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New Forests
International Journal on the Biology,
Biotechnology, and Management of
Afforestation and Reforestation
ISSN 0169-4286
Volume 43
Number 3
New Forests (2012) 43:267-286
DOI 10.1007/s11056-011-9280-x
Are composts from shredded leafy branches
of fast-growing forest species suitable as
nursery growing media in arid regions?
Mustapha Bakry, Mohammed
S.Lamhamedi, Jean Caron, Hank
Margolis, Abdenbi Zine El Abidine,
M’Hammed Bellaka & Debra C.Stowe
1 23
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Are composts from shredded leafy branches
of fast-growing forest species suitable as nursery growing
media in arid regions?
Mustapha Bakry •Mohammed S. Lamhamedi •Jean Caron •
Hank Margolis •Abdenbi Zine El Abidine •M’Hammed Bellaka •
Debra C. Stowe
Received: 30 November 2010 / Accepted: 5 August 2011 / Published online: 21 August 2011
ÓSpringer Science+Business Media B.V. 2011
Abstract The morpho-physiological quality of seedlings is negatively affected by the
wide scale use of forest soils as substrates in developing countries. With the objective of
finding long-term sustainable supply of growing media, compost was produced from
shredded branches of three fast growing species (Acacia cyanophylla (AA), Acacia cyclops
(AS) and Eucalyptus gomphocephala (EG). The composting process covered three different
periods over the course of a year. Pile temperatures were monitored daily and the composts
were routinely sampled and analyzed for 19 chemical variables. Although composting is
feasible year-round in arid climates, compost produced in the humid cool conditions of
autumn, winter and early spring reaches the maturation phase more quickly than compost
produced under hot, dry summer conditions. It also requires less turning and water. The
evolution of the composting process and quality of the final product can be assessed using
three chemical variables (C/N, pH, EC). Seed germination rates in the three types of
compost were similar to that in a peat:vermiculite substrate and vigorous high quality
seedlings were produced in the two acacia composts. However, compost-grown seedlings
M. Bakry (&)H. Margolis D. C. Stowe
De
´partement des Sciences du bois et de la fore
ˆt, Faculte
´de Foresterie,
de Ge
´ographie et de Ge
´omatique, Pavillon Abitibi-Price, Universite
´Laval, 2405 rue de la Terrasse,
Que
´bec, QC G1V 0A6, Canada
e-mail: bakry.mustapha@gmail.com
M. S. Lamhamedi
Direction de la Recherche Forestie
`re, Ministe
`re des Ressources Naturelles et de la Faune du Que
´bec,
2700 rue Einstein, Que
´bec, QC G1P 3W8, Canada
J. Caron
De
´partement des sols et de ge
´nie agro-alimentaire, Faculte
´des Sciences de l’Agriculture et de
l’Alimentation, Pavillon Comtois, Universite
´Laval, 2425 rue de l’Agriculture, Que
´bec,
QC G1V 0A6, Canada
A. Zine El Abidine
E
´cole Nationale Forestie
`re d’inge
´nieurs BP 511, Tabriquet, Sale
´, Morocco
M. Bellaka
Centre Re
´gional de la Recherche Forestie
`re de Marrakech, Circuit de la Palmeraie,
Km 2.5, B.P 13360, Poste Annakhil, Ain Itti, Marrakech, Morocco
123
New Forests (2012) 43:267–286
DOI 10.1007/s11056-011-9280-x
Author's personal copy
had significantly smaller shoots and root systems than those produced in peat substrate.
Principal components analyses showed that the quality of a compost-based substrate is
reproducible and that its final chemical composition can be predicted from its raw organic
materials. The EG composts had higher pH than the acacia composts, whereas the AA and
EG composts were higher in mineral salts than the AS.
Keywords Nursery substrates Compost Forest biomass Arid zones
Introduction
Among the key factors which have a significant effect on the germination, growth and
physiology of nursery-grown tree seedlings are the composition and physicochemical
properties of the substrate in which the plants are grown (Lazcano et al. 2010; Bernier and
Gonzalez 1995). These factors can be optimised to significantly improve seedling growth,
root plug cohesion, substrate water holding capacity, gas diffusion and nutrient uptake,
while reducing leaching of the substrate solution.
In several developing countries, substrates are generally composed of mineral soils,
forest humus, sand and manure (Miller and Jones 1995). The physico-chemical properties
vary from year to year and among nurseries, depending on the source of the components
and their availability. In addition to being a potential source of weeds and diseases
(Lamhamedi et al. 2000), this practice does not facilitate the standardization and continual
improvement of cultural techniques for seedling production in forest nurseries. The use of
such substrates in North Africa hinders the improvement of seedling growth and survival
rates in reforestation programs. This necessitates repeated fill planting because the planted
seedlings lack the morpho-physiological qualities for successful establishment under
conditions of severe temperature and water stresses. The increase in the price of peat
(Ribeiro et al. 2007), as well as its environmental importance in maintaining biodiversity
(Fenner et al. 2007; Warner and Asada 2006), have increased the social pressure against
peat exploitation for substrate use. This has forced nursery managers to search for peat
substitutes that are socially, economically and ecologically acceptable.
In an effort to find long term alternatives to peat substrates, several recent studies have
focused on aerobic composting of various locally-available organic materials (Abad et al.
2001). The most frequently used materials are solid municipal waste, (Dimambro et al.
2007), forest residue (Veijalainen et al. 2007b), agricultural waste (Manios 2004), garden
waste (Brewer and Sullivan 2003), sewage and papermill sludge (Man
˜as et al. 2009) and
livestock manure (Desalegn et al. 2008). These composts contribute to improving the
fertility of agricultural soils (Roe 2001), soils destined for the production of bare root forest
seedlings (Davis et al. 2006), horticultural plants (Fitzpatrick 2001) and the control of
pathogens (Noble and Coventry 2005).
The major disadvantages of these types of composts are the variability in composition
and the presence of pollutants that have the potential to negatively affect human health and
contaminate the water table (De
´portes et al. 1995). Developing countries are not neces-
sarily equipped with centers for treating and composting solid waste. Moreover, the fre-
quent use of certain very heterogeneous organic materials, notably municipal waste, makes
it difficult to attain the reproducibility and quality standards which meet the requirements
for forest nursery substrates. Particular attention must be paid to the use of simple, envi-
ronmentally acceptable composting techniques which are easily accessible to nursery
growers. Little work has focused on the valorization and composting of forest biomass,
268 New Forests (2012) 43:267–286
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particularly branches of fast growing broadleaved species adapted to arid and semi-arid
zones.
Recently, pure tree branch-based compost was successfully used for the first time on an
operational scale for the production of forest seedlings and ornamental plants (Lamhamedi
et al. 2006; Ammari et al. 2003). The global use of fast growing genera such as Eucalyptus
and Acacia in reforestation programs for wood production and dune stabilization prompted
us to evaluate the possibility of composting this biomass. There are three principal reasons
why this kind of compost might be useful: (1) to valorize early silvicultural operations
(thinning, pruning), which are generally not profitable given that the harvested biomass has
no marketable value; (2) to decrease the negative impact of eucalyptus leaves on bio-
geochemical cycles and herbaceous layer development; and (3) to find an alternative to the
importation of peat and improve forest nursery cultural techniques for the production of
consistent-quality organic substrates, while creating employment in arid and semi-arid
zones.
The objectives of the study consist of (1) studying the feasibility of producing different
composts and substrates from fresh shredded branches of fast growing broadleaved species
(Acacia cyanophylla Lindl, Acacia cyclops A. Cunn. ex G. Don (leguminous trees) and
Eucalyptus gomphocephala DC) (Myrtaceae) which are widely used in reforestation
programs in arid and semi-arid zones; (2) characterising the chemical properties of the
composts at different phases during a complete composting cycle and identifying the
properties that are integral to managing the composting process; (3) comparing the com-
posting process at different times of the year; (4) evaluating the possibility of using the
composts as growing media for seedling production; and (5) classifying composts into
homogeneous groups using principal components analysis.
