the degraded and mowed grassland, and the application value and popularization prospect are great. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 This is a schematic flowchart illustrating an embodiment of a method for restoring degraded pastureland through undisturbed reseeding according to the present invention.

[0029] Figure 2 This is a schematic diagram of the narrow slit of the disc cutter in an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram illustrating how the corrugated disc shreds the soil and roots in an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram showing the position of the seed bed, seeds, and fertilizer prepared by the inverted T-shaped seed bed preparer in an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the pressurizing seedbed in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram comparing the working depth of each step in the embodiments of the present invention.

[0034] Figure 7 This is a schematic diagram of the inverted T-shaped seed bed preparer in an embodiment of the present invention.

[0035] Figure 8 This is a side view of the inverted T-shaped seed bed preparer in an embodiment of the present invention.

[0036] Figure 9 This diagram illustrates the heat preservation and moisture retention effects of the inverted T-shaped seed bed preparation device in this embodiment of the invention.

[0037] Figure 10 This is a diagram showing the heat preservation and moisture retention effect of the inverted T-shaped seed bed preparer in an embodiment of the present invention.

[0038] Among them, 1-soil, 2-fine soil and roots shredded by the corrugated disc, 3-fine soil produced when preparing the seed bed by the inverted T-shaped seed bed preparer, 4-forage seeds and fertilizer, 5-soil after being compacted by the compactor, 6-compactor, 7-disc cutter, 8-corrugated disc, 9-inverted T-shaped seed bed preparer, 91-connecting rod, 92-bed-opening plow, 921-front end face, 922-gradient expansion section, 923-stabilizing section, 10-seed guide tube, a-cutting width, b-cutting depth, c-width of the vertical groove after the corrugated disc shreds the soil and roots, d-depth of the vertical groove after the corrugated disc shreds the soil and roots, e-seed bed depth, f-width of the bottom of the seed bed. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings.

[0040] like Figures 1-8 The embodiment of the present invention shown includes:

[0041] Step 1: Deep Slotting. Using a disc cutter, make a vertical, downward cut at least 10cm deep without tilling the soil surface of the degraded pasture. The disc cutter should have a smooth, non-wavy surface, with its edge thickness gradually decreasing from the center to the edge, forming a cutting edge at the outermost edge. The slot width should not exceed 1.5cm. Figure 2 The deep cut shown has a cut width a ≤ 1.5cm, preferably 1cm, and a cut depth b ≥ 10cm;

[0042] When carrying out mechanized operations, multiple cuts are arranged in parallel. The distance between two adjacent cuts in severely degraded grassland is 15cm, the distance between two adjacent cuts in moderately degraded grassland is 20cm, and the distance between two adjacent cuts in lightly degraded or non-degraded grassland is 40cm.

[0043] Step 2: Make medium-deep vertical trenches along the cuts, and use a corrugated disc to break up the soil and roots on the inner wall of the trenches to a depth of 6-8 cm, preferably 7 cm; Figure 3 As shown, taking advantage of the compact nature of degraded grassland soil, the upper part of the deep cut is widened to a certain extent. The chopped soil and roots fall into the bottom of the deep cut under gravity, forming a vertical furrow for sowing. The width between the most convex and most concave part of the outer edge of the corrugated disc (corrugated disc width) is 1.5-2.5cm, preferably 2cm. Figure 3 The image shows the soil and roots after the corrugated disc has chopped them up. The chopped width c of the corrugated disc is the same as the width of the corrugated disc, which is 1.5-2.5cm. The chopped depth d is 6-8cm. The finely chopped soil and roots 2 are at the bottom of the vertical trench.

[0044] Step 3: Create a mid-layer seedbed along the vertical trench. Using an inverted T-shaped seedbed preparer 9, prepare an inverted T-shaped seedbed in the lower part of the vertical trench, 4-6 cm from the ground surface. The seedbed depth is 4-6 cm, preferably 5 cm. The inverted T-shaped seedbed preparer 9 used is as follows: Figure 7 and Figure 8 As shown, it includes a connecting rod 91 and a bed-opening plow 92. The connecting rod 91 is fixed above the top surface of the bed-opening plow 92. The thickness of the connecting rod 91 is less than the width of the vertical trench. The bottom surface of the bed-opening plow 92 forms an angle of 15°-30° with the ground. The bed-opening plow 92 compresses the loose soil chopped by the corrugated disc to the bottom of the bed-opening plow 92 and slightly compacts it, thereby forming an inverted T-shaped seedbed that is narrow at the top and wide at the bottom in the lower part of the vertical trench. This seedbed has the function of increasing temperature and retaining moisture and is used to hold pasture seeds and fertilizer 4.

