research article role of inorganic and organic fractions...

Research ArticleRole of Inorganic and Organic Fractions in Animal ManureCompost in Lead Immobilization and Microbial Activity in Soil

Masahiko Katoh12 Wataru Kitahara34 and Takeshi Sato2

1Department of Agricultural Chemistry School of Agriculture Meiji University 1-1-1 Higashi-Mita Tama-kuKanagawa 214-8571 Japan2Department of Civil Engineering Faculty of Engineering Gifu University 1-1 Yanagido Gifu 501-1193 Japan3Department of Civil Engineering Graduate School of Engineering Gifu University 1-1 Yanagido Gifu 501-1193 Japan4In Situ Solutions Co Ltd 2-5-2 Kandasudamachi Chiyoda-ku Tokyo 101-0041 Japan

Correspondence should be addressed to Masahiko Katoh mkatohmeijiacjp

Received 20 November 2015 Accepted 15 December 2015

Academic Editor Ezio Ranieri

Copyright copy 2016 Masahiko Katoh 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

This study aimed to identify how the ratio of inorganic-to-organic components in animal manure compost (AMC) affected bothlead immobilization andmicrobial activity in lead-contaminated soil When AMC containing 50 or more inorganic fraction withhigh phosphorous content was applied to contaminated soil the amounts of water-soluble lead in it were suppressed by over 88from the values in the soil without compostThe residual fraction under sequential extraction increased with the inorganic fractionin theAMC however in those AMCs the levels ofmicrobial enzyme activity were the same or less than those in the control soilTheapplication of AMC containing 25 inorganic fraction could alter the lead phases to be more insoluble while improving microbialenzyme activities however no suppression of the level of water-soluble lead existed during the first 30 days These results indicatethat compost containing an inorganic component of 50 or more with high phosphorus content is suitable for immobilizing leadhowever in the case where low precipitation is expected for a month AMC containing 25 inorganic component could be used toboth immobilize lead and restore microbial activity

1 Introduction

Lead is one of the most common and harmful heavy-metalsoil contaminants worldwide particularly near mines andshooting ranges Lead contamination in the soil of suchsites poses a risk to human and animal health as well asplant growth Thus its mobility and bioavailability should bereduced by appropriate treatments In addition the rehabil-itation of soil ecosystems that have undergone destructionby lead contamination should be accomplished through theremediation of such soil Since contamination in these sitesis extensive and asset values are extremely low chemicalimmobilization capable of transforming lead into less solublephases is a cost-effective remediational approach Thus var-ious immobilization materials have been studied and devel-oped [1ndash7]

Animal manure compost (AMC) which is the mostabundantly found organic waste material in Japan canimmobilize heavy metals and improve plant growth andmicrobial activity [8ndash16] by supplying nutrients to plant andsoil biota Therefore in addition to lead immobilizationthe application of AMC to lead-contaminated soil can helprehabilitate soil ecosystems which inorganic immobilizationmaterials cannot [17] Numerous studies have investigatedthe effectiveness of AMC for lead immobilization [18 19]however consistent conclusions on the mechanisms behindthis process have not been obtained as such immobilizationthat greatly depends upon the AMC type that is AMCrsquosphysicochemical properties In particular the presence ofboth inorganic and organic components in AMC makes itcomplicated to understand lead immobilization

Hindawi Publishing CorporationApplied and Environmental Soil ScienceVolume 2016 Article ID 7872947 9 pageshttpdxdoiorg10115520167872947

2 Applied and Environmental Soil Science

Table 1 Physicochemical properties of contaminated soil used in this study (on the basis of air-dried weight)

Sand Silt Clay pH TC TN WSOCa WS-Pbb Total Amorphous Fe() () () (g kgminus1) (g kgminus1) (mg kgminus1) (mg kgminus1) Pb (g kgminus1) P (g kgminus1) Al (g kgminus1) Fe (g kgminus1) (g kgminus1)815 95 90 73 60 00 139 35 440 040 131 338 13aWater-soluble organic carbonbWater-soluble lead

