WO1997016954A1

WO1997016954A1 - Agricultural implement for no-till seeding

Info

Publication number: WO1997016954A1
Application number: PCT/AU1996/000689
Authority: WO
Inventors: Denis James Danaher; Derek Gilbert Barnstable
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-11-03
Filing date: 1996-11-01
Publication date: 1997-05-15
Anticipated expiration: 1998-05-03
Also published as: AUPN639195A0

Abstract

An agricultural implement includes a main body portion having leading edges (14) extending rearwardly and outwardly from a forward part of the main body portion. The main body portion includes an upper body portion (18a). At least the rear part of the upper surface of upper body portion (18a) is shaped to push soil generally upwardly and outwardly as the implement is moved through the soil. For example, the rear part of upper surface of upper body portion (18a) may be oriented generally obliquely. The implement furhter includes side body portions (20a) extending downwardly from the upper body portion. The side body portions (20a) preferably taper outwardly from the front to the back to also act to push the soil outwardly as the implement passes through the soil. As the implement passes through the soil, the leading edges (14) slice through the soil and the soil located above the upper surfaces (18a, 20a) is pushed upwardly and outwardly to thereby momentarily create a void in the soil. Seed supplied through seed supply means (34) is dropped into this void to allow for accurate placement of the seed in the soil. A press wheel (70) is positioned in a housing (74) located behind the implement to firmly press seeds into the soil to assist with germination. The implement is especially useful as a seeder. The implement may further include fertilizer delivery means (36) and delivery tubes (80, 82) for delivering other beneficial agents, such as herbicides and fungicides, to the soil.

Description

AGRICULTURAL IMPLEMENT FOR NO-TILL SEEDING The present invention relates to an agricultural implement. The agricultural implement is especially suitable for no-till planting seeds for crops in undisturbed soils Modern farming practices usually require that soil be tilled or ploughed prior to or during planting of crops. Seeding land for growing crops usually involves the use of seeding machines that include ground engaging devices, such as tines or plough discs, which rip or plough the soil. Seed supply means, such as chutes or supply lines, deposit the seeds into the soil that is disturbed by the seeding machine and the seeds are then generally covered with soil by further covering devices. Fertilizer is frequently deposited with the seed and other agents, such as herbicides, insecticides, fungicides and inoculants, may also be added with the seed.

Conventional seeding machines generally disturb all ofthe soil being worked and result in the formation of noticeable furrows in the ground. Moreover, it is difficult to control the placement of fertilizer using conventional seeding machines and there is the consequent risk that fertilizer may be deposited right next to the seed. Although fertilizer improves growth of the crop, contact between fertilizers and ungerminated seed can actually kill the seed, which then leads to crop losses.

It is an object of the present invention to provide an improved agricultural implement.

In a first aspect, the present invention provides an agricultural implement including a main body portion having leading edges extending rearwardly and outwardly from a forward part of the main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, at least rear parts of the upper surfaces effective to push soil positioned above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil, side body portions extending downwardly from the upper body portions, wherein in use the implement is passed through the soil and a band of soil located underneath the implement during passage thereof through the soil remains substantially undisturbed.

The agricultural implement of the present invention is especially useful for use as a seeding implement. Preferably the implement further comprises seed supply means for supplying seed to the substantially undisturbed band of soil. The seed is placed on the substantially undisturbed band of soil.

In a particularly advantageous embodiment, the upper surfaces ofthe upper body portion of the implement are shaped such that the passage of the implement through the soil pushes the soil located above the upper surfaces of the upper body portions upwardly and outwardly and momentarily creates a void above the band of substantially undisturbed soil, said seed supply means positioned to deliver seed to said void. This allows accurate delivery of seed to the substantially undisturbed band of soil. Once the implement has passed through the soil, the disturbed soil located above the upper surfaces ofthe upper body portions ofthe implement drops downwardly to fill the momentarily created void and cover the seed.

It will be appreciated that seed is delivered to the top of a band of substantially undisturbed soil. As the soil is substantially undisturbed, the tendency ofthe soil to rapidly dry out (as is well known to occur with heavily disturbed soil) is reduced and this provides more moisture for seed germination.

The side body portions of the implement will each have a leading edge and these may comprise downwardly extending extensions of the leading edges extending from the front portion of the main body portion. The leading edges act to split the soil into soil passing over the upper surfaces of the implement and soil passing underneath the implement whilst the tool is being moved through the soil. The soil that passes underneath the implement will remain substantially undisturbed. The band of undisturbed soil will have a cross-sectional shape that generally follows the profile ofthe bottom ofthe implement. The soil passing over the upper surfaces of the upper body portions and side body portions of the implement is somewhat disturbed by passage of the implement through the soil and thus enables excellent root penetration and elongation after seed germination, even if the soil was dense and compacted prior to seeding.

The upper body portions and side body portions of the implement are preferably shaped such that only a relatively small degree of working of the disturbed soil takes place. The disturbed soil may be broken, lifted and aerated and subsequently settles back into place following passage ofthe implement through the soil. This avoids the formation of prominent furrows in the soil and also does not bring excessive moisture to the surface when working moist soils. This avoids fouling of following press wheels with mud and also meets land care aims currently being promoted by public authorities in Australia.