Materials and methods
Raw organic material
Leafy branches of Acacia cyclops A. Cunn. Ex G. Don (AS) and Eucalyptus gompho-
cephala DC (EG) were collected in Sidi Jaber, an arid bioclimatic zone approximately
80 km northeast of the city of Marrakech, in a forest research arboretum and in a young
coppice forest, respectively. Leafy branches of Acacia cyanophylla Lindl. (AA) were
collected from le circuit de la palmeraie within the urban perimeter of Marrakech. Other
AS branches were collected from trees that had been planted to stabilize the coastal dunes
in Essaouira, 100 km west of Marrakech. These trees were directly exposed to ocean spray.
The foliage:woody biomass ratio, measured using a balance on the shredding platform,
represented, on average, 59, 56 and 47% of the total fresh branch mass for EG, AA and AS,
respectively.
Creation of the compost piles
Composting was done in unsheltered piles on a concrete surface. Ambient temperature and
precipitation were recorded using a meteorological station installed near the experimental
area. The total composting experiment lasted 11 months. Three different composting
periods of approximately 4 months in length were compared (Table 1). Each period was
characterized by the bioclimatic conditions of one of three seasons (winter, spring and
summer) during the thermophilic stage (T°[45°C). Winter-trend composting extended
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from November 1, 2004 to March 15, 2005, a period when temperatures are generally mild
and cool and atmospheric humidity is high. The spring- (March 30 to August 6, 2005) and
summer- (May 15 to September 20, 2005) trend composting periods were hot and dry. For
each composting period, one pile was prepared for each type of organic material (AA, AS
and EG). The dimensions of the piles were: 1.5 m in width at the base, 3 m in length and
1.5 m in height. The volumes of raw organic material and final compost product were
determined using a cubic-meter frame. Nitrogen, in the form of ammonium nitrate, was
added when each pile was created and when the piles were turned for the first time as
described by Lamhamedi et al. (2006) so that the C/N remained close to 30/1. The piles were
turned when it was necessary to aerate the piles, to adjust gravimetric water content to the
target level of 60% or to adjust pile temperature to the desired range (45–55°C). Optimal
aeration, moisture and temperature levels provide favorable conditions for aerobic degra-
dation of organic matter. Mid-day temperatures were measured at nine locations in each pile
with 90 cm-long thermometers (model 0.79, Pacific Transducers, Los Angeles, CA).
Chemical properties of the composts
The raw organic material was first sampled immediately after shredding. Subsequent
samples were taken 8 days after the start of composting, during the first days of the
thermophilic phase, and on a monthly basis thereafter for the duration of each composting
period. On each sampling date, four composite samples were randomly selected over the
length of the four sections constituting each pile. Each composite sample was a mix of six
samples (2L/sample). The samples were dried at 65°C to a constant weight, finely ground
(100 lm) and shipped to the Laboratoire de chimie organique et inorganique (ISO 17025)
at the Direction de la recherche forestie
`re (Que
´bec) for analysis.
The electric conductivity (EC
1/20
) of the composts was determined from filtered extracts
of substrate-water suspensions (1:20) measured with a conductivity meter (model CDM83,
Radiometer, Copenhagen, Denmark), whereas the pH was measured in the supernatant of a
1:4 compost:demineralised water suspension. Effective cation exchange capacity (CEC
eff
)
was calculated as the sum of the exchangeable bases and the effective acidity (Hendershot
et al. 2008). The exchangeable bases were determined by extraction with 1 M ammonium
chloride. After filtering the sample, the metals were measured using induced coupled
plasma spectrometry (ICAP 9000, Thermo Jarrell-Ash, Franklin, MA). The effective
acidity was calculated from the pH measurement and the aluminum concentration in the
ammonium chloride extract (Espiau and Peyronel 1976).
Table 1 Mean values of the environmental variables, measured during the three composting periods
Composting period Winter-trend
composting
(Nov. 1, 2004 to
March 15, 2005)
Spring-trend
composting
(March 30, 2005 to
August 6, 2005)
Summer-trend
composting
(May 15, 2005 to
Sept. 20, 2005)
Average temperature (°C)
a
13.5 26.4 26.6
Average of minima (°C)
a
5.0 17.0 17.8
Average of maxima (°C)
a
22.1 35.7 35.4
Precipitation (mm)
b
73.8 9.6 44.4
a
Mean value for the period
b
Cumulative value for the period
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Using the Kjeldahl method, samples were mineralized with sulphuric acid in the
presence of selenium and hydrogen peroxide at 370°C for an hour. Nitrogen content, in the
form of ammonia, was then determined using flow injection colorimetry (Quickchem 8000,
Lachat Instruments, Milwaukee, Wis.). P, Na, Ca, Mg, K, Al, Fe, Mn, Zn, Cu, and Mo were
directly measured in the diluted sulphuric acid solution by inductively coupled plasma
atomic emission spectrometry (model ICAP 9000, Thermo Instruments, Franklin, Mass.)
(Walinga et al. 1995). Total nitrogen (TN) was determined by the Kjeldahl method, dosing
the nitrite and nitrate extracts with a 2 M KCL solution for 30 min and using flow injection
colorimetry (model Quickchem 8000, Lachat Instruments, Milwaukee, Wis.). Total
organic carbon (TOC) was measured by combustion at approximately 1,350°C. The
resulting carbon dioxide was measured by an infrared detector (Analyseur LECO CR-412).
Forest seedling production and measurement of the composts’ physical properties
The two types of Acacia compost were used to produce tree seedlings. EG composts were
excluded because of their high pH values (8.2). Pure AA and AS composts were supple-
mented with 20% peat moss, by volume, to improve their initial pH values. The control
substrate was composed of peat:vermiculite (3:1; vol/vol). Four samples of each substrate
were analyzed for pH and electrical conductivity at saturation (EC
sat
).Carob seeds
(Ceratonia siliqua L., provenance: El Hoceima, Maroc) were scarified in sulphuric acid for
45 min before sowing one seed/cavity into IPL 15-320 containers. The experiment was
composed of three randomized complete blocks. Each substrate was represented by five
randomly distributed containers/block. The experimental design was installed in two
growth chambers (Conviron model PGW-36, Winnipeg, MB, Canada) at 24/18 ±0.5°C,
65/60 ±3% relative humidity (day/night), with a light intensity of 250 lmol m
-2
s
-1
and
a photoperiod of 16 h light/8 h darkness. The seedlings were watered twice daily during
the first 3 weeks, then once a day for the rest of the experiment. Seedlings were fertilized
on a weekly basis, with 4 mg nitrogen (N), 0.52 mg phosphate (P) and 2.6 mg potassium
(K), for a total of 104 mg N, 13.5 mg P et 67.6 mg K over the 6month growing season.
The fertilizer solution also contained calcium (Ca), magnesium (Mg) and micro-nutrients.
After 26 weeks, the height and root collar diameter of five randomly selected seedlings/
block were measured. Three of these five seedlings were then delicately extracted from
their respective cavities for destructive sampling. Root length was measured using
WinRHIZO software (Version 2002a, Regent Instrument INC., Que
´bec, QC). Dry root and
shoot mass were determined after oven-drying the tissue for 48 h at 65°C. Final substrate
EC
sat
and pH values were determined for four composite samples. Each composite sample
was a mixture of the substrate in the root plugs of the five seedlings randomly selected
from three blocks.
