WO1995011586A1

WO1995011586A1 - Improvements in or relating to windrows

Info

Publication number: WO1995011586A1
Application number: PCT/AU1994/000652
Authority: WO
Inventors: Thomas Gerard Williams; Brendon Lunney
Original assignee: Waste Organic Recycling Management Systems (Australia) Limited
Priority date: 1993-10-26
Filing date: 1994-10-26
Publication date: 1995-05-04

Abstract

A device (10) for ventilating windrows (15) is disclosed. The device (10) includes frame means for defining at least one channel within the windrow (15), the frame means being constructed and arranged to facilitate transfer of oxygen to the windrow (15) on ventilation of the windrow (15). A windrow including frame means as described is also disclosed. A method for digesting waste material is also disclosed. The method includes forming at least one channel defined by frame means constructed and arranged to facilitate transfer of oxygen to a windrow to be formed on or around the channel, forming a windrow of digestible material on or around the channel, introducing into the windrow worms capable of substantially digesting the digestible material, ventilating the windrow by natural or forced ventilation and maturing the windrow for a sufficient time to allow said worms to multiply and digest at least a substantial portion of said material.

Description

IMPROVEMENTS IN OR RELATING TO WINDROWS BACKGROUND OF THE INVENTION
The present invention relates to improvements in or relating to windrows, and more particularly to improvements to the transfer of oxygen to windrows.

Worms play an important role in the regeneration of soils, and in the conversion of organic matter to productive or fertile soil. Worm farming has assumed increasing importance in the context of the supply of worms to people desirous of utilising the benefits of worms. Worm farming has the two-fold benefit of returning the organic matter to soil, and in the generation of large numbers of worms.

Traditional worm farming comprises the formation of a mound or windrow from organic matter, poor quality soil and/or waste material, which is progressively built up to the desired dimension and to which worms are added. Mounds of standard formation are generally of rectangular configuration.

One of the main problems with this configuration is that its construction is such that worm productivity and generation is less than desirable in that it takes considerably longer than is tolerable to convert the organic matter to productive or fertile soil.

There is therefore a need for an arrangement whereby worm productivity and generation of an acceptable level is achieved.

SUMMARY OF THE INVENTION
Accordingly the present invention provides in one embodiment a device for ventilating a windrow, the device including frame means for defining at least one channel within the windrow, the frame means being constructed and arranged to facilitate transfer of oxygen to the windrow on ventilation of the windrow.

In another embodiment, the present invention provides in combination a device for ventilating a windrow and a cover for the windrow, said device including frame means for defining a channel within a windrow, the frame means being constructed and arranged to facilitate transfer of oxygen to the windrow formed on or around said device, said cover including cover means dimensioned to substantially cover the windrow, stiffening means to provide a desired cover profile, and tensioning means to tension the cover means.

In another embodiment, the present invention provides in combination a device for ventilating a windrow and a cover for the windrow, said device including frame means defining a channelled platform on or around which to form a windrow, said frame means having a plurality of apertured frame members connected side-by-side to define a plurality of channels of a cell-like structure whereby to facilitate transfer of oxygen to a windrow formed on or around the platform, said cover including cover means dimensioned to

substantially cover the windrow, stiffening means having one or more stiffening members defining a frame to provide a desired cover profile, and tensioning means to tension the cover means.

In another embodiment the present invention provides a windrow including a mound formed from digestible material, and having at least one channel within the windrow defined by frame means constructed and arranged to facilitate transfer of oxygen to the windrow on ventilation of the windrow.

In another embodiment, the present invention provides a device for ventilating a windrow, said device including frame means for defining a channelled platform on or around which to form a windrow, said frame means having a plurality of apertured frame members connected side-by-side to define a plurality of channels of a cell-like structure whereby to facilitate transfer of oxygen to a windrow formed on or around the platform.

