GB2180830A - Manure and/or mulch cake for plants - Google Patents

Abstract

A substantially dry, compressed plate-shaped manure and/or mulch cake, preferably having a centrally located opening, which is placed around the base of a plant. The manure/mulch cake is very effective for promoting plant growth. A method of manufacturing the manure/mulch cake is also described.

Description

SPECIFICATION Manure and/or mulch cake for plants The invention relates to a substantially dry, compressed, plate-shaped manure and/or mulch cake preferably having substantiallt centrally located opening which can be placed around the base of a plant to promote the growth of the plant.

The invention also concerns a method of manufacturing the manure and/or mulch cake, and a method of promoting plant growth.

In the past it has been know to apply manure or mulch material to the soil around plants in order to promote plant growth. The material is mixed with the soil, or applied in a loose layer on to the surface of the soil particularly around the base of the plants. This is known to improve plant growth mainly by aiding moisture retention in the soil, and in providing a source of nutrients to the plant as the mulch or manure breaks down. The main disadvantage of applying manure or mulch material in this way is the considerable inconvenience involved in spreading the material around the plants, and in obtaining the material and keeping it for use. Also, if the manure or mulch has not been aged there is a danger that the material will damage or "burn" the plants around which it has been placed.Furthermore, other disadvantages involve the sometimes unpleasant odour and appearance of the material, making its application disagreeable, and the considerable physical effort in distributing the material around the plant on the ground.

In addition, weeds can be introduced from their seeds which often are found in manure and mulch material.

It is an object of the invention to provide a substantially dry compressed plate shaped manure and/or mulch cake which is easy and convenient to apply to plants, and which substantially ameliorates or avoids the problems inherent in previously known mulch and manure application methods. It is also an object of the invention to provide a mulch and/or manure cake which has greater benefit for promoting plant growth than other previously known means.

The invention provides a substantially dry, compressed, plate-shaped manure and/or mulch cake which preferably has a substantially centrally located opening able to receive the base, stem or trunk of a plant or tree.

The invention also concerns a method of preparing such a manure and/or mulch cake, the method comprising the steps of preparing an aqueous slurry or moist mixture of the manure and/or mulch cake, placing the slurry or mixture in a mould of a suitable shape to form a plateshaped cake, and compressing and if necessary drying the material in the mould to form a substantially dry, compressed cake of the shape defined by the mould. The mould may, if desired, be of a shape to form in the cake a substantially centrally located opening of suitable dimensions to receive the base of a plant.

The invention furthermore concerns a method of promoting plant growth comprising placing the mulch and/or manure cake around the base of a plant, the plate-shaped cake covering the soil surface in the vicinity of the plant. If the cake has a central opening the base of the plant substantially occupies the opening.

If preferred, the manure cake may contain one or more additives chosen from plant nutrients, fertilizers, fungicides, herbicides, insecticides, plant hormones, or other growth promoting or protecting ingredients. The material may also contain a binder to assist in holding the cake together.

Preferably the plate-shaped cake is disc-shaped having a round central opening extending right through the cake from the top to the bottom. Such a disc may range in size between a disc having an outer diameter of 10cm and a thickness of 1cm to an outer diameter of im and a thickness of 15cm, for example.

It may also be preferred that the cake is dried at a sufficiently high temperature and for a sufficient amount of time for any seeds in the manure or mulch material to be killed. Generally the seeds would be of weeds or of other undesirable plants.

The mulch and/or manure material which comprises the cake may be any organic material.

Suitable material is animal manure, grass clippings, compost, agricultural byproducts, wood shavings, sawdust, diatomaceous earth, brown coal, cellulose fibre and the like, for example.

The ideally disc-shaped cakes are particularly suitable to be placed around plants such as flowers, vegetables, shrubs, trees and commercially produced crops for example. The discs will assist in suppressing weed growth, they will reduce the evaporation of moisture from the soil, and over time supply large quantities of both organic and inorganic nutrients to the soil, in a form safe to plants, in the immediate vicinity of the growing plant. It has been found that the cakes of the invention are surprisingly effective in promoting plant growth, and perform better than untreated compost, manure, shredded bark, inorganic fertilizer in this regard.

Generaliy the disc is placed on the soil around the base portion of the plant, although if desired, the disc can be buried in the soil or covered with soil.

While a circular disc form is a preferred shape for ease of placement of the cake around a growing plant any suitable plate-like shape can be used, including squares and hexagons for example. If a cake without a central hole is used then cakes of a hexagonal or square shape, for example, can be fitted together in a mosaic around the base of the plant. It is advantageous to use a generally symmetrical shape for convenience in manufacture, packaging, storage and use.