The physical properties of AA,AS and PV substrates were assessed at the beginning and
end of this experiment. Two containers were selected and randomly filled with the three
substrates (five cavities per substrate). The initial physical properties were directly mea-
sured on the first unseeded container. Carob seeds were sown into the second container and
seedlings were cultivated as previously described. After 26 weeks of growth, the seedlings
were cut at the root collar and the physical properties of the root plugs were measured. The
containers were saturated from below for 24 h prior to measuring the saturated hydraulic
conductivity (K
sat
) with a constant head infiltrometer (head of 5 cm). The water desorption
characteristic curve of each substrate was obtained by equilibrating the container on ten-
sion tables at -6, -15, -30, -50, and -100 cm of water potential (Allaire et al. 2005).
Air-filled porosity (h
a
,cm
3
cm
-3
) was calculated as the difference between total porosity
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(h
S
,cm
3
cm
-3
) and bag capacity (BC,cm
3
cm
-3
) corresponding to a tension equal to
-6 cm, which represents half of the cavity height. Total porosity was estimated from the
volumetric water content of the substrate measured at saturation. Easily-available water
content (EAW, cm
3
cm
-3
) corresponded to the difference between BC and the volumetric
water content at a water potential of -50 cm.
Experimental design and statistical analyses
To study the impact of organic matter (OM) and composting period on the temperature and
chemical composition of the composts at different times during the composting process, a
Principal Component Analysis (PCA) was first performed on the data. The objective of the
PCA was to reduce the number of dependent variables studied. Of the 19 chemical
components measured, 17 (TOC, C/N, TN, pH, EC
1/20
, CEC
eff
,NH
4
,NO
3
, Na, S, P, K, Ca,
Mg, Mn, Al, Fe) were considered in the PCA. Cu and Zn content showed very little
variation. Factors with eigenvalues higher than 1 were retained and a varimax rotation was
performed on the retained factors to simplify interpretation of the axes.
A repeated measures analysis of variance was then performed considering temperature
and each of the retained factors as dependant variables. OM, composting period (CP),
sampling date (D) and their interactions were considered as fixed factors, while pile
(CP 9OM) was considered as a random factor. The correlations among piles (CP 9OM)
over time were modeled with a first order autoregressive matrix (AR(1)). Since there was
no repetition of CP 9OM, only the main effect of D and interactions involving D could be
studied. Effects were considered significant at a threshold of 0.1%. Since all interactions
include D, an analysis by date was performed both to characterize the interaction and
evaluate the composting process with respect to the five dependent variables; temperature
and four first factors of the PCA. Analysis was performed using the MIXED procedure of
SAS software (V9.2, SAS Institute, Cary, North Carolina).
Morphological variables of the carob seedlings were subjected to an analysis of variance
(ANOVA) using the GLM procedure (SAS Institute, Cary, North Carolina). A least sig-
nificant difference (LSD) test at a significance level of 5% was used to compare the means
of each variable. To understand the effects of organic matter and composting period on
chemical composition of the final product, the data means corresponding to the compost
quality on day 128 (3 types of compost 93 periods) were subjected to multivariate
analyses using principal component analysis (PCA). All 19 measured chemical variables
had been previously centred and standardized and were included in the analysis. This PCA
permitted establishment of the typology of the composts by identifying the homogeneous
groups and the factors that describe them. The information about the composts was
summarized using a reduced number of principal components which are implicated in the
majority of the variability (Sena et al. 2002).
Results
Compost yield
Over the three composting periods, yield (final compost volume/initial volume of shredded
raw material) varied between 39.5 and 41.5%, averaging 40.5%. However, in the spring
and summer when it was hot and dry, compost piles needed to be turned more frequently
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(eight times vs four times during the winter). Additional water was also required to
maintain pile moisture content during the spring and summer composting periods.
Composting dynamics
During winter-trend composting (Table 1), the three piles reached the thermophilic stage
(T°[45°C) less than 24 h after their creation (Fig. 1a). This stage lasted 75, 60 and
82 days for the AA,AS and EG composts, respectively. Cold temperatures (minimum of
-5°C) in the composting area, in conjunction with aeration of the developing compost
during the fourth turning, contributed to cooling of the piles and a slowdown in biological
activity for approximately 28 days. With an improvement in meteorological conditions, the
stabilization stage resumed. As the piles entered the thermophilic stage, the temperature of
the EG pile remained lower than the two acacia piles for several days. However, the
temperature of the EG pile eventually surpassed that of the acacia piles, and remained that
way for the rest of the composting cycle.
The thermophilic stage during spring-trend composting was achieved within 30 h
after pile creation (Fig. 1b). This stage was maintained for 83, 77 and 110 days for AA,
AS and EG composts, respectively. During summer-trend composting, the themophilic
stage lasted 88, 78 and 130 days for AA,AS and EG composts, respectively (Fig. 1c).
Transition to the cooling stage was progressive, reflecting the maximum daily tem-
peratures registered at mid-day. Peaks of 60°C were reached and maintained over a
period of several weeks for the three compost types during the spring and summer.
Similar to the winter composting period, the temperature in the EG piles during spring
and summer composting remained inferior to that of the acacia piles for several days at
the beginning of the thermophilic stage. Afterwards, higher thermophilic temperatures
were maintained in the EG pile than in the AA and AS piles for the remainder of the
composting process.
Principal Component Analysis of the 17 chemical variables permitted retention of
four factors which explained 85.5% of the total variation in chemical variable dynamics
over the three composting periods. The first factor explained 30% of the total variation
with a strong contribution (0.70–0.95) of TOC, Ca, Mg, Mn, Al, and Fe. This axis
shows that TOC decreased continuously over composting process, while the cations Ca,
Mg, Mn, Al, and Fe increased. Furthermore, with the exception of Mn, these cations
were strongly correlated with the TOC, permitting the evolution of the composting
process to be assessed by measuring the decrease in TOC. The second factor explained
27% of the total variation with a strong contribution (0.61–0.91) of C/N, S, CEC
eff
,TN
and P. These variables increased continuously as composting progressed, while C/N
decreased. Except for sulphur, all of these variables were strongly correlated. This axis
reflects the stability of the composts throughout the entire composting process and
indicates that compost stability can be gauged by monitoring the C/N ratio. The third
factor explained 19% of the variation with a strong contribution (0.78–0.85) of pH, Na
and NH
4
. The fourth factor explained 9.4% of the variation with a strong contribution
(0.88) of EC
1/20
.
The repeated measures analysis of variance performed on these four factors, as well as
the temperature profile of the piles, revealed that organic matter and composting period had
a significant effect on the chemical composition of the compost and pile temperature for all
sampling dates. The interactions (CP 9D; OM 9D and CP 9OM 9D) were highly
significant (P\0.0001) for all dependant variables that were analyzed.
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1 102030405060708090100110120130
0
10
20
30
40
50
60
70
80
Temperature (°C)
SeptemberAugustJuly
JuneMay
(Tmax)
(Tmin)
Time (Days)
-
10
0
10
20
30
40
50
60
70
1 102030405060708090100110120130
Temperature (°C)
A. cyanophylla
A. cyclops
E. Gomphoc ephal a
November MarchFebruaryJanuaryDecember
(Tmin)
(Tmax)
thermophile
mesophile
0
10
20
30
40
50
60
70
80
Temperature (°C)
1 10 20 30 40 50 60 70 80 90 100 110 120 130
(Tmax)
(Tmin)
AugustJulyJune
MayApril
(a)
(b)
(c)
Fig. 1 Temperature profile
during, awinter composting
(November 1, 2004 to March15,
2005), bspring composting
(March 30 to August 6, 2005) and
csummer composting (May 15 to
September 20, 2005). Each point
represents the average of nine
temperature measurements. The
dotted lines represent the
minimum (T
min
) and maximum
(T
max
) daily temperature
recorded during the experiment.
Simple arrows indicate turnings
and the double arrows indicate
sampling dates
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Chemical properties of the composts
At the start of the composting process, the acidic pH of the organic matter increased to an
average of 7.0 for AA, 7.7 for AS and 8.2 for EG (Fig. 2a). These increases took place
during the first 2 months of composting, eventually reaching a stable plateau near the end
of the composting process. On the last sampling dates (day 128), a slight decrease in pH
was observed.
