United Kingdom
September 25, 2006
New research by the
University of Warwick
should have gardeners and commercial growers competing for both
recycled paper and organic waste composts. The University’s
plant research department, Warwick HRI, is finding that recycled
paper based composts are proving to be a major weapon in the
fight against a range of plant diseases.
A University of Warwick research team under Professor Ralph
Noble has recently shown that the use of composts can reduce the
incidence of some important plant diseases by as much as 72%.
That research, funded by the UK government’s Waste and Resource
Action Programme (WRAP), found that the replacement of around
20% of the volume of soil or peat by compost gave major disease
control benefits.
Professor Ralph Noble’s latest research appears to add another
ecological benefit. Early results from trials with conifers
using compost made from paper waste shows that it is providing
much the same disease suppressing effect as green compost made
from plant waste. This provides an obvious additional commercial
use for the vast amount of paper waste generated by offices and
homes.
Professor Noble said: “During paper recycling production a large
proportion of the fibres cannot be recycled. The useable fibres
are taken out to make new newsprint, and the small fibres are no
longer usable, they’re a waste by-product. In Britain, about
half a million tonnes of these small, unusable fibres are
produced each year. They have a potential use in growing media
because they hold a lot of water, just like peat and, being a
waste product, they have no other value. Obviously materials
that are going to replace peat have to be very cheap or waste
by-products. So, paper wastes fit this bill in terms of being
cheap and they also hold a lot of water, which is what you need
for plant growth”.
The suppression of plant diseases was particularly noticeable
when the green and recycled paper composts were added to peat.
Peat is used by many growers as it provides a clean and uniform
material that is suitable for plant growth – but its very
cleanliness makes the plants growing in it susceptible to
quickly spreading plant diseases. In contrast compost contains a
diversity of microbes that can suppress plant diseases. The
ecological benefits of this are obvious: less fungicide has to
be applied to plants, less peat is required thus preserving peat
bogs, and green waste and paper waste that would otherwise be
land-filled is recycled.
Professor Ralph Noble says: “This research shows that the use of
such compost could provide clear commercial benefits to growers
and ecological benefits for us all. There should be no
additional costs involved but we must still test the reliability
of using composts for a wide range of commercial crops. Those
growers who do change from using 100% peat could literally reap
significant rewards” |