GB2305914A

GB2305914A - Slow release fertilizer

Info

Publication number: GB2305914A
Application number: GB9520456A
Authority: GB
Inventors: Peter Arthur Charles Chown
Original assignee: ANGUS FERTILIZERS Ltd
Current assignee: ANGUS FERTILIZERS Ltd
Priority date: 1995-10-06
Filing date: 1995-10-06
Publication date: 1997-04-23
Anticipated expiration: 2015-10-06
Also published as: GB9520456D0; GB2305914B

Abstract

A slow release fertilizer product comprises a fertilizer and a slow release agent, the agent being a biodegradable agent whereby the biodegradable agent is able to provide for a controlled release of the fertilizer without ecologically damaging the environment, and the biodegradable agent being such that it is a water soluble binder for the fertilizer whereby the slow release fertilizer product is such that it does not crumble in dry conditions of use, whereby the fertilizer is only released in moist conditions of use, and whereby the fertilizer content of the slow release fertilizer product is consistent throughout the slow release fertilizer product. The release agent, a layer of which may cover the fertilizer, may be tallow, soap, coconut oil or animal fat and the product may contain a seed or seeds, or an agent e.g. wood flour edible by pests. The product may comprise layers of different fertilizers.

Description

A SLOW wwTwkSE FERTILIZER PRODUCT This invention relates to a slow release fertilizer product.

Slow release fertilizer products are known. They comprise a fertilizer and a slow release agent. The slow release agent ensures that the fertilizer is not made available to plants too quickly and thus used up too quickly.

The known slow release fertilizer products tend to suffer from one or more of the following three problems. Firstly, the known slow release fertilizer products often employ a polymer based slow release agent which can be damaging to the environment.

Secondly, the known slow release fertilizer products sometimes break up in dry conditions, thus releasing the fertilizer to the plants in dry conditions whereas the plants benefit most from receiving the fertilizer in moist conditions. Thirdly the fertilizer that is employed in the known slow release fertilizer products is often a blend of different fertilizers and this blend tends to vary from batch to batch. It is difficult to produce a consistent fertilizer blend from a dry mixture of different fertilizer ingredients. Often the different fertilizer ingredients have to be separately produced, for example as separate granules, and then mixed together.

It is an aim of the present invention to obviate or reduce the above mentioned problems.

Accordingly, in one non-limiting embodiment of the present invention there is provided a slow release fertilizer product comprising a fertilizer and a slow release agent, the slow release agent being a biodegradable slow release agent whereby the biodegradable slow release agent is able to provide for a controlled release of the fertilizer without ecologically damaging the environment, and the biodegradable slow release agent being such that it is a water soluble binder for the fertilizer whereby the slow release fertilizer product is such that it does not crumble in dry conditions of use, whereby the fertilizer is only released in moist conditions of use, and whereby the fertilizer content of the slow release fertilizer product is consistent throughout the slow release fertilizer product.

The slow release fertilizer product of the present invention works only in the moist conditions, for example when it is raining, or when plants are being artificially watered, or in damp conditions caused by dew. The use of the biodegradable slow release agent which is also a binder means that different compositions of fertilizer can be chosen to suit different plants and these different compositions can always be bound by the binder in a consistent manner which would not be possible if the binder were not present.

Preferably, the biodegradable slow release agent is an organic fat composition. Presently preferred organic fat compositions are tallow and soap. The biodegradable slow release agent may be other products, for example coconut oil and animal fats.

Preferably, the fertilizer is covered by the biodegradable slow release agent. Generally, the thicker the covering of the biodegradable slow release agent, then the slower will be the release of the fertilizer.

The fertilizer may be covered with a layer of the biodegradable slow release agent. If desired, the slow release fertilizer product may comprise a plurality of layers of fertilizer and the biodegradable slow release agent. In this case, the layers of the fertilizer may be layers of different types of fertilizers for providing different nutrients at different times during the degradation of the slow release fertilizer product. If desired, the different layers of the fertilizer may contain the same type of fertilizer.