The shredded AA branches exhibited a mean initial electrical conductivity (EC
1/20
)of
2.98 dS m
-1
(mean for the three composting periods), which was high in comparison with
those of AS (1.60 dS m
-1
) and EG (1.31 dS m
-1
). The salinity of the three compost types
evolved similarly over time: a significant decrease of about 50% of the initial value
occurred during the first 8 days of composting, followed by a progressive increase until the
last sampling date (Fig. 2b). The average final EC
1/20
values on day 128, for the three
composting periods, were 1.50, 0.76 and 1.40 dS m
-1
for AA,AS and EG, respectively.
The effective cation exchange capacity (CEC
eff
) evolved similarly for all three compost
types, a marked decrease during the first 8 days, followed by a continual increase for the
duration of the composting process (Fig. 2c). Although the average initial CEC
eff
values
varied among the composts (86, 66 and 54 meq/100 g, for AA,AS and EG, respectively),
the average values at the end of the process were similar for the AA and EG composts
(110 meq/100 g). These values were high in comparaison to that of AS compost with an
average of 90 meq/100 g.
Total organic carbon (TOC) decreased continuously, but remained low during the entire
composting process (Fig. 2d). The average loss of TOC over the three composting periods
was evaluated to be 7.28% for AA, 7.18% for AS and 9.38% for EG composts.
The initial C/N ratio decreased continually during the thermophilic stage (Fig. 2e), the
largest decrease occurred during the first month of composting. Average final C/N ratios
were 14, 18 and 16 for AA,AS and EG composts respectively.
Macro and micro-nutrients
Component analysis of the chemical variables for all sampling dates over the three
composting periods showed that the three compost types were enriched in total nitrogen,
sodium, calcium, magnesium, phosphorus, aluminum, iron, manganese, potassium, sulphur
and nitrate, but were impoverished in carbon and ammonium. For example, TN increased
to about 1.7, 2.2 and 3.3 times its initial concentration in AA, AS and EG compost
respectively. A marked decrease in the ammonium concentration was noted during the first
days of the thermophilic stage. Nitrate concentration varied very little during the active
composting stages. However, a slight increase in nitrate concentration was noted at the end
of the process. The copper concentration remained unchanged at levels below 0.02 g/kg
throughout all of the composting cycles while the zinc level changed little.
Forest seedling production and physicochemical properties of the composts
The addition of 20% peat (v/v) to the AA and AS composts resulted in an appreciable
reduction in pH: from 7.0 to 6.1 for AA and from 7.7 to 7.1 for AS. Their respective EC
sat
fluctuated little at the start of culture, but decreased with irrigation to a value of 0.95 dS
m
-1
, which is not statistically different from the optimal value of the peat:vermiculite
substrate. Physical analyses showed a high initial porosity and saturated hydraulic con-
ductivity (K
sat
) values, particularly for AS. Furthermore, a drastic decrease in the air filled
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porosity of both acacia composts occurred after 26 weeks of culture, reaching an average
value of 0.15 cm
3
cm
-3
(Tables 2and 3).
To evaluate the quality and maturity of the composts, seeds of two leguminous species
(Lens culinaris and Cicer arietinum) were sown into containers filled with AA,AS and EG
composts and PV substrate. Germination rates (98 and 87% for L. culinaris and C. ari-
etinum respectively) were very similar among the three types of compost and the
peat:vermiculite control substrate (results not shown).
After 26 weeks of culture, high quality Ceratonia siliqua seedlings were produced in
both the AA and AS composts. The morphological variables (diameter, shoot and root dry
4
4,5
5
5,5
6
6,5
7
7,5
8
8,5
0
0,5
1
1,5
2
2,5
3
3,5
20
30
40
50
60
70
80
90
100
110
120
0
10
20
30
40
50
60
70
450
455
460
465
470
475
480
485
490
4
4,5
5
5,5
6
6,5
7
7,5
8
8,5
0
0,5
1
1,5
2
2,5
3
3,5
40
50
60
70
80
90
100
110
120
0
10
20
30
40
50
60
70
430
440
450
460
470
480
490
500
4
4,5
5
5,5
6
6,5
7
7,5
8
8,5
0 163248648096112128
AA
AS
EG
a1
0 163248648096112128
a2
0 163248648096112128
a3
0
0,5
1
1,5
2
2,5
3
3,5
0 163248648096112128
b1
0 163248648096112128
b2
0 163248648096112128
b3
50
60
70
80
90
100
110
120
0 163248648096112128
c1
0 163248648096112128
c2
0163248648096112128
b3
0
10
20
30
40
50
60
0 163248648096112128
e1
0 163248648096112128
e2
0 163248648096112128
e3
380
400
420
440
460
480
500
0 163248648096112128
d1
0 163248648096112128
d2
0 163248648096112128
d3
pH
EC1/20 (dS m-1)
CECe(meg/100g)TOC (g/kg)C/N
Da
y
sDa
y
sDa
y
s
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
AA
AS
EG
Fig. 2 Evolution of apH, belectrical conductivity (EC), ceffective exchange capacity (CECeff), dtotal
carbon (TOC) and ecarbon/nitrogen ratio, during (1) winter composting (2) spring composting, and (3)
summer composting. N =4; mean ±SD
276 New Forests (2012) 43:267–286
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mass, shoot and root lengths) of the seedlings produced in AA compost were significantly
superior to those grown on the AS compost (Table 3). However, the shoot and root dry
mass and shoot and root lengths of seedlings grown in AA and AS were significantly
inferior to those produced in the PV substrate. The reduction in growth was estimated to be
39, 28, 29 and 51% in AA and 72, 54, 50 and 56% in AS for shoot mass, root mass, shoot
length and root length, respectively.
Using multivariate analysis to determine the typology of the composts
According to the principal components analysis (PCA) the first three factors explained 90%
of the total variation in the chemical composition of the end product. The first factor alone
explained 42% of the variation with a strong contribution (0.63–0.88) of C/N, EC
1/20
, CEC,
NO
3
, TN, P, K, Mg, Al, Fe, P and Zn. The second factor explained 28% of the variation
with a strong contribution (0.74–0.95) of pH, NH
4
, S, Mn and Ca. The third factor was
characterized by a strong contribution (0.63–0.81) of TOC, Na and Al and explained
19% of the total variation.
