research article nursery growing media: agronomic and...

Hindawi Publishing CorporationApplied and Environmental Soil ScienceVolume 2013 Article ID 565139 10 pageshttpdxdoiorg1011552013565139

Research ArticleNursery Growing Media Agronomic and Environmental QualityAssessment of Sewage Sludge-Based Compost

Barbara De Lucia1 Giuseppe Cristiano1 Lorenzo Vecchietti1

Elvira Rea2 and Giovanni Russo1

1 Department of Agro-Environmental and Territorial Sciences (DISAAT) University of Bari Aldo Moro Via G Amendola 165A70125 Bari Italy

2 CRA Agricultural Research Council Research Centre for the Soil-Plant System Via Della Navicella 2-4 00184 Rome Italy

Correspondence should be addressed to Barbara De Lucia barbaradeluciaunibait

Received 5 July 2013 Revised 26 August 2013 Accepted 13 September 2013

Academic Editor Giancarlo Renella

Copyright copy 2013 Barbara De Lucia et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

There is a stringent need to reduce the environmental impact of peat in the plant nursery production chain In this experimentthe use of different rates of sewage sludge compost in the preparation of growing media for potted Bougainvillea was evaluatedto assess its efficiency for the replacement of peat and to quantify the environmental impact of such alternative substrates bythe life cycle assessment (LCA) method Five substrates containing increasing proportion of composted sewage sludge to peat(0 25 40 55 and 70 vv) were used and their physicochemical properties were measured Bougainvillea plant growthbiomass production andmacro- andmicronutrient absorption were also determinedThemain results were that compost additionimproved the plant nutrient and increased the substrate pH electrical conductivity (EC) and dry bulk density values Globally theresults showed that compost could be used at up to 55 by volume with no negative effects on plant growth The LCA showedthat use of compost reduced the environmental loads of the growth media except the Global Warming Potential value (GWP100)Environmental implications of the use of compost in the plant nursery chain are discussed

1 Introduction

Ornamental plant nursery production is one of the mostspecialized examples of intensive agriculture with the largeuse of nonrenewable resources tomaximize plant growth andreduce production time in an effort to capitalize on-sale prof-its Because of this the ldquogreen industryrdquo is often considereda nonpoint (or diffused) polluting industry due to the lowefficiency in the management practices The most commongrowing media used in Mediterranean ornamental nurseryis peat alone or mixed with inorganic coarse materials [1]because of its good chemical and physical properties Thedevelopment of substrates alternative to peat is necessaryfor three main reasons (i) peat resources are limited andcostly (ii) the social pressure to reuse the waste resultingfrom human or industrial activities is growing rapidly (iii)the economic need for reusing locally produced waste is

more and more urgent [2 3] In Italian ornamental nurseriesthe cost of the substrate affects by up to 12ndash15 the overallproduction cost of the potted plants [4] It is appropriate toconsider replacing peat with other organic resources withfavorable economically and environmentally features [5]

Composted organic wastes properly mixed can makeexcellent substrates for vegetable transplants [6 7] especiallysewage sludge due to its widespread production Compostingtransforms sewage sludge into a drier more uniform andbiologically stable product potentially suitable for plant root-ing and rich in plant nutrients [8] However the proportionof compost in the final substrate is also very important inorder to minimize potential hazards due to the presenceof heavy metals and pathogens Combinations of peat withsewage sludge compost and other materials canminimize thenegative properties of single materials (high salinity hetero-geneity and contaminants) [9] Reduced use of nonrenewable

2 Applied and Environmental Soil Science

resources and use of newmaterials for production of growingmedia would allow a reduction in the environmental impactof industrial processes Positive results can be quantifiedby the life cycle assessments (LCA) analysis method ofenvironmental impact of the composting processes and to thegrowthmedia production [10 11]TheEuropeanCommissionconsiders the LCA method as an instrument with a scientificbases able to provide the overall environmental costs of anyproductive process throughout its whole life cycle

Previous studies on compost use in agriculture havefocused on specific agronomic aspects such as plant nutritionwater holding capacity and species specificity Differentlythe choice of a growing media composition is constrainedtechnical considerations (eg growing medium character-istics crop requirements safety reliability availability ofconstituents and price) In substituting a peat substrate fora peat-biosolid compost mix it is essential for the grower toconsider crop quality However few studies have addressedthe global quality (agronomical and environmental) of horti-cultural growingmedia [12] A previous study reported that toreduce the environmental impacts of a peat growingmediumit is necessary to replace peat for alternative materials (egperlite wood fiber and green compost) [13] Currently thereis a lack of environmental quality data relating to sewagesludge compost application and rates in ornamental nurseryas growing medium [14]

In this research the use of different rates of sewage sludgecompost in the preparation of growing media for pottedBougainvillea was evaluated in order to assess its efficacyas a peat replacement and to quantify the environmentalimpact of the substrate by the LCA method to optimizethe ornamental nursery production chain The simultaneousevaluation of the agronomic quality and environmentalimpact of the different rates in volume of biosolid compostin the production chain of the growing media consists inthe innovative aspect of this research actually data for theMediterranean shrubs production does not exist

In this research the use of different rates of sewage sludgecompost for the preparation of growing media for pottedBougainvillea was evaluated in order to assess its suitabilityto replace peat in the ornamental nursery production chainand to quantify the environmental impact of the substrate bythe LCA method

2 Materials and Methods

21 Characteristics of the Compost The compost used asa component of growing media for this experiment (SSC)was obtained by mixing of urban sewage sludge (30 byvolume) from Manduria municipality (TA Southern Italy)and pruning rejects urban ldquogreenrdquo and olive grower (70by volume) both locally available in a composting plantThe mixture (about 3m3) was composted in a pilot plantusing the Rutgers static pile composting system with forcedaeration and controlled temperature The mixture reachedtemperature values greater than 60∘C and the thermophilicphase lasted 60 days After 95 days the biooxidative phase of

Table 1 Physical and physicochemical characteristics of sewagesludge

Parameter Value in drysewage sludge (SS)

Limit value in dry SS(according to

Italian LegislationLgs D 991992)