The side body portions extend downwardly from the upper body portions. The side body portions also extend rearwardly from, and preferably outwardly from, the leading edges of the side body portions. Thus, the side body portions preferably taper generally outwardly in the direction of movement ofthe soil from the leading edges to the rear of the implement. In this embodiment, passage of the implement through the soil momentarily creates a void adjacent the side edges of the undisturbed band of soil. Once the implement has passed through the soil, the soil that had been pushed and disturbed by the upper surfaces of the side body portions of the implement falls back into contact with the side edges of the substantially undisturbed band of soil.

The momentary creation of a void adjacent to the edges of the substantially undisturbed band of soil allows for the possibility of precise placement of fertilizer and other beneficial agents with respect to the delivered seed. In a further embodiment, the implement further comprises delivery means for delivering one or more beneficial agents to the soil. The delivery means may include fertilizer supply means having associated fertilizer distribution means. The fertilizer supply means and associated fertilizer distribution means may be arranged such that fertilizer is delivered into the voids created by the upper surfaces of the upper body portions and for the side body portions. Preferably, the fertilizer distribution means is arranged such that the delivered fertilizer does not contact the seed. This allows for high concentrations of fertilizer to be delivered to the soil, but as the fertilizer does not contact the seed, excellent germination of the seed is greatly enhanced.

The fertilizer supply means may comprise a pipe or tube having an opening underneath the implement. The fertilizer distribution means may comprise an inverted "V" - shaped plate deflector for deflecting the fertilizer away from a central part of the band of substantially undisturbed soil (which is generally the location of the seed). The fertilizer distribution means may also include one or more adjustable deflector plates.

The implement may further comprise further delivery means for delivering one or more other beneficial agents to the soil. The further delivery means should have one or more openings that allow delivery of the agent to the soil underneath the implement. The further delivery means preferably deliver the agent(s) to the voids that are momentarily created by passage of the implement through the soil. The further delivery means may allow for the delivery of agents such as herbicides, pesticides, insecticides, fungicides and inoculants to the soil. The further delivery means may be associated with the fertilizer delivery means. For example, to deliver liquid agents to the soil, the further delivery means may comprise a liquid feed line passing along the fertilizer supply means and a spray located underneath or behind the fertilizer opening formed underneath the implement.

The further delivery means may be suitable for delivering liquid, gaseous, aerosol, powdered or solid beneficial agents to the soil.

The implement may also comprise a generally vertically extending forward leading edge to split the soil at the front of the implement. This enables easier passage ofthe implement through the soil and may eliminate the need to use rolling coulters in front of the implement. As mentioned earlier, the seed is delivered to the top of the band of substantially undisturbed soil. In order to allow for even more accurate placement of the seed, the implement may be provided with grooving means for forming a groove in the top ofthe band of substantially undisturbed soil, said grooving means being positioned forward of the seed supply means. The grooving means may comprise a grooving tool projecting downwardly from an upper surface of the underneath ofthe implement. The grooving means may be adjustable to allow the depth of the groove to be varied and/or to compensate for wear. The grooving means is preferably made from, or coated with, a wear resistant material. The grooving means may be placed at a front part ofthe implement, towards the middle of the implement or at a rear portion of the implement.

In an especially preferred embodiment, the lower part of the side body portions may each be provided with a bottom wing. The bottom wings may extend generally transversely to the longitudinal axis ofthe implement. The bottom wings may be generally triangular in shape. The purpose ofthe bottom wings is to shatter and lift soil adjacent to the substantially undisturbed band of soil to thereby extend the volume of disturbed soil. This improves root penetration of the growing crop. The bottom wings also act to draw the implement into the soil during use thereof, thereby minimising the amount of down force that needs to be applied to the implement to keep it in the ground. It is preferred that the bottom wings slope in a generally downwardly direction from the back to the front thereof. The bottom wings may be similar to the wings described in Australian patent No. 577275 in the name of one of the present applicants.

The implement of the present invention is adapted to be passed though the soil. To facilitate this, the implement should be provided with attachment means, for example, for attaching the implement to a tine. The attachment means is preferably arranged such that the tine does not extend a substantial distance into the ground, more preferably such that the tine does not extend into the ground, during use of the implement. The attachment means may comprise a rectangular-block male member adapted to mate with and connect to a corresponding square block female member on a tine. The implement of the present invention allows for precise delivery of seed to a substantially undisturbed band of soil located below the soil surface. The seed may be delivered to a groove in the top of the band of substantially undisturbed soil. As the seed is placed on substantially undisturbed soil, capillary action in the soil provides sufficient soil moisture to ensure excellent germination of seed. Problems of excessive drying in conventionally planted soils are also reduced.