In another embodiment, the present invention provides a method for digesting waste material including the steps of forming at least one channel defined by frame means constructed and arranged to facilitate transfer of oxygen to a windrow formed on or around the channel, forming a windrow of digestible material on or around the channel, introducing into the windrow worms capable of substantially digesting the digestible material and maturing the windrow for sufficient time to allow said worms to multiply and digest at least a substantial portion of said material.

It has been found in accordance with the present invention that by transferring oxygen to the windrow from within the windrow, the productive efficiency of the worms in the windrow is enhanced. An added benefit is that the device of the present invention results in an enhancement of the multiplication rate of worms in the windrow, leading to economic gains to the worm farmer.

We have found that windrows of standard formation do not have sufficient oxygen supplied to them, which means that the worms suffer oxygen deprivation, and as a result eat more slowly than is desirable. Oxygenating the windrow in accordance with the present invention provides an ample supply of oxygen to the worms, thus enhancing the worms' ability to consume greater amounts of organic matter.

We have also found in our studies of windrows that worms are top feeders, that is, they only eat that which is above or on top of them. With windrows of standard formation, we have found that a core of the windrow which is not eaten results. In a preferred embodiment of the present invention, the core is replaced by frame means generally defining a channel within the windrow, and hence a greater amount of the organic matter in the windrow is available for consumption by the worms.

The device of the present invention may be suitably positioned on the ground prior to formation of the windrow, and the windrow formed around the device. In a preferred embodiment, a single device in accordance with the present invention is positioned such that it defines a substantially central core of the windrow formed around the device. It is however also envisaged within the scope of the present invention that a plurality of devices be positioned, and a windrow formed around the plurality of devices.

In one such typical embodiment, one of the plurality of devices may be positioned centrally, with the other (s) offsetfrom the centre of the windrow. In another embodiment, the plurality of devices may be positioned symmetrically and the windrow formed around the plurality of devices.

The frame means may be of any suitable cross-sectional structural shape including, non-exhaustively, an A-frame, circular, semi-circular, square, rectangular, dome-shaped, gabled, hemispherical, triangular, corrugated and so on. The frame means may accordingly define a channelled platform or deck on or around which the windrow is formed.

In another embodiment, the frame means includes a plurality of frame members defining a plurality of channels within the windrow. The frame members may be disposed substantially side by side to define the plurality of channels within the windrow.

In yet another preferred embodiment, each of the plurality of frame members cooperate to define a channelled platform or deck on or around which the windrow may be formed. The platform may be planar. The construction and arrangement of such a planar platform enables use in a variety of configurations. In addition the substantially planar platform may be advantageously used in either a vertical configuration or more preferably in a substantially horizontal configuration.

In one particularly preferred arrangement the marginal edges of the substantially planar platform extend beyond the surface of the waste material in the windrow to facilitate the entry of ventilating air into the channels provided by the platform.

It will be appreciated that the frame means may be disposed within the windrow so that ventilation can be provided both above and below the frame means hence facilitating the use of taller windrows. This arrangement can be particularly suitable where limited land area is available for formation of windrows.

In one preferred arrangement according to the present invention the windrow may include a bed constructed from soil, preferably compacted soil, which may include aggregate or other components to facilitate drainage.

In this arrangement the frame means is preferably supported by the compacted bed which may extend beyond the extremities of the frame means.

In one preferred embodiment, the platform comprises a pair of substantially planar apertured frame members held in spaced apart relationship whereby the channels are formed therebetween.

In another arrangement, the frame means may comprise a platform including a substantially planar sheet having a plurality of elongated channels disposed adjacent one another to facilitate aeration of the windrow. The channels may be constructed and arranged to deliver ventilating air to the windrow in a number of different directions from the channels. The upper and or lower surfaces of the sheet may comprise a grate-like structure. In one embodiment, a plurality of planar sheets may be arranged in side by side relationship to define a plurality of channels within a windrow formed around the plurality of planar sheets so arranged. In another embodiment, a number of planar sheets are arranged one on top of the other to form a stack.

