WO2008107171A1

WO2008107171A1 - Soil tillage in arid conditions

Info

Publication number: WO2008107171A1
Application number: PCT/EP2008/001738
Authority: WO
Inventors: Magne Skjaeveland
Original assignee: Kverneland Asa
Priority date: 2007-03-06
Filing date: 2008-03-05
Publication date: 2008-09-12
Also published as: GB0704277D0

Abstract

A method of soil tillage, prior to seeding of a crop, comprises forming a pair of parallel seeding rows (10) by working the soil so that each seeding row comprises a strip of worked soil having a predetermined depth. The seeding rows are laterally spaced apart from each other to define an intermediate strip (12) of unworked soil. A roller (22) is applied to the intermediate strip (12) of unworked soil in order to compact the strip and shape the upper surface thereof so that rainwater falling on the intermediate strip drains towards and into at least one of the adjoining seeding rows.

Description

SOIL TILLAGE IN ARID CONDITIONS

This invention is concerned generally with the improvement of soil tillage in arid conditions, with a view to conserve and make the best use of limited water resources. However, it should be understood that the invention is not restricted to use in arid conditions, and may be used in other situations in agriculture and horticulture in which it is desirable to maximise the utilisation of water resources, whether from precipitation, or by irrigation.

It is well known that all plants can produce highest yields when they receive optimum amounts of water during the growth period. There are many areas in the world with climates which provide warmth and rainfall in such amounts that high yields of crop can be obtained. However, in areas having lower annual rainfall, the crop yields are generally reduced, unless irrigation additionally is employed.

Usually, major amounts of rainfall occur in the colder seasons i.e. other than the growth season, and some of this rainfall penetrates the soil, some drains away into ditches, streams and rivers, and the remainder evaporates. Furthermore, seeding usually takes place at the end of a cold and humid season, whereas the growth phase takes place when the weather becomes warmer and dryer.

Evidently, the more arid the climate, the greater the necessity to conserve and make most effective use of the more limited supply of rainwater in order to maintain worthwhile crop yields. The methods adopted to conserve rain water vary according to factors such as climate, type of crop and local conditions.

Also, areas with water shortage often have a hot climate in the summer period, and any water which is lying on the surface after rainfall, or from dew building up over night, evaporates quickly when the sun is at its highest. The fields are often vast in size, so that the action of wind also can be a major factor in drying up any water lying on the surface of a field. It is therefore very important to find improved methods and apparatus of soil tillage which can promote penetration of the soil as quickly as possible, to minimize water losses by evaporation.

The present invention has therefore been developed primarily with a view to providing an improved method, and improved soil tillage implement, which are capable of better utilisation of limited water supplies in order to obtain worthwhile crop yields, and especially to maximise the utilisation of limited rainfall in arid conditions.

According to one aspect of the invention there is provided a method of soil tillage, prior to seeding of a crop, and which comprises:

forming a pair of parallel seeding rows by working the soil so that each seed row comprises a strip of worked soil having a predetermined depth, said seeding rows being laterally spaced apart from each other to define an intermediate strip of unworked soil; and

applying a roller to the intermediate strip of unworked soil in order to compact the strip and to shape the upper surface thereof so that any rainwater falling on the intermediate strip drains towards and into at least one of the adjoining seeding rows.

Conveniently, a soil tillage implement is utilised having forward sets of tines which can form simultaneously pairs of parallel rows in the soil, with an intermediate strip of unworked soil between each adjacent pair of rows.

The invention therefore provides a unique method of soil tillage, in that the soil is only worked along parallel rows into which the seeds are subsequently introduced, whereas the strips defined between each pair of rows are unworked, in the sense of not being tilled, and the rolling action applied to the strips improves the ability of such strips to "shed" any rainwater falling on them into at least one, and preferably into both of the adjoining rows.

Therefore, even with what would otherwise be an insufficient supply of rainfall on a field having been tilled by conventional tillage operations (in which the entire surface is fully worked by ploughs, harrows and the like), the invention enables the bulk of rainfall on a field to be collected and to drain into the seeding rows which, in plan, represent only a small proportion of the surface area of the field. The rainfall is directed into the rows and penetrates the ground below, and the loss of otherwise useful rainfall by discharge to water courses, or by evaporation, is much reduced.

Preferably, the seeding rows are formed by passage of tines through the soil, and which may utilise an implement having successive arrays of tines operating at different depths; alternatively, an implement having one set of tines may carry out repeated passes through the soil with the tines operating at successively greater depths.

The roller has its outer surface shaped according to the required shape to be applied to the upper surface of each intermediate strip of unworked soil, but one particularly preferred shape is a continuous curved concave surface intermediate each of the opposed ends of the roller. Such a shape of roller will tend to form a curved domed surface on each strip, whereby any rainwater falling on such surface will tend to drain laterally into each of the adjoining rows.