It is preferred that the disc-shaped cakes vary in size from an outer diameter of 10cm and a thickness of 1cm to an outer diameter of 1 m and a thickness of 15cm for example. More preferably, the discs will vary between 15 and 35cm in diameter and the thickness varying from 3 to 5cm. However discs less than 10cm may be useful in small containers and large discs of one metre or more in diameter may be used with large plants or trees. The central opening is preferably circular, having a diameter suitable to receive a plant. It is strongly preferred that the surface area of the disc-shaped cake should be sufficient to cover a significant portion of soil around the base of the plant. This assists in preventing the growth of weeds in the vicinity of the plant which use up nutrients and moisture, and exclude sunlight that would otherwise be available to the plant.

The cake is sufficiently dry so that the cake is storage stable. Further drying may be needed if the cake is manufactured from a slurry or a particularly moist mixture of manure and/or mulch.- If a slightly moist mixture is used additional drying may not be necessary. In this case, it is preferred that the cake is dried at a sufficient temperature, and for a sufficient time period that any such seeds are killed or prevented from germinating. However such a drying temperature and time may not be required if the cake is manufactured from organic materials which do not.

include such seeds. Even when undesirable seeds are present, other methods may be used to kill them, such as irradiation for example. Also, if desired, other drying techniques may be used, such as microwave drying. The cake is compressed to ensure a material with a high integrity and strength and having a high solids content per unit volume, which reduces the bulk and the costs of transporting and storing the mulch cakes, as well as increasing their effectiveness.

The cakes may be prepared from an aqueous slurry or moist mixture of the organic mulch and/or manure material. After mixing, the slurry or moist mixture is poured or placed into a mould having a suitable shape to form the desired cakes. The central opening if required may be produced by the shape of the mould, or stamped or cut from the cake at a later date.

The material in the mould is then compressed and if necessary dried. Compression may be achieved by physically or mechanically applying pressure to the moist or partially dried material.

To dry the material, it may be heated at a temperature of 80 C for example, for up to four days. Under these conditions, the cake becomes substantially dry, and any weed seeds in the material are killed. Weed seeds will often be present if animal manure is present. The material may be dried at higher than 80 C, but the temperature should not be sufficient to enable combustion of the organic matter, unless oxygen is excluded from the drying process.

Certain preferred embodiments of the invention are now described with reference to examples.

EXAMPLE 1 PREPARATION OF ORGANIC MULCH DISCS Organic mulch discs were prepared in accordance with the invention as follows. An equal quantity of cow manure and fowl manure was mixed with water in a ratio of 1:1 of manure:water, until a slurry was formed. This was poured into circular moulds having a diameter of 30 cm and a depth of 4cm. A small solid cylinder was placed in th centre of each mould. The moulds containing the manure slurry were placed in an oven having a temperature of 85 C, and they were kept there for approximately two days until the material became dry and hard. Several times while the material was drying, the organic material was pressed together, compressing it.

At the end of the period, some shrinkage had occurred. The rigid organic mulch material discs having a central opening were released from the moulds. These discs could be stored for indefinite periods of time without deterioration.

The thus prepared organic mulch discs were placed upon the ground around tree seedlings which had already been planted in the soil. This was done either by passing the disc over small seedlings or by breaking the disc into roughly equal sections and placing each half section around the base of the tree and pressing them together again.

EXAMPLE 2 TESTS OF EFFECTIVENESS OF MULCH DISCS Mulch material was formed into discs (25cm diax5cm thick) in accordance with the method described in Example 1, and placed around the base of 4 month-old Eucalyptus scoparia seedlings growing in plastic pots in a glasshouse. The treatments tried were with and without discs, with and without fertilizer, and with and without weeds. The fertilizer used was all ground mixed general purpose fertilizer applied at 1842kg/ha or at a 9g/pot. This supplied 0.869 N, 0.339 P, .0.58g K and 1.40g S per pot.

At the end of the trial (after 8 weeks) the following results were obtained.

TABLE I Measurement With Disc Without Dise c Tree Height (cam) 58.67 53.68* Leaf area (m2/tree) 0.18 0.11* Trunk Thickness (cm) 0.56 0.46* Number of lateral branches/tree 8.81 6.25* Total length of laterals (cm/tree) 120.26 72.76* Dry weight of lateral branches (g/tree) 2.40 0.86* Dry weight of leaves (g/tree) 13.87 9.68* Dry weight of stems (g/tree) 6.85 4.90* Total dry weight of tops (g/tree) + weeds 23.56 12.91* - weeds 22.68 17.97* + fertilizer 23.15 16.02* - fertilizer 23.09 14.86* Average moisture used (litre/tree/week) 1.26 1.712 * Indicates the difference between with and without disc is statistically significant at the 5* level of probability.