In preferred embodiments of the invention, voids are momentarily created by passage of the implement through the soil. Indeed, observations made by the applicants during use of the implement have shown that the void may close at a distance of approximately 18 inches (45 cm) behind the implement when the implement is being pulled through the soil at 5 mph (8 km/hr). Seed, fertilizer and other beneficial agents may be delivered to the soil through the momentarily created voids. As the seeds, fertilizer and other beneficial agents pass through the voids, precise control over the positioning of the seeds, fertilizer and other beneficial agents is possible. Moreover, the implement may provide only gentle working to the soil, which minimises the amount of moisture raised to the surface during working, minimises soil degradation and avoids formation of furrows on the surface ofthe soil. This last feature is especially useful if the field is to be flood irrigated as the presence of furrows can hinder flood irrigation. In high rainfall situations where sloping soils are subject to erosive rains, the absence of furrows will lessen the risk of erosion rills starting in the plant row. The invention may further include a press-wheel positioned adjacent to the rear of the implement, said press wheel directly contacting a seed deposited on the substantially undisturbed band of soil to thereby force the seed into contact with the soil. The press-wheel may be located such that during use the press-wheel operates in the momentarily created void in the soil, thus enabling the press wheel to directly contact the seed before the soil has fallen back into the void.

From the foregoing description, it will be apparent that in a second aspect the present invention provides an agricultural implement having a main body portion including leading edges extending rearwardly and outwardly from a forward part of the main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, at least the rear parts of the upper surfaces effective to push soil located above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil, side body portions extending downwardly from the upper body portions, the side body portions extending rearwardly from leading edges of the side body portions, seed supply means for supplying seed to the soil, said seed supply means including an opening through which seed is delivered, wherein in use the implement is passed through the soil and a band of soil located underneath the implement during passage therethrough remains substantially undisturbed, passage of the implement through the soil momentarily creating a void above the band of substantially undisturbed soil, and the opening of the seed supply means being positioned such that in use seed passes through said void and is deposited on a top surface of the band of substantially undisturbed soil.

The implement of the second aspect is preferably provided with supply means for supplying one or more beneficial agents to the band of substantially undisturbed soil, the side body portions of the implement being arranged such that passage of the implement through the soil momentarily creates voids adjacent to side edges of the band of substantially undisturbed soil wherein said supply means is arranged to enable supply of the one or more beneficial agents to the soil by passing the one or more beneficial agents through the voids. Preferably, the side body portions extend rearwardly and outwardly from leading edges thereof. The side body portions may have a curved outer surface.

In a third aspect, the present invention provides a method for planting seed comprising providing an agricultural implement as described herein, passing the implement through the soil such that soil located underneath the implement during passage thereof through soil remains substantially undisturbed and said passage forms a band of substantially undisturbed soil and supplying seed to a top surface of said band. Preferably, the passage of the implement through the soil momentarily creates a void adjacent the top surface of the band of substantially undisturbed soil and the seed passes through the void during delivery. More preferably, the implement momentarily creates voids adjacent side edges of the band of substantially undisturbed soil and fertilizer is supplied by passing said fertilizer through the voids.

In a fourth aspect the present invention provides an agricultural implement having a main body portion including leading edges extending rearwardly and outwardly from a forward part of the main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, the upper surfaces including fore portions oriented generally horizontally and rear portions including generally obliquely oriented parts, side body portions extending downwardly from the upper body portions, the side body portions extending rearwardly from leading edges of the side body portions, seed supply means for supplying seed to the soil, said seed supply means including an opening underneath the implement through which seed is delivered. In another aspect, the present invention provides a seeder including a plurality of agricultural implements as described herein. The seeder may also include seed storage means, such as a hopper. The seeder may further include fertilizer supply means. The seeder may also include rearmost press-wheels aligned with the plurality of agricultural implements, the rear-most press wheels adopted to firm the soil located above a planted seed.

In another embodiment, the agricultural implement ofthe present invention may have no side body portions or bottom wings. This embodiment is designed to work only to the depth of seed placement and has been found to work very well in sandy or loamy soils where deep tillage is not required.

Accordingly, in yet another aspect, the present invention provides an agricultural implement comprising a body portion having leading edges extending rearwardly and outwardly from a forward part ofthe body portion, the body portion including two generally horizontal wings, each wing having a front edge defmed by one of said leading edges and a rear edge, each wing having an upper surface, at least a rear portion of each wing effective to push soil positioned above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil.

Preferred embodiments ofthe invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a perspective view of an agricultural implement in accordance with the present invention;

Figure 2 is a side elevation of the implement shown in Figure 1 ;

Figure 3 is a front elevation of the implement shown in Figure 1 ; Figure 4 is a plan view of the implement shown in Figure 1 ;

Figure 5 is a view from underneath of the implement shown in Figure 1 ;

Figure 6 is an end cross-sectional view showing planted soil after having been worked by the implement in accordance with the present invention;

Figure 7 shows a view generally similar to Figure 6 but showing further areas where fertilizer and other beneficial agents can be placed;

Figure 8 shows a perspective view of an agricultural implement of another embodiment of the present invention;

Figure 9 is a plan view of the implement shown in Figure 8;

Figure 10 is a side view of the implement shown in Figure 8;

Figure 11 is an underneath view of the implement shown in Figure 8; Figure 12A is a rear view of the implement shown in Figure 8 showing the fertilizer distribution and adjustable deflector plates;

Figure 12B is a rear view of the implement shown in Figure 8 showing the press wheel;

Figure 12C is a rear view of the implement shown in Figure 8 showing the delivery tubes for delivering liquid or gaseous agents to the soil;

Figure 13 shows a perspective view of another embodiment of the present invention;

Figure 14 shows a plan view of the embodiment of Figure 13;

Figure 15 shows a side view of the embodiment of Figure 13; Figure 16 shows an underneath view of the embodiment of Figure 13.