Conveniently, a soil tillage implement used to carry out the invention has an implement frame, a forward set of tines spaced apart by a distance corresponding to the required spacing apart of each pair of seeding rows, a pair of discs located on the frame rearwardly of each forward tine and arranged to enlarge and to consolidate the row formed in the soil by each tine, and a roller rotatably mounted on the frame rearwardly of the discs and laterally inwardly of each adjacent pair of the forward set of tines.

Advantageously, the strip of worked soil has a depth in the range 400-800mm, preferably 500-700mm, and a width in the range 150-300mm, preferably 200-250mm. The adjacent strips of worked soil may have a separation in the range 600- 1200mm, preferably 800- 1000mm.

According to another aspect of the invention there is provided a method of cultivating a crop, which comprises: tilling the soil by a method according to any one of the preceding statements of invention, and seeding the seeding rows formed by the tilling method.

According to a further aspect of the invention there is provided a soil tillage implement which comprises: an implement frame which can be propelled in a tilling direction; a forward set of tines mounted on the frame and spaced apart laterally with respect to the tilling direction so as to form spaced apart parallel seeding rows in the soil, wherein each seed row comprises a strip of worked soil having a predetermined depth; and a roller rotatably mounted on the implement frame rearwardly of the forward set of tines and arranged to compact an intermediate strip of un worked soil between each pair of seeding rows, and to shape the upper surface of the strip so as to promote drainage of any rainwater falling on the strip laterally into at least one of the adjoining seeding rows.

Preferably, the roller has a concave curved outer surface shaped so as to apply a domed shape to the upper surface of each intermediate strip.

The implement may also mount a respective pair of discs rearwardly of each forward tine, to enlarge and consolidate the seeding row.

Further sets of tines may also be mounted on the frame, to work at a greater depth than the forward set of tines.

A preferred example of soil tillage method, and soil tillage implement, according to the invention will now be described in detail, with reference to the accompanying drawings, in which:

Figure 1 is a schematic plan view illustration of the essential steps in carrying out an improved water conservation tillage method of the invention;

Figure 2 is a schematic and perspective illustration of the growth of crops planted in parallel seeding rows formed by the method of Figure 1;

Figure 3 is a side view of one preferred example of soil tillage implement according to the invention;

Figures 4a to 4e show successive sectional illustrations of the seeding rows or furrows formed by the implement of Figure 3; and

Figure 5 is a schematic plan view illustration of the implement of Figure 3. Referring first to Figure 1 of the drawings, this is a schematic illustration of the essential method steps in carrying out an improved method of water conservation soil tillage, prior to seeding of a crop.

The method essentially comprises forming a pair of parallel seeding rows 10 at a predetermined depth in the soil, and which are laterally spaced apart from each other to define an intermediate strip 12 of unworked soil. The seeding rows 10 are formed by a spaced apart forward set of tines 14, each of which cuts a furrow 16 in the soil. Each forward tine 14 is followed by a corresponding pair of discs 18, 20 which cut away the sides of the furrow 16 to enlarge and consolidate the seeding row formed by the tine 14.

Rearwardly of the forward set of tines 14, and also rearwardly of the discs 18, 20 the implement mounts on its frame a roller 22 that applies a rolling action to the intermediate strip 12 of unworked soil in order to compact the strip, and also to shape the upper surface thereof so that any rainwater falling on the intermediate strip 12 drains towards and into at least one of the adjoining rows 10.

Each roller 22 is located between a cooperating pair of intermediate tines 24 operating at a greater depth than the forward tines 14. Finally there is a trailing set of rearmost tines 26 operating at an even greater depth.

The implement will have an implement frame (not shown) on which adjacent pairs of forward tines 14 are mounted to form the parallel rows 10 with the intermediate strip 12 of unworked soil there between, and therefore the soil tillage method only works the soil along parallel rows into which the seeds are subsequently introduced. The strips 12 defined between the seeding rows 10 are unworked, in the sense of not being tilled, and the rolling action applied by rollers 22 to the strips 12 improves the ability of such strips to "shed" any rainwater falling onto them and into at least one, and preferably into both of the adjoining seeding rows 10.

The outer surface of each roller 22 is a continuous concave curved surface, so as to apply a domed shape to the upper surface of each strip 12, whereby rainwater falling on the domed surface is discharged laterally in order to drain into each of the adjoining seeding rows 10. Figure 2 illustrates schematically the growth of rows 28 of a crop that have been introduced into the parallel seeding rows 10 and have subsequently grown during the growth season, by drawing on the water which has been shed laterally from the domed surfaces of the compacted intermediate strips 12. Figure 2 also shows the regions of worked soil 30 that form the seeding rows and the intermediate regions 32 of un worked soil. During growth of the crop, water is drawn into each worked region 30 from a surrounding region 34 of the unworked soil.