Colour 75Y 21Moisture content () 118 mdashTotal OM ()a 423 mdashOxidizable OC ()a 219 ge200pH (H2O) 764 mdashEC (dSmminus1) 410 mdashC N ratio 612 mdashCaCO3 198CHACFA nd mdashTotal KjeldahlNitrogen TKN ()a 321 ge150

P2O5 ()a 191 ge040K2O ()a 021 mdashCEC (cmol(+) kgminus1) nd mdashPb ()a 490 750Cd ()a 521 200Ni ()a 240 300Zn ()a 1057 2500Cu ()a 216 1000Hg ()a 510 100Cr+6 ()a 120 mdashaValues on a dry matter basis data are mean values 119899 = 3

composting was over and then the pile was allowed tomaturefor an additional month

The main physical physicochemical and chemicalparameters were analyzed in sewage sludge (Table 1) and SSC(Table 2) and raw materials added subsequently to preparethe growing media (Table 3)

Concerning the dry sewage sludge (Table 1) the pHvalue was slightly alkaline and the EC value was medium-high whereas the CaCO

3content was largely due to the

wastewater treatments of the sewage sludge with CaO andFeCl3 The P content was in the common range of values

for an organic fertilizer whereas the K content was relativelysmall possibly due to its solubility and transport in sewagesludge wastewater According to Italian Law (LegislativeDecree 991992) the heavy metal contents measured in thedry sewage sludge sample were under the limits

The obtained compost showed a good degree of maturity(Table 2) according to different criteria suggested in theliterature [15] such as the ratio of total organic carbon to totalnitrogen (TOCTN)

The compost showed an absence of phytotoxicity accord-ing to the germination index (GI) gt 50 (data not shown)

The main physicochemical parameters of the used mate-rials are reported in Table 3 The commercial Sphagnum peat(P) fromGermanywas used in combinationwith pumice and

Applied and Environmental Soil Science 3

Table 2 Physical and physicochemical characteristics of sewagesludge compost

ParametersValue in sewagesludge compost

(SSC)

Limit values in SSC(according to ItalianLegislation Lgs D

752010)Colour 10YR 32Moisture content () 444 le500Total OM ()a 586 mdashOxidizable OC ()a 290 ge200C N ratio 102 le250CHACFA 196 mdashTotal KjeldahlNitrogen TKN ()a 283 mdash

P2O5 ()a 091 mdashK2O ()a 071 mdashCEC (cmol(+) kgminus1) 770 mdashPb ()a 640 140Cd ()a 010 150Ni ()a 320 100Zn ()a 394 500Cu ()a 141 230Hg ()a 010 150Cr+6 ()a 010 050aValues on a dry matter basis data are mean values 119899 = 3

pozzolana (volcanicmaterials) and almond shell that improveaeration and water holding capacity of the growth substrates

22 Experimental Procedure and Greenhouse Experiment Agreenhouse pot experiment was carried out to evaluate themain physical and chemical properties of five growing mediaobtained by mixing sewage sludge-based compost and peatin different ratios and to evaluate the potential use of thesesubstrates as growing media for commercial Bougainvilleaproduction

The five compared substrates were obtained by mixingincreasing rates of sewage sludge compost (25 40 55and 70 vv) with a fixed rate of inert the other materials(30 vv) to fulfillment to 100 of the substrate volumeincluding the Sphagnum peat A peat based and compost-freesubstrate (SSC0) typically used in the Apulia nurseries wasalso prepared as control by mixing peat (70) pumice (15)almond shells (10) and pozzolana (5)

Heavy metal content was also determine (Table 6)The experiment was conducted in a commercial nursery

located in Monopoli SE Italy 40∘ 571015840 0010158401015840N 17∘ 181015840 0010158401015840E 23masl) in a greenhouse at keeping the temperature between15 plusmn 2

∘C at night and 28 plusmn 2∘C during the day temperature60 relative humidity On December 4 2012 rooted cuttingsof Bougainvillea glabra ldquoSanderianardquo were potted singly inbrown plastic containers (5 L volume) Each pot was filledwith one of the test substrates The young plants (one month

old) had the following size 12 cm height 7 cm diameter and18 g fresh weight

The growing density on bench was 8 plants mminus2 fora total of 135 plants (27 plants per growing medium) Theirrigation system was a microdrip The plants were irrigatedwith only water during the first week and then they weredaily fed with a water soluble fertilizer N P K (5 1 75) plusmicroelements in dose of 05 gL water From the beginningof trial to 90 (days after transplant) DAT the nutrient solutionwas diluted according to the compost percentage of thesubstrate (Table 7) The plants grown in SSC45 and SSC70have shown N deficiency symptoms (91 DAT) then thesolutions were unified in all treatments with the dose 05 gLwater (N P K= 5 1 75)

From the beginning of the trial up to 90 DAT the nutrientsolution quantity per pot was of 250mLd then up to theMay 6 (trial end) they received 4 interventions per day witha volume of 250mLpot per intervention

23 Measurements and Analytical Methods The greenhouseexperiment ended at 150 DAT when on average the plantsreached the commercial size The plant growth was deter-mined after 90 120 and 150 DAT On each sampling datenine plants per treatment (three per replicate pot) wererandomly harvested and used for the following biometricmeasurements number of leaves leaf area (cm2) (LI-COR3100 area meter) and fresh and dry weight The growingmedia were dried in an air-forced oven at 60∘C to constantweight and milled to below 025mm by a Tecator Cyclotec1093 PBIThe parts of the plants above groundwere separatedfrom the roots and gently washed many times with tap waterand then finally with deionized water A mixed sample of allthe replications of each treatment was collected Next thesamples were dried at 60∘C to constant weight and crushedto 025mmThe total Kjeldahl nitrogen (TKN) wasmeasuredusing 1 g samples of both growing media and plant tissuesusing the Kjeldahl method after 96 H

2SO4hot digestion

Total phosphorus was determined (P) by the colorimetricmolybdovanadate phosphoric acid method The remainingnutrients and the heavy metal content were determined indigested samples by inductively coupled plasma atomic emis-sion spectrometry (ICP-AES) One gram of dried sampleswas mineralized using 20mL of 65 HNO

3solution After

digestion samples were transferred into 50mL volumetricflasks and then filtered through a Whatman 42 filter Theanalyses were carried out in triplicate