The slow release fertilizer product of the present invention may include an edible agent which does not ecologically damage the environment, and which is edible to pests in the soil, whereby the pests eat the edible agent during use of the slow release fertilizer product and do not eat the fertilizer. Thus the use of the edible agent provides for a more efficient use of the fertilizer and this is advantageous insofar as fertilizers are expensive.

Preferably, the edible agent is woodflour. Other types of edible agent may however be employed.

The slow release fertilizer product may include trace elements. Preferably the trace elements are applied in liquid form so that they are evenly distributed throughout the slow release fertilizer product. Preferably, the trace elements are applied in liquid form as blended seaweed extract liquid.

Examples of trace elements are zinc, copper and iron.

The slow release fertilizer product may contain a seed or seeds if desired. Thus, for example, the slow release fertilizer product may be made in pellet form with each pellet containing one or more seeds.

The slow release fertilizer product may be made as a dough. The use of the dough enables the slow release fertilizer product to be used in a variety of ways so that, for example, the dough can be cut up into any desired sized and shaped pellet which can then be dried. Alternatively the dough can be extruded and then cut to size directly on to plants.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 is a side view of apparatus for producing a slow release fertilizer product of the invention by a first method; Figure 2 is a top plan view of part of the apparatus shown in Figure 1; Figure 3 shows how the slow release fertilizer product produced by the apparatus shown in Figures 1 and 2 can be produced to different sizes and shapes; Figure 4 is a side view of apparatus for producing a slow release fertilizer product by a second method; Figure 5 is a side view of alternative apparatus to that shown in Figure 4; and Figure 6 is an end view of part of the apparatus shown in Figure 5.

Referring to Figures 1 and 2, there is shown apparatus 2 for making a slow release fertilizer product 4. The apparatus 2 comprises a dough mixer 6 comprising a container 8, a rotateable shaft 10 and mixing blades 12 which are mounted on the shaft 10.

The ingredients for the slow release fertilizer product 4 are inserted into the dough mixer 8 and they are mixed until a dough 14 is formed. The dough 14 is placed in a hopper 16. The dough 14 is extruded from the hopper 16 by extrusion means (not shown).

The extruded dough passes between rollers 18, 20 which form the dough 14 into a strip 22. The strip 22 passes on to a conveyor belt 24 and under a cutter 26.

The cutter 26 cuts the strip 22 into the finished slow release fertiliser product 4 which, as can be seen from Figure 2, is in the form of granules. The slow release fertiliser product 4 passes on the conveyor belt 24 and through an oven 28 where the slow release fertilizer product 4 is dried ready for use.

Figure 3 shows how the slow release fertilizer product 4 can be produced in a variety of shapes and sizes simply by using an appropriate design of cutter 26.

Figure 4 shows apparatus 30 for producing a slow release fertilizer product. The apparatus 30 comprises a hydraulic ram 32 which has a piston 34 for operating in a cylinder 36. The cylinder 36 contains dough 38. As the piston 34 moves down the cylinder 36, the dough 38 is extruded through an extruder portion 40 of the apparatus 30. The dough 38 is extruded as a strip 42. The strip 42 is cut into sections by a rotary knife 44 mounted on top of the extruder 40. The strip 42 may be of circular cross section or any other suitable and appropriate cross sectional shape. The cut up strip 42 is then in the form of pellets which can be bagged and sold as may be desired.

Figures 5 and 6 show apparatus 46 which is similar to the apparatus 30 but which is designed to be mounted on a tractor (not shown). Similar parts as in Figure 4 have been given the same reference numerals for ease of comparison and understanding. As can be seen from Figure 5, the cylinder 36 has a delivery arm 48 which terminates in the extruder portion 40. The use of the delivery arm 48 means that the extruder portion 40 is able to be positioned at ground level 50, for example in a trench 52 containing seeds or plants (not shown).

The extruder portion 40 shown in Figure 5 is able to extrude the dough 38 as a sheet 54 from one side or as a strip 56 of circular cross section from the other side, as shown in Figure 6. Figure 6 also shows how the strip 56 can be arranged to fall on a seed 58 in the trench 52.

