AU4255093A

AU4255093A - Seeding implement assembly and method

Info

Publication number: AU4255093A
Application number: AU42550/93A
Authority: AU
Inventors: Ellis John Aurisch
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-04-29
Filing date: 1993-04-29
Publication date: 1993-11-29

Description

"Seeding Implement Assembly and Method"

TECHNICAL FIELD

This invention relates to a seeding implement assembly and method which has particular, but not exclusive, utility in seeding paddocks for crop production having shallow clay soils or non-wetting soils which have a "hard pan" layer of soil below the surface.

BACKGROUND ART

"Hard pan" soils occur in many of the crop producing areas of Australia where fine, non-wetting sand gets compacted over time to form a hard layer of compacted soil approximately three inches below the surface of the soil and which generally is two to three inches thick. This layer can become so hard that it does not allow roots of the crop to penetrate through to the soil beneath and thus tends to inhibit deep rooted crop growth. A similar problem arises with shallow clay soils which also occur in many crop producing areas throughout the world.

In order to break-up this "hard pan" layer, it is usual for farmers to use agricultural implements for deep ripping of the soil prior to or in conjunction with seeding.

One problem encountered with previous deep ripping techniques is that they generally cause much disruption to the top soil and generally result in a tendency for "hard pan" or clay segments to be lifted onto the surface of the soil, subsequently causing sealing over of the surface which forms a hard crust through which the plant cannot penetrate.

With the increased sensitivity of farmers to soil erosion problems, there is a tendency to minimise working of the ground even in areas where "hard pan" or shallow clay soils are not a problem. Consequently, in recent times there is a much greater use made of chemicals to eradicate or cut back on the proliferation and regeneration of weeds, instead of relying upon conventional working back of paddocks with animal grazing or cultivating of the same^'. However, with increased environmental awareness, the wide spread use of chemicals has fallen out of favour and indeed, there is a belief amongst the farming community that the use of pre-emergent chemicals for stopping weed regeneration has a deleterious effect upon the crop.

In recent times, improved planting and sowing techniques have been adopted to provide for better crop growth and for more efficient utilisation of fertiliser. One of these techniques is known as "deep banding" which essentially involves depositing fertiliser at a prescribed depth below the seed so that as the seed germinates, an opportunity is provided for root growth to develop and establish itself before reaching the fertiliser, which otherwise "burns" new root growth destroying the seed. This technique is a vast improvement upon the prior art which simply involved depositing fertiliser concurrently with the seed, resulting in great wastage of both fertiliser and seed.

Notwithstanding the improvement achieved by adopting deep banding, present planting and seeding techniques for crop growing still involve the basic principle of forming a relatively deep furrow in which fertiliser is deposited, covering this partially with soil and then depositing a line of seed in a single row directly above the fertiliser. Accordingly, a ratio of seed to fertiliser in the order of 1:1 is used. A disadvantage of this, however, is that the fertiliser can often provide quite a satisfactory source of nutrition to more than one seed at a time, particularly with the wide spread use of super-phosphate which provides a very concentrated source of nutrition for plants. Therefore present single row sowing methods do not provide for efficient usage of fertiliser.

In addition, in order to maximise yield, it has been commonplace to dispose the rows of seed and the individual seeds themselves within a row, relatively closely. A disadvantage of this is that relative close spacing of seeds affects plant stooling, whereby it has been found that the more closely planted is the seed, the lesser the number of stools produced on each plant during growth.

DISCLOSURE OF INVENTION

In order to accommodate both soil erosion and chemical usage considerations, it is an object of one aspect of the present invention to provide a method of seeding a crop which mitigates soil erosion and enhances crop root growth, in particular where there are "hard pan" or shallow clay soils. Furthermore it is an object for the method to mitigate or dispense with the use of a pre-emergent chemical for stopping weed regeneration after the initial seeding stage.

It is an object of another aspect of the present invention to provide a seeding implement assembly which can be used in the aforementioned method.

An object of even further aspects of the invention involve providing an improved seeding method and planting system, which achieves more efficient utilisation of fertiliser and the ability to achieve greater plant stooling.

In order to achieve at least some of the aforementioned objects, certain aspects of the present invention contemplate cutting the ground initially to form an incision by means of either a cutting wheel or tyne and utilising a deep ripping implement which follows the track of the incision to deeply penetrate the ground causing minimal surface disturbance and consequently providing for deep band seeding and fertilising to be effected. A problem encountered with this technique, however, particularly in "hard pan" soils, is that it has been difficult to maintain an optimum and constant depth for deep ripping and banding of the seed and fertiliser due to obstacles encountered by the cutting wheel or tyne and/or deep ripping implement.

Consequently, it is a further and preferred object of certain aspects of the present invention to provide methods and apparatus where appropriate which can alleviate some or all of the aforementioned disadvantages associated with the use of previous methods and implements for seeding purposes.

In accordance with one aspect of the present invention, there is provided a method for seeding a crop comprising:-

continuously cutting an incision through the surface of the ground for a deep ripping implement to follow;

continuously deep ripping the ground along said incision below the surface of the ground, said deep ripping causing minimal surface disturbance;

continuously depositing seed in a furrow formed below the surface within the deeply ripped ground; and

continuously covering said furrow after the depositing of seed therein; wherein said deep ripping, depositing of seed and covering is performed continuously along the entire longitudinal extent of said incision and at substantially relatively constant depths with respect to each other, at least during the time that said cutting of said incision and said deep ripping is caused to temporarily fluctuate in depth due to minor obstacles or obstructions being encountered during said cutting.