Themain chemical and physicochemical properties of thefive growing media were determined according to the fol-lowing standardized UNI ENmethods 12579 (for sampling)13037 (for the pH value) 13038 (for electrical conductivityEC) 13041 (for dry bulk density and shrinkage) 13654-1(for nitrogen) and 13652 (for quantification of H

2O-soluble

nutrients and heavy metals) [16 17]The germination index (GI) was calculated using seeds of

Lepidium sativum L [18]

24 Statistical Analysis The greenhouse experiment wascarried out following a randomized block designedwith three


Table 3 Physical and physicochemical characteristics of the raw materials used compost (SSC) almond shell (A) pumice (Pu) pozzolana(S) and sphagnum peat (P)

Raw materials pH EC Dry bulk density Easily available water Shrinkage(dSmminus1) (g cmminus3) (V) (V)

SSC 790 554 045 993 1317A 571 026 038 119 0000Pu 672 008 081 288 0000S 643 010 162 1043 0000P 562 033 013 653 1533Data are mean values 119899 = 3

Table 4 Physical and physicochemical characteristics of the growing media used (at transplant)

Growing medium pH EC Bulk dry density Easily available water Shrinkage(dSmminus1) (g cmminus3) (V) (V)

Acceptable range (1) 52ndash65 lt05 le04 20ndash30 lt30SSC0 580c 045e 028c 1371a 1587a

SSC25 636b 152d 035b 1201a 1497a

SSC40 650b 215c 039b 601b 1410b

SSC55 685a 285b 045ba 586b 1340c

SSC70 690a 380a 055a 506b 1301c

Significance lowast lowastlowast lowast lowastlowast lowast

(1) ideal substrate Data are mean values 119899 = 3In each column different letters indicate significant differences for 119875 le 005 (test SNK)lowastindicates difference at 119875 le 005 lowastlowastindicates difference at 119875 le 001

Table 5 Chemical characteristics of the growing media used (at transplant)

Growing mediummg kgminus1

TotalN P K Ca Mg Fe Mn

SSC0 330d 1561d 1027c 5927c 660e 239c 69b

SSC25 550c 2962c 2058b 17346b 1682d 933b 114a

SSC40 790b 3050c 2765a 18652b 2783c 1056ab 128a

SSC55 890b 3858b 2692a 20857ab 3732b 1188a 136a

SSC70 1010a 4413a 2805a 22328a 4040a 1320a 151a

Significance lowastlowast lowastlowast lowastlowast lowastlowast lowastlowast lowastlowast lowastlowast

Data are mean values 119899 = 3 lowastlowastindicates difference at 119875 le 001In each column different letters indicate significant differences for 119875 le 005 (test SNK)

Table 6 Average values of the heavy metals content of the growing media used (at transplant)

Growing medium mg kgminus1

Pb Cd Ni Zn Cu Cr+6

Italian Law value 140 150 100 500 230 lt05SSC0 1204c 006b 158c 12c 13b lt05SSC25 3323b 019a 178c 82b 13b lt05SSC40 3400b 022a 256b 102ab 15ab lt05SSC55 3566b 028a 333ab 122a 19a lt05SSC70 4749a 031a 413a 143a 18a lt05Significance lowastlowast lowast lowastlowast lowastlowast lowastlowast nsData are mean values 119899 = 3In each column different letters indicate significant differences for 119875 le 005 (test SNK)lowastindicates difference at 119875 le 005 lowastlowastindicates difference at 119875 le 001 ns indicates nonsignificant difference


Table 7 Dilution ratio of nutrient solution supplied to the growingmedia from 1 to 90DAT

Growing medium Dilution ratio ( V V)Nutrient solution Water

SSC0 100 0SSC25 6429 3571SSC40 4284 5716SSC55 2143 7857SSC70 0 100

Table 8 Raw materials used for the production of the testedgrowing media and their transport distance from the productionareas to the firm

Materials Transport distance (km)Urban sewage sludge 130Green wastes 40Peat 2500Pumice 600Almond shell 150Pozzolana 100Sewage sludge compost 0

replications To compare the differences between specifictreatments the SNK test was used All statistical tests wereconducted using the CoStat software package (2002)

25 Environmental Analysis A comparison of the growingmedia production used in the experimental test was carriedout (from June to November 2012) by means of a life cycleassessment (LCA) analysis to gain more knowledge aboutthe environmental impact and the resource use along thesubstrate production chain The LCA is a method to analyseand assess the potential environmental impact caused by theusedmaterials (ISO 14040-44) [19]The product system com-prising the composting plant and technique the compostableorganic sewage sludge the produced compost peat pumicealmond shell and pozzolana and the five formulated growingmedia were included in the LCA In accordance to the ISO14040 standards the inventory of the inputs (matter andenergy) and the environmental outputs (water air and soilemissions) was accomplished using data obtained by directinterviews with the entrepreneurs business inspections andpreviously published data [20]The transport distance of eachraw material from the production area to the compostingfarm was also included as an input value (Table 8)

The data were elaborated using GABI 04 software withthe CML2010 interpretation method [21] to determine theimpacts indexes expression of the environmental load of thegrowing media productive process In the LCA evaluation ofthe composting process and all the assumptions about theboundaries of the production system the adopted functionalunit and the objectives of the study were evaluated inaccordance with [12 22] For the growingmedia comparisonthe process functional unit has been set at 1 kg The limitsof the productive system include the wastes transport to the

firm and the growing media components production andpackaging

3 Results and Discussion

31 Physical and Chemical Characteristics of the GrowingMedia Main physicochemical properties of the different rawmaterials and growing media used are shown in Tables 3 and4 and the values established for an optimal substrate [23]At start of the experiment the percentage in the mixtures ofcompost fromurban sludge significantly affected values of thephysical and physicochemical properties in relation to thoseobserved in the control treatment (SSC0) (Table 4) Compostaddition produced increased the values of pH and electricalconductivity (EC)The pH values of SSC0 SSC25 and SSC40were within or close to the acceptable range (52ndash65) andsignificantly increased with the highest proportion of CSS(55 and 70) in the substrate