[0045] The opening plough 92 is composed of a front expanding part 922 and a rear stabilizing part 923, wherein the expanding part 922 is an isosceles trapezoid in plan view, with a thickness of 0.5 cm and a width of 2.5-3.5 cm in the left-right direction; the front end surface 921 of the expanding part 922 is perpendicular to the advancing direction to minimize wear; the rear stabilizing part 923 is a rectangle in plan view and has the same width as the rear part of the expanding part 922; the length of the stabilizing part 923 in the front-rear direction is 0.5 cm, and the thickness of the rear stabilizing part 923 is the same as that of the expanding part 922 (0.5 cm); the front end surface of the connecting rod part 91 is located behind the front end surface 921; as shown in Figure 4 the seedbed depth is 4-6 cm, and the width of the lower part of the seedbed is the same as the width of the furrow plough 92, i.e. 2.5-3.5 cm;

[0046] In this embodiment, the upper end of the connecting rod part 91 is fixed to the single profiling structure and can move up and down with the uneven ground surface, so that the depth of the seedbed prepared thereby is consistent with the relative position of the uneven ground surface, thereby ensuring the uniformity of the planting depth.

[0047] Step 4: first blow the seeds and fertilizer into the vertical groove, and then use the roller to compact the seedbed,

[0048] The process of blowing seeds and fertilizer is as follows: the seeds and fertilizer are blown into the prepared seedbed by air and are preliminarily mixed with the fine soil 3 generated when the inverted T-shaped seedbed maker prepares the seedbed; the use of air blowing overcomes the problem of seed and fertilizer delivery caused by the small size and irregular shape of the grass seeds, thereby enabling the seeds and fertilizer to fall more accurately into the interior of the seedbed, which not only facilitates the germination of the seeds in the good soil structure created thereby, but also avoids waste of seeds, improves work efficiency, and reduces repair costs.

[0049] In this embodiment, the reference amount of brome grass seeds for sowing on severely degraded grassland is 1-1.5 kg per mu, and 3 kg of diammonium phosphate is used as seed fertilizer. After successful establishment, 10-15 kg of diammonium phosphate is applied per mu per year for topdressing. For sowing alfalfa and other legumes + grasses on moderately degraded grassland, the reference amount of alfalfa seeds is 0.5-1.0 kg per mu, and the reference amount of brome grass seeds is 0.5-0.75 kg per mu. The cross-seeding method of first sowing grasses and then sowing legumes is adopted. For each sowing, 3 kg of diammonium phosphate is used as seed fertilizer. After successful establishment, 5-7 kg of diammonium phosphate is applied per mu per year for topdressing. For sowing alfalfa and other legumes on slightly degraded or non-degraded grassland, the reference amount of alfalfa seeds is 1.0-1.5 kg per mu, and 10 kg of superphosphate is used as seed fertilizer. After successful establishment, 10-15 kg of superphosphate is applied per mu per year for topdressing.

[0050] In this embodiment, the same seed guide pipe 10 is used for blowing seeds and fertilizers, the seed guide pipe is fixed with the connecting rod part 91, and the outer diameter of the seed guide pipe 10 does not exceed the width of the vertical trench. When adjusting, the lowermost end of the inverted T-shaped seedbed preparer 9 and the lowermost end of the seed guide pipe 10 are kept horizontal.

[0051] When using the roller to compact the seedbed, as shown in Figure 5 , the seedbed is compacted using the roller to make the seeds in the seedbed tightly contact with the soil above and below, which is convenient for the seeds to absorb water and germinate. The outer edge of the roller is "U" shaped, and the thickness of the roller is consistent with the width of the connecting rod of the inverted T-shaped seedbed preparer.

[0052] As shown in the following Figure 9 , Figure 10 and Table 1, the seedbed is kept warm and the soil is kept in place. The monitoring time is from June 17, 2020 to September 6, 2020. The monitoring site is the ninth team of Teneihe Farm in Chenbaerhu Banner, Inner Mongolia Autonomous Region. The soil moisture of the seedbed created by the V-shaped furrow opener of the conventional no-tillage planter is increased by about 50%, the emergence rate and survival number of the supplemental seeding of pasture grass are increased by 50-100% compared with the conventional no-tillage planter, and the emergence rate and uniformity are significantly improved.