Lead immobilization by AMC can be separated into indi-rect and direct mechanismsThe typical indirect mechanismsof lead immobilization are explained by the pH increaseowing to the alkalinity of the inorganic component in AMCthis pH increase can promote the precipitation of leadcarbonate and hydroxide minerals resulting in a reductionof lead mobility and bioavailability [1 20] The direct mecha-nisms of lead immobilization by AMC have been consideredto be the reaction of the lead with the inorganic and organiccomponents in AMC Phosphorus sulfate and iron in theinorganic component and humic substances in the organiccomponent in AMC seem to be the sources responsible forthe reaction with lead [10 18 21ndash23] Katoh et al [24] applieda specific method for the fractionation of the inorganic andacid-insoluble organic components from AMC to elucidatetheir separate contributions to lead immobilization Theyindicated that the inorganic component in AMC couldimmobilize leadmore effectively than its organic components[24] These results imply that the inorganic component inAMC has a crucial role in lead immobilization and AMCwith a higher inorganic content is more suitable Howeverto rehabilitate microbial activity the organic component inAMC is also required since it supplies sufficient nutrientsto soil microorganisms [17] This component however maynegatively affect lead mobility water-soluble organic matterin AMC reacts and forms complexes with lead ions resultingin enhancements in lead mobility Therefore a suitable ratioof inorganic and organic components in AMC should beclarified to reduce themobility and bioavailability of lead andenhance the microbial activities in the soil AMC has a widerange of the inorganic-to-organic component ratios [25]however to our knowledge the optimal ratio of inorganic-to-organic components in AMC for lead immobilization andthe rehabilitation of microbial activity have not been studied

We investigated the mobility and bioavailability of thelead lead phases and microbial activities in soil amendedwith the AMCs of various inorganic-to-organic componentratiosThe inorganic fractionwas derived from swinemanurecompost and the acid-insoluble organic fraction was derivedfrom cattle manure compost These fractions can immobilizelead more effectively than other AMCs owing to the highcontent of phosphorus and mature organic matter in theinorganic and acid-insoluble organic fractions respectively[24] We aimed to identify how the ratio of inorganic-to-organic components in AMC affected the mobility andbioavailability of lead lead phase and microbial activity Onthe basis of the obtained results we discuss the optimalratio of the inorganic and organic components in AMC toimmobilize lead and rehabilitate microbial activity in soil

Table 2 Chemical properties of inorganic and acid-insolubleorganic fractions used in this study (on the basis of air-dried weightmg gminus1) [24]

Characteristic Inorganic fraction Acid-insolubleorganic fraction

Total calcium 152 NDlowast1

Total magnesium 44 NDTotal potassium 53 NDTotal iron 7 NDTotal phosphorus 131 NDTotal carbon ND 452ADF-Clowast2 ND 344Humic acid carbon ND 25Fulvic acid carbon ND 52lowast1Not determinedlowast2Acid detergent fiber carbon

2 Materials and Methods

21 Preparation of Soil The lead-contaminated soil usedherein was collected from depths of 5ndash15 cm at a shootingrange located at 35∘281015840610158401015840N and 137∘291015840210158401015840E in Gifu JapanThe soil sample was air-dried passed through a 2mm sieveand was used for chemical analysis and incubation testsThe selected physicochemical properties of the soil used areshown in Table 1The soil had a sandy loam textureThe totallead content of the soil was 440 g kgminus1 and the soil pH was73

22 Preparation of Animal Manure Compost Commercialswine and cattle manure composts were used herein toobtain the inorganic and acid-insoluble organic fractionsrespectively We selected these composts since each fractionof the compost can immobilize lead more effectively thanother composts [24] The fractionation followed the methoddescribed by Katoh et al [24] In brief the swine manurecompost was combusted at 600∘C for 2 h the residue aftercombustion was used as the inorganic fraction The cattlemanure compost was subjected to extraction with 1M HClfor 1 h to remove almost all inorganic components and theresidue after extractionwas used as the acid-insoluble organicfraction The pH of each fraction was adjusted to 7 to matchthat of the soil Table 2 shows the selected chemical propertiesof each fraction [24] The calcium magnesium potassiumiron and phosphorus contents in the inorganic fraction were152 44 53 7 and 131mg gminus1 respectively moreover thetotal acid-detergent fiber humic acid and fulvic acid carbon

Applied and Environmental Soil Science 3

contents in the acid-insoluble organic fraction were 452 34425 and 52mg gminus1 respectively [24] After pH adjustment thefractions were well mixed at the inorganic-to-acid-insolubleorganic fraction ratios of 1000 7525 5050 2575 and 0100the mixed samples were used as the AMCs herein (hereafterreferred to AMC with inorganic-to-organic ratios of 10007525 5050 2575 and 0100)