Table 2 Comparison of substrate physical properties (means ±SD) at the beginning and end of 26 week
growing season of containerized Ceratonia siliqua seedlings (air-filled porosity, h
a
:n=5; easily available
water, EAW: n =5 and saturated hydraulic conductivity, K
sat
:n=3)
h
a
(cm cm
-1
) EAW (cm
3
cm
-3
)K
sat
(cm s
-1
)
Beginning End Beginning End Beginning End
PV 0.31 ±0.03b 0.25 ±0.01a 0.30 ±0.03a 0.27 ±0.04a 0.11 ±0.02c 0.17 ±0.06ab
AA 0.32 ±0.05b 0.15 ±0.01b 0.31 ±0.01a 0.32 ±0.05a 0.26 ±0.01b 0.12 ±0.03b
AS 0.39 ±0.06a 0.15 ±0.03b 0.25 ±0.04b 0.32 ±0.05a 0.78 ±0.04a 0.23 ±0.02a
In each column, means followed by the same letter are not significantly different at PB0.05 according to
LSD test
AA, Acacia cyanophylla compost; AS, Acacia cyclops compost; PV, peat-vermiculite
Table 3 Comparison of means of morphological variables (±SE) of containerized Ceratonia siliqua
seedlings grown in the two composts and the control substrate, peat-vermiculite at the end of the 26 week
growing season
Root collar Shoot length SHOOT dry Roots dry Roots length
Diameter (mm) (cm) Mass (g) Mass (g) (cm)
PV 4.24 ±0.25a* 19.14 ±1.18a 4.88 ±0.45a 1.34 ±0.13a 95.23 ±11.3a
AA 3.87 ±0.23b* 13.51 ±1.14b 2.97 ±0.38b 0.97 ±0.13b 47.04 ±11.4b
AS 3.28 ±0.28c* 09.48 ±1.17c 1.37 ±0.48c 0.61 ±0.15c 42.04 ±11.3b
In each column, means followed by the same letter are not significantly different at PB0.05 according to a
LSD test
Root collar diameter and shoot length are presented with the average value for the 3 blocks 95 seedlings =
15 seedlings ±SE. Shoot and root dry mass and length are presented with the average value of
3 blocks 93 seedlings =9 seedlings ±SE. The evaluation was made after 26 weeks of growth
AA, Acacia cyanophylla compost; AS, Acacia cyclops compost; PV, peat-vermiculite
* Significant at PB0.1
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Figure 3a presents the treatment projections of the first principal component plot,
defined by Factor1 and Factor2, which explain 70% of the total variation. This projection
reveals the presence of three distinct compost groupings (AA,AS and EG), each composed
of three composting periods. On the first axis of this plane salts (cations and anions), EC
1/20
and CEC
eff
are plotted against C/N. This axis illustrates that the compost richest in salts
also has the highest EC
1/20
and CEC
eff
and the lowest C/N. Thus, Factor1 separated the
composts into two groups. The EG and AA composts rich in salts and the second, the
AS composts with lower salt contents. The correlation matrix illustrates the strong positive
correlation between EC
1/20
and Na, K, P and Mg salts. However, the strong negative
Factor2: (28.4 % of total variation)
Factor1: (41.8 % of total variation)
High EC
and pH
High EC and
lowpH
Low EC
neutral pH
Factor3: (19.3 % of total variation)
Factor2: (28.4 % of total variation)
(a)
(b)
Fig. 3 Principal component
plots related to the final chemical
characteristics of composts:
afirst plot (F1 vs F2); bsecond
plot (F2 vs F3). EG =
E. gomphocephala,AA=
A. cyanophylla and AS =
A. cyclops.1,2and
3=respectively winter, spring
and summer composting.
(EG3) =E. gomphocephala
compost of the summer
composting sampled at 128 days.
The stars (*) in the plot indicate
the position of the treatments
278 New Forests (2012) 43:267–286
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correlation between Factor1 and C/N ratio led to the conclusion that the AS1, AS2 and
AS3 composts, which all had low salt contents, possessed elevated C/N ratios. This first
factor therefore summarizes the information about the degree of compost stability and
salinity and consequently, fertility.
For Factor2, the correlation matrix showed that pH exhibited a strong positive corre-
lation with Ca (0.80), Mg (0.62), Na (0.68) and Mn (0.84). On this axis, an elevated pH
translates to high concentrations of Ca, Mg and Na, while a low pH reflects high con-
centrations of NH
4
, S and P. Factor2, defined as the basicity axis, distinguished the
composts with high pH values (three composting periods of EG) from those with low (three
composting periods of AA), or intermediate (AS composts) pH values.
The second principal component plot (Fig. 3b), defined by the Factor2 and Factor3,
which together explained 47.8% of the total variation, clearly separated the winter com-
posts from those of the spring and summer. In addition, the composts from the spring
composting were intermediate, between summer and winter composts. Meanwhile, the AS
spring compost (AS2) was projected close to the origin (centre of gravity of the principal
component plot), indicating its impoverishment in mineral nutrients, relative to the other
composts. The Factor3 revealed the richness of AS summer compost (AS3) in sodium (Na).
This richness is in line with the pH of the compost and the fact that its EC
1/20
is higher than
those of AS2 and AS1.
Discussion
Shredding and composting of leafy branches from forest tree species (AA, AS and EG),
produced composts of satisfactory quality which contributed to high seed germination
rates, were free of toxins and supported the growth of quality seedlings. The volume loss
during the thermophilic phase was slightly higher during the hot and dry conditions of
summer than in the cooler and humid composting periods of winter and early spring. This
result was predictable given the importance of water loss during hot weather and high
frequency of turning (Larney et al. 2000, Larney and Hao 2007). The relatively small
reduction in TOC during the composting process (Fig. 2d) was associated with the com-
position and abundance in lingo-cellulose components whose recalcitrant fraction, con-
sisting of condensed tannins and lignins, retard the decomposition process (Said-Pullicino
and Gigliotti 2007; D’Imporzano and Adani 2007). Condensed tannins (soluble and
insoluble) are known to inhibit microbial activity and fungal growth (Schultz et al. 1992).
Despite the short duration of the stabilization phase, the highest C/N values remained
between 15/1 and 20/1, values considered to be favorable in composts that are ready for
use (Rosen et al. 1993). Figure 2e1, e2 and e3 show that C/N ratio curves are approaching
their asymptotes, suggesting that the compost curing processes are nearing completion. In
the present study, the stability of the compost yield and chemical composition over the
three composting periods assured compost quality and enabled us to envision the possi-
bility of a reliable supply of substrate for forest nurseries. By securing the profitability of
the biomass removed for composting during early silvicultural operations such as thinning
and pruning, more intensive sylvicultural programs can be instituted.
The composting process: evolution of temperature and chemical variables
In our trials, the thermophilic phases lasted 90 days or less, with the exception of the EG
pile during spring and summer composting, which lasted 110 and 130 days, respectively.
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This is comparable to other studies. Sale
`tes et al. (2004) reported a thermophilic stage of
63 days for oil palm (Elaeis guineensis Jacq.) compost. The thermophilic phase lasted
approximately 106 days in the composting of a mixture of nursery waste (rejected seed-
lings, growing media, weeds, grass clippings and dead leaves) and horse manure (Veija-
lainen et al. 2007a), 112 days for a mixture of paper sludge and poultry manure (Charest
and Beauchamp 2002) and 183 days during the composting of olive oil mill sludge
(Manios et al. 2006).
The longer thermophilic phases for the EG piles, compared to those of the acacia
species, may be caused by the higher initial ratio of foliar to woody biomass of the EG raw
material (59%) relative to those of either AA (56%) or AS (47%). Shredded green biomass
is a readily available source of energy whose structure promotes the conservation of heat
within the pile for a longer period (Manios 2004; Manios et al. 2003). However, it is
important to note that the low initial nitrogen concentration of the EG leaves (0.8%),
compared to that of the acacia leaves (AA: 1.6%, AS: 1.1%) probably contributed to
prolonging the thermophilic phase (Wedderburn and Carter 1999; Aggangan et al. 1999).
The addition of nitrogen at the beginning of the process was not effective due to the
important lost of ammonium and nitrate with only a slight increase in total nitrogen in the
first 8 days. This was also reported by Sale
`tes et al. (2004). The low temperature profile of
the EG piles, compared to those of the two acacia species, at the beginning of the ther-
mophilic phase may have been due to the relatively strong acidity of the EG tissue (4.9)
versus those of AA (5.3) and AS (5.5) (Sundberg et al. 2004). This level of acidity is
unfavourable to microbial activity (Rosso et al. 1995), especially in the case of EG. The
abundance of monoterpenes in eucalyptus leaves also contributes to the inhibition of
autotrophic aerobic bacterial activity (Ward et al. 1997). Decomposition of eucalyptus
leaves requires more time than for species such as poplar due to the toxicity of the
allelochemical components to the microorganisms that decompose the litter (Chander et al.