In another arrangement, the frame means may include a structure having a plurality of channels, each of the channels disposed one on top of the other to define a layered frame. The layered frame may be constructed and arranged to deliver ventilating air to the windrow in a number of different directions from the layered frame. Each layer of the frame may comprise a channelled platform, or any other suitable construction.

In another arrangement, the frame means may include a central web defining a channel having a plurality of lateral conduits along its length whereby to facilitate aeration of the windrow. The central web and/or the lateral conduits may be constructed and arranged to deliver ventilating air to the windrow in a number of different directions from the web and/or lateral conduits. In one embodiment, a plurality of frame means of this construction may be arranged in side by side relationship to define a plurality of webs and conduits within a windrow formed around frame means so arranged.

The frame means may be formed from any suitable material which enables the required transfer of oxygen to the windrow to be effected, and which provides the device with the desired structural integrity, having regard to the weight of the windrow and the length of time the windrow is likely to be in place. In a presently preferred embodiment, the frame means includes a mesh, mesh-like, cell-like or cellular structure. The frame means is also preferably constructed from a suitable biocompatible material.

The frame means is preferably constructed and arranged such that worms, soil and organic matter from the windrow do not pass through the device, or do not pass through the device to any appreciable extent, whilst permitting oxygen to be transferred to the windrow. To this end, the frame means may include membrane means. The membrane means is preferably a permeable membrane to permit oxygen transfer on ventilation of the windrow. The membrane means may in one preferred embodiment be

integral with the frame means. In an alternative embodiment, the membrane means may be laid over the surface of the frame means. In the case of a mesh or mesh-like frame structure, the membrane means may be arranged so as to fill the interstices of the mesh or mesh-like structure.

In one embodiment, the frame means may include a pair of opposed members defining a closed upper (with respect to the windrow) end and an open lower (also with respect to the windrow) end. The opposed members may be leaves connected at their upper extremities, forming in a preferred embodiment a substantially A-shaped frame. In a preferred embodiment, the frame means is demountable or collapsible. The leaves in this embodiment are preferably pivotably connectable. In this manner, when lifted vertically, the leaves collapse together to form a substantially planar member which can be removed from the windrow without unduly disturbing the windrow or damaging the worms in the windrow.

To facilitate removal of the device of the present invention from the windrow, the frame means may include one or more handle means. The handle means is preferably located at one, or in a preferred embodiment, at both ends of the device. Handle means may, in an alternative embodiment, or additionally, be provided intermediate the ends of the device. The removal of the device of the present invention from a windrow may also be effected by external means such as a hook (or an operator's fingers) which engage and lift the frame out of the windrow.

The frame means is preferably of sufficient length to define a channel within the windrow so as to extend substantially the full length of the windrow. As noted above, in a preferred embodiment the channel generally defines the core of the windrow.

The windrow is preferably formed from digestible material such as organic matter, earth, waste material or a combination of one or more of these. The worms are introduced to the windrow to facilitate regeneration of the organic matter, waste material and perhaps poor quality soil into usable earth. A typical windrow in accordance with the present invention is progressively built up, around and over the device of the present invention. In a preferred embodiment, the windrow may be defined by angled wall members and a substantially horizontal top. The windrow may be of any desired dimension depending on space limitations. A typical windrow may be approximately 750 mm high, 2.5 metres wide at the base and 25 metres long.

For economic reasons, natural ventilation is preferred for ventilating the windrow in accordance with the present invention. However, forced ventilation, aeration and/or oxygen injection into the channel defined by the frame means is also envisaged within the scope of the present invention.

In another embodiment, the present invention provides a cover for a windrow, the cover including cover means which in use is shaped and dimensioned so as to substantially cover the windrow, the cover also including stiffening means shaped to provide a desired cover profile, and tensioning means to tension the cover means.