The electrical conductivity (EC) values of the growthmedia were strongly affected by the addition of CSS thevalues exceeded the limit for an optimal growth substratein the mixtures having more than 25 compost the SSC0being the only substrate that fulfilled optimal reference level(Table 4)

The physical parameters at transplanting were influencedby the percentage of compost in the growing media Theincreases in bulk density were within acceptable values onlyin SSC0 SSC25 and SSC40 treatments Compost additionto the mixtures decreased the values of shrinkage and easilyavailable water and only the substrate with SSC25 showedsimilar values to those found in the control treatmentas regards the shrinkage Main macro- and micronutrientcontents were also significantly affected by compost ratein the media (Table 5) The TKN quantity was more thantriple in peat free substrate (SSC70) compared to the controlThe heavy metal content was also increased by the higherproportions of compost additions but all themeasured valueswhere under the Italian legal thresholds for its safe use inagriculture (Table 6)

32 Plant Growth and Tissue Composition Significantincreases were observed in the growth of Bougainvilleaplants with increasing compost rates in the mixtures (Figures1(a)ndash1(d))

On average at 120 and 150 DAT leaves number increasedin SSC40 SSC55 and SSC70 growing media (Figure 1(a))The leaf area only differed between treatments only at 150DATwith the lowest value found in plants grown on SSC0 andSSC25 substrates (Figure 1(b)) The weight also increased at120 DAT in compost enriched substrates (Figure 1(c)) withthe highest values recorded for SSC55 and SSC70 (peat free)substrates The increasing rates of compost at 120 DAT alsoincreased the dry weight values compared to the controlwith no difference between the rates (Figure 1(d)) at 150DAT the dry weight showed the highest values in SSC55 andSSC70

The increase in plant biomass production with the use ofcompost as a growing media component could be attributed


5075

100125150175200225250275

90 120 150

ns

abbcc

aabcc

DAT

Leav

es (n

plan

tminus1)

(a)

500150025003500450055006500750085009500

90 120 150

ns

ns

aabcc

DAT

Tota

l lea

f are

a (cm

minus2

plan

tminus1)

(b)

40

140

240

340

440

540

640

90 120 150

ns

aaaab

aabbb

DAT

SSC0SSC25SSC40

SSC55SSC70

Fres

h w

eigh

t (g

plan

tminus1)

(c)

10

30

50

70

90

110

130

150

90 120 150DAT

SSC0SSC25SSC40

SSC55SSC70

aabbc

aaaab

ns

Dry

wei

ght (

g pl

antminus

1)

(d)

Figure 1 Leaves number (a) leaf area (b) fresh (c) and dry (d) weight in Bougainvillea potted plants at 90 120 and 150 DAT as influenced bygrowing media Each point is the mean of three replications Within the same DAT values with the same letter are nonsignificantly different119875 le 005

to the high input of nutrients provided by composts and inour experiment increases in P Ca Mg Fe Mn Cu and Zn(Tables 5 and 6) likely played a key role Improvement of plantbiomass production by CSS was higher on a dry basis than ona fresh basis confirming the increased plant uptake of nutri-ents In general compost addition significantly influenced thenutritional status of the Bougainvillea aerial part (Tables 9and 10) Macronutrient contents were significantly enhancedwith the increasing rate of compost in the substrate Thisresult is probably due to a higher macronutrient availabilityin compost based growing media (Table 5)

A decrease of Mn concentration in plant tissue wasobservedwith increasing compost presence in growingmedia(Table 10)

Tognetti et al (2007) reported that the pH increaseswhen mature composts are applied [24] The increase inEC values with rising proportions of composts in amendedsoils was reported by De Lucia et al [25] where compostedsewage sludge was incorporated into urban soils for threelandscaping plants (Phillyrea angustifoliaMyrtus communis

and Pistacia lentiscus) The results showed that the chemicalproperties of the amended soils were also directly affected bythe SSC rate but the effect of the compost on organic mat-ter nitrogen and potassium contents decreased over timePerez-Murcia et al (2006) in experiments using substratesobtained bymixing sewage sludge compost with peat to growhorticultural plants (broccoli) found that the EC values ofthe growth media were strongly affected by the addition ofCSS the values exceeded the limit for an ideal substrate inthemixtures havingmore than 30compost [9] Bulk densityincreasedwith the adding of compost as reported in previousstudies that used compost as substrate component [26]

Hidalgo and Harkess [27] evaluated vermicompost asa substrate amendment mixed at different ratios with peatmoss for chrysanthemum production and reported that thebulk density the percentage of pore space and water holdingcapacity increased as the vermicompost content increasedPresence of coarse particles in the compost increased thesubstrate aeration and water retention in compost enrichedplant growth substrates [27 28] Macro- and micronutrients


Table 9 Concentrations of macronutrients in tissues of Bougainvillea plants as influenced by growing media (150DAT on dry matter basis)


N P K Ca Mg NaSSC0 251c 653d 383c 197c 963c 401b

SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a

Significance lowast lowast lowastlowast lowast lowast lowast

Data are mean values 119899 = 3In each column different letters indicate significant differences for 119875 le 005 (test SNK)lowastindicates difference at 119875 le 005 lowastlowastindicates difference at 119875 le 001

Table 10 Concentrations of micronutrients in tissues of Bougainvillea plants as influenced by growing media (150DAT on dry matter basis)


Fe B Mn Cu ZnSSC0 138c 321 1210a 279b 754c

SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a

Significance lowast ns lowastlowast lowast lowastlowast

Data are mean values 119899 = 3In each column different letters indicate significant differences for 119875 le 005 (test SNK)lowastindicates difference at 119875 le 005 lowastlowastindicates difference at 119875 le 001 ns indicates nonsignificant difference

increased in compost-based mixtures compared to the con-trol confirming that sewage sludge compost can be a sourceof macro- andmicronutrients [29]The increase in macronu-trient levels with compost incorporation was also observedby in an experiment of potted Pelargonium production [30]Research has shown that the use of sewage sludge generallyincreases the heavy metal contents in compost comparableresults were reported by Wuest et al (1995) in experimentsinvolving aged mushroom compost [31]

