FR2609593A1 - Method for improving, maintaining and regenerating stabilised and semi-stabilised turfed areas and appliance for implementing the method and area thus produced - Google Patents

Abstract

The invention relates to a method for improving, maintaining and regenerating turfed areas and to an appliance for implementing the method and to the area thus produced. According to the invention, the area is provided at its surface with microslits 6, 6', 7, 7' whose depth is between 4 and 15 cm and preferably of the order of 10 cm, whose width is between 1 and 3 cm and preferably of the order of 1.5 cm, the said micro-slits being spaced apart by a gap of the order of 15 to 25 cm, and the micro-slits including at their bottom a strip 8 of fertiliser in the granular state covered by a layer of silica sand 9 spilling over above ground level. The machine for implementing the method includes rotary cutters 12, 12' mounted upstream of a ploughshare 15 for tipping out the strip of fertiliser and of sand from a hopper with two compartments 18, 16 and followed downstream by compacting wheels 19, 20, 21.

Description

The present invention relates to a method, and a device for its implementation, with a view to ensuring the structural improvement of the receiving substrate of a plant cover of the lawn, lawn type, in particular in the context of maintenance, regeneration and improvement of a field constituting a green space or a sports field.

The maintenance in good condition of a grassy field intended to support walking, or repeated trampling during trips or physical exercises, poses specific problems and difficult to solve given the often difficult conditions that must endure such fields, particularly in the context of sports fields.

Current techniques aim to create, with a view to keeping such land in good condition, a structure allowing on the one hand the aeration of the support substrate of the plant cover as well as the evacuation of precipitation and runoff water.

However, it is frequent that as it is used, the land experiences vicissitudes linked to the severe conditions to which it is subjected, in particular in the case of repeated use.

And under these conditions the ground initially ventilated and provided with a draining network sees destroying or handicapping its possibilities to maintain in good condition the plant cover and to evacuate the excess waters.

This is firstly due to clogging on the surface of the drainage network, in particular at the level of the slots which are intended to collect and evacuate runoff water to direct it towards the lower draining massif, we then witness a partial waterproofing of the ground surface and the latter being no longer able to evacuate runoff water we are witnessing on the one hand a degradation by dilution of the substrate and asphyxiation of the lawn.

Once the phenomenon has started, there is a cumulative process, the partial waterproofing of the ground tending to be maintained and to increase automatically with subsequent degradation of the plant cover which in turn leads to degradation of the substrate subjected to the trampling without surface protection.

The grassy grounds serving as a surface for the exercise of sport also undergo a phenomenon of compaction as and when the repeated uses to which they are subjected the physical compaction of the soil increases the waterproofing and its degradation during precipitation; and in addition and by itself it prevents respiration and the normal development of the roots and leads to a poor state or even disappearance of the grass cover.

We are therefore led under these conditions, in the absence of a current maintenance technique, to envisage the complete repair of the ground which represents costs and an investment often disproportionate given that a sports field subjected to repeated use therefore risks to be rapidly degraded and to have, under these conditions, to be subjected to a total repair after a few years.

The invention makes it possible to resolve these drawbacks and for this purpose relates to a method allowing the creation of a substrate suitable for the development and maintenance of a grassed surface with a view to the creation of an initial surface as in the context of regeneration and maintenance of a pre-existing surface.

Under these conditions, the invention has a very wide range of indications and can be applied both at the stage of creating a sports ground or an initial green grassy surface created from scratch, just as at opportunity to restore a pre-existing grassed area, regardless of the lower structure and the drainage network that may have been set up previously.

The invention therefore represents a method of initial improvement or maintenance and regeneration of a grassy area which represents only a slight modification of the surface thus achieving a "soft medicine" of the terrain suitable for enabling it to recover its ventilation and drainage functions without modification in depth and therefore without having to question the structure of the land or to consider its total repair.

Under these conditions, the implementation of the invention proves to be light and involves only limited costs.

And the invention will be applicable, by its flexibility of use, to various types of terrain whether it is a pedestrian lawn, traditional grassed sports fields stabilized or semi-stabilized, course or "green" golf.

To this end, the invention relates firstly to a method for improving the structure of a grassy substrate with a view to the creation, maintenance or regeneration of green spaces such as lawns, sports grounds or similar, and the method is characterized in that one proceeds, by means of rotary knives mechanically driven, to the formation of parallel micro-slits which run through the whole of the ground and in that one deposits in the bottom of these micro-slots an appropriate fertilizer ribbon, the rest of the micro-slot, above the fertilizer being filled with fine sand.