1995). The anatomy of eucalyptus leaves may have also contributed to this result. Their
thick, waxy cuticles constitute a physical barrier to breakdown by microorganisms
(Canhoto and Grac¸a 1999). Osawa and Namiki (1981) showed that the leaf wax of several
eucalyptus species contains powerful antioxydants capable of inhibiting or slowing
microbial activity. It is therefore important to shred the vegetative material as small as
possible. This operation will initiate the rapid breakdown of organic matter by putting the
parenchyma, collenchyma and mesophyll tissues, which are rich in soluble carbons and
nutrients, in direct contact with the decomposing organisms. It is also necessary to
acknowledge the importance of low temperatures in the autumn and winter (Fig. 1a) which
permit a reduction in the length of the thermophilic phase during winter composting as well
as a quicker initiation of the maturation phase.
The four first axes of the first PCA performed on all data for the three composting
periods, in the basis of the Eigen values (Tables 2and 3) and correlation matrix (not
presented), illustrates that the composting process and its dynamics can be reasonably
monitored by three of the 19 variables analyzed, C/N, pH and EC
1/20
. These variables are
inexpensive and simple to analyze accurately and in real time in the composting area. By
combining a simple composting process and a simplified and efficient method of moni-
toring, this result would be important for developing countries with limited resources.
Unlike the pattern that is normally observed in compost production (Mustin 1987), little
or no decrease in pH was observed in the first few days following the launch of the
composting process. This was most likely due to the high initial NH
4
/NO
3
ratio. The low
accumulation of organic acids, given the sluggish deterioration during the transitional
phase, may have contributed to this result. Consequently, the pH of the three composts
280 New Forests (2012) 43:267–286
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increased continuously over the first 2 months of composting. Although the pH values
obtained by the volume method were slightly overestimated with respect to those measured
by the saturated extract method (Sullivan and Miller 2001), the pH of the AA and AS
composts were close to neutrality, the range deemed satisfactory for nursery growing
media. However, given the elevated pH of the EG compost (pH
EG
=8.2), this compost
should either be mixed with other, more acidic, substrates before being suitable for forest
nursery use (Lamhamedi et al. 2009) or be used for the production of broadleaved species,
which are more tolerant basic conditions.
Both AA and AS are nitrogen-fixing species. The high initial EC
1/20
values of their
composts reflected the high mineral salt content (high fertility) of the raw organic materials
(Landis and Khadduri 2008). During the first 8 days of composting, the EC
1/20
of the three
types of compost decreased sharply, probably due to the leaching of mineral salts (Dewes
1992). The continual increase in EC
1/20
after this period was due to the liberation of salts
associated with the deterioration of organic matter. The final EC
1/20
values on day 128
were comparable to EC
1/5
values of composted yard waste analyzed in a study by Corti
et al. (1998). These values are in the acceptable range for growing media used for con-
tainerized horticultural and forest seedling production (Bunt 1988). The salinity of the
three types of composts (AA, AS and EG) is therefore not a limiting factor for the pro-
duction of the principal Mediterranean ornamental and forest species (Lamhamedi et al.
2006).
Given that the pH values obtained for the three compost types at the end of composting
cycle (day 128) were neutral to basic, the associated CEC
eff
values are comparable to CEC.
The CEC values for AA and EG were within the range for peat moss (100–180 meq/100 g)
(Bunt 1988, Landis 1990). Whereas, the average value for AS compost was lower
(90.11 meq/100 g). These values are interesting given that Harada and Inoko (1980)
proposed a CEC [60 meq/100 g as an index of maturity for city refuse compost. Compost
CEC increases with composting time, therefore providing a greater buffering capacity
against changes in pH (Sullivan and Miller 2001). In the present study, CEC and C/N ratio
were the main variables used to assess compost stability (Muhammad Khalid et al. 2010).
Similar to evolution of the C/N ratio, the CEC curves (Fig. 2c) are also approaching
asymptotic conditions, suggesting that the compost curing processes are nearing comple-
tion (Aparna et al. 2008).
In general, all three composts types possessed a good level of fertility and were char-
acterized by elevated organic matter and total nitrogen contents as well as by high levels of
micro- and macro-elements. The marked drop in NH
4
([50%) during the first eight days of
composting was probably due to leaching and, to a lesser extent, immobilization in its
organic form in the tissues of rapidly reproducing microorganisms (Bernal et al. 1996, Pare
´
et al. 1998). Losses by NH
3
volatilization were very low due to the acidity of the organic
matter at this stage (Sanchez-Monedero et al. 2001). However, nitrate levels increased
slightly during the thermophilic phase due to the inhibition of nitrifying bacteria by high
temperatures (Ko et al. 2008).
Forest seedling production and composts’ physicochemical properties
The suboptimal pH values obtained when the composts were augmented with 20% peat
were still slightly higher than the values recommended for the uptake of the most readily
available microelements (Brady 1974; Lamhamedi et al. 2009). It is unlikely that the high
initial air filled porosity of the A. cyclops compost affected plant performance. Compacting
the acacia composts after 26 weeks of culture resulted in a drastic decrease in air filled
New Forests (2012) 43:267–286 281
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porosity, bringing it below the optimal value of 0.20 cm
3
cm
-3
(Agnew and Leonard 2003;
Heiskanen 1993). This may have negatively affected root growth and dry mass (Table 3).
However, the final air filled porosity of both acacia composts (15%), was between 11.3 and
20%, a range considered by Bugbee and Frink (1986) to be optimal for the growth of potted
plants. On the other hand, the initial K
sat
values, which were initially very high, particularly
for AS and to lesser extent for AA, are far above the commonly attained values of
0.08–0.12 cm s
-1
. This may have resulted in excessive drainage and some nutrient
leaching. Under our experimental conditions, the seedlings produced in the AA and AS
composts were as vigorous as those grown in the PV substrate. The significant inferiority of
the morphological variables of the seedlings grown in the two composts, relative to those
grown in PV, may be due to their initial high saturated hydraulic conductivities and the
significant reduction in their air-filled porosities (Table 2). It is therefore important to be
familiar with a substrate’s physical properties so that irrigation schedules can be optimized
(Caron and Nkongolo 2004). This is particularly important in the case of composted
substrates, which require a more intensive irrigation schedule at the beginning of the
production cycle (Lemaire et al. 2003).
Compost typology
The projection of the three distinct groups of composts (AA, AS and EG) on the first
principal component plot of the PCA revealed the relationship between the quality of the
end product and the initial chemical properties of its raw materials. This relationship is
very important because it signifies that compost fertility at the end of the composting
process can be predicted from the chemical characteristics of the vegetative matter from
which was formed, which is something that can easily be controlled. The abundance of
salts in the EG and AA composts, as revealed by Factor1 (Fig. 3a), was due to the relatively
high ratio of leafy biomass to woody biomass of their raw materials (EG: 59% and AA:
56%, vs. 47% for AS). Leafy biomass constitutes an important source of nitrogen and
mineral nutrients. Because mineralization in the AA and EG composts was more advanced,
these composts were richer in mineral elements than the AS composts which had relatively
higher C/N ratios. The elevated pH of the EG composts revealed by Factor2 is due to the
chemical composition of their raw materials. The biomass of this forest species, which
used exclusively for reforestation of calcareous soils in North Africa, is very rich in Mg, Ca
and Na (Lapeyrie and Chilvers 1985). Whereas, the homogeneous group comprised of the
AA composts reflects the high tissue nitrogen content of Acacia cyanophylla, a nitrogen-
fixing species (Wedderburn and Carter 1999;Pe
´rez-Corona et al. 2006).
The distinct separation between the composts from the winter composting (AA1,AS1,
EG1) and those from the spring and summer composting, as defined by Factor3, followed
the rate of TOC decrease. The rate of decrease in TOC is a good indication of how well
the composting process is progressing. The projection of the treatments on Factor3
(Fig. 3b) followed the gradient of seasonal temperature increase from the cool temper-
atures of autumn/winter (winter composting with lowest carbon ratio, bottom of the plan),
through the milder temperatures of spring (spring composting, middle of the plan) to the
heat of summer (summer composting, top of the plan). The cool winter temperatures
probably contributed to shortening of the thermophilic phase in favor of more rapid
transition to the maturation phase. However, the high EC
1/20
of the AS3 compost, as
revealed by Factor3, is probably due to its Na-rich biomass, which was harvested from
trees directly in the path of the ocean spray on the Atlantic coast.
