GB2246566A

GB2246566A - Growing medium

Info

Publication number: GB2246566A
Application number: GB9115680A
Authority: GB
Inventors: Christopher Paul Turner
Original assignee: Sinclair Horticulture & Leisur
Current assignee: Sinclair Horticulture & Leisur
Priority date: 1990-07-19
Filing date: 1991-07-19
Publication date: 1992-02-05
Anticipated expiration: 2011-07-19
Also published as: GB9115680D0; GB9015842D0; GB2246566B

Abstract

A growing medium is produced from composted paper pulp mixed with bark, composted wood residues and, optionally, peat. Each of the composted paper pulp and bark and composted residue is preferably present in the range 20-30% by volume and peat 40-60% by volume in a low peat formulation and in the range 30-40% by volume in a peat-free formulation. The composted paper pulp and bark and composted wood residues are produced by the addition of urea to a large heap which is left to compost for 10 to 12 weeks. Various additives may be included in the growing medium to suit specific applications, e.g. perlite, vermiculite, grit, sand, coir, composted town refuse, composted sewage, spent mushroom compost and acrylic polymer.

Description

GROWING MEDIUM This invention relates to growing media, and in particular to composts.

Growing media have traditionally been peat based. However, peat resources are limited; current estimates of available reserves vary from 10 to 30 years. In addition, it is now recognised that peat cutting could have serious environmental consequences and the resultant loss of wetland habitat- has prompted discussions as to whether peat harvesting should continue. It is therefore desirable that alternative products to peat be developed as growing media. Such products should either replace peat completely or reduce the amount of peat needed to lessen environmental impact and to extend existing reserves.

The invention in its broadest aspect provides a growing medium which includes a proportion of industrial cellulose waste.

We have appreciated that a growing medium which satisfies the above requirements may be produced from either or both of composted paper pulp and bark mix and composted wood residues.

These two components may be used individually or together with or without a proportion of peat.

The invention provides a growing medium having the above composition and also provides a method of manufacturing the growing medium from waste products.

More specifically, the invention is defined in the accompanying claims to which reference should now be made.

The invention has the advantage that the peat content of the growing medium is reduced or eliminated. Furthermore, the invention utilises waste paper pulp produced from paper mills and off-cuts and other residues produced by the timber and fibre-board industries.

Preferably, composting of the waste paper pulp and bark mix and the wood waste is accelerated by the addition of urea.

The addition of nitrogen may be delayed until after composting.

Examples of the method of manufacture and growing medium embodying the invention will now be described.

Paper mills produce vast quantities of waste paper pulp. This pulp is approximately 70% water and 30% dry matter by weight.

The dry matter consists of cellulose fibres and sometimes a small proportion of clay. Timber off-cuts are widely available as they are at present stockpiled by timber manufacturers.

Paper pulp, or effluent cake, is first milled and blended 1:1 by volume with bark. The blend is then left in a large heap to compost for about 10 to 12 weeks, during which the temperature of the heap rises to about 700 centigrade. By the end of the composting period the temperature of the compost falls back to near ambient. The composting process is enhanced by the addition of nitrogen, usually in the form of urea.

Simultaneously, the wood residues are composted. The composting process is similar and also lasts for 10 to 12 weeks. Initially, the residues are shredded (if necessary) and screened for undesirable objects. Urea is then blended prior to composting. During the composting process the heap undergoes similar temperature variations as the paper pulp composting process.

Once the wood residues and the paper pulp and bark mix have been composted, a growing medium can be obtained as will be described. However, it is preferred, although not essential, that each of the compost heaps are mixed and turned and allowed to undergo further composting cycles. Such cycles are accompanied by further rises and falls in temperature and improve the decomposition of the constituent elements; The composting time of the further cycles is not as important as that of the initial cycle. Material that has been composted for only one cycle may be used in the finished product as well as material which has been composted for, for example, a year.

The latter material may have been turned two, three or more times. The final compost may contain a mix of single and multiple composted materials.

At the end of the composting process the two different composts may be mixed together and a proportion of peat added to that mix. However, peat need not be added and, if peat is present, only one of the composted mixes is necessary.

At present, we consider that the growing medium made by the method described should consist of the following compost ion: Ingredient Ranee (by Volume) Composted paper pulp bark mix 0-60% Composted wood residues 0-60t Peat 0-608 At present, the preferred composition for a low peat formulation is as follows: Ingredient Range (by Volume) Composted paper pulp bark mix 5-40% Composted wood residues 5-40% Peat 25-60% The preferred formulation for a peat free preparation is as follows: Ingredient Range (bv Volume) Composted paper pulp bark mix 30-50% Composted wood residues 30-50% Other non-peat additives 30-50W In addition to the basic components specified above, various further ingredients may be added according to the specific application of the compost.A liming agent may be included to raise the pH to around 5.5-6.0. The amount of liming agent will be dependent on the particular composition of the formulation and will increase with increasing quantities of peat. A complete nutrient range should be added, giving all the essential plant nutrients including trace elements. The amount of each nutrient, or fertiliser, is dependent on the purpose for which the final growing medium is intended and such nutrients and amounts are well known to those skilled in the art. A wetting agent may be added when required to aid water management.

In addition, the following ingredients may be included in the preparation: Inqredient Maximum Range (by Volume) Preferred Range (by Volume) Spent mushroom compost 0-60% 5-30% Acrylic polymers 0-30% 5-15% Perlite 0-40% 5-25% Vermiculite 0-40% 5-25% Grit 0-30% 5-15% Sand 0-30% 5-15% Bark 0-60% 5-35% Coir 0-60% 5-35% Composted town refuse 0-60% 5-35% Composted sewage 0-60% 5-35% The total percentage by volume of all the above additives should not exceed 65%.