The dominant effect found in the experiment was due to the presence or absence of an organic mulch disc with the presence or absence of weeds or fertilizer having relatively little effect, especially when an organic mulch disc was used. The most pronounced effect of the discs was the very great increase in branch and subsequent leaf area which occurred when the discs were used. It is particularly significant that the use of an inorganic fertilizer had very little effect on growth, and that any growth suppression caused by the weeds was eliminated by the presence of the discs. Also worthy of note is the great reduction in moisture use attributable to the disc (27% less water was used than without the disc).

The total nutrient content of the organic mulch material used in the above trial was 1.41%N, 0.24% P, 0.21% S, 0.7% K, 0.22% Na, 0.07% Ca, 0.27% Mg, 46.3 ppm Mn, 2.4 ppm Cu, 9.9 ppm Fe and 9.7 ppm Zn. This concentration would have resulted in the addition of 8.469 N, 1.439 P, 4.1 7g K, and 1.259 S per pot.

EXAMPLE 3 COMPARISON OR ORGANIC MULCH DISCH WITH OTHER MEANS OF PROMOTING PLANT GROWTH A second test was conducted to compare the effectiveness of the organic manure/mulch discs in accordance with the invention, with other materials. In a similar manner to that de scribed in Example 2, the effectiveness of the discs was compared with: dried cow pats, shredded bark, and no addition to act as a control. Each test involved the use of four plants, and the whole experiment was conducted over 100 days. The results are shown in the following table.

TABLE II Test Plant height Average no. Weed score (cam) leaves/plant Disc 78.25 85.25 0 Wood chips 54.50 57.25 2.75 Cow pats 20.50 12.50 2.0 Control 70.50 58.50 1.75 **Ranking of weed growth: 0 s no weeds 5 1 complete cover-of weeds EXAMPLE 4 COMPARISON OF THE INVENTION WITH KNOWN METHODS The following table sets out the differences between the various prior art methods for improving the growth of plants and the discs of the present invention.

TABLE III Properties Organic Cow Shredded Fertilizer Pelletised Mulch Disc Pats Bark Spikes or Fertilizer Pllls Effect on Reduces May Reduces Increases Increases weeds markedly introduce weeds Effect on moisture loss Reduces Reduces Reduces May increase May increase (indirectly) (indirectly) Insulation properties (reducing soil temp) Excellent Fair Fair None None Nutrient Supply Excellent Poor Very poor Good Good Convenience Excellent Poor Reasonable Excellent Good Effect on tree growth Excellent Poor Good Reasonable Reasonable From considering the Examples, it is apparent that the manure and/or mulch cakes of the current invention are surprisingly effective in promoting the growth of plants, and have significant unexpected advantages over alternate methods claimed to promote plant growth. The discs are extremely effective for this purpose, and are also convenient and easy to transport, store, and package, and economical to manufacture and sell.

Claims (11)

1. A substantially dry, compressed, plate-shaped manure and/or mulch cake.

2. The manure and/or mulch cake defined in claim 1, having a subtantially centrally located opening able to receive the base of a plant.

3. The manure and/or mulch cake defined in claim 1 or 2 which contains one or more additives chosen from plant nutrients, fertilizers, fungicides, herbicides, insecticides, plant hormones and binders.

4. The manure and/or mulch cake defined in any one of claims 1 to 3 wherein the plateshaped cake is in the shape of a disc having a size range from a diameter of 10cm and a thickness of 1 cm to a diameter of im and a thickness of 15cm.

5. A method for preparing a substantially dry, compressed, plate-shaped manure and/or mulch cake, said method comprising the steps of: preparing an aqueous slurry or moist mixture of said manure and/or mulch; placing said slurry or mixture in a mould of suitable shape to form a plate-shaped cake; compressing and if necessary drying said material to form said cake.

6. The method defined in claim 5 for preparing a manure and/or mulch cake having a subtantialiy centrally located opening able to receive the base of a plant wherein said mould is a suitable shape to form a plate-shaped cake having a substantially centrally located opening.

7. The method defined in claim 5 or 6 wherein drying occurs and is conducted at a sufficient temperature for a sufficient period of time to kill any seeds in said manure and/or mulch material.

8. A method of promoting the growth of a plant comprising placing a substantially dry, compressed, plate-shaped manure and/or mulch cake as defined in claim 1 or claim 2 around the base of said plant, said plate-shaped cake covering the soil surface in the vicinity of the plant.

9. A manure and/or mulch cake according to Claim 1 composed and made substantially as herein described with reference to the Examples.

10. A method according to Claim 5 substantially as herein described.

11. A method according to Claim 8 substantially as herein described.