GB2257697A - Horticultural growth media - Google Patents

Abstract

A horticultural growth media including short fibre paper waste as a peat substitute. The paper waste comprises 10 to 70% by volume and preferably from 25% to 35% for optimum growth characteristics. The remainder of the growth media comprises organic and inorganic growth materials, plant nutrient additives and trace elements. As the waste paper has a tendency to "lock-up" nitrogen the nutrients preferably include nitrogen nutrients to make up for this deficiency. Comparative tests of the growth media including waste paper with other medias such as peat, cocoa fibres etc. gave results at least as good as some alternatives and for some plant species growth characteristics were better using the paper waste.

Description

HORTICULTURAL GROWTH MEDIA This invention relates to an improved horticultural growth media, especially such a media intended as a substitute for peat either as a growth media or as a soil conditioning agent.

Over the last thirty years peat has been the most commonly used material as a horticultural growth media.

As a growth media for plant raising, peat is probably the most suitable material to give uniform growth of containerised plants. Additionally peat is widely used as a soil conditioning agent or organic matter source in amenity landscaping uses.

The continuing use of peat on a large scale however is now questioned by various ecological and environmental pressure groups. The extraction of peat from UK bogs and mosses is leading to the destruction and depletion of these environments as the time required for the replacement of peat within such areas is far greater than the rate at which the peat is being used. Additionally the use of peat as a soil conditioning agent or as a source of organic matter is not particularly efficient.

It has been shown that less than three inches of peat offers little enhancement of the soil's own organic matter content.

It is an object of the invention therefore to provide a horticultural growth media which is at least partially composed of a peat substitute whilst retaining adequate growth and nutritional qualities.

With this object in view the present invention provides a horticultural growth media including from 10 to 70t by volume of paper waste, the remainder comprising organic and inorganic growth material, plant nutrient additives and trace elements.

The term 'paper waste' is to be taken to refer to short fibre waste obtained as a by-product of paper recycling processes. Such processes extract long fibres from bulk waste paper to form recycled tissue paper. The remaining short fibres along with some filler materials, for example, china clay, form a currently unused paper waste.

The paper waste preferably forms from 25% to 35% by volume of the growth media, advantageously 30% by volume.

The additional organic growth material is preferably crushed bark with the addition of fertilisers, lime etc.

as required according to the characteristics of the plant which is to be grown in the media.

It has been found that nitrogen present in the media tends to be locked-up in the paper waste and thus it is advantageous to provide additional nitrogen nutrients to ensure proper growth characteristics. The paper waste used, formed substantially from short fibres, provides ideal water drainage and air flow characteristics which permit growth of plants through the media whilst avoiding problems of excessive "wetness" or solidity.

A further advantage of the use of paper waste is that it avoids problems caused by secondary composting which often occurs in other similar organic materials for example, animal wastes. Additionally the paper waste used does not appear to contain any phytotoxic element which would adversely affect the plant or its growth characteristics.

Whilst the paper waste described is intended to be used as a replacement for peat it may be preferable in certain instances to use some peat as at least part of the organic growth material mixed with paper waste according to the invention. This will provide a comparatively peat rich media with the required physical characteristics whilst avoiding the use of large quantities of peat as would be required for a 100% peat media.

The invention will be described further by way of example with reference to the following embodiments.

The following examples all make use of paper waste obtained as a by-product of the manufacture of recycled paper. Tissue paper formed from recycled paper requires the use of long paper fibres only. Thus, in order to form the necessary bulk paper for such uses it is usual to separate the long fibres from the short fibres present in waste paper entering the process.

The resultant short fibres together with the filler used in forming the original paper, for example, china clay, and other components, then forms the bulk of paper waste which is normally unusable and is usually disposed of by dumping. The invention thus provides a use for this normally unwanted by-product and will reduce the amount of waste material which is required to be dumped on waste tips.

Example 1 Paper waste as described above was added to peat at 15% and 30% by volume. No additional nutrients were added. This test was intended as a comparison to the performance characteristics of peat alone. A perennial ryegrass was used as the test plant and seeds thereof were sown on top of pots containing the various materials.

Plant growth was then observed and photographed and grass cuts and tissue analysis of the results were undertaken.

The ryegrass germinated well on the mixes including the paper waste and the peat mix and the growth obtained was generally uniform. In comparison to some of the high nitrogen containing treatments the growth on the paper waste was not as vigorous. It was noted however that the paper waste treatment left the resultant plant less open to fungal disease attack. Results of the tests are summarised in the following table.