Preferably, the relative angular position of the deep ripping is altered in response to said temporary fluctuations in depth so as to mitigate the lifting effect of deep ripping closer to the surface of the ground.

Preferably, said method includes the step of continuously depositing fertiliser proximate to the bottom of said incision immediately following the deep ripping of the ground therealong and forming said furrow at a level above the incision bottom, so as to deep band said seed.

Preferably, the method includes forming said furrow separately of said deep ripping. Preferably, -said method includes forming a pair of said furrows, one at either side of said incision, each of said furrows being respectively covered after the depositing of the seed therein. In this manner the one line of deposited fertiliser serves to fertilise the two lines of deposited seed, thereby reducing the amount of fertiliser required relative to the amount of seed. Furthermore, the plurality of rows of seed enables the effective concentration of seed to be reduced, resulting in increased spacing between the seed which produces much improved stooling.

Preferably, said method includes forming a central ridge of soil between the covered furrows. In this manner, water is subsequently channelled into the covered furrows by the effect of the ridge, aiding germination of the seed which is especially advantageous for non-wetting soils.

Preferably, said deep ripping, depositing of seed and covering is rapidly ceased upon encountering a major obstacle during said cutting after the entire longitudinal extent of said incision is deeply ripped, said furrow is formed, deposited with seed and covered.

In accordance with another aspect of the present invention, there is provided a seeding implement assembly for mounting to a travelling frame so as to engage the ground traversed by the travelling frame, said assembly comprising:—

a linkage for connection to the travelling frame;

a tyne for being directly connected to said linkage and having a deep ripping point disposed at the base of the tyne;

ground cutting means disposed anteriorly of said tyne for cutting an incision through the ground for said tyne to follow;

a seed discharge means for mounting to the rear of said tyne;

said linkage being adapted to normally suspend said ground cutting means, said tyne and said seed discharge means in a prescribed operative working position with respect to the travelling frame and the ground, so that there exists a working spatial relationship between said cutting means, tyne and seed discharge means; and

biasing means for biasing said tyne into said prescribed operative working position; wherein said linkage includes compensating means for use in clearing an obstacle obstructing the travel of said cutting wheel, said compensating means being adapted to elevate said cutting means, said tyne and said seed discharge means so as to clear the obstacle whilst simultaneously substantially maintaining the relative said prescribed operative working position between said cutting means, said tyne and said seed discharge means until at least said tyne is impeded from maintaining said working position by the obstacle.

Preferably, the relative angular position of said point is altered in response to elevation of said tyne so as to mitigate the lifting effect of deep ripping caused by said point as the position of said point nears the surface of the ground.

Preferably, said compensating means is formed by said linkage being constructed in the form of an offset parallel linkage assembly, comprising a pair of depending arms offset from the parallel with respect to each other, whereby the first arm is pivotally connected at one end to the frame and at the other end to the front of said tyne, and the second arm is pivotally connected at one end thereof to the frame rearwardly in spaced relation to the pivotal axis of said one end of said first arm, and at the other end of said second arm to said tyne rearwardly and in spaced relation to the pivotal axis of said other end of said first arm, such that the pivotal axis of said other end of said second arm is more elevated and closer spaced to said pivotal axis of the other end of said first arm than is the corresponding relationship between the pivotal axes of the one ends of said first and second arms.

Preferably, said cutting means comprises a nose portion projecting anteriorly from the front of said tyne for cutting through the ground.

Preferably, said nose is planar and is provided with a leading rectilinear cutting edge sloped rearwardly from the bottom thereof. By this arrangement, the tyne is able to slice through the ground and lift any surface material free from the ground* enabling the material to flow around the front, disposing with the need for a cutting wheel.

Preferably, the seeding implement assembly includes a fertiliser discharge means interposed between said tyne and said seed discharge means so that fertiliser can be deposited into the incision formed by said tyne immediately behind the point of said tyne.

Preferably, the seeding implement assembly includes a trailing furrowing means for opening up the ground behind said tyne to form a furrow in which seed may be deposited at a level above the incision bottom, and covering means disposed behind said furrowing means to cover said seed deposited into the furrow.

Preferably, a pair of said furrowing means are disposed either side and rearwardly of said tyne for forming a furrow on each side of said tyne, and a corresponding pair of said covering means are provided for covering said furrows.

Preferably, said pair of covering means are arranged to deflect covering soil for said furrows so as to form a central ridge of soil between the furrows additional to covering said furrows.

Preferably, said biasing means comprises a pair of springs respectively connected at one of their ends to the frame and at the other of their ends to the respective arms of said linkage between the opposing ends of said arms.

In accordance with a further aspect of the present invention, there is provided a method for seeding a crop comprising:

depositing fertiliser at a first prescribed level in a first line beneath the surface of the ground; and depositing seed in second lines at a second prescribed level above the first prescribed level, one said second line being disposed laterally to one side of said first line and the other said second line being disposed laterally to the other side of said first line.

Preferably, the method includes forming a central ridge along the surface of the ground between the second lines.

In accordance with another aspect of the present invention, there is provided a planting system comprising:

a line of fertiliser disposed at a first prescribed level beneath the surface of the ground; a pair of lines of seed disposed at a second prescribed level above the first prescribed level, so that one of the lines of seed is disposed laterally to one side of the line of fertiliser and the other of the lines of seed is disposed laterally to the other side of the line of fertiliser.

