Evaluating Paper Sludge in Container Media Used for Mum Production 1994 Proposal
Evaluating Paper Sludge in Container Media Used for Mum Production
During paper production, over 4 million dry tons of pulp and paper sludge
(waste)
are generated per year in the U.S. This sludge is fibrous in nature, resistant
to rapid
decomposition and shrinkage, and has a moderate cation exchange capacity
(CEC),
making it potentially useful as an alternative amendment in container growth
media used
for production of floral crops. The objectives of this study are to compare
chemical and
physical characteristics of sludge-amended media with those of commercial
mixes and
compare the effects of sludge-amended media against those of commercial
media on
the growth of chrysanthemum.
Two media will be made with composted pulp and paper sludge from a newsprint
mill (nonbleached material) mixed with perlite, vermiculite, and peat moss
in various
proportions. Two commercial mixes will also be used as potting media in
the
experiment. All media will be analyzed for pH, porosity, container capacity,
carbon:nitrogen (C:N) ratio, soluble safts, CEC, and media shrinkage. ‘Iridon’
chrysanthemum cuttings (one per pot) will be planted 4.5-inch pots that
contain one of
the various media. A commercial growing regime will be used to produce
the crop.
Plant growth analyses will include plant height, pot width, shoot dry weight
and flower
number. Some plants will also be retained for postharvest study including
days to wilt
and flower quality.
This study should demonstrate the suitability of paper sludge as an amendment
in
container media used for chrysanthemum production. If the sludge can be
used,
growers may be able to reduce their production costs since they could use
sludge-
amended media and reduce their reliance on peat moss-based mixes.
INTRODUCTION
The U.S. pulp and paper industry generates about 4 million dry tons of
sludge per
year, based on 80 million tons of annual production. Traditionally, the
vast majority of
this by-product has been dumped at landfills even though the paper sludge
is a
decomposable organic material. Many states, however, are banning decomposable
organic materials from landfills. One alternative use of paper sludge could
be as an
amendment in potting mixes since this material has some physical and chemical
qualities
that could be suitable for plant growth.
Composted paper sludge may be useful as a substitute for peat moss in
container media, since peat is expensive, sometimes variable, and could
become harder
to obtain as people question the effects of draining bogs and mining the
material.
Composted paper sludge that originates from a newsprint mill (rather than
a bleached
paper process) is nontoxic, fibrous, and resistant to rapid decomposition.
In addition,
this material has a moderate CEC, a pH near neutral, and a moderate level
of soluble
salts.
LITERATURE REVIEW
Very little research has been conducted on using pulp and paper sludge
in
potting mixes for production of floral crops, whereas paper sludge has
been used in
container media experiments for nursery stock production. Based on my research
and
that of Chong (3-5) and Michael (6), pulp and paper sludge generated from
paper
production (rather than paper recycling) has proven to be a useful potting
mix
amendment for nursery stock production. In my work with amur maple and
blue spirea
(Caryopteris incana), plants potted in 25% or 50% sludge-amended media
grew as tall
and produced as much foliage as plants grown in 25% or 50% peat moss-amended
media (unpublished data). Chong and colleagues (3, 4) reported that spirea
(Spiraea x
bumulda) and two cultivars of euonymus grew well in media containing up
to 50% pulp
and paper sludge. Michael (6) found that ‘Hetzi’ Japanese holly and ‘Sea
Green’
Chinese
juniper planted in 33% paper sludge (by volume) significantly grew better
than
plants
grown in other media including five commercial mixes.
Even though only a few studies on the use pulp and paper sludge in potting
mixes
have been
published, my colleagues and I have been studying composted newsprint mill
sludge
for several years. This paper sludge has a moderate CEC (60 to 90 cmol(+)/kg),
a pH near
neutral (6.6 to 6.9), and a good C:N ratio (2). In addition, the sludge
contains
slowly
available nutrients. This material has a low heavy metal (Cd, Pb, Ni, Cu,
Cr, and
Zn) content
and a low Na content. When sludge is mixed with perlite and vermiculite
(75%:15%:10%
by volume), aeration is about 24% and water-holding capacity is about
43% (unpublished
data).