Concerning the plant growth positive correlationsbetween the leaf area and the shoot dry weight have beenreported by Tremblay and Senecal [32] The increase in plantbiomass production with the use of compost as a growingmedia component has been previously reported [9 33] Themacronutrient availability improved with compost additionto the media our results are in agree with Stellacci et al inthe growth of containered Quercus ilex [34] Similar to ourfindings Ostos et al found that the P uptake was notablyenhanced in Pistacia lentiscus cultivation [29] Pinamontiet al [35] found significant increases in the N P and Kcontents in cucumber tomato and strawberry plants grownin peat-sewage sludge compost media Falahi-Adrakani etal (1987) reported that cabbage and broccoli accumulatedgreater amounts of N and K from the composted sewagesludge amended medium [36] The Mn decreases have beenreported by other authors [5] and it is probably a consequenceof the reducedMn availability induced by the high pH valuesof these growing media (Table 5)

33 Life Cycle Analysis (LCA) Analysis The results of theenvironmental analysis are reported in Figure 2

The environmental burden of SSC25 was considered as areference value equal to 100 of environmental burden Thegrowing media environmental loads decreases by reducingthe peat content for all the compared indexes apart fromGWP

100(Global Warming Potential) even if the compost

content increases atmospheric emissions due to the compost-ing process emissions and waste transport (Figure 2)

These results were influenced by the long distance of thepeat production areas (North Europe) from the compostingand packaging plant The GWP

100index showed an opposite

trend indicating a potential growing media environmentalburden increase as the added compost dose increases Thiscould be attributed to to the increase of atmosphere emissionsassociated to the composting process Our results were in linewith previously published data on the environmental impactof growing media [13] The LCA also showed that the SSC70medium produced the best environmental performance forall the indices except for GWP This environmental benefitcould be attributed to the absence of peat in such substrate

In addition a higher use of compost produces C sinkphenomena [37ndash39] because the composting process retainspart of the original sewage sludge C in the mature compostrather than its release by oxidation or fermentation when thesame wastes are landfilled

Considering the environmental burdens avoided by theaccumulation of organic waste in landfills and the reduction


020406080

100120140160180

ADP AP EP GWP ODP POCP Energy(

)

Impact index

SSC25SSC40SSC55

SSC70SSC0

Depletion of the abiotic resources ADP kg Sb eq

Climate change

Ozone layer depletion ODP

Acidification AP

Eutrophication EP

Formation of photochemical oxidants POCP kg of ethylene eq

Primary nonrenewable energy consumption Energy MJ

GWP100 kg of CO2 eq

kg R-11 eqkg of SO2 eq

kg of PO4

3minus eq

Figure 2 LCA of growing media compared analysis results

of fertilizers some authors [22 40 41] have obtained anenvironmental credit for the production of compost In thiscase the use of compost can reduce the overall environmentalload of the substrates or field crops Finally by maximizingthe peat replacement by compost produced near the growingmedia production farms the impact due to its transport isfurther reduced [42]

4 Conclusion

The presented results showed that replacement of peat bysewage sludge compost can increase as compared to thetypical plant nursery substrates mainly by increasing macro-and micronutrients supply to plants In our experimentreplacement of peat up to 55 yielded in Bougainvillea plantsof comparable quality as to the typical peat based substrateThe LCA showed that the addition of compost greatlyreduced the environmental impact of the plant nursery chain

Acknowledgments

This work has been financed by the Italian Ministry ofUniversity and Research (MIUR) through ldquoPON 01-01611SoProMerdquo The authors also thank Eden rsquo94 Compostingfarm (Manduria Italy) and Tony and Gregory Leone fortheir help in the practical development of this experimentThe experimental tests the data processing and the editorialwork were shared within the competencies of the researchgroup equally between the authors

References

[1] E Rea F Pierandrei S Rinaldi B De Lucia L Vecchietti andA Ventrelli ldquoEffect of compost-based alternative substrata inpotted Aloe vera (L) Burm Frdquo Acta Horticulturae vol 807 pp541ndash546 2009

[2] M Raviv ldquoThe future of composts as ingredients of growingmediardquo Acta Horticulturae vol 891 pp 19ndash32 2011

[3] M Abad P Noguera and S Bures ldquoNational inventory oforganic wastes for use as growing media for ornamental pottedplant production case study in Spainrdquo Bioresource Technologyvol 77 no 2 pp 197ndash200 2001

[4] B De Lucia L Vecchietti and A Leone ldquoItalian buckthornresponse to compost based substratesrdquo Acta Horticulturae vol891 pp 231ndash236 2011

[5] C Mininni P Santamaria H M Abdelrahman et alldquoPosidonia-based compost as a peat substitute for lettucetransplant productionrdquo HortScience vol 47 no 10 pp 1438ndash1444 2012

[6] O Verdonck ldquoComposts from organic waste materials assubstitutes for the usual horticultural substratesrdquo BiologicalWastes vol 26 no 4 pp 325ndash330 1988

[7] F R Gouin ldquoUtilization of sewage sludge compost in horticul-turerdquo HortTechnology vol 3 no 2 pp 161ndash163 1993

[8] L Mancini and B De Lucia ldquoOrganic and mineral soil fertili-sation in gladiolusrdquo Compost Science and Utilization vol 19 no3 pp 178ndash181 2011

[9] M D Perez-Murcia R Moral J Moreno-Caselles A Perez-Espinosa and C Paredes ldquoUse of composted sewage sludge ingrowth media for broccolirdquo Bioresource Technology vol 97 no1 pp 123ndash130 2006


[10] G Russo and B De Lucia Zeller ldquoEnvironmental evaluation bymeans of LCA regarding the ornamental nursery production inrose and sowbread greenhouse cultivationrdquo Acta Horticulturaevol 801 pp 1597ndash1604 2008

[11] G Russo G ScarasciaMugnozza and B De Lucia Zeller ldquoEnvi-ronmental improvements of greenhouse flower cultivation bymeans of LCA methodologyrdquo Acta Horticulturae vol 801 pp301ndash308 2008

[12] M A Anton P Munoz F Castells J I Montero and MSoliva ldquoImproving waste management in protected horticul-turerdquo Agronomy for Sustainable Development vol 25 no 4 pp447ndash453 2005