Preferably, a central ridge of soil is disposed between said furrows to channel water into the furrows.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be better understood in the light of the following description of two specific embodiments thereof. The description is made with reference to the accompanying drawings, wherein:-

Figure 1 is a side elevation of a seeding implement assembly disposed in its normally operative working position with respect to the travelling frame and the ground in accordance with the first embodiment;

Figure 2 is a similar view to figure 1 showing a partially retracted position of the assembly whereby the cutting wheel is marginally elevated to overcome a minor obstacle whilst the' tyne and seed discharge means substantially maintain their prescribed operative working position;

Figure 3 is a side elevation of the assembly from the opposite side to that shown at figure 1 of the drawings, and showing the assembly in its maximum retracted position with both the cutting wheel and tyne elevated from the ground as would arise when encountering an immovable obstacle;

Figure 4 is an end view of figure 1 with the stubble guard removed;

Figure 5 is a side elevation of a seeding implement disposed in its normally operative working position with respect to the travelling frame and the ground in accordance with the second embodiment;

Figure 6 is a similar view to figure 1 showing the assembly in its maximum retracted position with both the tyne and the seed discharge means elevated from the ground as would arise when encountering a relatively immovable obstacle; Figure 7 is a front end view of the seeding implement assembly as shown in figure 5 of the drawings with the springs removed;

Figure 8 is a rear end view of the seeding implement assembly as shown in figure 5 of the drawings;

Figure 9 is a side elevation of the seeding implement assembly with the linkage and travelling frame removed, but showing the seed discharge means in more detail with the seeding and fertiliser boots attached thereto;

Figure 10 is a perspective view of the tyne and seed discharge means of the seeding implement assembly in accordance with the second embodiment;

Figure 11 is a perspective view of the support plate for the seed discharge means;

Figure 12 is a rear top view of the support plate shown in figure 11 of the drawings;

Figure 13 is an underside view of the support plate shown in figure 11 of the drawings;

Figure 14 is a rear end underside view of the support plate shown in figure 11 of the drawings; and

Figure 15 is a cross-sectional ground profile taken across a portion of ground which has been sown using the method and the seeding implement assembly described in the second embodiment, which shows the relative positioning of the covered furrows, the central ridge and the sown seed and fertiliser. MODES FOR CARRYING OUT THE INVENTION

The first embodiment is directed towards a seeding implement assembly 11 which is one of a bank of such assemblies adapted to be mounted to a travelling frame (not shown) which is trailed along the ground behind a primeover (not shown) in accordance with conventional farming practice and will be described with reference to Figures 1 to 4.

The assembly 11 is suspendedly mounted to a fixed bar 13 extending longitudinally of the frame with respect to the intended direction of travel of the frame.

The assembly generally comprises a carriage 15 suspended below the bar 13 by means of a linkage 17 comprising a pair of first arms 17a and a pair of second arms 17b, a ground engaging cutting wheel 19, a deep ripping tyne 21, a fertiliser discharge means 23, a seed discharge means 25, biasing means 27 and a trailing covering wheel 29.

The carriage 15 is effectively in the form of-an inverted U-shape channel member the front bottom corners 15a of which are truncated and the bottom trailing edges of which are formed with a pair of skids 31, one at either side for resting upon the surface of the ground.

The cutting wheel 19 is rotatably mounted towards the bottom of the carriage 15 about a central axis 33 extending transversely of the carriage and coincident with an axle 35 upon which the wheel is mounted. The cutting wheel 19 has a V-shaped edge in section instead of a conventional thin wheel so that the cutting wheel can cut through the surface of the ground making a deep incision which can be used as a furrow for subsequent seeding in stubble covered paddocks where a following tyne cannot be used. In the present embodiment, however, where the assembly has particular utility for "hard pan" soils which require deep ripping, the cutting wheel 19 is adapted to cut through the surface of the ground so as to form an incision along which the tyne 21 may subsequently pass through without unduly disturbing the surface of the ground and thus minimising the likelihood of soil erosion.

The front of the carriage has a stubble guard 37 mounted thereto to deflect minor obstacles such as twigs and stubble away from the cutting wheel 19.

The linkage 17 is arranged so that the pair of first arms 17a are pivotally mounted at their upper end to either side of the bar 13 and their lower ends to either side of the carriage 15, so that the pivotal axis of the lower end of the arms is coincident with the central axis 33 of the cutting wheel. The pair of second arms 17b are relatively disposed with respect to the first arms, so that the first and second arms form an offset parallel linkage arrangement as shown in the drawings. The upper ends of the second arms are similarly pivotally mounted to the bar 13 at a rearwardly spaced position relative to the first arms 17a and the lower ends of the second arms 17b are pivotally mounted to the carriage 15, but instead of being disposed to either side of the carriage, the lower ends of the arms are joined together to be pivotally mounted inside of the carriage 15 between the inner sides thereof. The pivotal axis 39 of the lower end of the second arms 17b is similarly rearwardly spaced with respect to the corresponding pivotal axis of the first arms 17a, but in contrast to the relative disposition of the pivotal axes of the upper ends of the first and second arms, the pivotal axes of the lower ends of the first and second arms are closer spaced and furthermore the pivotal axis 39 of the second arms 17b is marginally elevated on the carriage 15 with respect to the corresponding pivotal axis of the first arms which is coincident with the central axis 33.

The tyne 21 is fixedly mounted to the second arms 17b between the lower ends thereof so as to be capable of pivotal movement in conjunction with the second arms 17b relative to the carriage 15. The tyne 21 is characterised by having a shank portion of a narrow transverse extent of marginally lesser dimension than the corresponding transverse extent of the cutting wheel 19, as shown in figure 2 of the drawings, and has a larger longitudinal extent in the direction of travel for strength. The shank portion is tapered towards the leading edge 21a thereof so as to facilitate deep ripping through the "hard pan" layer, and has a flattened rear trailing end 21b to provide a pathway for fertiliser which will be described in more detail later.