In a preferred embodiment, the stiffening means generally defines a frame which provides the cover means with the desired rigidity and shape to cover the windrow in a ground-hugging arc. The stiffening means is preferably in the form of one or more stiffening members. The or each stiffening member preferably extends from one side and/ or end of the cover means to the other. The stiffening means may in one embodiment be located intermediate the ends of the cover means. Stiffening means in the form of stiffening members may also be provided at or adjacent the perimeter of the cover means. In this latter embodiment, the stiffening members so located may serve the function of tensioning means for the cover means. Preferably, stiffening members are provided at one or both ends of the cover means.

In one preferred embodiment, the stiffening means may include rods, lengths or tubes of a preferably resiliently flexible material.

The stiffening means may be integral with the cover means, or may be attached to the cover means in any suitable manner. The cover means may for example include one or more pockets to receive the stiffening means in the form of stiffening members. In this embodiment, the pockets preferably extend over substantially the full width and/or length of the cover means.

The cover means may be any desired shape, depending on the desired shape of the windrow the cover of the present invention is intended to protect. The cover means is preferably of substantially rectangular shape when laid flat. In a preferred embodiment, the cover means is substantially longer than it is wide.

The cover means may be constructed of any suitable material which is able to deflect rain, direct sunlight and/or protect the windrow from excessive disturbance by the wind. The cover means is preferably constructed from a material which is or includes an ultra-violet resistant material such as a solar weave fabric.

In a preferred embodiment, the cover means may include one or more eyelets, preferably positioned adjacent the aforementioned pockets for the stiffening members.

The eyelets are adapted to receive stays, such as guy ropes. The stays are in turn secured to securing means such as pegs, posts or in a preferred embodiment, star pickets, which are driven into the ground to tension the cover and securely position the cover in place over the windrow. The stays may be integral with the cover means, or may be separate from, and attachable to, the cover means.

In a preferred embodiment, the stiffening members are constructed and arranged so as to engage one or more star pickets. In the case where the stiffening members are of tubular construction, a portion of the star picket is adapted to be received in an end of the tubular stiffening member.

The cover means may also include one or more stays at or adjacent the end or ends of the cover means to facilitate securing of the ends of the cover means to the ground.

The tensioning means may be any means which retains the cover means in use substantially tensioned. As noted above, one or more stiffening members located at or adjacent the perimeter of the cover means may serve as suitable tensioning means for the cover means. As also noted above, in a preferred embodiment the cover means is secured to the ground by means of a plurality of pegs or posts such as star pickets, which serve as tensioning means for the cover means.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
To further assist in the understanding of the present invention, particularly preferred embodiments for the invention will now be described in relation to the accompanying drawings.

In the drawings, in which like features are indicated by common numerals,
FIGURE 1 is a perspective view of a device for ventilating a windrow according to one embodiment of the present invention,
FIGURE 2 is an end elevation of the device of Figure 1,
FIGURE 3 is a perspective view of a windrow formed around the device of Figure 1,
FIGURE 4 is an end elevation of a cover in accordance with another embodiment of the present invention,
FIGURE 5 is a cut-away perspective view of a cover according to one embodiment of the present invention,
FIGURE 6 is a cut-away detailed perspective of an arrangement for securing a cover to the ground in accordance with one embodiment of the present invention,
FIGURE 7 is a cut-away elevation of a portion of the cover secured to the ground,

FIGURE 8 is a perspective view of a cover in accordance with one embodiment of the present invention secured to the ground,
FIGURE 9 is a perspective view of the a covered windrow according to another embodiment of the present invention,

FIGURE 10 is a section along the line 10-10 of Figure 9,
FIGURE 11 is a detailed elevation of the drainage pattern of the embodiment of
Figures 9 and 10, and
FIGURES 12,13 and 14 are perspective views of alternative embodiments of devices for ventilating a windrow according to the present invention.