23 Soil-Incubation Experiment The contaminated soil wasmixed with each AMC sample at 10 wt and incubated atroom temperature (25∘C) for 184 days Soil without AMCwasalso prepared as a control Three replicates were prepared foreach treatment The water content in the soil was maintainedat 60 of its maximum water-holding capacity during theincubation period Soil samples were collected at 0 7 30 90and 184 days the samples were freeze-dried and analyzed todetermine the levels of water-soluble lead and water-solubleorganic carbon The soil sampled on day 184 was analyzedto assess lead phases by sequential extraction and microbialenzyme activities Herein the level of water-soluble lead wasemployed as an indicator of lead mobility and bioavailabilityin the soil because its water-soluble form is easily mobile andutilized by plant and soil biota

Another soil-incubation experiment was conducted toevaluate CO

2

emission from the soil with the AMCs withinorganic-to-organic ratios of 1000 5050 and 0100 A100mL polypropylene bottle including the soil with andwithout the AMC and two glass beakersmdashone having 05MNaOH and the other having 05M H

2

SO4

mdashwere placed intoa 5 L glass bottle and incubated at room temperature (25∘C)A 5 L bottle without soil was also prepared Three replicateswere prepared for each treatment At days 7 14 30 60120 and 194 the glass beaker containing 05M NaOH wasreplaced with a fresh 05M NaOH-containing beaker Thecollected NaOH was titrated with 02M HCl and the CO

2

emission was calculated from the following equation

119862119904

=119881 times 119865 minus 119862

119887

119878 (1)

where 119862119904

is the amount of CO2

emission (mol g-soilminus1) 119881 isthe amount of 02MHCl titrated (mL)119865 is the factor of 02MHCl (mol-CO

2

mLminus1) 119862119887


emission inthe blank (mol) and 119878 is the amount of soil (100 g) The CO

2

emission derived from AMC was calculated by subtractingthe emission by the AMC-treated soil samples from that bythe control soil sample

24 Analytical Methods The soilrsquos pH value was measuredin ultra-pure water using a pH meter (MM-60M DKK-TOACo Japan) Soil texture was determined using the hydrome-termethod [26]The total carbon andnitrogen contents in thesoil were determined using a carbon hydrogen and nitrogenelemental analyzer (MT-6 Yanaco New Science Inc Japan)

The water-soluble lead and organic carbon in soil wereextracted using ultra-pure water (1 10 soil solution ratio)and analyzed using an inductively coupled plasma-atomicemission spectrometer (ICP-AES ULTIMA2 HORIBA LtdJapan) and a total organic carbon analyzer (TOC-VWS

Shimadzu Co Japan) The amorphous iron was extractedusing Shumanrsquos method [27] The total lead phosphorusaluminum and iron contents in the soil were determinedby acid digestion with HNO

3

and HCl using a microwaveA sequential extraction procedure was performed on thesoil samples in accordance with the procedure describedby Tessier et al [28] In brief each fraction was extractedwith a 1M MgCl

2

solution (exchangeable fraction) 1Msodium acetate solution at pH 5 (carbonate fraction) 004MNH2

OH-HCl in 25 (vv) HOAc solution in a water bathat 95∘C with occasional agitation (FeMn oxide fraction)002M HNO

3

solution 5mL 30 H2

O2

solution in a waterbath at 85∘Cwith occasional agitation (organic fraction) and5mL of HNO

3

and 2mL of HCl using a microwave oven(residual fraction) All of the extracted or digested solutionswere passed through a 045120583m filter and analyzed to deter-mine the elemental concentration using ICP-AES

Three different microbial enzyme activitiesmdashdehydro-genase urease and saccharasemdashwere measured in the soilsampleThe dehydrogenase activity was determined in accor-dance with the method described by Tabatabai [29] usingtriphenyltetrazolium chloride The triphenylformazan pro-duced was measured using spectrophotometry at 485 nmThe urease activity was monitored using the methoddescribed by Kandeler and Gerber [30] by measuring theNH4

+ produced after the incubation of soil with urea Thesaccharase activity was determined in accordance with themethod described by Frankenberger and Johanson [31]

25 Statistical Analysis Statistical analyses were performedusing JMP Ver 802 (SAS Institute Inc) An analysis ofvariance was used to measure microbial enzyme activitiesThe differences between the mean values were determinedusing Tukeyrsquos honestly significant difference test at a 95confidence level