The bottom of the tyne is fitted with a suitable delta shaped point 41 having a downwardly depressed and blunt nose to facilitate formation of a deep furrow for deep banding the seed with fertiliser.

As shown in figure 1 of the drawings, the major longitudinal axis of the tyne 21 is angularly offset with respect to the corresponding longitudinal axis of the pair of second arms 17b so as to define a rearward obtuse angle which presents the tyne with a lagging angle of attack relative to the ground.

The fertiliser discharge means 23 effectively comprises a fertiliser boot 43 fixedly mounted within the confines of the carriage 15 between its inner sides directly behind the pair of second arms 17b and the tyne 21. The fertiliser discharge means also includes a fertiliser deflector plate 45 mounted vertically to the rear of the pair of second arms 17b and which extends contiguously to adjoin the trailing end 21b of the shank of the tyne so as to form a pathway for falling fertiliser to travel along the rear trailing end 21b and deposit itself into the furrow at the trailing end of the point 41 immediately upon it being formed by the tyne. Accordingly, the fertiliser boot 43 is connected to a conventional fertiliser delivery tube (not shown) which is in turn connected to a fertiliser discharge source mounted in association with the travelling frame.

The seed discharge means 25 similarly comprises a seeding boot 47 again fixedly mounted within the confines of the carriage 15 between the inner sides thereof, but rearwardly of the fertiliser discharge means 23. The seed discharge means 25 also includes a seed deflector plate 49 which forms part of a triangular U-shaped bracket 51 pivotally mounted about a transverse axis 53 at the end of the carriage for supporting the covering wheel 29. The seed deflector plate 49 incorporates a lip which protrudes from the bottom of the bracket 51 downwardly so as to extend a marginal distance beyond the bottom of the carriage defined by the skids 31. The seed deflector plate 49 is disposed in a corresponding angular disposition to the major longitudinal axis of the tyne 21 so that seed falling from the boot 47 may strike the seed deflector plate 49 and follow a path therealong to be deposited into the furrow at a location rearwardly spaced from the corresponding position of the tyne at that instant. This rearward spacing between the deflector plate 49 and the rear trailing end 21b of the tyne is sufficient to allow partial covering of the fertiliser deposited into the bottom of the furrow by the end of the deflector plate 49 so that the seed may be deposited at a marginally higher position within the furrow, thereby achieving deep banding of the seed. As with the fertiliser discharge means, the seeding boot 47 of the seed discharge means 25 is connected to a seed delivery tube (not shown) which in turn is connected to a seed discharge source (not shown) also mounted in association with the travelling frame.

The triangular bracket 51 is pivotally mounted to the carriage about the transverse pivotal axis 53 which is disposed rearwardly and towards the top of the carriage between the fertiliser boot 43 and seeding boot 47. The sides of the bracket project rearwardly from the rear of the carriage 15 in parallel spaced relationship to each other to rotatably support the trailing covering wheel 29 at the rear of the carriage. The covering wheel 29 is much wider than the cutting wheel 19 to compress the top of the furrow and thus close the incision formed by the cutting wheel 19 and hence cover the deposited seed with soil.

The biasing means 27 comprises a tension spring which is adjustably mounted at one end 27a tb a pendent bracket 55 fixedly mounted to the bar 13 of the frame and pivotally mounted at the other end between the second arms 17b at a position intermediately disposed between the upper and lower ends of the second arms. The one end 27a of the spring is formed with a threaded bolt end which receives a nut which can be turned to adjust the tension in the spring extending between the pendent plate 55 and the pair of second arms 17b. In this manner, rearward deflection and thus retraction of the carriage from its normally prescribed operative working position as shown in figure 1 of the drawings is opposed by the tension in the spring, causing the assembly to return to its prescribed operative working position when a force causing such retraction dissipates or is overcome.

Importantly, the linkage 17 includes compensating means which comes into operation when the carriage is retracted for the purposes of clearing an obstacle. Moreover, the compensating means is formed by the construction of the linkage as an offset parallel linkage assembly, whereby the first and second arms are offset from the parallel with respect to each other, as shown in figure 1 of the drawings, when in the normal operative working position. Consequently, when the cutting wheel encounters an obstacle such as a rock, twig or even hard ground, it is caused to lift whereupon the compensating means elevates the cutting wheel from its working spatial relationship with the tyne and the seed discharge means so as to clear the obstacle. The arrangement of the compensation means, however, simultaneously causes the tyne to lag this upward lifting movement by being substantially independently connected of the carriage, whereby its relative position is dictated by the disposition of the pair of second arms 17b. The offset parallel linkage assembly of the arms is such that the tyne and pair of second arms 17b correspondingly move at a different and retarded rate relative to the cutting wheel 19 and pair of first arms 17a. Consequently, the tyne substantially maintains its prescribed operative working position simultaneously with the elevation of the cutting wheel, thereby allowing deep ripping and the seeding of the furrow to be completed all the way along the incision made by the cutting wheel 19 at a constant maximal depth even though there may be fluctuations in the depth of the incision caused by obstacles encountered by the cutting wheel.

Notwithstanding this, however, when a major obstruction is encountered by the cutting wheel causing it to lift significantly and disengage from the ground, the linkage assembly will come into operation causing the tyne to lift entirely from engagement with the ground as in a conventional stump jump mechanism so as to avoid permanent damage being caused to the tyne by the obstacle. Furthermore, once the tyne commences significant rearward movement, it will move both rearwardly and upwardly quickly to disengage from the ground.