In the past year, I have grown two floral crops in sludge-amended media.
During
the fall
of 1992, I grew a poinsettia crop in two pulp and paper sludge media and
compared
plant growth to that of plants grown in four commercial mixes. In brief,
plants
potted
in pulp and paper sludge media were 1 to 2 inches shorter, produced 10
to 20%
less shoot
growth (based on dry weight), and were more susceptible to disease than
plants
grown in any of the commercial mixes (manuscript in preparation). Although
the
plants
growing in sludge-amended media were salable, the poinsettias were of
noticeably
lower quality than those grown in two of the commercial mixes.
During the past spring, ‘Iridon’ chrysanthemum cuttings were planted in
the same
sludge-amended
media that were used in the poinsettia experiment. The mums were
planted
in 4.5-inch pots, given 3 weeks of long days, given short-day treatments
and
then allowed
to grow without any height limiting treatments (B-9). Mums grown in
sludge-amended
media were similar in height, number of flowers, pot width, and shoot
dry weight
compared to those grown in two commercial mixes. In this experiment,
however,
foliar nutrition and chemical analyses of all the potting mixes were not
determined
since I lacked the funds to complete this work. In addition, since the
mums
were allowed
to grow without any B-9 treatments, the results from this study may not
reflect those obtained when the plants are grown under a commercial production
regime.
OBJECTIVES
The overall goal of the proposed study is to determine the effects of paper
sludge-
amended media on the growth of ‘Iridon’ chrysanthemum produced under a
commercial
growing regime. The specific objectives include:
1. Compare chemical and physical characteristics of two sludge-amended
media with
those of two commercial mixes.
2. Compare the growth of mums grown in two sludge-amended media against
those
planted in two commercial mixes.
ANTICIPATED BENEFITS
This study will demonstrate the suitability of pulp and paper sludge as
an
amendment in container media used for commercial mum production. If the
sludge can
be used for mum production, growers may be able to reduce their use of
peat moss-
based mixes and thereby reduce crop production costs. Growers should be
able to
receive a relatively consistent material at a low price. In fact, since
the paper industry
has a sludge waste problem, growers may receive the sludge for free or
be paid to take
it.
MATERIALS & METHODS
Rooted cuttings of Dendranthema grandiflora Tzvelev. ‘Iridon’ (1) will
be obtained
from a commercial grower and planted (one per pot) in 4.5-inch pots. Two
paper
sludge-amended and two commercial media will be used in this study. One
sludge-
amended medium will consist of 75%:15%:10% sludge:perlite:fine vermiculite
by volume,
whereas the other medium will contain 50%:33%:17% sludge:peat moss:perlite;
in this
latter medium, paper sludge is used as a “peat extender”. Metro-Mix 350
and Fison’s
Postharvest Mix will be used as the commercial mixes in this study. Ten
replicates
(plants) will be used for each medium, of which four will be randomly assigned
for use in
a postharvest
study, three for foliar nutrient analysis and three for shoot dry weight
(see
below).
A growing regime that is similar to commercial greenhouse practices will
be used
in this
study. After one rooted cutting is planted per pot, they will be placed
in a
glasshouse
and receive 1 week of long days before starting the short-day treatment.
Plants
will receive 350 ppm N with every irrigation until about one month before
flowering.
When the plants have added about 1.5 inches of new growth, they will be
pinched.
Two to three B-9 treatments (2500 ppm) will be used to control plant height
and be
applied at 2-week intervals starting 2 weeks after pinching. All flower
buds will be
left intact
on the plants.
Physical and chemical characteristics of all media will be determined.