282 New Forests (2012) 43:267–286
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Conclusion
This research shows that composting of shredded leafy branches of Acacia cyanophylla,
A. cyclops and Eucalyptus gomphocephala on an operational scale is possible throughout
the year in arid zones. The composts produced were of reproducible quality and suitable
for use as growing media for the nursery production of forest seedlings. In comparison to
substrates from other sources, our approach for producing standardized nursery substrates
constitutes a simplified, integrated and long term viable alternative. Compost dynamics,
stability and quality can be monitored on an operational scale using variables that are
easily measured (C/N, pH and EC), which is very important in countries with limited
resources. Germination of seeds sown in the three composts was uniform and rapid.
Although the two acacia composts assured the production of high quality forest seedlings,
the dry mass, height and root length of the plants produced in these composts were inferior
to seedlings grown in a peat-vermiculite substrate. To improve seedling quality, the
physical and hydrodynamic properties of the composts must be evaluated over a complete
seedling production cycle to determine their degree of stability and to optimize irrigation
and fertilization regimes.
Acknowledgments To the team of employees and research assistants at the Centre re
´gional de la
recherche forestie
`re de Marrakech, Dr. Mohamed Abourouh of la Division de Recherche et d’Expe
´rimen-
tations Forestie
`res a
`Rabat as well as Mario Renaud, Linda Veilleux and Denis Langlois of la Direction de la
recherche forestie
`re de Que
´bec. We are also grateful to Dr. Papaniokhor Diouf for his assistance with the
chemical tests and to Arthur Goussanou and Denis Talbot for their contribution to the statistical analyses.
Financial support for this project was provided to Dr. Mohammed S. Lamhamedi by the ministe
`re des
Ressources naturelles et de la Faune du Que
´bec (project: 112310094) and to Dr. Hank Margolis by the
Fonds de recherche sur la nature et les technologies (project 2008-FT-124372).
References
Abad M, Noguera P, Bure
´s S (2001) National inventory of organic wastes for use as growing media for
ornamental potted plant production: case study in Spain. Bioresour Technol 77:197–200
Aggangan RT, O’Connell AM, McGrath JF, Dell B (1999) The effect of Eucalyptus globulus Labill. leaf
litter on C and N mineralization in soils from pasture and native forest. Soil Biol Biochem
31:1481–1487
Agnew JM, Leonard JJ (2003) The physical properties of compost. Compos Sci Util 1(3):238–264
Allaire SE, Caron J, Menard C, Dorais M (2005) Potential replacements for rockwool as a growing substrate
for greenhouse tomato. Can J Soil Sci 85:67–74
Ammari Y, Lamhamedi MS, Akrimi N, Zine El Abidine A (2003) Compostage de la biomasse forestie
`re et
son utilisation comme substrat de croissance pour la production de plants en pe
´pinie
`re forestie
`res
modernes. Revue de l’I.N.A.T., Tunisie 18:99–119
Aparna C, Saritha P, Himabindu V, Anjaneylu Y (2008) Techniques for the evaluation of maturity for
composts of industrially contaminated lake sediments. Wast Manag 28:1773–1784
Bernal MP, Navarro AF, Roig A (1996) Carbon and nitrogen transformation during composting of sweet
sorghum bagasse. Biol Fertile Soils 22:141–148
Bernier PY, Gonzalez A (1995) Effects of the physical properties of Sphagnum peat on the nursery growth
of containerized Picea mariana and Picea glauca seedlings. Scand J Forest Res 10:176–183
Brady N (1974) The nature and properties of soils, 8th edn. Macillan Publishing Co., Inc. New York, NY
Brewer LJ, Sullivan DM (2003) Maturity and stability evaluation of composted yard trimmings. Compos Sci
Util 11(2):96–112
Bugbee G, Frink CR (1986) Aeration of potting media and plant growth. Soil Sci 141:438–441
Bunt AC (1988) Media and mixes for container-grown plants. Second edition of modern potting composts: a
manual on the preparation and use of growing media for pot plants. Unwin Hyman, London
Canhoto C, Grac¸a MAS (1999) Leaf barriers to fungal colonization and shredders (Tipula lateralis) con-
sumption of decomposing Eucalyptus globulus. Microb Ecol 37:163–172
New Forests (2012) 43:267–286 283
123
Author's personal copy
Caron J, Nkongolo NV (2004) Assessing gas diffusion coefficients in growing media from in situ water flow
and storage measurements. Vadose Zone J 3:300–311
Chander K, Goyal S, Kapoor KK (1995) Microbial biomass dynamics during the decomposition of leaf litter
of poplar and eucalyptus in a sandy loam. Biol Fertil Soils 19:357–362
Charest MH, Beauchamp CJ (2002) Composting of de-inking paper sludge with poultry manure at three
nitrogen levels using mechanical turning: behavior of physico-chemical parameters. Bioresour Technol
81:7–17
Corti C, Crippa L, Genevini PL, Cetemero M (1998) Compost use in plant nurseries: Hydrological and
physiochemical characteristics. Compos Sci Util 6(1):35–45
Davis AS, Jacobs DF, Wightman KE, Birge ZKD (2006) Organic matter added to bareroot nursery beds
influences soil properties and morphology of Fraxinus pennsylvanica and Quercus rubra seedlings.
New For 31:293–303
De
´portes I, Benoit-Guyod JL, Zmirou D (1995) Hazard to man and the environment posed by the use of
urban waste compost: a review. Sci Total Environ 172:197–222
Desalegn G, Binner E, Lechner P (2008) Humification and degradability evaluation during composting of
horse manure and biowaste. Compos Sci Util 16(2):90–98
Dewes T (1992) Loss of nitrogenous compounds during composting of animal wastes. Bioresour Technol
42:103–111
D’Imporzano G, Adani F (2007) The contribution of water soluble and water insoluble organic fractions to
oxygen uptake rate during high rate composting. Biodegradation 18:103–113
Dimambro ME, Lillywhite RD, Rahn CR (2007) The physical, chemical and microbial characteristics of
biodegradable municipal waste derived composts. Compos Sci Util 15(4):243–252
Espiau P, Peyronel A (1976) L’acidite
´d’e
´change dans les sols. Methode de de
´termination de l’aluminium
e
´changeable et des protons e
´changeables. Science du Sol 3:161–175
Fenner N, Ostle NJ, McNamara N, Sparks T, Harmens H, Reynolds B, Freeman C (2007) Elevated CO
2
effects on peatlands plant community carbon dynamics and DOC production. Ecosystems 10:635–647
Fitzpatrick GE (2001) Compost utilization in ornamental and nursery crop production systems. In: Stoffella
PJ, Kahn BA (eds) Compost utilization in horticultural cropping systems. Lewis Publishers. CRC Press
LLC, pp, pp 135–149
Harada Y, Inoko A (1980) Relationship between cation exchange capacity and degree of maturity of city
refuse. Soil Sci Plant Nutr 26:353–362
Heiskanen J (1993) Favourable water and aeration conditions for growth media used in containerized tree
seedling production: A review. Scand J Forest Res 8:337–358
Hendershot WH, Lalande H, Duquette M (2008) Ion exchange and exchangeable cations. 2nd edn. In: Carter
MR, Gregorich EG (eds) Soil sampling and methods of analysis. CRC Press Boca Raton, FL,
pp 197–206
Ko HJ, Kim KY, Kim HT, Kim CN, Umeda M (2008) Evaluation of maturity parameters and heavy metal
contents in composts made from animal mature. Waste Manage 28:813–820
Lamhamedi MS, Ammari Y, Fecteau B, Fortin JA, Margolis H (2000) Proble
´matique des pe
´pinie
`res fo-
restie
`res en Afrique du Nord et strate
´gie de de
´veloppement: synthe
`se. Cah Agric 9:369–380
Lamhamedi MS, Fecteau B, Godin L, Gingras C (2006) Guide pratique de production en hors sol de plants
forestiers, pastoraux et ornementaux en Tunisie. Projet ACDI E 4936-K061229. Pampev Internatio-
nale, Direction Ge
´ne
´rale des Fore
ˆts, Tunisie (eds). ISBN:9973-914-08-2
Lamhamedi MS, Abourouh M, Fortin JA (2009) Technological transfer: the use of ectomycorrhizal fungi in
conventional and modern forest tree nurseries in northern Africa. In: Khassa D, Piche
´Y, Coughlan AP
(eds) Advances in mycorrhizal science and technology. NRC-CNRC Press, Ottawa, pp 139–152
Landis TD (1990) Growing media. In: Containers and growing media, Vol. 2, The Container Tree Nursery
Manual. Agric. Handbook 674. USDA(FS) Washington
Landis TD, Khadduri N (2008) Composting application in forest and conservation nurseries. USDA(FS).