Thus, the compensating means is characterised by two important features, one being that the tyne movement is dampened significantly with minor fluctuations in the height of the cutting wheel so as to effectively operate independently of the height of the cutting wheel during minor fluctuations in the height of the cutting wheel, but will rapidly retract from the ground upon the cutting wheel continuing elevation beyond a prescribed threshold height determined by the parallel offset to avoid major obstacles.

Now describing the method of seeding a crop which can be achieved using the assembly described in the present embodiment, initially an incision is continuously cut through the surface of the ground for a deep ripping implement to follow. The ground is then continuously ripped deeply along the incision to form a narrow furrow below the surface of the ground for depositing seed, whereby the deep ripping causes minimal surface disturbance. Fertiliser is then continuously deposited into the narrow furrow immediately upon it being formed and covered. Seed is then continuously deposited into the narrow furrow at a depth which is marginally higher than the fertiliser, and finally is continuously covered over to deeply band the seed.

The deep ripping, fertiliser and seed depositing and covering are all performed continuously along the entire longitudinal extent of the incision in the direction of the seeding operation and at a substantially constant depth which is largely independent of the depth of the incision at least during the time that the cutting of the incision is caused to temporarily fluctuate in depth due to minor obstacles or obstructions being encountered during the cutting operation. Furthermore, the deep ripping, depositing of fertiliser and seed and covering is rapidly ceased upon encountering a major obstacle during the cutting, after the entire longitudinal extent of the incision is deeply ripped, deposited with seed and covered.

The second embodiment is different from the first embodiment in many respects and will be described with reference to figures 5 through to 15. Moreover, the second^' embodiment is directed towards a seeding implement assembly 111 which is suspendedly mounted to a fixed bar 113 arranged similarly with respect to a travelling frame as in the first embodiment. The assembly 111 however, dispenses with the use of a carriage, a cutting wheel and a trailing covering wheel but maintains a linkage 117 comprising a pair of first arms 117a and a pair of second arms 117b, a deep ripping tyne ^'121, a fertiliser discharge means 123, a seed discharge means 125 and biasing means 127. Instead of a ground engaging cutting wheel, the assembly includes a ground cutting means in the form of a nose portion 119 which projects anteriorly from the front of the tyne 121 for cutting through the ground, and instead of the trailing covering wheel, the assembly includes a covering means in the form of a pair of covering soil deflector plates 129.

Additional to the assembly of the first embodiment, the assembly 111 includes a furrowing means in the form of a pair of furrowing soil deflector plates 115.

The nose 119 is planar and is provided with a leading rectilinear cutting edge which in the prescribed operative working position as shown in figure 5 of the drawings, is sloped rearwardly from the bottom 131a to the top 131b. The nose 119 projects anteriorly from the tyne quite considerably as shown in the drawings and as a consequence of being formed of relatively thin material, for example, six millimetre thickness steel plate, the nose can cut through the ground creating a requisite incision just as effectively as can a cutting wheel as is the case in the first embodiment. Indeed, as the nose 119 extends all the way along the front of the tyne 121, right down to the bottom of the tyne, a deeper incision is created than is the case with the cutting wheel.

As noted in the drawings, the top 119a and bottom 119b of the nose portion are strengthened by being formed of marginally thicker steel plate, e.g. 16 millimetres. The nose portion 119 is provided with a bottom edge 119c which projects anteriorly from the bottom of the tyne and is disposed in a substantially horizontal plane when in the prescribed operative working position and thus intersects with the leading edge 131 at an acute angle so as to form a leading point at the bottom 131a thereof. Consequently this facilitates cutting through the ground and in conjunction with the rearward slope, allows the assembly to pass through stubble and other surface material without major blockages. Any extraneous surface material tends to be lifted free from the ground enabling it to flow around the front of the tyne, avoiding the likelihood of it being pressed into the ground where it can rot and effect germination, a problem encountered with the use of cutting and press wheels. Additionally, loose obstacles can flow past the tyne in a similar manner without causing undue lifting of the assembly, a problem arising with the use of wheels which tend to roll over obstacles such as stumps causing undue lifting.

The linkage 117 is substantially similar to the linkage of the first embodiment except that the pair of first arms 117a are pivotally mounted at their lower ends to either side of the front part of the top 119a of the nose portion 119, instead of to the carriage and cutting wheel as in the first embodiment. In addition, both the first arms 117a and second arms 117b are respectively outwardly curved as shown in figures 5 and 6 of the drawings. This curvature is important to maximise the elevation that can be achieved from lifting of the assembly with respect to the fixed bar 113, enabling the relative angular position of the tyne 121 to be altered and be maintained in its altered position to mitigate the lifting effect of the deep ripping caused by it, as it approaches the maximal elevated position, as shown particularly in figure 6 of the drawings. Importantly, the off-set parallel linkage arrangement of the arms which form the compensating means^' is maintained, whereby the spacing between the pivotal axes of the upper ends of the first and second arms is marginally greater than the spacing between the pivotal axes of the lower ends of the first and second arms. In a typical example of the present embodiment, this spacing between the upper ends is approximately 9.25 inches and the corresponding spacing between the lower ends is 8.875 inches.

The biasing means 127 again is marginally different to the biasing means adopted in the first embodiment. Moreover, the biasing means 127 comprises two tension springs, 127a and 127b which are respectively connected to the pair of first arms 117a and the pair of second arms 117b, as shown in figure 1 of the drawings. Notwithstanding the plurality of tension springs involved in the second embodiment, the biasing effect of these springs on the linkage arrangement in biasing the tyne 121 into the prescribed working position, is precisely the same as the biasing means of the first embodiment.