Referring now to Figures 1 to 5, the agricultural implement 10 in accordance with the present invention has a main body portion 12 having leading edges 14. Main body portion 12 includes an upper body portion having upper surfaces 16 and 18. Upper surface 16 extends generally horizontally, whilst upper surfaces 18 flare upwardly and outwardly from surfaces 16. Upper surfaces 16 may gently flow into upper surface 18, as is shown in the embodiment of Figures 1 to 5. Alternatively, surfaces 16 and 18 may be delineated by sharp demarcation lines.

The main body portion 12 further includes side body portions 20 which may be described as downwardly extending wings. Wings 20 have a leading edge 22. Although not clearly shown in the drawings, wings 20 extend rearwardly and outwardly from leading edges 22. The bottom of side body portions 20 are provided with bottom wings 24 welded thereto. These bottom wings are generally triangular in shape.

Implement 10 is provided with a generally vertically extending front edge 26. This front edge 26 extends rearwardly and flares outwardly as shown at reference numeral 28. Leading edge 26 is used to split the soil in front of the implement whilst the outward flaring at 28 acts to further separate the soil and assists in passing the soil over the upper surfaces ofthe implement. Figure 1 shows the bottom part of front edge 26 extending below the level of leading edge 14. However, front edge 26 may terminate at its lowest end at the level of leading edge 14.

The implement is also provided with a male block connecting member 30 that forms part of a rectangular section block connection element 32. Rectangular section block connection element 32 mates with a corresponding connection element on a tine (not shown) to thereby enable the implement to be connected to the tine. As is best shown in Figures 1 and 2, implement 10 is also provided with a seed supply means 34 and a fertilizer supply means 36. Seed supply means 34 comprises an open rectangular section tube through which seed can pass. Fertilizer supply means 36 comprises an open tube through which fertilizer can pass. Although not shown in Figures 1 to 5, the upper parts of seed supply means 34 and/or fertilizer supply means 36 may become round tubes to allow easier mating with supply tubes or conduits from seed or fertilizer hoppers. As is best shown in Figure 5, seed supply tube 34 has an opening 38 that opens to the underneath part of the implement. Fertilizer supply tube 36 has a V-shaped deflector plate 40 mounted in its outlet and fertilizer exits through openings 41 and 42 in the underneath part of the implement. Although not shown in the drawings, exits 38, 41 and 42 may be each provided with adjustable deflector plates in order to control the positioning of the seed and the fertilizer, respectively.

As is most clearly shown in Figure 5, the implement is also provided with a grooving tool 44 that extends down into the underneath part of the implement. Grooving tool 44 is located directly in front of outlet 38 of the seed supply means. Grooving tool 44 extends through slot 46 (refer to Figure 4) and is provided with a series of spaced holes which allows for adjustment of the depth of grooving tool 44.

In use ofthe implement shown in Figures 1 to 5, the implement is connected to a tine block and is pushed or pulled through the ground, usually with the aid of a tractor. The implement is set to a depth such that the top surface of the soil is located just below surface 32a (refer to Figure 1) which represents the lowermost position of the tine. Therefore, the tine does not extend into the ground and this reduces wear on the tine.

As the implement 10 is passed through the soil, leading edge 26 acts to separate the soil at the front of the implement and this eases the passage of the implement through the soil. Leading edges 14 and 22 of the main body portion 12 cut through the soil and separate the soil into soil passing underneath the implement and soil passing above the working surfaces of the implement. The soil that is contacted by leading edge 14 and passes above leading edge 14 passes over upper surface 16 and then comes into contact with upper surface 18. Upper surface 18 imparts generally upwardly and outwardly components of motion to the soil passing thereby and this tends to move the soil in a generally upwardly and outwardly direction. At the same time, the soil that passes over the outer surface of wings 20 is also caused to flow outwardly. The soil that passes underneath the implement remains substantially undisturbed and forms a band of substantially undisturbed soil 50 (refer to Figure 6). Band 50 includes top surface 52 and side edges 54,56. Grooving tool 44 acts to form a groove 58 in the top surface of the band of substantially undisturbed soil. In Figure 6, the soil that is disturbed by passage of the implement through the soil is shown by cross-hatching.

During passage of the implement through the soil, the arrangement of upper surfaces 16 and 18 and the generally outward taper of the side wings 20 momentarily causes voids to form immediately adjacent the top surface 52 and side edges 54,56 ofthe band of substantially undisturbed soil. These voids momentarily exist only while the implement 10 is passing through any particular piece of soil. The voids that are momentarily created by passage of the implement through the soil are positioned with respect to the implement such that seed delivered through the seed delivering means 34 and fertilizer delivered through the fertilizer delivery means 36 passes through those voids during use of the implement . As the seed and fertilizer are passing through voids, the positioning of the seed and fertilizer can be closely controlled and this enables precise positioning of the seed and fertilizer. In particular, the positioning ofthe fertilizer can be controlled such that high fertilizer concentrations can be provided around the seed whilst avoiding close contact between the fertilizer and the seed which would otherwise tend to damage the seed. This is clearly shown in Figure 6 where seed 60 is positioned in groove 58 in the top surface 52 of the band of substantially undisturbed soil. However, fertilizer 62 is located along the edges 54,56 of the bank 50 of substantially undisturbed soil.