Although bark is present in the original basic formulation it is, in some instances, desirable to include more bark in the mixture.

Mixtures of growing media made according to the above formulations may be used for a variety of purposes which include sowing seeds, pricking out seedlings, potting up plants, repotting plants, taking cuttings, potting up rooted cuttings, preparing hanging baskets, filling containers for houseplants and patios, etc, preparing growing bags for tomatoes etc. Those skilled in the art will realise that this list is by no means exhaustive and the media are suited to a wide variety of plants, for example bedding plants, nursery stock shrubs, ornamental plants, pot plants etc.

Specific examples of formulations made by the method of the invention and their applications are hereinafter set out. It should be understood that these formulations are given by way of example only: Examoles 1 to 4 A growing bag containing a growing medium embodying the invention typically may have one of the following formulations: A B C D E Peat 50 25 Composted wood waste 25 30 30 40 40 Composted paper pulp & bark 25 30 30 40 40 Perlite - 20 20 - Vermiculite - - 20 Composted town refuse - - - 20 Bark - - - - 20 These figures are percentages by volume. If necessary dolomitic limestone is added to raise the pH of the medium and additional nutrients included in the form of a blend of powdered fertilisers; the exact nature of this nutrient blend will depend on the precise chemical composition of the various raw materials used.

ExamPles 5 to 8 A multipurpose compost embodying the invention may have one of the following formulations: F G H I J % % % % % Peat 50 20 - - Composted wood residues 15 20 20 20 20 Composted paper pulp & bark 15 20 20 20 20 Perlite 10 20 20 - 10 Vermiculite 10 20 20 20 20 Coir - - 20 30 Grit/Sand - - - 10 Bark - - - - 30 These figures are again precentages by volume and nutrients,a wetting agent and dolomitic limestone will be added at various rates.

Claims

1. A growing medium comprising composted industrial cellulose waste enriched with nitrogen.

2. A growing medium according to claim 1, wherein the composted industrial cellulose waste comprises composted waste paper pulp and bark.

3. A growing medium according to claim 2, wherein the composted waste paper pulp and bark comprises up to 60% by volume of the growing medium.

4. A growing medium according to claim 3, wherein the composted waste paper pulp and bark is in the range 5-50% by volume of the growing medium.

5. A growing medium according to any of claims 1 to 4, wherein the industrial cellulose waste comprises composted wood waste.

6. A growing medium according to claim 5, wherein the composted wood waste comprises up to 60% by volume of the growing medium.

7. A growing medium according to any preceding claim, wherein the composted wood waste is in the range 5-50% by volume of the growing medium.

8. A growing medium according to any preceding claim, comprising up to 60% by volume of peat.

9. A growing medium according to claim 8, comprising peat in the range of 25-60% by volume.

10. A growing medium according to any preceding claim, further comprising a liming agent.

11. A growing medium according to any preceding claim, comprising up to 65% by volume of additives selected from the group comprising Perlite, Vermiculite, grit, sand, bark, coir, composted town refuse composted sewage, spent mushroom compost and acrylic-polymer.

12. A growing medium according to claim 11, wherein said additives are in the range 5-40% by volume.

13. A growing medium according to any preceding claim, comprising by volume, 50% peat, 25% composted wood waste and 25% composted paper pulp and bark.

14. A growing medium according to any preceding claim, comprising by volume7 25% peat, 30% composted wood waste, 30% composted paper pulp and bark, and 20% perlite.

15. A growing medium according to any preceding claim7 comprising by volume, 30% composted wood waste, 30% composted paper pulp and bark, 20% perlite, and 20% vermiculite.

16. A growing medium according to any preceding claim, comprising by volume, 40% each of composted wood waste and composted paper pulp/bark mix, and 20% composted town refuse.

17. A growing medium according to any preceding claim, comprising by volume, 50% peat, 15% each of composted wood waste and composted paper pulp/bark mix, and 10% each of perlite and vermiculite.

18. A growing medium according to any preceding claim, comprising by volume 20% each of peat, composted wood waste, composted paper pulp and bark, perlite, and vermiculite.

19. A growing medium according to any preceding claim, comprising by volume, 20% each of composted wood waste, composted paper pulp and bark, perlite, vermiculite and coir.

20. A growing medium according to any preceding claim, comprising by volume, 20% each of composted wood waste, composted paper pulp and bark, and vermiculite, 30% coir and 10% grit or sand.

21. A method of producing a growing medium, comprising composting industrial cellulose waste and enriching the waste with nitrogen.

22. A method according to claim 21, comprising enriching with nitrogen prior to composting.

23. A method according to claim 21 or 22, wherein the industrial cellulose waste is paper pulp, further comprising milling the paper pulp and blending with bark prior to composting.

24. A method according to claim 21, 22 or 23, wherein the cellulose waste comprises wood waste, the method further comprising shredding the wood waste prior to composting.

25. A method according to claim 24, comprising screening the wood waste prior to composting.

26. A method according to any of claims 21 to 25, wherein the industrial cellulose waste is left to compost for 10 to 12 weeks.

27. A method according to claim 26, wherein after composting for 10 to 12 weeks, the composted industrial cellulose waste is mixed, turned and left to compost for a further period.

28. A method according to any of claims 21 to 27, comprising blending the composted industrial cellulose waste with peat.

29. A method according to any of claims 21 to 28, comprising blending with the composted industrial cellulose waste additives selected from Perlite, Vermiculite, grit, sand, bark, coir, composted town refuse7 composted sewage, spent mushroom compost, and acrylic polymer.

30. A growing medium substantially as herein described.

31. A method of producing a growing medium substantially as herein described.