The main body of the tyne 121 as opposed to the first embodiment, is not integrally formed with the second arms 117b. Consequently, the relative angular position of the tyne 121 is allowed to alter with respect to changes in the angular positioning of the pair of second arms 117b, enabling a different lifting effect on the tyne to be achieved than is the case in the first embodiment. Moreover, the tyne 121 is similarly provided with a deep ripping point 141 at the base thereof which is substantially planar, delta shaped and blunt nosed, as is the case in the first embodiment, however the angular positioning of this point during elevation of the assembly with respect to the fixed bar 113, is opposite to that achieved in the first embodiment. That is, due to the relative pivoting between the pair of second arms 117b and the tyne 121, the general plane of the point 141 is brought from an initial attacking angle with respect to the ground, as is shown in figure 5 of the drawings, when in the prescribed operative working position as is required for deep ripping, to a substantially parallel position with respect to the ground as the assembly is elevated as is shown in figure 6 of the drawings. Thus, as the tyne 121 progressively elevates, the lifting effect on soil caused by the point 141 reduces as it nears the surface of the ground, enabling the point to be lifted from out of the ground, minimising soil disturbance at the surface and mitigating the lifting of any underlying clay to the surface.

Thus, as a result of the off-set linkage arrangement, the front of the tyne is tilted marginally upwardly relative to the rear of the tyne, simultaneously with the elevation of the tyne as a whole. This arrangement also enhances the rapid clearance of the cutting nose from the ground when encountering an immovable obstacle.

It should be noted that the nose portion 119 is disposed contiguously with the front of the ripping point 141 and consequently with the resultant tyne, there is no leading catching edge or face, as is in the case of a normal tyne and point configuration, on which stubble can accumulate and catch, making it difficult to remove without manual effort. Moreover, due to there being no catching edge or face, any stubble accumulated at the leading edge of the nose portion can simply drop and fall away from the tyne by elevating it from the ground and shaking it if necessary. Due to the forward projection of conventional tynes and points, removal of the accumulated stubble cannot be achieved so easily, due to the fact that the forward projection of the point provides a retaining surface on which the stubble is prevented from simply sliding off the tyne, even when it is lifted free from the ground.

It should also be noted that the central location of the ripping point with respect to the front and rear of the tyne as a whole has the advantageous effect of lessening the side draft force upon the frame when turning.

The furrowing means and covering means are integrally formed in a saddle shaped bracket arrangement which is fixedly attached at the sides of the main body of the tyne 121 to extend rearwardly therefrom by suitable means such as welding and pinning provided by the pins 133. A cover plate 135 surmounts at the pair of furrowing soil deflector plates 115 so that the plates 115 effectively depend from the cover plate 135 in a substantially upright position when in the prescribed operative working position. The furrowing soil deflector plates 115 are substantially planar and winged shaped, being oppositely angled to project out laterally from either side of the tyne. In this manner, they are able to engage the ground behind the tyne and deflect soil laterally either side of the tyne to form a pair of discrete furrows 151 for the seed. The lower most ends 115a of the plates are disposed at a level above the position of the point 141 so that the depth of the furrows is significantly less than the depth of the incision formed by the tyne.

The covering soil deflector plates 129 are integrally formed with the cover plate 135, essentially forming a pair of trailing wings which project rearwardly and obliquely from the end of the assembly. The covering soil deflector plates 129 are also substantially planar and of triangular shape, being disposed in alignment directly behind the respective furrowing soil deflector plates 115 so ^"as to engage the soil at the outside of the respective furrows 151 and deflect the same laterally across the furrows, inwardly to the other side of the furrows. The shape of the deflector plates 129 form a central passage directly aligned with the rear of the tyne, which passage is an inverted V-shape. Consequently, the deflector plates 129 with the soil deflected across to the inside of the furrows 151 shape the soil between the two furrows into a central ridge 153 as can be best seen in figure 15.

The cover plate 135 is formed with a plurality of apertures, two of these apertures 137 accommodate fertiliser boots 143 which form part of the fertiliser discharge means and two of the apertures 139 accommodate seed boots 147 which form part of the seed discharge means.

The two fertiliser apertures and boots are disposed centrally in a series immediately behind the rear of the tyne 121 and are connected to fertiliser delivery tubes 149 to deposit fertiliser 155 from a fertiliser discharge source, behind the tyne and into the bottom of the incision formed behind the deep ripping point 141.

The seed apertures and boots are disposed rearwardly of the fertiliser apertures and boots, but are disposed laterally with respect to either side of the centre line formed by the tyne and the fertiliser apertures and boots, and anteriorly with respect to the covering means.. The seed apertures and boots are precisely positioned so that seed 157 delivered thereto from a seed discharge source via respective seed delivery tubes 151 is .deposited directly into each furrow 151 immediately after soil is deflected to the outside by the furrowing means forming the furrow and prior to the soil being deflected back to the inside by the covering means.

A fertiliser deflector plate 145 is fixedly attached to the underside of the cover plate 135 to depend therefrom between the fertiliser apertures and boots and the seed apertures and boots so as to partition discharged fertiliser from discharged seed. This deflector plate is centrally disposed and projects anteriorly to deflect fertiliser 155 anteriorly towards the rear of the tyne so that it may be deposited at the bottom of the incision created by the tyne prior to this being covered by soil as a consequence of the subsequent furrow formation and covering.