As shown in Figure 7, the implement ofthe present invention also allows the application of liquid fertilizers and other beneficial agents to be closely controlled. In particular, such fertilizers or agents may be applied anywhere to the zone marked by reference numeral 64. This may allow, for example, placement of a nitrogen fertilizer directly onto the seed, placement of a phosphate fertilizer a short distance away from the seed, a herbicide near reference numeral 66 to inhibit weed growth, and more fertilizer near reference numeral 68 to encourage root growth of any weeds away from the seed.

The bottom wings 24 of the implement 10 act to shatter and lift the soil adjacent to the undisturbed band of soil on which the seed is placed. This increases the volume of soil around the seed that has been disturbed and loosened and facilitates penetration of roots into the soil once the seed has germinated. Bottom wings 24 also act to draw (or suck in) the implement into the soil during passage therethrough. The wings preferably are mounted at the rearmost portion of wings 20, although they could also be suitably mounted at other portions of wings 20. As best shown in Figure 3, the rear part of the wings 24 is raised above the front part of wings 24 to thereby provide wings 24 with a sloping surface. As is clearly shown in Figure 6, the seed 60 is positioned on the band 50 of substantially undisturbed soil. This allows natural capillary action of the undisturbed soil to bring water to the seed 60, which assists in promoting germination of the seed. Moreover, the soil located adjacent to the band 50 of substantially undisturbed soil has been worked to a depth that is greater than the depth of planting of the seed and this facilitates root penetration once the seed has germinated. The implement of the present invention is especially suitable for planting maize seeds. Maize crops require high nitrogen fertilizer contents in order to grow at acceptable rates. However, if the high concentration of nitrogen fertilizer is placed too close to the seed, germination will be reduced. The implement of the present invention, in allowing precise location of both the seed and the fertilizer, overcomes any difficulties in this regard.

Another embodiment of the invention is shown in Figures 8 to 12. This embodiment is generally similar to that shown in Figures 1 to 5 and like parts will be given like reference numerals. The main difference between the embodiment shown in Figures 1 to 5 and the embodiment shown in Figures 8 to 12 resides in a less pronounced differentiation, or a more gradual merging, of surfaces 16 and 18 shown in Figures 1 to 5. In particular, in the embodiment shown in Figures 8 to 12, the implement is manufactured by pressing the portion of the body denoted by reference numerals 18a and 20a in a hydraulic press. As a result, top surface 18a (best shown in Figures 8, 9 and 10) smoothly curves upwardly from leading edge 14 to the rearmost edge. In contrast to the embodiment shown in Figures 1 to 5, the top surface 18a of the implement shown in Figures 8 to 12 does not include such a pronounced demarcation between surfaces 16 and 18 of the embodiment of Figures 1 to 5.

Another difference between the embodiment shown in Figures 1 to 5 and that shown in Figures 8 to 12 resides in the side wings 20a being significantly more back swept than the side wings 20 shown in Figures 1 to 5. In particular, leading edges 22a of the wings 20a shown in Figures 8 to 12 sweep backwardly at a much greater angle than leading edges 22 of the embodiment shown in Figures 1 to 5. Use of the implement shown in Figures 1 to 5 revealed that roots and other trash would tend to accumulate on leading edges 22, which would reduce the effectiveness of the implement. To overcome this difficulty, the wings 20a were given a much greater backsweep which has been found to be effective in assisting to prevent the build up of roots and trash on the leading edges 22a.

In Figures 8 to 11, the implement also includes generally vertical front edge 26a that is provided with a sloping upper surface 26b. Again, the sloping upper surface 26b was provided to reduce the build up of mud, roots and other trash on the front edge 26.

The embodiment shown in Figures 8 to 12 also includes an additional press wheel 70 mounted on sealed bearings 72 in a press wheel housing 74. An adjustable spring 76 is used to vary the pressure applied to press wheel 70. In operation, press wheel 70 is positioned such that it operates within the momentarily created void in the soil. Therefore, when a seed is dropped onto the band of undisturbed soil that passes underneath the implement, especially into the groove formed by the grooving tooth ofthe implement, press wheel 70 can directly contact the seed and thereby force the seed more firmly into contact with the soil. This assists in germination. The press wheel 70 may be provided with a scraper 76, if desired. However, as the pressure applied by press wheel 70 is only relatively small, scraper 76 has the potential to act as a brake on press wheel 70 and therefore operation of scraper 76 must be carefully controlled.

As best shown in Figure 10, seed supply tube 34 is located towards the rear of the implement and rearwardly of fertilizer supply tube 36. Seed supply tube 34 is fitted with an electronic seed sensor 78 that may comprise a conventional electric eye or similar mechanism. When a seed passes through electronic seed sensor 78, a noise will sound or a light will be lit to thereby indicate to the operator that seeds are flowing effectively through seed supply tube 34. This assists in ensuring that any blockages in the seed supply tube 34 are quickly noticed by the operator.