Chemical
properties
measured will include pH, CEC, C:N ratio, and electrical conductivity (EC)
(as
an indirect
measure of soluble salts). Micro- and macronutrients in the media will
also be
determined.
Physical properties of the potting mixes that will be determined include
aeration,
container capacity, total porosity and bulk density.
The effects of the various media on the growth of ‘Iridon’ plants will
be determine
in several
ways at the end of the experiment. Plant height, average pot width and
shoot
diameter
will be measured on all plants. Total number of flowers, number of open
flowers,
and number of axillary breaks will also be counted at the end of the study.
Three
plants grown in each mix will be cut off at the medium surface, and shoot
dry
weight
will be determined. Foliar nutrient content (macro- and micronutrients)
will also
be determined
for three plants at the end of the study. Postharvest quality of four plants
grown
in each medium will also checked to ensure that plants grown in sludge-amended
media
are retain their flowers and foliage as well as those in commercial mixes.
Flower
quality
will be rated 10 days after the experiment ends (”harvest”). After rating
the
flowers,
all containers will be brought to field capacity, and the number of days
to wilt will
be determined.
A completely randomized design will be used in this study. Differences
among
potting media and plant growth indices will be determined by analysis of
variance.
Significant differences among treatment means will be determined by protected
Fisher’s
Least Significant Difference Test at the 5% level.
LITERATURE CITED
1. Anderson, N.O. 1987. Reclassifications of the
genus Chrysanthemum L.
HortScience 22:313.
2. Campbell, A.G., R.R. Engebretson, R.R. Tripepi.
1991. Composting a combined
RMP/CMP pulp and paper sludge. Tappi Journal 74:183-191.
3. Chong, C., R.A. Cline, M. Koole. 1990. Container
media compared in trial at
Brucedale. Landscape Trades 12(5):13-14, 16.
4. Chong, C., R.A. Cline, D.L. Rinker. 1988. Use
of papermill sludge in container
crop culture. Landscape Trades 10(7):17-18.
5. Cline, R.A., C. Chong. 1991. Putting paper mill
waste to use in agriculture.
Highlights 14(l):16-19.
6. Michael, A. 1992. Container growing mixes. Pennsylvania
Nurserymens
Association Newsletter p. 48-50
BUDGET
1.
Personnel and Fringe Benefits
Part-time (student) help
$1,800
Fringe benefits (13%)
234
2.
Supplies
500
3.
Analyses (media & plants)
1,200
TOTAL
$3,734
Funding for part-time help, supplies, and analyses is requested for this
research.
A student interested
in production of floral crops will be hired on a part-time basis ($6/hr
x 15 hr/wk x
20 weeks) to help with this experiment. As project leader, I will provide
5%
of my time to
this research project, with salary and benefits covered by the University
of
Idaho. Supplies
including fertilizer, commercial media, and black cloth will be
purchased. Funds
are also requested for analyses of potting mixes (CEC, EC, C & N
determinations,
etc.) and analyses of foliar nutrition of the lants. Foliar analyses of
plants from
the first mum experiment will also be completed. Funding for this research
will also be
supplemented as needed by operational funds from my Hatch research.
LEADER QUALIFICATIONS
I, Robert Tripepi, have been involved in evaluating the suitability of
agricultural and
forest products
wastes for over three years. During this time, one paper has been
published (see
ref. 2), two are being submitted to a peer-reviewed journal and two
papers are in
preparation. As mentioned above, I have grown poinsettias and mums in
paper sludge-amended
media as well as six species of nursery stock. Other wastes I
have used in
potting experiments include bluegrass straw residue, rapeseed meal,
biosolids (sewage
sludge), landscape debris (grass and leaves), log yard waste, and
sludge from
a kraft mill (bleached material). During the past three years, this research
has provided
me with invaluable experience and in-sights on important properties of
potting mixes
amended with various wastes and on plant responses to the wastes and
their degradation
products.