[0053] Table 1 Influence of new inverted T-shaped furrow opener on emergence rate and survival rate

[0054]

Claims

1. A method of reestablishing a native sod cover on a degraded pasture, the method comprising: It comprises: Step 1, deep slitting, using a disc cutter to vertically cut a deep slit of no less than 10 cm on the surface of the degraded grassland without turning the ridge, the surface of the disc cutter being smooth without corrugation; The slit width is less than 1.5 cm; Step 2, medium-deep vertical trenching along the slit, using a corrugated disc to cut the soil and roots on the inner wall of the deep slit, the cutting depth being 6-8 cm; Step 3, medium bed preparation along the vertical trench, using a reverse T-shaped bed preparation device to prepare a reverse T-shaped bed in the lower part of the vertical trench along the direction of the vertical trench, the bed depth being 4-6 cm; the reverse T-shaped bed preparation device comprises a connecting rod part (91) and a bed preparation plough (92), wherein the connecting rod part (91) is fixed above the top surface of the bed preparation plough (92), the thickness of the connecting rod part (91) being less than the width of the vertical trench, the bottom surface of the bed preparation plough (92) being at an angle of 15-30° with the ground; the bed preparation plough (92) extrudes the soil cut by the corrugated disc to the lower part of the bed preparation plough (92), thereby forming a reverse T-shaped bed with the upper part being narrow and the lower part being wide in the lower part of the vertical trench, the reverse T-shaped bed having the functions of temperature increase and soil conservation, and being used for containing grass seeds and seed fertilizer; the upper end of the reverse T-shaped bed preparation device (9) is fixed with a single body profiling structure, a seed guide tube (10) being fixed behind the reverse T-shaped bed preparation device (9) to ensure the consistency of the seeding depth; the lowermost end of the reverse T-shaped bed preparation device (9) is kept horizontal with the lowermost end of the seed guide tube (10); Step 4, seed blowing and fertilizer blowing along the vertical trench, followed by bed pressing using a presser.

2. A method of reestablishing a degraded pasture according to claim 1, wherein, The edge thickness of the disc cutter gradually decreases from the center to the edge and forms a blade at the outermost edge.

3. A method of reseeding a degraded sown pasture according to claim 1 or 2, characterised in that, When mechanical operation is performed, a plurality of slits are arranged in parallel, the distance between two adjacent slits of the severely degraded grassland being 15 cm, the distance between two adjacent slits of the moderately degraded grassland being 20 cm, and the distance between two adjacent slits of the slightly degraded grassland being 40 cm.

4. The method of reestablishing a degraded pasture according to claim 1, wherein, The width between the most protruding part and the most recessed part of the outer edge of the corrugated disc is 1.5-2.5 cm.

5. A method of reestablishing a degraded pasture according to claim 4, wherein, The bed preparation plough (92) is composed of a gradually expanding part (922) in front and a rear stabilizing part (923) integrally formed, wherein the gradually expanding part (922) is an isosceles trapezoid in plan view, the rear stabilizing part (923) being a rectangle in plan view, the width of the rear stabilizing part (923) in the left-right direction being not greater than the width of the rear part of the gradually expanding part (922).

6. A method of reseeding a degraded sown pasture to restore the original cover according to claim 5, characterised in that, The front end surface of the connecting rod part (91) is behind the front end surface (921); the front end surface (921) of the gradually expanding part (922) is perpendicular to the forward direction to minimize wear; the length of the stabilizing part (923) in the front-rear direction is 1-2 cm, and the thickness of the stabilizing part (923) and the thickness of the gradually expanding part (922) are both 0.5 cm to form the bed.

7. A method of reestablishing a degraded pasture according to claim 1, wherein, The process of seed blowing and fertilizer blowing is that the seeds and seed fertilizer are blown into the prepared bed and preliminarily mixed with the fine soil generated when the reverse T-shaped bed preparation device prepares the bed, so that the virtual soil above the bed covers the surface of the seeds.

8. A method of reestablishing a degraded pasture according to claim 1, wherein, The process for pressing the seedbed by using the presser is: the seedbed is pressed by using the presser, so that the seeds in the seedbed are in close contact with the soil above and below the seeds, and the seeds are facilitated to absorb water and germinate; the outer edge of the pressing wheel is in "U" shape, and the thickness of the pressing wheel is consistent with the width of the connecting rod of the inverted T-shaped seedbed preparation device.

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