3 Results

31 Soil pH Water-Soluble Lead and Organic Carbon in Soilwith AMC The pH in the control soil was not significantlychanged and ranged from 75 to 77 throughout the incubationperiod (Table 3) Moreover the soil pH levels in all the AMCswere not significantly different from that in the controlindicating that the soil pH did not affect the enhancement orreduction in the lead mobility and bioavailability in the soilwith AMC

Figure 1(a) shows the amount of water-soluble lead inthe soil with AMC The amount of water-soluble lead in thecontrol soil ranged from 35 to 44mg kgminus1 throughout theincubation period The amount of water-soluble lead in thesoil treated with AMC with an inorganic-to-organic ratio of0100 was higher than that in the control soil throughoutthe incubation period The amount of water-soluble lead inthe soil treated by AMC with an inorganic-to-organic ratioof 2575 was equal to or at a higher level than that in thecontrol soil before day 30 but it decreased to 36 of that inthe control soil on day 184The amounts of water-soluble leadin the soil samples treated byAMCwith inorganic-to-organic


Table 3 pH in soils amended with simulated compost during incubation period (119899 = 3)

Compost Days of incubation(Inorganicorganic) 0 7 30 90 1841000 77 plusmn 00 75 plusmn 00 76 plusmn 01 78 plusmn 00 78 plusmn 007525 77 plusmn 00 75 plusmn 00 77 plusmn 00 78 plusmn 00 78 plusmn 015050 76 plusmn 00 76 plusmn 00 77 plusmn 01 78 plusmn 00 76 plusmn 002575 74 plusmn 00 74 plusmn 00 78 plusmn 00 78 plusmn 00 76 plusmn 000100 72 plusmn 00 73 plusmn 00 76 plusmn 01 78 plusmn 00 75 plusmn 02Control 75 plusmn 01 76 plusmn 00 77 plusmn 00 75 plusmn 01 75 plusmn 02

0

20

40

60

80

100

0 7 30 90 184Incubation time (days)

Wat

er-s

olub

le le

ad (m

g kgminus

1)

75255050

25750100

1000

Control(a)

0

600

1200

1800


Wat

er-s

olub

le o

rgan

ic ca

rbon

(mg

kgminus1)

75255050

25750100

1000

Control(b)

Figure 1 Water-soluble lead (a) and organic carbon (b) in soil amended with AMC of inorganicorganic = 1000 7525 5050 2575 and0100 and without AMC (control) Vertical bars indicate the standard error

ratios of 5050 7525 and 1000 were 34ndash12 01ndash08and 01ndash02 respectively of the value in the control soilThe amount of water-soluble organic carbon in the soil isshown in Figure 1(b) At the beginning of the incubationperiod the amounts of water-soluble organic carbon inthe soils treated with different AMC compositions werearranged in the following order inorganicorganic = 0100 gtinorganicorganic = 2575 gt inorganicorganic = 5050 gtinorganicorganic = 7525 gt control gt inorganicorganic =1000 The amounts of water-soluble organic carbon in thesoil treated by AMC with inorganic-to-organic ratios of5050 7525 and 1000 remained at their initial values duringthe incubation period The amounts of water-soluble organiccarbon in the soil treated by AMC with inorganic-to-organicratios of 0100 and 2575 had rapidly decreased between days0 and 7 after which gradual decreases were observed Thedecreases inwater-soluble organic carbon between days 0 and184 were 1071 and 615mg kgminus1 under inorganic-to-organicratios of 0100 and 2575 respectively

32 CO2 Emission from Soil Amended with AMC Thecumulated CO

2

emission derived from AMC is shown inFigure 2 The level of CO

2

emission from the AMC withan inorganic-to-organic ratio of 0100 increased during theearly stage of incubation and then remained at approximately500mg-C kgminus1TheCO

2

emission trends from theAMCwithinorganic-to-organic ratios of 5050 and 1000 were similarthey slightly increased at the beginning of incubation andthen remained at approximately 100mg-C kgminus1

33 Lead Phases by Sequential Extraction in Lead-Contam-inated Soil Figure 3 shows the lead fraction results undersequential extraction The average recovery which wasdefined herein as the ratio of the sum total level of eachfraction (Figure 3) to the total level of lead in the soil (Table 1)was 119 plusmn 20 The composition of the control soil wasas follows 128 exchangeable fraction 512 carbonatefraction 207 FeMn oxide fraction 93 organic fractionand 60 residual fractionThepercentage of organic fraction