[13] Quantis Sarl ldquoEPAGMA Project-final report-comparative lifecycle assessment of horticultural growing media based on peatand other growing media constituentsrdquo Parc Scientifique delrsquoEPFL Batiment D Quantis Sarl Lausanne Switzerland 2012

[14] U Sonesson A BjorklundM Carlsson andMDalemo ldquoEnvi-ronmental and economic analysis of management systems forbiodegradable wasterdquo Resources Conservation and Recyclingvol 28 no 1-2 pp 29ndash53 2000

[15] A Bernal-Vicente M Ros F Tittarelli F Intrigliolo and J APascual ldquoCitrus compost and its water extract for cultivation ofmelon plants in greenhouse nurseries Evaluation of nutriactiveand biocontrol effectsrdquo Bioresource Technology vol 99 no 18pp 8722ndash8728 2008

[16] ldquoEuropean Standard 12579 12580 Determination of a quantityrdquoin Soil Improvers and Growing Media European Committee forStandardization Brussels Belgium 1999

[17] ldquoEuropean Standard 13037 38 41 Sample preparation for chem-ical and physical tests determination of dry matter contentmoisture content and laboratory compacted bulk densityrdquo inSoil Improvers and Growing Media European Committee forStandardization Brussels Belgium 1999

[18] F Zucconi A Monaco and M Forte ldquoPhytotoxins during thestabilisation of organic matterrdquo in Composting of Agriculturaland Other Wastes J K R Gasser Ed pp 73ndash85 ElsevierApplied Science Publications London UK 1985

[19] ISO ldquoInternational Organization of Standardization 14040-environmental management-life cycle assessment-principlesand frameworkrdquo Tech Rep 14040 International Organisationfor Standardization Geneva Switzerland 1999

[20] E Cadena J Colon A Sanchez X Font and A Artola ldquoAmethodology to determine gaseous emissions in a compostingplantrdquoWaste Management vol 29 no 11 pp 2799ndash2807 2009

[21] J B Guinee M Gorree R Heijungs G Huppes R Kleijnand A de Koning ldquoLife cycle assessment An operational guideto the ISO standardsrdquo Final Report Ministry of HousingSpatial Planning and Environment (VROM) andCentrum voorMilieukunde (CML) Rijksuniversiteit Den Haag Leiden TheNetherlands 2001

[22] G Russo S Ingravalle B De Lucia Zeller and L VecchiettildquoEnviromental and productive comparison of growing-mediaobtained by composts of different organic wastesrdquo in Proceed-ings of International Conference on Agricultural Engineering ampIndustry Exhibition pp 23ndash25 EURAGENG (European Societyof Agricultural Engineers) Crete Greece June 2008

[23] T G L Aendekerk H Cevat N Dolmans et al InternationalSubstrate Manual Analysis Characteristics RecommendationsElsevier International Business Doetinchem Amsterdam TheNetherlands Frank-Paul Ter Berg

[24] C TognettiM JMazzarino and F Laos ldquoImproving the qualityof municipal organic waste compostrdquo Bioresource Technologyvol 98 no 5 pp 1067ndash1076 2007

[25] B De Lucia G Cristiano L Vecchietti and L Bruno ldquoEffect ofdifferent rates of composted organic amendments on urban soilproperties growth and nutrient status of three Mediterraneannative hedge speciesrdquo Urban Forestry amp Urban Greening 2013httpdxdoiorg101016jufug201307008

[26] B De Lucia L Vecchietti S Rinaldi CM Rivera A Trincheraand E Rea ldquoEffect of peat-reduced and peat-free substrates onRosmarinus officinalis L growthrdquo Journal of Plant Nutrition vol36 no 6 pp 863ndash876 2013

[27] P R Hidalgo and R L Harkess ldquoFertilizer effect on chrysan-themum production by vermicompost of different substratesrdquoInternational Journal of Environmental Science and EngineeringResearch vol 3 no 2 pp 32ndash45 2012

[28] MA Sanchez-Monedero A Roig C Paredes andM P BernalldquoNitrogen transformation during organic waste composting bythe Rutgers system and its effects on pH EC andmaturity of thecompostingmixturesrdquo Bioresource Technology vol 78 no 3 pp301ndash308 2001

[29] J C Ostos R Lopez-Garrido J M Murillo and R LopezldquoSubstitution of peat for municipal solid waste- and sewagesludge-based composts in nursery growing media effects ongrowth and nutrition of the native shrub Pistacia lentiscus LrdquoBioresource Technology vol 99 no 6 pp 1793ndash1800 2008

[30] H M Ribeiro E Duarte and J Q Dos Santos ldquoMunicipalsolid waste compost as a growing-media component for pottedpelargonium (Pelargonium zonale cv Meridonna)rdquo in iquestProceed-ings of the 9th International Symposium for the Optimization ofPlant Nutrition pp 499ndash501 Prague Czech Republic 1997

[31] P J Wuest H K Fahy and J Fahy ldquoUse of spent mushroomsubstrate (SMS) for corn (maize) production and its effect onsurface water qualityrdquo Compost Science amp Utilization vol 3 no1 pp 46ndash54 1995

[32] N Tremblay and M Senecal ldquoNitrogen and potassium innutrient solution influence seedling growth of four vegetablespeciesrdquo HortScience vol 23 pp 1018ndash1020 1988

[33] B De Lucia ldquoResponse of potted australian ornamental plantsto different soil water conditionsrdquo Acta Horticulturae vol 807pp 277ndash282 2009

[34] A M Stellacci G Cristiano P Rubino B De Lucia and ECazzato ldquoNitrogen uptake nitrogen partitioning and N-useefficiency of container-grown holm oak (Quercus ilex L) underdifferent nitrogen levels and fertilizer sourcesrdquo InternationalJournal of Food Agriculture amp Environment vol 11 no 3-4 pp132ndash137 2013

[35] F Pinamonti G Stringari and G Zorzi ldquoUse of compost insoilless cultivationrdquo Compost Science and Utilization vol 5 no2 pp 38ndash46 1997

[36] A Falahi-Adrakani J C Bouwkamp F R Gouin and R LChaney ldquoGrowth response and mineral uptake of vegetabletransplants grown in a composted sewage sludge amendedmedium I Nutrient supplying power of the mediumrdquo Journalof Environmental Horticulture vol 5 no 3 pp 107ndash111 1987