Now describing the method by which seeding of a crop is achieved, using the seeding implement assembly of the second embodiment, the travelling frame is set up so that a bank of seeding implement assemblies are provided which are spaced apart laterally an optimum distance to promote stooling, for example, in some soil types, 14 inches apart. The fertiliser and seed discharge means of the assemblies are respectively connected via fertiliser and seed delivery tubes to fertiliser and seed discharge sources and the travelling frame is drawn by a prime mover along a paddock to be sown, with the assemblies being brought into engagement at a prescribed working position with respect to the ground. The cutting means of each assembly continuously cuts an incision through the surface of the ground through which the tyne constituting the deep ripping implement can follow. The tyne continuously deep rips the ground along the incision by virtue of the deep ripping point being disposed at an appropriate angle of attack with respect to the ground below the surface. The narrow extent of the cutting means and tyne and the consequent incision that is formed enables deep ripping to occur with minimal surface disturbance.

The fertiliser discharge means continuously deposits fertiliser proximate to the bottom of the incision immediately upon the deep ripping of the ground by the tyne so that fertiliser is disposed centrally of the row at maximum depth. Simultaneously, the furrowing means forms two furrows either side of the incision at a relatively close spacing, for example 4-6 inches apart, and at a much shallower depth than the incision. The seed discharge means subsequently and continuously deposits seed into the furrows which then are immediately covered by the covering means deflecting soil on the outside of the respective furrows, not only across the furrows, but also to the centre, concentrating the soil so as to form a central ridge which remains after the passage of the implement.

A ground profile is consequently achieved as shown in figure 15, where the seed is deep banded with fertiliser.

Significantly, the one line of fertiliser provides adequate nutrient to the two lines of seed within a row. This not only maximises the effect of the fertiliser used, but also reduces the proportional amount of fertiliser required for the seed. Thus a seed to fertiliser ratio in the order of 2:1 can be achieved. Furthermore, greater spacing between the rows can be achieved whilst maintaining yield, a corollary of which is improved stooling. Additionally, the remaining central ridge channels water resulting from precipitation into the covered furrows, which is particularly advantageous in non-wetting soils.

Importantly, whilst the assembly is operational, obstacles causing some impediment to the forward movement of the assembly will force the assembly rearwardly against the tension provided by the biasing means. The parallel linkage arrangement translates this retardation into an elevation of the assembly with respect to the fixed bar of the travelling frame and by virtue of the off-set parallel arms, causes the front of the tyne to elevate more quickly than the rear of the tyne decreasing the angle of attack of the point thereby mitigating the lifting effect and the deep ripping caused by the tyne as the point moves towards the surface. Consequently, minimal surface disturbance is caused mitigating the lifting of any underlying clay or the like, improving conservation of the soil. *

It should be appreciated that the scope of the present invention is not limited to the particular embodiments herein described. In particular, it should be appreciated that notwithstanding the fact that the seeding method and planting system have been described within the specific embodiments directed towards the seeding implement assembly, they nonetheless constitute independent forms of the invention.

In addition, changes in accordance with conventional design practice can be made to the specific design of the seeding implement assembly to allow the compensating means to function in the same or a similar manner as provided by the offset parallel linkage assembly of the linkage arms, without necessarily utilising the precise design described herein.

Claims

THE CLAIMS defining the invention are as follows:-

1. A method for seeding a crop comprising:-

continually cutting an incision through the surface of the ground for a deep ripping implement to follow; continuously deep ripping the ground along said incision below the surface of the ground, said deep ripping causing minimal surface disturbance; continuously depositing seed in a furrow formed below the surface within or proximate to the deeply ripped ground; and continuously covering said furrow after the depositing of seed therein; wherein said deep ripping, depositing of seed and covering is performed continuously along the entire longitudinal extent of said incision and at substantially relatively constant depths with respect to each other, at least during the -time that said cutting of said incision and said deep ripping is caused to temporarily fluctuate in depth due to minor obstacles or obstructions being encountered during said cutting.

2. A method as claimed in claim 1, including altering the relative angular position of the deep ripping in response to said temporary fluctuations in depth so as to mitigate the lifting effect of deep ripping closer to the surface of the ground.

3. A method as claimed in claim 1 or 2, including continuously depositing fertiliser proximate to the bottom of said incision immediately following the deep ripping of the ground therealong and forming said furrow at a level above the incision bottom, so as to deep band the seed.

4. A method as claimed in any one of the preceding claims, including forming said furrow separately of said deep ripping.

5. A method as claimed in any one of the preceding claims, including forming a pair of said furrows, one at either side of said incision, each of said furrows being respectively covered after the depositing of the seed therein.

6. A method as claimed in claim 5, including forming a central ridge of soil between the covered furrows.

7. A method as claimed in any one of the preceding claims, including rapidly ceasing said deep ripping, depositing of seed and covering upon encountering a major obstacle during said cutting, but after the entire longitudinal extent of said incision is deeply ripped, said furrow is formed, deposited with seed and covered.

8. A seeding implement assembly for mounting to a travelling frame so as to engage the ground traversed by the travelling frame, said assembly comprising:-

a linkage for connection to the travelling frame; a tyne for being directly connected to said linkage and having a deep ripping point disposed at the base of the tyne; ground cutting means disposed anteriorly of said tyne for cutting an incision through the ground for said tyne to follow; a seed discharge means for mounting to the rear of said tyne; said linkage being adapted to normally suspend said ground cutting means, said tyne and said seed discharge means in a prescribed operative working position with respect to the travelling frame and the ground, so that there exists a working spatial relationship between said cutting means, said tyne and seed discharge means; and biasing means for biasing said tyne into said prescribed operative working position; wherein said linkage includes compensating means for use in clearing an obstacle obstructing the travel of said cutting wheel, said compensating means being adapted to elevate said cutting means, said tyne and said seed discharge means so as to clear the obstacle whilst simultaneously substantially maintaining the relative said prescribed operative working position between said cutting means, said tyne and said seed discharge means until at least said tyne is impeded from maintaining said working position by the obstacle.