Preferably, the micro-slot has a depth of between 4 and 15 cm and advantageously this depth will be of the order of 10 to 12 cm.

More particularly, the width of the micro-slot is between 0.5 and 3 cm and advantageously this thickness will be close to 1.5 cm.

The spacing between the slots, thus adjusting their density, is between 10 and 25 cm and preferably this spacing is close to 20 cm.

According to another characteristic, the sand consists of river sand of the "Loire sand" type with a fine particle size of the order of 0.6 millimeters.

According to a characteristic representing a method of implementation, the sand is mechanically packed after its installation in the receiving micro-slot.

There is also parallel sanding on the surface at the level of the micro-cracks, a thickness of sand overflowing above the level of the natural ground, and the sand thus overflowing is swept to be spread and distributed over the entire surface of the soil by covering the plants making up the lawn substantially up to the collar.

According to another feature of the invention, the fertilizer constitutes a continuous net deposited in the bottom of the slots with a thickness of a few millimeters.

And this fertilizer intended to promote the development of rooting of the lawn is based on phosphoric acid and potash.

According to another characteristic of the invention, the width of the slots is adapted to their location within the terrain, the more heavily trampled areas formed by the central third of the terrain receiving slots with a higher density (that is to say say with a smaller spacing) than the less trampled areas and formed by two lateral thirds or low sides.

The method of the invention can be used for the improvement of an existing site and provided with a drainage network comprising in particular primary slits intersecting trenches provided with evacuation drains, and in this case micro-slits are drawn on the ground perpendicularly and so as to cut all the primary slits.

 In the case where the method of the invention is used with a view to creating an initial site, in a known manner, a draining block made up of a plurality (for example 4 to 5) drainage trenches provided with a drainage drain, which are intersected by transverse primary slots, after which a network of micro-slots is cut on the surface perpendicularly intersecting the primary slots.

The invention also relates to a machine with a view to implementing the method previously specified and the machine is characterized in that it comprises mechanical drive means such as a heat engine or a hydraulic pump itself driven by a heat engine, a rotary assembly consisting of an axis carrying parallel knives, the rotary axis being mounted perpendicularly to the axis of advance of the machine, the advance of the machine and the rotation of the axis carrier of the knives being able to cut the ground to create the micro-slots, and the machine also comprises means for discharging and dispersing fertilizer in the form of granules in the bottom of the micro-slots, downstream of the knives, as well as sand pouring means filling the micro-slots above the fertilizer layer.

And according to another characteristic, the machine comprises a set of pouring and placing of fertilizer and sand, this set consisting of a hollow ploughshare forming a shoe penetrating into the micro-slot and receiving successively from the upper hoppers and in the direction of advancement of the machine, the ribbon of fertilizer poured out and placed in the bottom of the shoe and on which the layer of sand is brought.

And preferably the device comprises at least one wheel disposed at the outlet of said shoe capable of packing the sand placed in the micro-slot.

Preferably the device comprises two successive compacting wheels penetrating, at decreasing heights in the micro-slot.

And more specifically, the two compacting wheels are followed, behind, by a distribution wheel and placement of a strip of sand overflowing above the ground level.

According to another characteristic of the machine, the frame supporting the rotary knives, the hollow base and the compacting wheels is provided adjustable in height relative to the ground by a set of support jacks.

Other characteristics and advantages of the invention will emerge from the description which follows and which is given in connection with a few nonlimiting examples.

FIG. 1 represents a schematic view showing the location of the micro-slots with respect to the lower drainage network.

FIG. 2 represents a schematic view of creation and filling of the micro-slots by means of a machine according to the invention.

Figure 3 shows a schematic view of the micro-slots viewed transversely.

Figure 4 shows a detail view and the exter-eur of a shoe for placing the fertilizer and sand assembly in the micro-slot.

FIG. 5 represents a detailed perspective view of the assembly of the wheels for compacting and spreading the sand at the rear of the machine.

FIG. 6 represents a plan view of an alternative embodiment of a machine according to the invention more particularly assigned to the work of a golf "green".

FIG. 7 represents a sectional view of the machine of FIG. 6.

According to Figure 1 is shown in the lower position the conventional drainage network composed here of trenches 1.1 'constituting the draining bed, the trenches being equipped with drainage drains 2.2'.

In this draining massif penetrates through their base the primary slits 3,4 and 5 which intersect the trenches 1,1 '.

When (in the case of improvement and regeneration of a preexisting ground) the trenches 3,4 and 5, which outcrop at ground level, begin to be significantly clogged, the evacuation of water becomes more and more difficult to the point where water runoff stagnates in the event of heavy precipitation, leading to land degradation, especially if it continues to be used when the water has not been or is poorly evacuated.