In the embodiment shown in Figure 1, a device 10 for ventilating a windrow includes frame means including a pair of opposed frame members 11 and 12. The opposed members 11 and 12 are adapted to sit on the ground 14, and windrow (15 of figure 3) formed around the device 10. The frame means is constructed and arranged to enable oxygen to be transferred to the windrow from within the windrow on ventilation of the windrow.

Opposed members 11 and 12 are generally in the form of leaves, connected to one another at their upper extremities, to define a closed upper end and an open lower end. In this manner, opposed members 11 and 12 define a frame means generally Aframe shape or, in cross-section, of triangular shape. It will be appreciated that the frame means may be any number of different cross-sectional shapes including, non-exhaustively, square, rectangular, semi-circular, dome-shaped, gabled and so on.

It will be also be appreciated that the frame means may include a plurality of frame members connected to define a channelled platform on or around which the windrow is formed.

The leaves in the embodiment shown are connected together by hinge members 13. Hinge members 13 are in the embodiment shown H-clips and are adapted to permit pivotal connection of opposed members 11 and 12. In this manner, opposed members 11 and 12, when lifted vertically, collapse together by pivoting about hinge members 13 such that the respective inner faces of opposed members 11 and 12 contact each other to form a substantially planar member which when removed from the windrow such as by lifting the collapsed leaves substantially vertically out of the windrow will not unduly disturb the contents of the windrow nor unduly damage the worms in the windrow.

In the embodiment shown, the frame means of device 10 includes an open mesh or mesh-like structure 16 constructed and arranged to facilitate oxygen transfer to a windrow 15 on ventilation of the windrow. The frame means may include membrane means 17. The membrane means 17 is preferably arranged such that worms, soil and organic matter from the windrow do not pass through the device 10, or do not pass through the device 10 to any appreciable extent. Membrane means 17 is preferably of a permeable material to enable oxygen to be transferred through the device on ventilation of

the windrow. The membrane means 17 may be integral with the frame means defined by opposed members 11 and 12. In an alternative embodiment, the membrane means 17 may be laid over the surface of the frame means.

In a preferred embodiment, the opposed members 11 and 12 are constructed from a pair of mesh leaves having a membrane thereon or integral therewith. In a preferred form, the leaves may be constructed from Smorgon ARC Shade Mesh (trade mark) which is a reinforcing mesh with an integrated shade cloth membrane.

The embodiment shown in Figure 3 illustrates a windrow 15 formed about the device 10 laid on the surface of the ground 14. The frame means thus generally defines a channel within windrow 15, which in the embodiment shown extends substantially the length of windrow 15. The windrow 15 illustrated includes a pair of angled walls 18 and a substantially flat top 19. It will be appreciated that the windrow may be of any of a number of different shapes including, for example, a dome-shape, triangular hemispherical, rectangular, square and so on.

Turning to Figures 4 to 8, there is illustrated a cover 20 for a windrow (not shown). In the embodiment shown, the cover 20 includes cover means 21, one or more pockets 23 for receiving stiffening means (not shown), and tensioning means 26 in the form of posts or star pickets.

Cover means 21 is preferably formed from an ultra-violet resistant material such as a solar weave fabric to protect the windrow from potentially harmful ultra-violet light.

The cover 21 is also preferably constructed and arranged to prevent water such as rain water falling on the windrow, but permits oxygen to permeate to the windrow.

Cover means 21 includes one or more pockets 23 to receive one or more stiffening members (not shown). The stiffening members provide the cover means 21 with the desired rigidity and define the desired shape of the cover 20 in use.

It will be appreciated that the stiffening members may be attached to the cover 21 in any other suitable manner.

In the embodiment shown in Figure 6, the portion of cover 21 adjacent to pockets 23 may include a plurality of eyelets 24. Eyelets 24 are adapted to receive lengths of rope 25 which in turn are secured to pegs 26 which are subsequently driven into the ground 22.