[37] J Pretty and A Ball ldquoAgricultural influences on carbonemissions and sequestration a review of evidence and theemerging trading optionsrdquo Occasional Paper 2001-03 Centrefor Environment and Society University of Essex Essex UK2001


[38] C Rosenzweig and D Hillel ldquoSoils and global climate changechallenges and opportunitiesrdquo Soil Science vol 165 no 1 pp47ndash56 2000

[39] P Smith ldquoCarbon sequestration in croplands the potential inEurope and the global contextrdquo European Journal of Agronomyvol 20 no 3 pp 229ndash236 2004

[40] J Martınez-Blanco P Munoz A Anton and J RieradevallldquoAssessment of tomato Mediterranean production in open-field and standard multi-tunnel greenhouse with compost ormineral fertilizers from an agricultural and environmentalstandpointrdquo Journal of Cleaner Production vol 19 no 9-10 pp985ndash997 2011

[41] G Russo B De Lucia L Vecchietti E Rea andA Leone ldquoEnvi-ronmental and agronomical analysis of different compost-basedpeat-free substrates in potted rosemaryrdquoActaHorticulturae vol891 pp 265ndash272 2011

[42] A Boldrin K R Hartling M Laugen and T H ChristensenldquoEnvironmental inventory modelling of the use of compost andpeat in growthmedia preparationrdquoResources Conservation andRecycling vol 54 no 12 pp 1250ndash1260 2010

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Environmental and Public Health

Journal of



EcosystemsJournal of


MeteorologyAdvances in

EcologyInternational Journal of


Marine BiologyJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Advances in


Environmental Chemistry

Atmospheric SciencesInternational Journal of



Waste ManagementJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics


Geological ResearchJournal of

EarthquakesJournal of


BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


resources and use of newmaterials for production of growingmedia would allow a reduction in the environmental impactof industrial processes Positive results can be quantifiedby the life cycle assessments (LCA) analysis method ofenvironmental impact of the composting processes and to thegrowthmedia production [10 11]TheEuropeanCommissionconsiders the LCA method as an instrument with a scientificbases able to provide the overall environmental costs of anyproductive process throughout its whole life cycle

Previous studies on compost use in agriculture havefocused on specific agronomic aspects such as plant nutritionwater holding capacity and species specificity Differentlythe choice of a growing media composition is constrainedtechnical considerations (eg growing medium character-istics crop requirements safety reliability availability ofconstituents and price) In substituting a peat substrate fora peat-biosolid compost mix it is essential for the grower toconsider crop quality However few studies have addressedthe global quality (agronomical and environmental) of horti-cultural growingmedia [12] A previous study reported that toreduce the environmental impacts of a peat growingmediumit is necessary to replace peat for alternative materials (egperlite wood fiber and green compost) [13] Currently thereis a lack of environmental quality data relating to sewagesludge compost application and rates in ornamental nurseryas growing medium [14]

In this research the use of different rates of sewage sludgecompost in the preparation of growing media for pottedBougainvillea was evaluated in order to assess its efficacyas a peat replacement and to quantify the environmentalimpact of the substrate by the LCA method to optimizethe ornamental nursery production chain The simultaneousevaluation of the agronomic quality and environmentalimpact of the different rates in volume of biosolid compostin the production chain of the growing media consists inthe innovative aspect of this research actually data for theMediterranean shrubs production does not exist

In this research the use of different rates of sewage sludgecompost for the preparation of growing media for pottedBougainvillea was evaluated in order to assess its suitabilityto replace peat in the ornamental nursery production chainand to quantify the environmental impact of the substrate bythe LCA method

2 Materials and Methods

21 Characteristics of the Compost The compost used asa component of growing media for this experiment (SSC)was obtained by mixing of urban sewage sludge (30 byvolume) from Manduria municipality (TA Southern Italy)and pruning rejects urban ldquogreenrdquo and olive grower (70by volume) both locally available in a composting plantThe mixture (about 3m3) was composted in a pilot plantusing the Rutgers static pile composting system with forcedaeration and controlled temperature The mixture reachedtemperature values greater than 60∘C and the thermophilicphase lasted 60 days After 95 days the biooxidative phase of

Table 1 Physical and physicochemical characteristics of sewagesludge

Parameter Value in drysewage sludge (SS)

Limit value in dry SS(according to

Italian LegislationLgs D 991992)

Colour 75Y 21Moisture content () 118 mdashTotal OM ()a 423 mdashOxidizable OC ()a 219 ge200pH (H2O) 764 mdashEC (dSmminus1) 410 mdashC N ratio 612 mdashCaCO3 198CHACFA nd mdashTotal KjeldahlNitrogen TKN ()a 321 ge150

P2O5 ()a 191 ge040K2O ()a 021 mdashCEC (cmol(+) kgminus1) nd mdashPb ()a 490 750Cd ()a 521 200Ni ()a 240 300Zn ()a 1057 2500Cu ()a 216 1000Hg ()a 510 100Cr+6 ()a 120 mdashaValues on a dry matter basis data are mean values 119899 = 3

composting was over and then the pile was allowed tomaturefor an additional month

The main physical physicochemical and chemicalparameters were analyzed in sewage sludge (Table 1) and SSC(Table 2) and raw materials added subsequently to preparethe growing media (Table 3)

Concerning the dry sewage sludge (Table 1) the pHvalue was slightly alkaline and the EC value was medium-high whereas the CaCO

3content was largely due to the

wastewater treatments of the sewage sludge with CaO andFeCl3 The P content was in the common range of values

for an organic fertilizer whereas the K content was relativelysmall possibly due to its solubility and transport in sewagesludge wastewater According to Italian Law (LegislativeDecree 991992) the heavy metal contents measured in thedry sewage sludge sample were under the limits

The obtained compost showed a good degree of maturity(Table 2) according to different criteria suggested in theliterature [15] such as the ratio of total organic carbon to totalnitrogen (TOCTN)

The compost showed an absence of phytotoxicity accord-ing to the germination index (GI) gt 50 (data not shown)