Figure 1 is a schematic illustration of a soil tillage implement for use in carrying out the method of the invention, and one practical example of an implement for working five seeding rows simultaneously is shown in more detail in Figures 3 to 5.

The soil tillage implement of Figures 3 to 5 is designated generally by reference 36 and has an implement frame 38 that can be propelled in a tilling direction 40. The frame 38 carries a forward set of tines 14 that operate at a first predetermined depth A, each of which is followed by a cooperating pair of discs 18 and 20. These are then followed by the concave rollers 22, which are rotatably mounted on frame 21, each roller 22 being located between the furrows 16 made by the corresponding forward pair of tines 14, so as to apply a rolling action to the intermediate strip 12 defined between each pair of parallel seeding rows 10.

Each roller 22 is located between a cooperating pair of intermediate tines 24 operating at a greater depth B than the forward tines 14, and finally there is a trailing set of rearmost tines 26 operating at an even greater depth C. The three sets of tines may be fitted with standard reversible points or with winged shares, or any other suitable working points. Preferably, the intermediate tines 24 are fitted with winged shares for cutting and lifting the soil and the rearmost tines 26 are fitted with winged shares that make a flat and even base at the bottom of the seeding row 10.

A soil tilling method carried out using the implement of Figures 3 and 5 is illustrated in Figures 4a to 4e. As the implement is drawn forwards in the tilling direction, each forward tine 14 cuts a furrow 16 in the soil having a depth A of typically 200mm. The soil worked by the forward tine 14 mostly stays within the furrow 16 but is loosened and broken up. Some of this worked soil may however spill out of the furrow onto the surface of the surrounding unworked soil 12.

The furrow 16 is then widened and consolidated by the discs 18, 20, which cut away first one side 36 of the furrow (Fig. 4b) and then the other side 38 (Fig. 4c) to the same depth A. This provides a clean, sharp cut on each side of the furrow 16, which helps to prevent the unworked soil on either side of the furrow being broken up subsequently by the intermediate and rearmost tines. Again, most the soil cut away from the sides of the furrow falls back into the furrow, although some may be deposited on the surface of the unworked soil 12 on either side of the furrow. Typically, the furrow 16 has a width of 200- 250mm. The separation of adjacent furrows depends on the crop to be planted but for maize it is typically approximately 900mm.

In the next stage shown in Fig. 4d, the intermediate tine 24 cuts into the soil 40 at the base of the furrow to increase the depth of the furrow to a depth B of typically 400mm. It also works the soil within the furrow for a second time, thus breaking it into smaller particles. At the time, the rollers 22 on either side of the furrow shape the surface 42 of the unworked soil between the furrows into a convex curve that slopes downwards on either side towards the furrow. Any worked soil ejected from the furrow by the tines and the discs is incorporated into this intermediate curved surface 42.

Finally, the rearmost tine 26 cuts the furrow to an even greater depth C, typically 600mm, to complete the seeding row 10. This tine 26 is narrower than the forward and intermediate tines so that it does not increase the width of the furrow or cause soil to be thrown out of the furrow. As the rearmost tine 26 passes along the furrow in works the soil 44 within the furrow for a third time, thus breaking the soil into even smaller particles. The rearmost tine is designed to provide the furrow with a clean-cut base 46 to prevent water draining away from the finely-worked soil 44 within the furrow.

Once the soil has been prepared as described above, the seeding rows 10 are seeded. The fine tilth of soil at the top of each seeding row 10 helps to reduce evaporation from the seeding row, while the rolled and profiled surface 42 of the unworked soil 12 between the rows reduces evaporation and encourages any rainwater to flow into the seeding rows 10. The great depth of the seeding rows provides a large water storage capacity and encourages deep root growth, allowing the planted crops to obtain water from a large reservoir stored within the seeding rows. Optionally, a mulch for example of cut straw from a previous crop may be spread on top of the seeding rows 10 to further reduce evaporation.

As an alternative to use of a soil tillage implement having more than one set of tines, a method according to the invention may be carried out using a simpler form of soil tillage implement, having one set of tines only, but which can carry out repeated passes through the soil at progressively greater operating depths.

The method of soil tillage (working) should preferably be done shortly after harvesting of a previous crop, or at least prior to the rainy season, such that rain water can penetrate the prepared soil during this period and be stored there.