These disorders can be remedied in the context of the implementation of the method according to the invention.

However, the method of the invention can also be used as a preventive measure in the context of the creation of a new site to precisely prevent the formation of the clogging phenomenon following repeated use of the site.

And according to the invention there is created on the surface of the ground a network of micro-slots, represented in the upper part of FIG. 1, these micro-slots 6,6 ′, 7,7 ′ being created in series by means mechanical and more particularly by parallel rotary knives and driven by a machine whose characteristics will be described later.

The mechanical implementation and the production of micro-slots in series allows rapid work without affecting or distorting the structure of the pre-existing network.

These micro-slots represent only a relatively minimal implantation since they represent in width a dimension comprised between 0.5 and 3 cm and for example and preferably of the order of 1.5 crr for a depth of l '' from 10 to 12 cm.

The spacing between the micro-slots is around 10 to 25 cm, for example of the order of 22 cm.

The micro-slits thus cut across the network of primary slits and makes it possible to create a surface mesh which is widely open towards the outside and therefore constituting an opening and a very large absorption capacity for the runoff water in the event of precipitation.

Figure 3 and in particular the detail view of Figure 3 shows the tillage carried out after passage of the machine and formation of the micro-slot.

It is thus seen on the only mechanical plane, that of the absorption and evacuation surfaces, that each of the vertical walls of the micro-slot, filled within it with sand, consequently allowing the flow of water, represents a capacity to absorb and evacuate excess water to the mass of the substrate and below to the lower drainage network.

Thus, without appreciably affecting the mass of the ground, an extremely large drainage surface which makes it possible to double the volume of water absorbed.

This prevents clogging or the phenomenon of clogging, that is to say the inability of the soil to ensure the evacuation of surface runoff in the event of prolonged or significant precipitation.

Of course the micro-slit, and this thanks to the interstitial sand that it contains between its walls, allows to ensure the aeration of the soil and therefore promotes the development of the roots and the good health of the plant.

In parallel and according to an important characteristic of the invention, a substantially continuous strip of granular materials constituting a fertilizer 8 has been deposited in the bottom of the micro-slot in a layer of variable thickness but of the order of a few millimeters.

The fertilizer is thus brought to a suitable depth where it can disintegrate by ensuring a supply of suitable mineral matter to the roots which are located at this level.

 The fertilizer being buried at a certain depth (of the order of 5 to 10 cm) therefore provides the food and the mineral elements necessary for the development of the roots, at a suitable depth, and such that the roots located closer to the surface will work to get closer to this source of material specific to their development; positioning the fertilizer at this depth will therefore facilitate root development in the right direction.

The density which is provided for the micro-slots, makes that all the tufts of grass will be located at a maximum of the order of 10 cm from a source of fertilizer which ensures a sufficiently dense distribution of clean mineral matter to ensure the development of grass cover.

As indicated, above the light layer of fertilizer 8 is a filling of sand, in particular silica sand of the "river sand" type and of suitable granulometry. , 6 millimeter.

This filling allows the aeration of the earth on each side of the walls of the micro-slit while ensuring the evacuation of runoff from the surface by their distribution in the mass of earth and their evacuation to the primary slits.

As can be seen in FIG. 7, the layer of sand overflows slightly relative to the level of the natural ground 10, and the surface layer 11 overflowing beyond the ground 10, is swept so as to be distributed on the surface by covering substantially the collar of the plants making up the lawn.

We see in Figure 2 the method of forming micro-slots from the knives 12,12 'mounted on a rotary support 13 lul-meme driven by the central axis 14.

On a machine the axis 14 comprises a plurality (from 4 to 12) rotors 14 carrying a set of knives.

The positioning of the knives on the rotors is offset from one rotor to the other so as to obtain an even distribution of the working effort of the machine.

Immediately downstream of the knife, the machine carries a shoe 15 (FIG. 4) made up of a hollow ploughshare penetrating into the micro-slot produced by the knife and serving for the distribution of the materials coming from the upper reserves and hoppers.

In the bottom of the shoe are poured the granules forming a continuous ribbon 8 which will be deposited in the bottom of the micro-slot. These granules constituting the fertilizer come from the reserve 16 and are conveyed by the discharge pipe 17.

The shoe 15 travels in the newly notched micro-slot and deposits between the two side walls of a Dart of the fertilizer tape 8 and on the other hand interstitial sand 9 (Figure 3).

The sand which comes from the hopper 18 is therefore thus distributed throughout the micro-slot where it is packed by the play of successive wheels 19 and 20.