The main physicochemical parameters of the used mate-rials are reported in Table 3 The commercial Sphagnum peat(P) fromGermanywas used in combinationwith pumice and




(SSC)














2SO4hot digestion


3solution After



2O-soluble











SSC25 636b 152d 035b 1201a 1497a

SSC40 650b 215c 039b 601b 1410b

SSC55 685a 285b 045ba 586b 1340c

SSC70 690a 380a 055a 506b 1301c






SSC0 330d 1561d 1027c 5927c 660e 239c 69b

SSC25 550c 2962c 2058b 17346b 1682d 933b 114a

SSC40 790b 3050c 2765a 18652b 2783c 1056ab 128a

SSC55 890b 3858b 2692a 20857ab 3732b 1188a 136a

SSC70 1010a 4413a 2805a 22328a 4040a 1320a 151a





Pb Cd Ni Zn Cu Cr+6




















5075

100125150175200225250275

90 120 150

ns

abbcc

aabcc

DAT

Leav

es (n

plan

tminus1)

(a)

500150025003500450055006500750085009500

90 120 150

ns

ns

aabcc

DAT

Tota

l lea

f are

a (cm

minus2

plan

tminus1)

(b)

40

140

240

340

440

540

640

90 120 150

ns

aaaab

aabbb

DAT

SSC0SSC25SSC40

SSC55SSC70

Fres

h w

eigh

t (g

plan

tminus1)

(c)

10

30

50

70

90

110

130

150

90 120 150DAT

SSC0SSC25SSC40

SSC55SSC70

aabbc

aaaab

ns

Dry

wei

ght (

g pl

antminus

1)

(d)











SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a






SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics

















(SSC)














2SO4hot digestion


3solution After



2O-soluble











SSC25 636b 152d 035b 1201a 1497a

SSC40 650b 215c 039b 601b 1410b

SSC55 685a 285b 045ba 586b 1340c

SSC70 690a 380a 055a 506b 1301c






SSC0 330d 1561d 1027c 5927c 660e 239c 69b

SSC25 550c 2962c 2058b 17346b 1682d 933b 114a

SSC40 790b 3050c 2765a 18652b 2783c 1056ab 128a

SSC55 890b 3858b 2692a 20857ab 3732b 1188a 136a

SSC70 1010a 4413a 2805a 22328a 4040a 1320a 151a





Pb Cd Ni Zn Cu Cr+6




















5075

100125150175200225250275

90 120 150

ns

abbcc

aabcc

DAT

Leav

es (n

plan

tminus1)

(a)

500150025003500450055006500750085009500

90 120 150

ns

ns

aabcc

DAT

Tota

l lea

f are

a (cm

minus2

plan

tminus1)

(b)

40

140

240

340

440

540

640

90 120 150

ns

aaaab

aabbb

DAT

SSC0SSC25SSC40

SSC55SSC70

Fres

h w

eigh

t (g

plan

tminus1)

(c)

10

30

50

70

90

110

130

150

90 120 150DAT

SSC0SSC25SSC40

SSC55SSC70

aabbc

aaaab

ns

Dry

wei

ght (

g pl

antminus

1)

(d)











SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a






SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics





















SSC25 636b 152d 035b 1201a 1497a

SSC40 650b 215c 039b 601b 1410b

SSC55 685a 285b 045ba 586b 1340c

SSC70 690a 380a 055a 506b 1301c






SSC0 330d 1561d 1027c 5927c 660e 239c 69b

SSC25 550c 2962c 2058b 17346b 1682d 933b 114a

SSC40 790b 3050c 2765a 18652b 2783c 1056ab 128a

SSC55 890b 3858b 2692a 20857ab 3732b 1188a 136a

SSC70 1010a 4413a 2805a 22328a 4040a 1320a 151a





Pb Cd Ni Zn Cu Cr+6




















5075

100125150175200225250275

90 120 150

ns

abbcc

aabcc

DAT

Leav

es (n

plan

tminus1)

(a)

500150025003500450055006500750085009500

90 120 150

ns

ns

aabcc

DAT

Tota

l lea

f are

a (cm

minus2

plan

tminus1)

(b)

40

140

240

340

440

540

640

90 120 150

ns

aaaab

aabbb

DAT

SSC0SSC25SSC40

SSC55SSC70

Fres

h w

eigh

t (g

plan

tminus1)

(c)

10

30

50

70

90

110

130

150

90 120 150DAT

SSC0SSC25SSC40

SSC55SSC70

aabbc

aaaab

ns

Dry

wei

ght (

g pl

antminus

1)

(d)











SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a






SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics
































5075

100125150175200225250275

90 120 150

ns

abbcc

aabcc

DAT

Leav

es (n

plan

tminus1)

(a)

500150025003500450055006500750085009500

90 120 150

ns

ns

aabcc

DAT

Tota

l lea

f are

a (cm

minus2

plan

tminus1)

(b)

40

140

240

340

440

540

640

90 120 150

ns

aaaab

aabbb

DAT

SSC0SSC25SSC40

SSC55SSC70

Fres

h w

eigh

t (g

plan

tminus1)

(c)

10

30

50

70

90

110

130

150

90 120 150DAT

SSC0SSC25SSC40

SSC55SSC70

aabbc

aaaab

ns

Dry

wei

ght (

g pl

antminus

1)

(d)











SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a






SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics


















SSC25 273c 702c 404c 191c 124b 455b

SSC40 302b 751b 452b 209b 143b 530a

SSC55 315b 774b 483b 211b 157b 570a

SSC70 354a 840a 562a 234a 185a 592a






SSC25 141c 303 906b 305b 1247b

SSC40 146b 333 883b 322b 1331b

SSC55 156ab 3095 822c 369a 1517a

SSC70 169a 314 854bc 402a 1608a















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics















020406080

100120140160180


)

Impact index

SSC25SSC40SSC55

SSC70SSC0


Climate change


Acidification AP

Eutrophication EP



GWP100 kg of CO2 eq


kg of PO4

3minus eq



4 Conclusion


Acknowledgments


References

















































Journal of












Volume 2014

Advances in









Geophysics





















































Journal of












Volume 2014

Advances in









Geophysics














research article nursery growing media: agronomic and...

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