0

200

400

600

800


100050500100

CO2

emiss

ion

deriv

ed fr

om co

mpo

st (m

g kgminus

1)

Figure 2 Cumulative CO2

emission derived from AMC withinorganicorganic = 1000 5050 and 0100 Vertical bars indicatethe standard error

1000 7525 5050 2575 0100 Control0

20

40

60

80

100

Lead

frac

tion

of su

m to

tal (

)

ResidualOrganicFeMn oxide

CarbonateExchangeable

Figure 3 Sequential extraction of lead from soil amended withAMC of inorganicorganic = 1000 7525 5050 2575 and 0100and without AMC (control) after 184 days of incubation Verticalbars indicate the standard error

by sequential extraction in the soil treated by AMC with aninorganic-to-organic ratio of 0100 increased compared withthat in the control soil whereas that of carbonate decreasedThe addition of AMCwith a higher ratio of inorganic fractionresulted in a greater enhancement in the residual percentageFurthermore in soils with the AMCs containing an inorganic

fraction of 25 or more the percentage of organic fractionwas at the same level as that in the control soil

34 Microbial Enzyme Activities in Lead-Contaminated SoilThe dehydrogenase and urease activities in the soil treatedby AMC with inorganic-to-organic ratios of 0100 and2575 respectively were significantly higher than that inthe control soil however those in the soil treated by AMCwith inorganic-to-organic ratios of 7525 and 1000 weresignificantly lower or on the same level (Figure 4)

4 Discussion

41 Role of Organic Component in Animal Manure CompostLead Immobilization and Rehabilitation of Microbial ActivityThe water-soluble lead level in the soil treated by AMC withan inorganic-to-organic ratio of 0100 did not become lowerthan that in the control soil during the incubation period(Figure 1(a)) whereas the lead phases in the soil by sequentialextraction were altered to be more insoluble the organicfraction was increased (Figure 3) Moreover at the early stageof incubation the water-soluble lead level remained at ahigher level in the soil treated by AMC with an inorganic-to-organic ratio of 2575 However the water-soluble leadlevel decreased as the incubation time increased in soil withboth compostsThese observationswould be explained by thehigher level of water-soluble organic matter and its sorptionand decomposition in the soil thereby increasing the incuba-tion time The water-soluble organic matter can easily formcomplexes with lead ions and its complexes could enhancethe lead mobility in the soil [17 32 33]Therefore at the earlystage of incubation the high level of water-soluble organiccarbon would result in an enhancement of the lead mobilityin the soil treated by AMC with inorganic-to-organic ratiosof 0100 and 2575 The water-soluble organic matter wasderived from the compost containing humic and fulvic acidswith relatively low molecular weight [34 35] These organiccompounds are also readily decomposable and sorbed on thesoil surface [36 37] According to the result for CO

2

emission(Figure 2) the amount of CO

2

emission was lower than thatof water-soluble organic carbon-decrease from day 0 to day184 suggesting that some of the water-soluble organic matterderived from the compost was decomposed and some of itwas sorbed in the soil with the increase in the incubationperiod Thus the level of water-soluble lead would decreasewith that water-soluble organic carbon in the soil treated byAMC with inorganic-to-organic ratios of 0100 and 2575 Ithas been known that the compost amendment induced thevery short-term leaching pulses of lead after the application[38] and lead was redistributed to the soil component bythe decomposition of dissolved organic matter [39] Theseresults suggest that the organic component in the AMC doesnot considerably contribute to the immobilization of leadand suppression of lead mobility and bioavailability Thiswas comparable with the results of Schwab et al [19] and Lev-onmaki et al [40] who reported that water-soluble organicmatter enhanced the lead mobility by the formation ofcomplexation However all of themicrobial enzyme activities


00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)