In the embodiment shown in figure 7, peg 26 in the form of a star picket includes an engaging portion 28 which, when the cover is assembled, engages the tubular end of a stiffening member located in pocket 23 of cover means 21 whereby to secure the cover to the ground under the desired tension.

The ends of the cover 20 may also be secured to the ground by one ore more guy end stays 27 attached to pegs 29.

The alternative embodiment of Figures 9,10 and 11 shows a device 30 for ventilating a windrow 31, the windrow 31 including a bed 32 on which the device 30 is positioned. The windrow 31 may be covered by cover means (not shown). Device 30 includes frame means in the form of a platform 33 having a corrugated upper surface within the windrow 31 and extending in the embodiment shown beyond the marginal edges of the windrow 31. Corrugations 34 in effect define hollow sections between valleys 35 forming a plurality of channels to facilitate transfer of ventilating air to a windrow 31 formed around the platform 33.

Platform 33 includes a cell-like structure to facilitate drainage of the windrow as shown at Figure 11. This is particularly advantageous in damp regions. A cell-like structure has also been found to assist in delivering ventilating air in a number of directions to the windrow 31 through the channels defined by corrugations 34.

The embodiment shown at Figure 12 comprises a device 40 in the form of an apertured substantially planar sheet. The sheet is capable of being positioned within a windrow and the construction and arrangement of the planar sheet is such that a plurality of channels 41 is defined therein. The channels may be arranged so that ventilating air 42 is delivered to a windrow (not shown) in a number of directions as shown by the arrows.

A plurality of planar sheets may be arranged either one on top of the other whereby to form a layered stack, or may be disposed in side by side relationship to form a platform within the windrow.

The embodiment of Figure 13 shows a device 50 including a central web 51 from which a plurality of lateral conduits 52 extend. Central web 51 and lateral conduits 52 are arranged to deliver ventilating air to a windrow (not shown) formed around device 50.

The arrangement of central web 51 and lateral conduits 52 may be such that air is delivered to the windrow in a number of different directions as shown by the arrows.

The embodiment of Figure 14 shows a device 60 comprising frame means having a layered structure whereby a plurality of channels are disposed one on top of the other to define a device according to the present invention. Ventilating air 62 delivered to a windrow (not shown) formed around device 60 passes through the channels defined by the layered structure. The arrangement may be such that air is delivered to the windrow in a number of different directions as shown by the arrows.

In use, a channel or channels are formed by placing a device in accordance with the present invention on a suitable surface, preferably the ground, and a windrow of desired dimension formed around the channel defined by the device. The material for the windrow preferably includes waste material such as organic matter. Worms are added to the windrow to facilitate digestion of the waste material and its conversion to usable soil.

A protective cover in accordance with the present invention may be positioned around the windrow. The windrow is then left for a sufficient time to permit the waste material to be digested by the worms to the level desired.

While it has been convenient to describe the invention herein in relation to particular preferred embodiments, it is to be appreciated that other constructions and arrangements are also considered as falling within the scope of the invention. Various modifications, alterations, variations and/or additions to the constructions and arrangements described herein are also considered as falling within the ambit and scope of the present invention.

Claims

CLAIMS 1. A device for ventilating a windrow, the device including frame means for defining at least one channel within the windrow, the frame means being constructed and arranged to facilitate transfer of oxygen to the windrow on ventilation of the windrow.

2. A device according to claim 1, wherein said frame means defines a substantially central core for the windrow and includes opposed frame members connected to define said channel.

3. A device according to claim 1, wherein said device includes a mesh, mesh-like or cellular structure to facilitate ventilation and drainage of the windrow.

4. A device according to claim 1, and further including permeable membrane means capable of preventing solids from passing through the device to any appreciable extent whilst permitting oxygen to be transferred to the windrow.