Table 1 Sample Dry Nitrogen Phosphorus Potasstype Matter % % % ium % 15% paper waste + peat 14.9 2.6 0.28 2.29 30% paper waste + peat 13.6 2.6 0.27 3.11 Control peat only 21.4 2.0 0.2 1.19 It will be seen from the above results that the inclusion of paper waste at both 15% and 30% by volume provided plant growth characteristics at least as good as those obtained by using peat only. The paper waste produces slightly lower dry matter percentages than the control peat only which reflects a higher nitrogen content. It is noted that little nitrogen is available from peat alone.

Example 2 30% by volume of paper waste was mixed with crushed bark and 1 gm per litre of fertiliser. Additionally a controlled release fertiliser of 4 gm per litre was added and additional lime was also provided at 2 gm per litre.

Four species of bedding plants were raised in the mixes above, the species being impatiens, begonias, ageratums and nicotiana. These plants were potted into 7cm diameter pots and watered as necessary. Again the plants were photographed at various growth stages and compared with plants growing in peat, coconut fibre or peat and bark, coconut fibre and bark.

The growth of the plant in the paper waste/bark mixture was acceptable if not the best obtained compared to all the treatment. One problem which did arise from this test was that the plants were basically short of nitrogen. Such a result was anticipated from the results of Example 1. The requirement therefore for a nitrogen fertiliser to adjust the amount of "lock-up" of nitrogen in the paper waste is justified.

It was noted however, that there was no growth distortion of the plants thereby suggesting that there was no residual organic compound or heavy metal toxicity in the paper waste. Thus whilst nitrogen management will need to be looked at carefully in order to balance for the growth of specific plants there is no problem as regards compatability with the waste paper.

Example 3 This example was intended as a long term look at the use of waste paper as a horticultural growth media.

Accordingly a paper waste/bark mix at 30% by volume of paper waste was produced with fertiliser and lime additions as specified in Example 2. Root development of plants in the media were scored on a O to 5 basis after one and two months to judge the effectiveness of the paper waste media in comparison to peat, cocoa fibre etc. The results of this test are summarised in Table 2.

Table 2 Plant Type Conifer Eleagnus Viburnum Cazzanala Campanala Lcbellia Lamiastrum Verutam Cerise taki Dark hennans nigra Crusader 'Pride' Peat 2 2 1 2 3 2 3 Cscefibre 4 4 1 2 4 3 2 2 Peat Bark 1 2 0 Coco-bark 4 4 1 Waste ) 1 3 1 3 2 2 3 Paper (3) (4) (1) (1) (4) (4) (3) (1) ;Bark) 5 = very ocod establlshment of roots I = very psor 0 = none visible ( )= after 2 months As can be see from the table the rooting in the paper waste was at least as good as some of the other materials used although not as good as cocoa fibre or cocoa fibre or bark. However, after the two month period there was a considerable improvement in all of the plants with the exception of the viburnum species which was slow to root.

The actual portions of the plants above soil level were generally comparable. However, it was noticeable that the plants growing in the paper waste mixture were showing some visual signs of nitrogen deficiency. It will be seen however that the results of growth in the paper waste mixture are not greatly different from the best treatments which were found to be the peat/bark mixture and cocoa fibre. The performance however in the paper waste is certainly adequate and with some supplementary nitrogen fertiliser it is probable that performance could have been boosted.

The invention is not confined to the foregoing details and variations may be made thereto within the scope of the invention.

Claims (7)

1. A horticultural growth media including from 10 to 70% by volume of paper waste, the remainder comprising organic and inorganic growth material, plant nutrient additives and trace elements.

2. A growth media as claimed in Claim 1 in which the paper waste is short fibre waste obtained as a by-product of paper recycling.

3. A growth media as claimed in Claim 1 or 2 in which the paper waste forms from 25% to 35% by volume of the growth media.

4. A growth media as claimed in Claim 1, 2 or 3 in which the additional organic growth material includes crushed bark with the addition of fertilisers and lime.

5. A growth media as claimed in any preceding claim in which nitrogen nutrients are provided to ensure proper growth characteristics.

6. A growth media as claimed in any preceding claim in which peat is provided as at least part of the organic growth media.

7. A horticultural growth media substantially as hereinbefore described with reference to the examples.