Figure 4 Enzyme activities of dehydrogenase (a) urease (b) and saccharase (c) in soil amended with AMC of inorganicorganic = 10007525 5050 2575 and 0100 and without AMC (control) after 184 days of incubation Vertical bars indicate the standard error Differentletters indicate significant difference at 119875 lt 005

measured herein increased in the soil treated by AMC withan inorganic-to-organic ratio of 0100 despite the fact thatthe level of water-soluble lead was higherThe dehydrogenaseactivity which is an indicator of the overall microbial activity[8 9 41ndash43] in the soil treated by AMC containing 50 ormore inorganic fraction was the same level as that in thecontrol soil suggesting that the inorganic component in theAMC did not significantly contribute to the enhancement inthe microbial activity despite the fact that the lead mobilityand bioavailability are greatly decreased by its additionFarrell et al [44] also showed that themicrobial enzyme activ-ities in the soil amended with the compost became higherthan that in the inorganicmaterialThewater-soluble organicmatter derived from the compost is utilized as a nutrientsource by microorganisms thus the addition of AMC withhigh organic matter content would induce the rehabilitation

of microbial activity owing to the large amount of readilydecomposable organic matter

42 Role of the Inorganic Component in Animal ManureCompost on Lead Immobilization The addition of AMC con-taining 50 or more inorganic fraction reduced the water-soluble lead by over 88 during the incubation period(Figure 1(a))Moreover the addition of AMC containing 25or more inorganic fraction could alter lead phases to bemore insoluble These results indicate that AMC containing50 or more inorganic fraction could immobilize lead andreduce the lead bioavailability in the soil The inorganic frac-tion used herein contained a considerable amount of phos-phorus which results in the precipitation of lead phosphateminerals such as pyromorphite [24] Pyromorphite is ther-modynamically stable with a solubility product of log119870sp =


minus2505 [45] Therefore the phosphorus in the AMCrsquos inor-ganic component was responsible for the increase in thepercentage of the residual fraction and decrease in the water-soluble lead level This is supported by the results of Walkeret al [10] Liu et al [11] and Clemente et al [18] who sug-gested that the immobilization of lead and cadmium wouldbe due to the precipitation of insoluble phosphate saltsThe percentage of FeMn oxide and organic fractions bysequential extraction in the soil with AMC containing 25or more inorganic fraction was lesser than or approximatelyequal to that in the control soil although the residual fractionincreased with increase in the inorganic fraction ratio inAMC Moreover in the soil treated by AMC containing 50or less inorganic fraction the level of water-soluble organiccarbon was higher than that in the control soil These resultssuggest that the phosphorus in the inorganic component ofAMC could immobilize lead-precipitating lead phosphateminerals even if the AMC contained more organic thaninorganic components This may be because the magnitudeof lead immobilization by the inorganic component of AMCsuppressed the magnitude of the facilitation of lead mobilityby the organic component in AMC

The level of water-soluble lead in the soil treated by AMCwith an inorganic-to-organic ratio of 2575 was higher thanthat in the control soil during the first 30 days of incubationwhereas the lead phases were altered to be more insolubleThis was attributed to incomplete immobilization Scheckelet al [46] demonstrated that not all lead in soil could beimmobilized by phosphorus material according to extendedX-ray-absorption fine-structure analysis The percentages ofexchangeable and carbonate fractions by sequential extrac-tion in the soil treated by AMC with an inorganic-to-organicratio of 2575 were higher than that in the soil treatedby AMC that was 50 or more inorganic fraction Thelevels of water-soluble organic carbon in the soil treated byAMC with an inorganic-to-organic ratio 2575 were alsohigher particularly during the first 30 days of incubationThe higher amount of water-soluble organic matter formedcomplexes with lead dissolved from the exchangeable andcarbonate fractions resulting in an enhancement in the levelof water-soluble lead in the early stage of incubation Withthe increasing incubation time water-soluble organic matterwas decomposed and the level ofwater-soluble lead decreasedbelow that in the control soil

43 Optimal Ratio of Inorganic and Organic Componentsin Animal Manure Compost for Lead Immobilization andthe Rehabilitation of Microbial Activity Various inorganicpercentages are used in the AMC ranging from 73 to 828[25] The ranges of the inorganic fraction of AMC in thisstudy fall within this range On the basis of this studyrsquos find-ings an inorganic component with a high phosphorus con-tent of 50 or more is required to alter lead phases to bemore insoluble and reduce the water-soluble lead level to lessthan that in the soil without compost although the microbialactivities are not enhanced The importance of an inorganiccomponent for the immobilization of heavy metals includinglead in soil is pointed out by other researchers [21 47 48]