It should also be noted that, by following the method of tillage described above, the soil is partly worked up to three times, so forming a fine seed bed. The upper layer is worked at three times, the next layer two times, and the deepest layer once.

Therefore, the tillage method can work the soil some two to three times as deep as normal, but since only narrow strips are being worked, the energy consumption per unit area of the field is less than that required during normal soil working methods, in which the entire area is worked uniformly.

Furthermore, while it is true that surface water can penetrate into soil just as well with conventional soil tillage methods, by adopting the method according to the invention the surface water is directed to the areas where it is most needed, namely into the rows where the plants will actually carry out their growth.

The rollers 22 are positioned between the intermediate tines 24 because these tines are near to the surface, and are likely to break up large clods at the surface of the soil. The rollers help to prevent this such that the work width is reduced to the width defined by the set of discs. The first tine 14 is intended to scratch and break up the surface layer down to a small depth and it will therefore not break up large clods. The trailing final tines 26 are working much deeper, and are not likely to break up clods at the surface. It is envisaged that the method and implement of the invention will be particularly effective for use in arid conditions, but also may be of use in agriculture and horticulture in other situations in which water conservation is particularly useful, e.g. in order to minimise use of independent supplies of water for irrigation purposes.

The invention may be utilised for any suitable type of seed crop planted in the ground, but it is believed will be particularly effective in the preparation of the soil for the growth of maize.

Various modifications of the method and the apparatus described herein are of course possible. For example, the rearmost tine may be attached to the intermediate tine so that it engages and works the soil just behind and below the working point of the intermediate tine.

Claims

Claims:

1. A method of soil tillage, prior to seeding of a crop, and which comprises: forming a pair of parallel seeding rows (10) by working the soil so that each seeding row comprises a strip of worked soil having a predetermined depth, said seeding rows being laterally spaced apart from each other to define an intermediate strip (12) of unworked soil; and applying a roller (22) to the intermediate strip (12) of unworked soil in order to compact the strip and to shape the upper surface thereof so that rainwater falling on the intermediate strip drains towards and into at least one of the adjoining seeding rows.

2. A method according to claim 1, in which the seeding rows (10) are formed by the passage of tines (14) through the soil, and utilising an implement which carries out repeated passes through the soil with the tines operating at successively greater depths.

3. A method according to claim 1, in which the seeding rows (10) are formed by the passage of tines (14,24,26) through the soil, utilising a soil tillage implement having at least two sets of soil working tines (14,24,26) arranged at successively greater working depths in the tilling direction.

4. A method according to any one of claims 1 to 3, in which the roller (22) has a curved concave surface intermediate the opposed ends of the roller, to apply an upwardly curved surface (42) on each of the intermediate strips (12) of unworked soil.

5. A method according to any one of the preceding claims, in which the strip of worked soil has a depth in the range 400-800mm, preferably 500-700mm.

6. A method according to any one of the preceding claims, in which the strip of worked soil has a width in the range 150-300mm, preferably 200-250mm.

7. A method according to any one of the preceding claims, in which adjacent strips of worked soil have a separation in the range 600- 1200mm, preferably 800- 1000mm.

8. A method of cultivating a crop, which comprises: tilling the soil by a method according to any one of the preceding claims, and seeding the seeding rows formed by the tilling method.

9. A soil tillage implement (36) which comprises: an implement frame (38) which can be propelled in a tilling direction (40); a forward set of tines (14) mounted on the frame (38) and spaced apart laterally with respect to the tilling direction so as to form spaced apart parallel seeding rows (10) in the soil, wherein each seeding row 910) comprises a strip of worked soil having a predetermined depth; and a roller (22) rotatably mounted on the implement frame (38) rearwardly of the forward set of tines (14) and arranged to compact an intermediate strip (12) of un worked soil between each pair of seeding rows (10), and to shape the upper surface of the intermediate strip (12) so as to promote drainage of any rainwater falling onto the strip (12) laterally into at least one of the adjoining seeding rows (10).

10. An implement according to claim 9, in which the roller (22) has a concave curved outer surface shaped so as to apply an upwardly curved shape to the upper surface of the intermediate strip (12).

11. An implement according to claim 9 or 10, in which the implement frame (36) also mounts a respective pair of discs (18, 20) rearwardly of each forward tine (14), to enlarge and consolidate the seeding rows (10).

12. An implement according to any one of claims 9 to 11, in which further sets of tines (24, 26) are mounted on the frame (36), to work at a greater depth than the forward set of tines (14).

13. An implement according to any one of claims 9 to 12, in which the strip of worked soil has a width in the range 150-300mm, preferably 200-250mm.

14. An implement according to any one of claims 9 to 13, in which adjacent strips of worked soil have a separation in the range 600- 1200mm, preferably 800- 1000mm.