The embodiment shown in Figures 8 to 12 is also provided with a grooving tool for forming a groove in the top of the band of undisturbed soil that passes underneath the implement. The grooving tool may be located in one of three positions, these being at the front ofthe implement (as shown by reference numeral 44a), towards the middle part of the implement (as shown by reference numeral 44b) or at the rearmost of the implement (as shown by reference numeral 44c). It is noted that grooving tool 44a is a forward sloping grooving tool whereas positioning the grooving tool at locations indicated by 44b and 44c enables a rearward facing grooving tool to be used. The implement shown in Figures 8 to 12 also includes bottom wings 24 positioned at the lower end of side wings 20a. Bottom wings 24 are generally triangular in shape and the back edge of the bottom wings 24 is positioned above the front of bottom wings 24 so that the wings slope downwardly from back to front.

The implement of Figures 8 to 12 also includes gas or liquid delivery tubes 80, 82 for delivering liquid or gaseous beneficial agents to the soil. As best shown in Figure 12c, the ends of tube 80, 82 may be positioned in desired locations to ensure accurate delivery ofthe liquids and/or gases. The liquids and/or gases may be herbicides, insecticides, fungicides, inoculants, fumigants and fertilizers, along with any other flowable material required.

As best shown in Figure 12A, the exits 41 and 42 may be provided with adjustable deflector plates 85, 86 in order to control the positioning ofthe fertilizer. Deflector plates 85, 86 may be adjustable by use of pneumatic pressure. In manufacturing the implement of the embodiment shown in Figures 8 to

12, a plate of suitable material, such as steel, is hydraulically pressed, hot formed or otherwise formed to produce the implement having surfaces 18a and 20a. Bottom wings 24 may be either integrally formed in the forming process or may be later welded onto the implement. The "super structure" ofthe implement located above surface 18 may be welded thereto.

The implement shown in Figures 8 to 12 may suitably form part of a seeder. The seeder may comprise a plurality of implements mounted to tines 88. The seeder may include seed storage means, such as a hopper, and fertilizer storage means, such as a hopper. The seeder may also include rearmost press wheels (not shown in the Figures) which are located behind press wheel 70 and act to firm down the soil above the seed once the voids that are momentarily created by passage ofthe implement through the soil have closed. The seeder may include any other features known to be suitable by the skilled person for use on seeders.

The embodiment shown in Figures 13 to 16 shows an agricultural implement in accordance with the present invention which is particularly suitable for use in sandy or loamy soil conditions where deep tillage is not required. The embodiment shown in Figures 13 to 16 is generally similar to those shown in Figures 1 to 12, with the exception that the side wings and bottom wings ofthe embodiment shown in Figures 1 to 12 are not present. The embodiment of Figures 13 to 16 operates in a similar fashion in that soil located above the upper surface of the implement is pushed upwardly and outwardly by passage ofthe implement through the soil to momentarily create a void in the soil, with seed being supplied to the void. Except for the side wings and bottom wings, the embodiment of Figures 13 to 16 includes all of the features of the embodiments of Figures 1 to 12.

In particular, the embodiment shown in Figures 13 to 16 includes an agricultural implement 100 having a body portion 102 that is defined by a leading edge 103 and a rear edge 104. As can be seen in Figure 13, the body portion 102 may be considered to define two generally horizontally extending wings. The wings 102 have an upper surface that includes a rear portion 105 that extends generally obliquely and this acts to push the soil travelling over the upper surface upwardly and outwardly to thereby momentarily create a void in the soil as the implement passes therethrough.

The implement also includes a vertically extending front splitting edge 106 that splits open the soil in front of the implement. Splitting edge 106 includes a sloped upper surface 107 to assist in ensuring that roots and other trash are cleared therefrom. The implement also includes a press wheel 108 mounted in press wheel housing 109. The press wheel 108 is located behind the seed supply means 110 and acts to directly contact seeds that have been deposited on the soil to ensure that the seeds firmly contact the soil. To assist in preventing the seeds rolling away from their desired position, the implement is provided with a grooving tool 111 which may be located at any of the three positions designated as 11 la, 11 lb or 11 lc. As can be seen, the grooving tool is always positioned forward ofthe outlet ofthe seed supply means.

The implement is also provided with attachment means 112 to enable a tine 113 to be attached thereto. The implement also includes delivery tubes 114, 115 for delivering beneficial agents to the soil, particularly gaseous or liquid agents. Fertilizer delivery means 116 are also provided for delivering fertilizer to the soil. As best shown in Figure 16, the outlet of fertilizer delivery means 116 includes adjustable deflector plates 117 to enable the position of the fertilizer to be controlled.

In use of the implement shown in Figures 13 to 16, the implement passes through the soil. Soil positioned above the upper surfaces of wings 102 is pushed upwardly and outwardly by the wings whilst the soil positioned underneath the implement is largely undisturbed. Grooving tool 111 creates a groove in the substantially undisturbed soil underneath the implement and seed is dropped into the groove. Press wheel 108, which operates in the momentarily created void in the soil caused by the passage of the implement through the soil, directly contacts the seeds to more firmly push the seeds into contact with the soil in the groove. Fertilizer and other beneficial agents may be also added to the soil.