In contrast 25 inorganic AMC can alter lead phases tobe more insoluble and simultaneously enhance microbialactivities whereas the water-soluble lead level is higher thanthat in the soil without compost during the first 30 daysafter the application This is consistent with the result ofKatoh et al [17] who indicated that the application of 25inorganic swine manure compost could alter lead phases tobe more insoluble and improve plant growth and microbialenzyme activities however the level of water-soluble leadwashigher than that in the cattle manure compost during theearly stage of incubation (90 days after application) Thesefindings suggest that AMCs cannot immobilize both lead andrestore microbial activity Therefore to immobilize lead andsuppress the lead mobility and bioavailability using AMCAMC that is 50 inorganic or more and contains a largephosphorus component should be applied to contaminatedsites However in the case of low precipitation over a monthfor example during a dry season 25 inorganic AMCshould be used to both immobilize lead and restoremicrobialactivity

5 Conclusion

The amount of water-soluble lead in the soil treated by 100organic AMC remained higher than that in the control soilthroughout the 184-day incubation period although it tendedto decrease with increasing incubation time The amountof water-soluble lead in the soil treated by AMC with aninorganic-to-organic ratio of 2575 was higher than that inthe soil without compost during the early stage of incubationbut it reached a lower level than that in the soil withoutcompost after 90 days The amounts of water-soluble lead inthe soil treated by AMC containing 50 or more inorganicfraction were suppressed by over 88 from the value inthe soil without compost and remained low throughoutthe incubation period The reduction in the level of water-soluble lead in the soil treated by AMC with inorganic-to-organic ratios of 0100 and 2575 would be explained by thedecomposition of water-soluble organic matter The ratio ofthe residual fraction after sequential extractionwas enhancedand the readily soluble lead fractions (exchangeable andcarbonate fractions) were reduced in soils treated by AMCcontaining 25 or more inorganic fraction In soil treatedwith fully organic AMC the readily soluble lead fraction insequential extraction did not change in comparison with thatin the control soil whereas the organic fraction in sequentialextractionwas enhancedThe compost containing 25or lessinorganic fraction could improve the microbial activity butthe compost containing 50ormore inorganic fraction couldnot These results indicate that the compost containing 50or more inorganic fraction with a high phosphorus contentis suitable for immobilizing lead and reducing lead mobilityand bioavailability in the soil However to immobilize leadand improve themicrobial activity at the same time theAMCwith 25 inorganic and 75 organic components should beused as a lead immobilization material but note that higherlead mobility at the initial stage after the application shouldbe considered


Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The ICP-AES and CHN elemental analyzer instruments usedfor the chemical analysis in this study were made availableby the Division of Instrumental Analysis at Gifu UniversityThe authors are grateful to Professor F Li and Professor TYamada (Gifu University) for allowing the use of the TOCanalyzer This study was supported by the Japan Society forthe Promotion of Science (JSPS) KAKENHI [Grant no23710089]

References

[1] D JWalker R Clemente andM P Bernal ldquoContrasting effectsof manure and compost on soil pH heavy metal availabilityand growth of Chenopodium album L in a soil contaminatedby pyritic mine wasterdquo Chemosphere vol 57 no 3 pp 215ndash2242004

[2] J H Park N Bolan M Megharaj and R Naidu ldquoComparativevalue of phosphate sources on the immobilization of lead andleaching of lead and phosphorus in lead contaminated soilsrdquoScience of the Total Environment vol 409 no 4 pp 853ndash8602011

[3] X Cao A Wahbi L Ma B Li and Y Yang ldquoImmobilization ofZn Cu and Pb in contaminated soils using phosphate rock andphosphoric acidrdquo Journal of Hazardous Materials vol 164 no2-3 pp 555ndash564 2009

[4] X Cao D Dermatas X Xu and G Shen ldquoImmobilization oflead in shooting range soils bymeans of cement quicklime andphosphate amendmentsrdquo Environmental Science and PollutionResearch vol 15 no 2 pp 120ndash127 2008

[5] G M Hettiarachchi G M Pierzynski and M D Ransom ldquoInsitu stabilization of soil lead using phosphorus and manganeseoxiderdquoEnvironmental Science andTechnology vol 34 no 21 pp4614ndash4619 2000

[6] ADavis L E Eary and SHelgen ldquoAssessing the efficacy of limeamendment to geochemically stabilize mine tailingsrdquo Environ-mental Science and Technology vol 33 no 15 pp 2626ndash26321999

[7] E Lombi F-J Zhao G Zhang et al ldquoIn situ fixation of metalsin soils using bauxite residue chemical assessmentrdquo Environ-mental Pollution vol 118 no 3 pp 435ndash443 2002