The sand is poured with a flow such that it fills, being packed, the whole of the micro-slit and overflows slightly above ground level.

The rear wheel 21 ensures the equalization and distribution of the sand above and on each side of the micro-slot and the assembly is swept so as to distribute and equalize this surface layer 11 which is flush with the pasted plants making up the lawn.

As has been explained, the micro-slots thus put in place provide on the one hand a physical unclogging effect by ensuring aeration and by increasing the possibilities of evacuation of surface water while ensuring the setting in place and supplying an appropriate level of mineral matter suitable for ensuring the development of the turf cover.

However, the operation can be done easily thanks to the passage and the mechanical work carried out by the machine which is the subject of the invention and the diagram of which is shown in FIG. 2 and details of embodiment are shown in FIGS. 4 and 5.

FIGS. 6 and 7 show two views respectively in plan and in longitudinal section of a machine according to the invention and making it possible to produce micro-slots, the machine here being more particularly suitable for working on grassed surfaces such as greens of golf.

The machine is here produced in a miniaturized and compacted form allowing in particular manual guidance, the machine however being self-propelled.

However, it is easy to produce, using the same tools and the same operating principles, a machine with a supported pipe.

We find on the machine of Figures 6 and 7 the rotary earth working member for the formation of the micro-slot and consisting of knives 30,30 ', 30 "mounted on a rotor 31 itself carried by transverse axis 32.

Downstream the hopper 33 pours into the slot 34 obtained by working the knives, a flow of sand 35 subjected to compaction by the wheels 36,37; the latter forming the rear wheel to a wider tread extends beyond each side of the slot, being located above the slot while the upstream wheel 36 penetrates inside the slot to ensure the compaction of the sand.

The height positioning of the chassis 38 carrying the knives, wheels and hoppers can be adjusted by a jack system resting on the support assembly formed by the rear wheels.

The assembly is driven by a heat engine which actuates a hydraulic pump providing and transmitting energy to the entire machine, in particular to the axis 32 carrying the knives as well as to the axis driving the driving wheels, thus easily controlled from a control body within the mechanic's reach.

This machine can thus work a surface according to a desired length by creating the micro-slots in which the sand is deposited possibly and advantageously accompanied by a bottom of fertilizer in the form of granules.

The invention and its implementation resulting in only a superficial work of the ground makes it possible to ensure its regeneration, its unclogging and its aeration without deeply modifying the structure of the ground.

 Under these conditions, the process of the invention can be easily renewed at regular intervals, that is to say after several years, depending on the intensity of use.

We understand that the micro-slots can, after a few years of intensive use, disperse in the mass of the ground by exhausting their effects.

But it is then easy to pass the machine again to recreate a network of micro-slots in a direction, for example perpendicular to the initial micro-slots.

We then find the effects of aeration and unclogging as well as enrichment of the substrate and subsequent development of the grass cover.

The treatment can thus be repeated regularly without causing or modifying in depth the structure of the ground and the repetition of this treatment can be carried out without limitation.

So that the process of the invention is presented as a particularly effective regular maintenance technique acting in depth and without harmful adverse effect.

The invention will be applicable to the work of any grassed surface and subject to trampling and will receive numerous applications even outside sports grounds, for example on racetracks, golf, tennis or camping.

The machine can include numerous developments, for example the rotors carrying the knives can include ancillary equipment such as aeration knives the system for spreading and distributing the fertilizer in the form of micro-granules can be optionally compied by a spreading of fertilizer in liquid form brought to the appropriate level within the micro-slot.

The distribution and distribution of both the sand and the fertilizer are controlled by a shutter system with adjustable flow rate and controlled for example by the forward speed of the machine.

The second compacting wheel or wheel (reference 20) may include notches distributed around its periphery as seen in particular in FIG. 5.

While the rear wheel or press wheel 21 with a large rim, produced in particular from unalterable synthetic material, may include a scraper preventing deposits on its surface.

The conduits, in particular the fertilizer delivery pipe 17 may also receive an automatic device capable of adjusting the delivery speed of the latter and at the same time avoiding clogging of the pipe; and similarly the hopper carrying the sand reserve may include a stirring device avoiding blockage and the formation of vault within the hopper.

 The invention also relates to a grassy field, in particular a sports field having been subjected to the method described above and comprising on the surface microfentes 6,6 ', 7,7' of depth between 4 and 15 centimeters and preferably of the order of 10 years, of width between 0.5 and 3 cm and preferably of the order of 1.5 cm, said micro-slots being spaced at an interval of the order of 10 to 25 cm, and the micro-slots comprise at their bottom a ribbon 8 of fertilizer in the granular state covered with a layer of silica sand 9 projecting above the ground level.