In all ofthe embodiments shown in Figures 1 to 16, the leading edges of the implement act to cut or slice through the soil and therefore it is preferred that the leading edges of the implement include a relatively sharp edge to facilitate cutting or slicing of the soil. In order to further assist in separating the soil, it is also preferred that the upper body portions and side wing portions of the embodiment shown in Figures 1 to 12 and the side wings 102 shown in Figures 13 to 16 be relatively thin at the front thereof and have an increase in the thickness towards the rear edges thereof. It is also preferred that all leading surfaces of the implement be made from wear resistant materials.

The agricultural implement of Figures 1 to 5, 8 to 12 and 13 to 16 has been designed to provide only a small degree of working to the soil that is located above the implement. This results in little or no disturbance being made to the surface of the soil, which tends to minimise the formation of clods or furrows on the surface. This assists in minimising any structural damage to the soils whilst allowing for good aeration, good water infiltration and sound drainage.

A number of other modifications and variations to the implement are also possible. For example, the implement may be provided with further supply means for supplying other beneficial agents, such as herbicides, pesticides, fungicides and inoculants to the soil. The further supply means may comprise further supply tubes formed in the implement. Alternatively, the further supply means may form part of either the seed supply means 34 or the fertilizer supply means 36. Advantageously, the further supply means includes a feed pipe and spray means arranged in the fertilizer supply means and outlet, which enables liquid, gaseous or aerosol products to be sprayed onto the band of undisturbed soil.

The working surfaces of the implement are preferably formed from wear resistant materials that will be well known to those skilled in the art. More preferably, the areas that are prone to wear may be made such that they are easily replaced by the farmer or other user of the implement. The implement may be formed by casting.

It will also be appreciated that the seed supply means and the fertilizer supply means may be provided with adjustable deflector plates. This enables even closer control of the positioning ofthe seed and/or fertilizer. For example, it may be possible to spread the fertilizer such that it extends from the edges of top surface 52 of the band 50 of undisturbed soil and right along side edges 54,56 ofthe band 50 of undisturbed soil. Alternatively, the fertilizer may be provided such that it is all positioned at the bottom of edges 54,56 or such that it is all positioned near the top surface 52.

A further advantage of the relatively small amount of working done to the soil by the implement of the present invention is that the amount of sub-soil moisture brought to the surface during working of the soil is minimised. This prevents excessive or premature drying of the soil and also avoids the fouling of any following wheels with mud.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically disclosed. It is to be understood that the invention is considered to encompass all such variations and modifications that are all within its spirit and scope.

Claims

CLAIMS:

1. An agricultural implement including a main body portion having leading edges extending rearwardly and outwardly from a forward part of the main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, at least rear parts of the upper surfaces effective to push soil positioned above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil, side body portions extending downwardly from the upper body portions, wherein in use the implement is passed through the soil and a band of soil located underneath the implement during passage thereof through the soil remains substantially undisturbed.

2. An agricultural implement as claimed in claim 1 wherein the side body portions each have a leading edge, each leading edge comprising a downwardly extending extension of the leading edges extending from the front portion of the main body portion.

3. An agricultural implement as claimed in claim 1 or claim 2 wherein the side body portions extend rearwardly from and outwardly from the leading edges of the side body portions such that the side body portions taper generally outwardly in the direction of movement of the soil from the leading edges to the rear of the implement.

4. An agricultural implement as claimed in any one of claims 1 to 3 further comprising seed supply means for supplying seed to the substantially undisturbed band of soil.

5. An agricultural implement as claimed in claim 4 wherein the upper surfaces of the upper body portion of the implement are shaped such that the passage of the implement through the soil pushes the soil located above the upper surfaces of the upper body portions upwardly and outwardly and momentarily creates a void above the band of substantially undisturbed soil, said seed supply means positioned to deliver seed to said void.

6. An agricultural implement as claimed in claim 4 or claim 5 further comprising grooving means for forming a groove in the top of the band of substantially undisturbed soil, said grooving means being positioned forward ofthe seed supply means.

7. An agricultural implement as claimed in claim 6 wherein the grooving means comprises a grooving tool projecting downwardly from an upper surface of the underneath of the implement.

8. An agricultural implement as claimed in claim 7 wherein the grooving tool is placed at a front part of the implement, towards a middle part of the implement or at a rear portion of the implement.

9. An agricultural implement as claimed in any one of the preceding claims wherein the lower part of the side body portions are each provided with a bottom wing.

10. An agricultural implement as claimed in claim 9 wherein the bottom wings extend generally transversely to the longitudinal axis of the implement.

11. An agricultural implement as claimed in claim 9 or claim 10 wherein the bottom wings slope in a generally downwardly direction from the back to the front thereof.

12. An agricultural implement as claimed in any one of claims 9 to 11 wherein the bottom wings are generally triangular in shape.

13. An agricultural implement as claimed in any one of the preceding claims further including a generally vertically extending forward leading edge for splitting the soil at the front of the implement.

14. An agricultural implement as claimed in any one of the preceding claims further comprising delivery means for delivering one or more beneficial agents to the soil.

15. An agricultural implement as claimed in claim 14 wherein said delivery means includes fertilizer supply means.

16. An agricultural implement as claimed in claim 15 wherein the fertilizer supply means includes associated fertilizer distribution means.