Forest Nursery Notes 28(2):9–18
Lapeyrie FF, Chilvers GA (1985) An endomycorrhiza-ectomycorrhiza succession associated with enhanced
growth of Eucalyptus dumosa seedlings planted in a calcareous soil. New Phytol 100:93–104
Larney FJ, Hao X (2007) A review of composting as a management alternative for beef cattle manure in
southern Alberta, Canada. Bioresour Technol 98:3221–3227
Larney FJ, Olson AF, Carcamo AA, Chi Chang (2000) Physical changes during active and passive com-
posting of beef feedlot manure in winter and summer. Bioresour Technol 75:139–148
Lazcano C, Sampedro L, Zas R, Dominguez J (2010) Vermicompost enhances germination of the maritime
pine (Pinus pinaster Ait.). New For 39:387–400
Lemaire F, Dartigues A, Rivie
`re LM, Charpentier S, Morel P (2003) Cultures en pots et conteneurs:
Principes agronomiques et applications. INRA, France
284 New Forests (2012) 43:267–286
123
Author's personal copy
Man
˜as P, Castro E, De las Heras J (2009) Quality of maritime pine (Pinus pinaster Ait.) seedlings using
waste materials as nursery growing media. New For 37:295–311
Manios T (2004) The composting potential of different organic solid wastes: experience from the island
Crete. Environ Int 29:1079–1089
Manios T, Maniadakis K, Frantzeskaki N, Stentiford EI, Manios V, Kritsotakis I, Dialynas G (2003) Sewage
sludge composting on the Island of Crete. BioCycle 44:53–55
Manios T, Maniadakis K, Kalogeraki M, Mari E, Stratakis E, Terzakis S, Boytzakis P, Naziridis Y,
Zampetakis L (2006) Efforts to explain and control the prolonged thermophilic period in two-phase
olive oil mill sludge composting. Biodegradation 17:285–292
Miller JH, Jones N (1995) Organic and compost-based growing media for tree seedling nurseries. World
Bank Technical Paper Number 264. Forestry series
Muhammad Khalid I, Tahira Sh, Khurshed A (2010) Effect of different techniques of composting on
stability and maturity of municipal solid waste compost. Environ Technol 31(2):205–214
Mustin M (1987) Le compost: Gestion de la matie
`re organique. Tec & Doc, Paris
Noble R, Coventry E (2005) Suppression of soil-borne plant diseases with composts: A review. Biocontrol
Sci Technol 15:3–20
Osawa T, Namiki M (1981) A novel type of antioxidant isolated from leaf wax of Eucalyptus leaves. J Agric
Biol Chem 45(3):735–739
Pare
´T, Dinel H, Schnitzer M, Dumontet S (1998) Transformation of carbon and nitrogen during composting
of animal manure and shredded paper. Biol Fertil Soils 26:173–178
Pe
´rez-Corona ME, Pe
´rez-Hernandez MC, De Castro FB (2006) Decomposition of alder, ash, and poplar
litter in a Mediterranean riverine area. Comm Soil Sci Plan 37:1111–1125
Ribeiro HM, Romero AM, Pereira H, Borges P, Cabral F, Vasconcelos E (2007) Evaluation of a compost
obtained from forestry wastes and solid phase of pig slurry as a substrate for seedlings production.
Bioresour Technol 98:3294–3297
Roe NE (2001) Compost effects on crop growth and yield in commercial vegetable cropping systems. In:
Stoffella PJ, Kahn BA (eds) Compost utilization in horticultural cropping systems. Lewis Publishers,
CRC Press, LLC, pp 123–133
Rosen CJ, Halbach TR, Swanson TR (1993) Horticultural uses of municipal solid waste components.
HortTechnology 3:167–173
Rosso L, Lobry JR, Bajard S, Flandrois JP (1995) Convenient model to describe the combined effects of
temperature and pH on microbial growth. Appl Environ Microbiol. Am Soc for Microbiol
61(1):610–616
Said-Pullicino D, Gigliotti G (2007) Oxidative biodegradation of dissolved organic matter during com-
posting. Chemosphere 68:1030–1040
Sale
`tes S, Siregar FA, Caliman JP, Liwang T (2004) Ligno-cellulose composting: Case study on monitoring
oil palm residuals. Compos Sci Util 12(4):372–382
Sanchez-Monedero MA, Roig A, Paredes C, Bernal MP (2001) Nitrogen transformation during organic
waste composting by the Rutgers system and its effects on pH, EC and maturity of the composting
mixtures. Bioresour Technol 78:301–308
Schultz JC, Hunter MD, Appel HM (1992) Antimicrobial activity of polyphenols mediates plant-herbivore
interactions. In: Hemingway RW, Laks PE (eds) Plant polyphenols: synthesis. properties, significance.
Plenum Press, New York NY, pp 621–637
Sena MM, Frighetto RTS, Valarini PJ, Tokeshi H, Poppi RJ (2002) Discrimination of management effects
on soil parameters by using principal component analysis: a multivariate analysis case study. Soil Till
Res 67:171–181
Sullivan DM, Miller RO (2001) Compost quality attributes, measurements, and variability. In: Stoffella PJ,
Kahn BA (eds) Compost utilization in horticultural cropping systems. Lewis Publishers. CRC Press
LLC, pp, pp 95–120
Sundberg C, Smars S, Jo
¨nsson H (2004) Low pH as an inhibiting factor in the transition from mesophilic to
thermophilic phase in composting. Bioresour Technol 95:145–150
Veijalainen AM, Juntunen ML, Lilja A, Heinonen-Tanski H (2007a) Forest Nursery waste composting in
windrows with or without horse manure or urea–the composting process and nutrient leachting. Silva
Fenn 41:13–27
Veijalainen AM, Juntunen ML, Heiskanen J, Lilja A (2007b) Growing Picea abies container seedlings in
peat and composted forest-nursery waste mixtures for forest regeneration. Scand J Forest Res
22:390–397
Walinga I, Van Der Lee JJ, Houba VJG, Van Vark W, Novozamsky I (1995) Plant analysis manual. Kluwer
Academic Publishers, Dordrecht, Netherlands
New Forests (2012) 43:267–286 285
123
Author's personal copy
Ward BB, Courteney KJ, Langenheim JH (1997) Inhibition of Nitrosomonas europaea by monoterpenes
from coastal redwood (Sequoia sempervirens) in whole-cell studies. J Chem Ecol 23(11):2583–2598
Warner BG, Asada T (2006) Biological diversity of peatlands in Canada: Overview article. Aquat Sci
68:240–253
Wedderburn ME, Carter J (1999) Litter decomposition by four functional tree types for use in silvopastoral
systems. Soil Biol Biochem 31:455–461
286 New Forests (2012) 43:267–286
123
Author's personal copy