As will be appreciated from Figures 5 and 6, the slow release fertilizer product is deposited exactly where it is required. This means that the fertilizer is much more efficiently used than is often the existing case where fertilizer is just distributed at random over a field containing plants and whereby much of the fertilizer is deposited on the ground too far away from the plants to do any real good. Such fertilizer is often simply washed into the ground and subsequently washed into rivers and streams.

Irrespective of whether the slow release fertilizer product of the present invention is distributed in the form of a dough or is distributed in the granules as shown in Figure 3, the slow release fertilizer product can always be distributed near to plants if desired.

As the slow release fertilizer product degrades, it will not harm the environment due to the use of the slow release agent which is biodegradable. Still further, the use of a slow release agent which acts as a binder for the fertilizer ensures that the fertilizer is consistently distributed throughout the slow release fertilizer product.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected.

Thus, for example, the granules shown in Figure 3 may alternatively be in the form of pellets or discs. The drying in the oven 28 is preferably by hot air but other types of drying may be employed. The produced granules, pellets or discs can be stored in bags, sacks or any other suitable and appropriate containers. When the slow release fertilizer product is used in the dough form, then the dough will usually be despatched in a semi-dry form for use. Various fertilizer blends may be formulated using dry powder fertilizer containing different mixtures of fertilizer ingredients as may be required. Trace elements may be added and these are preferably added in the form of a blended seaweed extract liquid. Water may be added as required to form the dough into the required consistency. Preferred biodegradable slow release agents are tallow or a detergent soap but other biodegradable slow release agents may be employed. If it is not desired to cut the extruded dough into granules, pellets or discs, then the extruded dough may be rolled into balls of various sizes. The balls may then be packed and sold. If desired, seeds may be dropped into the fertilizer prior to sowing or when being sown. Thus, for example, the slow release fertilizer product could be in the form of a granule, disc or pellet and of a dough like consistency to receive one or more seeds.

Claims

1. A slow release fertilizer product comprising a fertilizer and a slow release agent, the slow release agent being a biodegradable slow release agent whereby the biodegradable slow release agent is able to provide for a controlled release of the fertilizer without ecologically damaging the environment, and the biodegradable slow release agent being such that it is a water soluble binder for the fertilizer whereby the slow release fertilizer product is such that it does not crumble in dry conditions of use, whereby the fertilizer is only released in moist conditions of use, and whereby the fertilizer content of the slow release fertilizer product is consistent throughout the slow release fertilizer product.

2. A slow release fertilizer product according to claim 1 in which the biodegradable slow release agent is an organic fat composition.

3. A slow release fertilizer product according to claim 2 in which the organic fat composition is tallow or soap.

4. A slow release fertilizer product according to claim 1 in which the biodegradable slow release agent is coconut oil or an animal fat.

5. A slow release fertilizer product in which the fertilizer is covered by the biodegradable slow release agent.

6. A slow release fertilizer product according to claim 5 in which the fertilizer is covered with a layer of the biodegradable slow release agent.

7. A slow release fertilizer product according to claim 5 and comprising a plurality of layers of fertilizer and the biodegradable slow release agent.

8. A slow release fertilizer product according to claim 7 in which the layers of the fertilizer are layers of different types of fertilizers for providing different nutrients at different times during the degradation of the slow release fertilizer product.

9. A slow release fertilizer product according to any one of the preceding claims and including an edible agent which does not ecologically damage the environment, and which is edible to pests in the soil, whereby the pests eat the edible agent during use of the slow release fertilizer product and do not eat the fertilizer.

10. A slow release fertilizer product according to claim 9 in which the edible agent is woodflour.

11. A slow release fertilizer product according to any one of the preceding claims and including trace elements.

12. A slow release fertilizer product according to claim 11 in which the trace elements are applied in liquid form such that they are evenly distributed throughout the slow release fertilizer product.

13. A slow release fertilizer product according to claim 12 in which the trace elements are applied in liquid form as blended seaweed extract liquid.

14. A slow release fertilizer product according to any one of the preceding claims and containing a seed or seeds.

15. A slow release fertilizer product according to any one of the preceding claims and which is made as a dough.

16. A slow release fertilizer product substantially as herein described with reference to the accompanying drawings.