Turf treatment

Abstract

A method for the treatment of turf (11) comprising grass (12) growing in a matrix (15, 16) comprising removing matrix (15, 16) including any thatch and other infestation by blading (18) moving through the matrix (15, 16) to a predetermined depth (d). The method may be used to treat turf (11) reinforced with artificial grass (13). Equipment for carrying out the treatment comprises a bladed rotor (17) rotating about a horizontal axis.

Claims

1. A method for treating turf comprising grass growing in a matrix consisting of at least one of sand and humus, and which is infected with at least one of thatch, alga, moss, fungi and slime mould, the method for treating turf comprising: providing a cylindrical rotor having a cylindrical axis and having a given length and circumference disposed for rotation about the cylindrical rotors cylindrical axis with said cylindrical axis being horizontal; the cylindrical rotor being provided with blading having teeth disposed around the cylindrical rotor such that there is no part of the given length of the cylindrical rotor that does not have at least one tooth at some part of the cylindrical rotors circumference; providing means to rotate and traverse the cylindrical rotor over the turf at a given rate of rotation and a given speed of traverse so that the teeth drive into the matrix to a given depth therein to remove infected matrix; the given rate of rotation and the given speed of traverse being selected such that no part of the turf traversed by the rotor is left untreated.

2. A method according to claim 1, in which the given depth is such that the grass growing in the turf is removed.

3. A method according to claims 2, in which matrix material is applied to the turf after treatment, and the turf is then reseeded.

4. A method according to claim 1, adapted for treating turf reinforced with artificial grass, in which the given depth is above that at which artificial grass would be removed by the blading.

5. A method according to claim 1, in which the blading is angled with respect to the cylindrical axis of the cylindrical rotor.

6. A method according to claim 1, in which the teeth have a thickness of from 5 mm to 10 mm.

7. A method according to claim 1, in which the cylindrical rotor is rotated so that the blading moves forwardly through the matrix.

8. A method according to claim 1, in which the blading is in the form of hooked teeth, the hooked teeth comprising hooks facing in a direction of travel.

9. A method according to claim 1, in which the thatch and the matrix are removed to a predetermined depth above that at which grass roots are found.

Description

(1) A method for treating turf, and one embodiment of turf treatment equipment according to the invention will now be described with reference to the accompanying drawings, in which:

(2) FIG. 1 is a cross section of turf;

(3) FIG. 2 is a cross section of artificial-grass reinforced turf;

(4) FIG. 3 is an end-on view of a rotor adapted to carry out the method of the invention;

(5) FIG. 4 is a front view of the rotor of FIG. 3;

(6) FIG. 5 is a close-up view of a tooth of blading of the rotor of FIG. 3, and

(7) FIG. 6 is a rear view of a rotor in use.

(8) The drawings illustrate a method for the treatment of turf 11, FIG. 1, comprising natural grass 12, sown, particularly in sports surfaces such as tennis courts and football and rugby pitches, in a matrix 15 of sand, silt and clay. The grass roots 12a are connected by rhizomes 12b. Over time and as a result of mowing and wear, the turf acquires an accumulation of dead grass known as ‘thatch’, and can also become infested with algae, moss, fungi, slime mould and other problems.

(9) FIG. 2 illustrates turf 11 like that shown in FIG. 1, which is reinforced with artificial grass fibres 13 which extend a given height h above turf level 14, typically 25 mm. This is usually sown in a matrix 15a of sand with just a thin upper layer 16 of humus, and can be more at risk of infestation through needing to be more heavily fertilised.

(10) The artificial grass fibres 13 are injected a depth D, usually some 20 cm deep, through the humus 16 into the sand 15a.

(11) An infected layer is shown in FIGS. 1 and 2 by the bracket B.

(12) The treatment method comprises lifting thatch, natural grass 12 and matrix 15, 16 with a horizontal rotor 17, FIGS. 3, 4, 5, traversed and rotated over the turf 11 and having helical blades 18 having teeth 19, in which the teeth 19 extend a depth d below the turf level 14, so that the blades move through the turf 11 pulling out thatch, natural grass 12 and matrix material.

(13) Usually, a treatment to a depth d at which at least some natural grass, roots, crowns, rhizomes, perhaps some culm, is left in the matrix will suffice, and the grass will grow back. However, when the matrix is badly infected with algae, all the natural grass may be removed by driving the blading sufficiently deep, and new matrix laid down and reseeded. So long as, when treating reinforced turf, the depth d is less than the depth of any backing such as disclosed in U.S. Pat. No. 5,489,317 or U.S. Pat. No. 6,094,860, and, in particular with the Desso Grassmaster® system, which does not have a backing, the depth to which the artificial fibres are injected, any artificial grass will remain in place.

(14) The teeth 19 extend below turf level 14, and may have a length l of 50 mm or more. The teeth 19 are on blade segments 18a that are bolted to the rotor 17. The blade segments 18a are fashioned from steel or like hard, rigid and wear resistant material, typically 10 mm thick.

(15) The depth d to which the teeth 19 are required to penetrate may be determined by core sampling the matrix, or estimated by the skilled greenkeeper from knowledge and experience.

(16) The rotor 17 is mounted on a tractor 41, FIG. 6, carrying the rotor 17 in a chassis 42 with a ground roller 43 and a blade height control arrangement 44 adapted to deploy the teeth 19 below turf level 14. The tractor 41 is driven to traverse the rotor 17 over the turf so deployed and has a power take-off transmission 45 to rotate the rotor 17 so that the blades 19 move through the turf 11 pulling out thatch, natural grass 12 and matrix material, soil and/or sand. The rotor is driven so that the hooks 19 drive into the turf as it moves forward. The material lifted from the turf is driven to the right of the tractor 41 by the action of the helical blading and is lifted on an elevator 45 into a trailer 46 drawn behind a second tractor 47.

(17) The height control arrangement 44 is adapted to extend the blades 19 as deep as may be desired into the soil 16.

(18) The blades 18 have a saw tooth profile, with the saw teeth 19 inclined to the direction of motion, the teeth being so dimensioned that the anchored artificial turf is deflected by passage of the tooth, and then springs back, without being removed or damaged. The teeth 19 have tips 19a reinforced against wear with, for example, tungsten or other carbide, and are hooked in shape. The tips 19a are configured to be square on to the direction (arrow A, FIG. 5) at which the tips enter the turf Teeth 19 are typically 35 mm from tip to root (T in FIG. 5).

(19) There may be any number of helical blades 18; four are illustrated in FIG. 4. There may be three, for example, but if there are four, two of them may be removed to reconfigure the rotor without unbalancing it. Such reconfiguration may be desirable to give more or less intensive treatment, or, for example, to leave furrows in the surface into which treatment media may be introduced, such as disinfectant, weed treatment, fertiliser and so forth, before backfilling with fresh matrix and perhaps reseeding.

(20) Treatment can, as described, be carried out using equipment attached as an implement on tractors conventionally used for turf treatment, yet can selectively remove the top surface of turf evenly, ready for resurfacing without requiring the use of heavy ploughs and graders. A rotor as described can treat a football pitch, with one or at most two passes, in a single day, leaving the surface ready for reseeding.