17. An agricultural implement as claimed in claim 15 or claim 16 wherein the fertilizer supply means includes a tube having an opening underneath the implement.

18. An agricultural implement as claimed in claim 16 wherein the fertilizer distribution means includes one or more adjustable deflector plates.

19. An agricultural implement as claimed in claim 14 wherein the delivery means includes one or more tubes for delivering aqueous or gaseous agents.

20. An agricultural implement as claimed in any one of the preceding claims further including attachment means to facilitate attachment ofthe implement to a tine.

21. An agricultural implement having a main body portion including leading edges extending rearwardly and outwardly from a forward part ofthe main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, the upper surfaces including fore portions oriented generally horizontally and rear portions including generally obliquely oriented parts, side body portions extending downwardly from the upper body portions, the side body portions extending rearwardly from leading edges of the side body portions, seed supply means for supplying seed to the soil, said seed supply means including an opening underneath the implement through which seed is delivered.

22. An agricultural implement including a main body portion including leading edges extending rearwardly and outwardly from a forward part ofthe main body portion, the main body portion including an upper body portion having upper surfaces extending rearwardly from the leading edges, at least the rear parts of the upper surfaces effective to push soil located above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil, side body portions extending downwardly from the upper body portions, the side body portions extending rearwardly from leading edges of the side body portions, seed supply means for supplying seed to the soil, said seed supply means including an opening through which seed is delivered, wherein in use the implement is passed through the soil and a band of soil located underneath the implement during passage therethrough remains substantially undisturbed, passage of the implement through the soil momentarily creating a void above the band of substantially undisturbed soil, and the opening of the seed supply means being positioned such that in use seed passes through said void and is deposited on a top surface of the band of substantially undisturbed soil.

23. An agricultural implement as claimed in claim 22 further comprising a press wheel positioned adjacent to the rear of the implement, said press wheel directly contacting seeds deposited on the band of substantially undisturbed soil.

24. An agricultural implement as claimed in claim 23 wherein the press wheel is located such that during use the press wheel operates in the momentarily created void in the soil.

25. A seeder including a plurality of agricultural implements as claimed in any one of claims 1 to 24.

26. An agricultural implement comprising a body portion having leading edges extending rearwardly and outwardly from a forward part ofthe body portion, the body portion including two generally horizontal wings, each wing having a front edge defined by one or said leading edges and a rear edge, each wing having an upper surface, at least a rear portion of each wing effective to push soil positioned above the upper surfaces generally upwardly and outwardly as the implement is moved through the soil.

27. An agricultural implement as claimed in claim 26 wherein the rear portion of each wing includes a generally obliquely extending portion.

28. An agricultural implement as claimed in claim 26 or 27 further comprising seed supply means for supplying seed, said seed supply means including an opening underneath the implement.

29. An agricultural implement as claimed in claim 28 wherein, the upper surfaces are shaped such that the passage of the implement through the soil pushes the soil located above the upper surfaces upwardly and outwardly and momentarily creates a void above the band of substantially undisturbed soil, said seed supply means positioned to deliver seed to said void.

30. An agricultural implement as claimed in claim 28 or claim 29 further comprising grooving means for forming a groove in the top of the band of substantially undisturbed soil, said grooving means being positioned forward ofthe seed supply means.

31. An agricultural implement as claimed in claim 30 wherein the grooving means comprises a grooving tool projecting downwardly from an upper surface of the underneath of the implement.

32. An agricultural implement as claimed in claim 31 wherein the grooving tool is placed at a front part of the implement, towards a middle part of the implement or at a rear portion of the implement.

33. An agricultural implement as claimed in any one of claims 26 to 32 further including a generally vertically extending forward leading edge for splitting the soil at the front of the implement.

34. An agricultural implement as claimed in any one of claims 26 to 33 further comprising delivery means for delivering one or more beneficial agents to the soil.

35. An agricultural implement as claimed in claim 34 wherein said delivery means includes fertilizer supply means.

36. An agricultural implement as claimed in claim 35 wherein the fertilizer supply means includes associated fertilizer distribution means.

37. An agricultural implement as claimed in claim 35 or claim 36 wherein the fertilizer supply means includes a tube having an opening underneath the implement.

38. An agricultural implement as claimed in claim 36 wherein the fertilizer distribution means includes one or more adjustable deflector plates.

39. An agricultural implement as claimed in claim 34 wherein the delivery means includes one or more tubes for delivering aqueous or gaseous agents.

40. An agricultural implement as claimed in any one of claims 26 to 39 further including attachment means to facilitate attachment of the implement to a tine.

41. A seeder including a plurality of agricultural implements as claimed in any one of claims 26 to 40.

42. A seeder as claimed in claim 41 wherein each implement has a press wheel associated therewith, said press wheel positioned adjacent to the rear of the implement, said press wheel directly contacting seeds deposited in the soil.

43. A seeder as claimed in claim 42 wherein the press wheel is located such that during use the press wheel operates in the momentarily created void in the soil.

44. A seeder as claimed in claim 42 or claim 43 further including an adjustable spring for adjusting pressure applied by the press wheel.