9. A seeding implement assembly as claimed in claim 8, including a fertiliser discharge means interposed between said tyne and said seed discharge means so that fertiliser can be deposited into the incision formed by said tyne immediately behind the point of said tyne.

10. A seeding implement assembly as claimed in claim 8 or 9 wherein the relative angular position of said point is altered in response to elevation of said tyne so as to mitigate the lifting effect of deep ripping caused by said point as the position of said point nears the surface of the ground.

11. A seeding implement assembly as claimed in any one of claims 8 to 10, wherein said compensating means is formed by said linkage being constructed in the form of an offset parallel linkage assembly, comprising a pair of depending arms offset from the parallel with respect to each other, whereby the first arm is pivotally connected at one end to the frame and at the other end to the front of said tyne. and the second arm is pivotally connected at one end thereof to the frame rearwardly in spaced relation to the pivotal axis of said one end of said first arm, and at the other end of said* second arm to said tyne rearwardly and in spaced relation to the pivotal axis of said other end of said first arm, such that the pivotal axis of said other end of said second arm is more elevated and closer spaced to said pivotal axis of the other end of said first arm than is the corresponding relationship between the pivotal axes of the one ends of said first and second arms.

12. A seeding implement assembly as claimed in claim 11, wherein said arms are outwardly curved so that as said tyne is elevated and the angular position of said point is altered, the tyne may be accommodated at a maximal elevated position where the general plane of said point is substantially parallel to the ground, minimising the lifting effect thereof, and said cutting means is elevated from said working spatial relationship with respect to said tyne.

13. A seeding implement assembly as claimed in any one of claims 8 to 12, wherein said cutting means comprises a nose portion projecting anteriorly from the front of said tyne for cutting through the ground.

14. A seeding implement assembly as claimed in claim 13, wherein said nose is planar and is provided with a leading rectilinear cutting edge sloped rearwardly from the bottom thereof.

15. A seeding implement assembly as claimed in any one of claims 8 to 14, wherein said deep ripping point is substantially delta shaped and is disposed at an attacking angle with the leading edge lower than the rear edge when in said normal operating position.

16. A seeding implement assembly as claimed in claim 15, wherein said point is formed with a truncated blunt nose.

17. A seeding implement assembly as claimed in any one of claims 8 to 16, including a trailing furrowing means for opening up the ground behind said tyne to form a furrow in which seed may be deposited at a level above the incision bottom, and covering means disposed behind said furrowing means to cover said seed deposited into the furrow.

18. A seeding implement assembly as claimed in claim 17, wherein a pair of said furrowing means are disposed • either side and rearwardly of said tyne for forming a furrow on each side of said tyne, and a corresponding pair of said covering means are provided for covering said furrows.

19. A seeding implement assembly as claimed in claim 8, wherein said pair of covering means are arranged to deflect covering soil for said furrows so as to form a central ridge of soil between the furrows additional to covering said furrows.

20. A seeding implement assembly as claimed in any one of claims 17 to 20, wherein said furrowing means comprises a furrowing soil deflector plate disposed when in said prescribed operative working position to engage the ground and deflect soil laterally to one side behind said tyne to form the furrow.

21. A seeding implement assembly as claimed in any one of claim 17 to 20, wherein said covering means comprises a covering soil deflector plate disposed when in said prescribed operative working position to engage the soil at the outside of the furrow and deflect the soil laterally across the furrow covering the furrow and further to the other side of the furrow.

22. A seeding implement assembly as claimed in claim 20 or 21, wherein said furrowing soil deflector plate is substantially planar and wing shaped, and is disposed substantially upright in said prescribed operative working position.

23. A seeding implement assembly as claimed in any one of claims 20 to 22, wherein said covering soil deflector plate is substantially planar and of triangular shape, and is disposed obliquely in said prescribed operative working position.

24. A seeding implement assembly as claimed in any one of claims 20 to 23, wherein said seed discharge means fertiliser discharge means include a cover plate overlying said furrowing means formed with apertures to accommodate respective seed and fertiliser boots, said apertures being disposed such that a said aperture for accommodating a fertiliser boot is disposed centrally with respect to the tyne and anteriorly with respect to said aperture(s) for accommodating one or more seeding boots, such that fertiliser may be deposited immediately rearwardly and at the base of the deep ripping tyne.

25. A seeding implement assembly as claimed in claim 24, wherein said apertures for accommodating at least a pair of seeding boots are disposed laterally with respect to the tyne and anteriorly with respect to said covering means so that seed may be deposited directly into the respective furrows formed on either side of said tyne prior to covering by said covering means.

26. A seeding implement assembly as claimed in claim 24 or 25, wherein a fertiliser deflector plate is provided to depend from the underside of said cover plate between said apertures for fertiliser boot(s) and seed boot(s) so as to partition discharged fertiliser from discharged seed and to deflect discharged fertiliser anteriorly towards the rear of said tyne.

27. A method for seeding a crop comprising:

28. A method as claimed in claim 27, including forming furrows for depositing the seed therein and subsequently covering the furrows.

29. A method as claimed in claim 27 or 28, including forming a central ridge along the surface of the ground between the second lines.

30. A planting system comprising:

31. A planting system as claimed in claim 30 wherein said lines of seed are disposed in covered furrows.

32. A planting system as claimed in claim 30 or 31, wherein a central ridge of soil is disposed between said furrows to channel water into the furrows.

33. A method for seeding a crop substantially as herein described in any one of the preceding embodiments.

34. A seeding implement assembly substantially as herein described with reference to the accompanying drawings in any one of the preceding embodiments.

35. A planting system substantially as herein described with reference to the accompanying drawings in any one of the preceding embodiments.