5. A device according to claim 4, wherein said membrane means is integral with said frame means.

6. A device according to claim 1, wherein said frame means defines a channelled platform on or around which to form a windrow.

7. A device according to claim 6, wherein said platform comprises a pair of substantially planar apertured frame members held in spaced apart relationship whereby said channels are formed therebetween.

8. In combination a device for ventilating a windrow and a cover for the windrow, said device including frame means for defining a channel within the windrow, the frame means being constructed and arranged to facilitate transfer of oxygen to the windrow on ventilation of the windrow, said cover including cover means dimensioned to substantially cover the windrow, stiffening means to provide a desired cover profile, and tensioning means to tension the cover means.

9. In combination a device for ventilating a windrow and a cover for the windrow, said device including frame means defining a channelled platform on or around which to form a windrow, said frame means having a plurality of apertured frame members connected side-by-side to define a plurality of channels of a cell-like structure whereby to facilitate transfer of oxygen to a windrow formed on or around said platform, said cover including cover means dimensioned to substantially cover the windrow, stiffening means having one or more stiffening members defining a frame to provide a desired cover profile, and tensioning means to tension the cover means.

10. A windrow including a mound formed from organic matter, and having at least one channel within the windrow defined by frame means constructed and arranged to facilitate transfer of oxygen to the windrow on ventilation of the windrow. <Desc/Clms Page number 13> 11. A windrow according to claim 10, wherein said frame means defines a substantially central core of the windrow and includes opposed frame members connected to define said channel.

12. A windrow according to claim 10, wherein said frame means includes a plurality of frame members defining a plurality of channels within the windrow.

13. A windrow according to claim 10, wherein said frame means includes a mesh, mesh-like or cellular structure to facilitate ventilation and drainage of the windrow.

14. A windrow according to claim 10, and further including permeable membrane means capable of preventing solids from passing through the frame means to any appreciable extent whilst permitting oxygen to be transferred to the windrow.

15. A windrow according to claim 14, wherein said membrane means is integral with said frame means.

16. A windrow according to claim 10, wherein said frame means defines a channelled platform on or around which the windrow is formed.

17. A windrow according to claim 16, wherein said platform comprises a pair of substantially planar apertured frame members held in spaced apart relationship whereby said channels are formed therebetween.

18. A windrow according to claim 17, wherein said platform projects beyond said windrow and wherein ventilating air enters the channels by passing between said frame members and enters the windrow through apertures in either or both of said frame members.

19. A windrow according to claim 17, wherein said windrow includes a bed on which the channelled platform is supported.

20. A method for digesting waste material including the steps of forming at least one channel defined by frame means constructed and arranged to facilitate transfer of oxygen to a windrow to be formed around the channel, forming a windrow of digestible material on or around the channel, introducing into the windrow worms capable of substantially digesting the digestible material, ventilating the windrow by natural or forced ventilation, and maturing the windrow for a sufficient time to allow said worms to multiply and digest at least a substantial portion material.

21. A method according to claim 20, wherein a plurality of channels are formed by placing frame means having a plurality of members defining a plurality of channels on a selected surface and forming the windrow around the plurality of channels.

22. A method according to claim 21, wherein each of said plurality of frame members cooperate to define a channelled platform on or around which the windrow is formed. <Desc/Clms Page number 14> 23. A method according to claim 22, and further including forming a soil bed and positioning the platform on said bed.

24. A method according to claim 20 and further including harvesting worms generated in said windrow and recovering the digested material from said windrow.

25. A method according to claim 20, wherein said windrow is subjected to natural ventilation.

26. A method according to claim 20, wherein said windrow is subjected to forced ventilation.

27. A method according to claim 20, and further including covering the windrow by spreading a cover substantially over the windrow, tensioning the cover and securing the cover to the ground, the cover including cover means dimensioned to substantially cover the windrow, stiffening means having one or more stiffening members defining a frame to provide a desired cover profile, and tensioning means to tension the cover means.