Claims (17)

REVENvICATIONS 1 - Method for improving the structure of a grassy substrate for the creation, maintenance or regeneration of green spaces such as lawn, sports ground or the like, characterized in that one proceeds, by means of rotary knives (12,12 ') mechanically driven, to the formation of parallel micro-slots (7,7', 6,6 ') which traverse the whole of the ground and in which one deposits in the bottom of these micro-slots a suitable fertilizer ribbon, the rest of the micro-slot, above the fertilizer being filled with this fine sand. 2 - Process according to claim 7, characterized in that the micro-slot has a depth between 4 and 15 cm and avartageusemen ce = te depth will be of the order of 10 to 12 cm. 3 - Method according to claim 1 or 2, characterized in that the width of the micro-slot is between 0.5 and 3 cm and advantageously this thickness will be close to 1.5 cm.  4 - Method according to one of claims 1 to 3, characterized in that the spacing between the slots, thereby adjusting their density, is between 10 and 25 cm and preferably this spacing is close to 20 cm. 5 - Method according to one of claims 1 to 4, characterized in that the sand consists of river sand of the type "Loire sand" with a fine particle size close to 0.6 millimeters. 6 - Method according to one of claims 1 to 5, characterized in that the sand is mechanically packed after its establishment in the receiving micro-slot. 7 - Method according to one of claims 1 to 6, characterized in that one also proceeds in parallel with a sandblasting surface at the micro-slots, a thickness of sand (11) overflowing above ground level natural, and the sand thus overflowing is swept to be spread and distributed over the entire surface of the soil, covering substantially the plants making up the lawn. 8 - Method according to one of claims 1 to 7, characterized in that the fertilizer constitutes a continuous net deposited in the bottom of the slots with a thickness of a few millimeters. 9 - Process according to claim 8, characterized in that this fertilizer intended to promote the development of the rooting of the lawn is based on phosphoric acid and potash. 10 - Method according to one of claims 1 to 9, characterized in that the width of the slots is adapted to their location within the terrain, the areas more heavily trampled and formed by the central third of the terrain receiving slots according to a density higher (that is to say with a smaller spacing) than the less trampled areas and constituted by two lateral thirds or low sides. 11 - Machine for implementing the method according to one of claims 1 to 10, characterized in that it comprises mechanical drive means such as a heat engine or a hydraulic pump itself driven by a heat engine, a rotary assembly consisting of an axis (14) carrying parallel knives (12,12 '), the rotary axis (14) being mounted perpendicularly to the axis of advance of the machine, l advancement of the machine and the rotation of the axis carrying the knives being able to cut the ground to create the micro-slots (6,6 ', 7,7'), and the machine also comprises means of pouring and dispersion of fertilizer in the form of granules in the bottom of the micro-slits, downstream of the knives, as well as means for pouring sand filling the micro-slits above the layer of fertilizer. 12 - Machine according to claim 11, characterized in that it comprises a set of pouring and placement of fertilizer and sand, this set consisting of a hollow ploughshare (15) forming a shoe penetrating into the micro slot and receiving, from the upper hoppers (16,18) successively and in the direction of advancement of the machine, the fertilizer ribbon (8) pours and placed in the bottom of the shoe and on which is brought the layer of sand (9). 13 - Machine according to one of claims 11 or 12, characterized in that it comprises at least one wheel (19) disposed at the outlet of said shoe capable of packing the sand placed in the micro-slot. 14 - Machine according to claim 13, characterized in that it comprises two wheels (19,20) of successive compaction penetrating, at decreasing heights in the micro-slot. 15 - Machine according to claim 14, characterized in that the two compacting wheels (19,20) are followed, at the rear, by a wheel (21) for distributing and placing a ribbon of sand projecting over the above ground level. 16 - Machine according to one of claims 11,12,13,14 or 15, characterized in that the frame supporting the rotary knives (12,12 '), the hollow base (15) and the compacting wheels (19, 20,21) is provided adjustable in height with respect to the ground by a set of support jacks.  17 - Grassed field, in particular a sports field having been subjected to the method according to one of claims 1 to 10 and comprising on the surface micro-slots (6,6 ', 7,7') of depth between 4 and 15 cms and preferably of the order of 10 cms, of width between 1 and 3 cm and preferably of the order of 1.5 cm, said micro-slots being spaced at an interval of the order of 15 to 25 cm, and the micro-slots have at their bottom a ribbon (8) of granular fertilizer covered with a layer of silica sand (9) overflowing above ground level.