[8] P Alvarenga A P Goncalves R M Fernandes et al ldquoEvalua-tion of composts and liming materials in the phytostabilizationof a mine soil using perennial ryegrassrdquo Science of the TotalEnvironment vol 406 no 1-2 pp 43ndash56 2008

[9] P Alvarenga A P Goncalves R M Fernandes et al ldquoOrganicresidue as immobilizing agents in aided phytostabilization (I)Effects on soil chemical characteristicsrdquo Chemosphere vol 74no 10 pp 1292ndash1300 2009

[10] D JWalker R Clemente A Roig andM P Bernal ldquoThe effectsof soil amendments on heavy metal bioavailability in two con-taminated Mediterranean soilsrdquo Environmental Pollution vol122 no 2 pp 303ndash312 2003

[11] L Liu H Chen P Cai W Liang and Q Huang ldquoImmobiliza-tion and phytotoxicity of Cd in contaminated soil amendedwith

chicken manure compostrdquo Journal of Hazardous Materials vol163 no 2-3 pp 563ndash567 2009

[12] A Sato H Takeda W Oyanagi E Nishihara and M Murak-ami ldquoReduction of cadmium uptake in spinach (Spinacia oler-aceaL) by soil amendmentwith animalwaste compostrdquo Journalof Hazardous Materials vol 181 no 1ndash3 pp 298ndash304 2010

[13] H-S Chen Q-Y Huang L-N Liu P Cai W Liang andM LildquoPoultry manure compost alleviates the phytotoxicity of soilcadmium influence on growth of pakchoi (Brassica chinensisL)rdquo Pedosphere vol 20 no 1 pp 63ndash70 2010

[14] R Clemente C Almela and M P Bernal ldquoA remediation stra-tegy based on active phytoremediation followed by naturalattenuation in a soil contaminated by pyrite wasterdquo Environ-mental Pollution vol 143 no 3 pp 397ndash406 2006

[15] E Doelsch A Masion G Moussard C Chevassus-Rossetand O Wojciechowicz ldquoImpact of pig slurry and green wastecompost application on heavy metal exchangeable fractions intropical soilsrdquo Geoderma vol 155 no 3-4 pp 390ndash400 2010

[16] R P Narwal and B R Singh ldquoEffect of organicmaterials on par-titioning extractability and plant uptake of metals in an alumshale soilrdquo Water Air and Soil Pollution vol 103 no 1ndash4 pp405ndash421 1998

[17] M Katoh W Kitahara R Yagi and T Sato ldquoSuitable chemicalproperties of animal manure compost to facilitate Pb immobi-lization in soilrdquo Soil and Sediment Contamination vol 23 no 5pp 523ndash539 2014

[18] R Clemente A Escolar and M P Bernal ldquoHeavy metals frac-tionation and organic matter mineralisation in contaminatedcalcareous soil amended with organic materialsrdquo BioresourceTechnology vol 97 no 15 pp 1894ndash1901 2006

[19] P Schwab D Zhu and M K Banks ldquoHeavy metal leachingfrom mine tailings as affected by organic amendmentsrdquo Biore-source Technology vol 98 no 15 pp 2935ndash2941 2007

[20] R Clemente and M P Bernal ldquoFractionation of heavy metalsand distribution of organic carbon in two contaminated soilsamended with humic acidsrdquo Chemosphere vol 64 no 8 pp1264ndash1273 2006

[21] A Baghaie A H Khoshgoftarmanesh M Afyuni and RSchulin ldquoThe role of organic and inorganic fractions of cowmanure and biosolids on lead sorptionrdquo Soil Science and PlantNutrition vol 57 no 1 pp 11ndash18 2011

[22] S Deiana C Gressa B Manunza R Rausa and R SeeverldquoAnalytical and spectroscopic characterization of humic acidsextracted from sewage sludge manure and worm compostrdquoSoil Science vol 150 no 1 pp 419ndash424 1990

[23] M A A Zaini R Okayama and M Machida ldquoAdsorption ofaqueous metal ions on cattle-manure-compost based activatedcarbonsrdquo Journal of Hazardous Materials vol 170 no 2-3 pp1119ndash1124 2009

[24] M Katoh W Kitahara and T Sato ldquoSorption of lead in animalmanure compost contributions of inorganic and organic frac-tionsrdquoWater Air and Soil Pollution vol 225 no 1 article 18282014

[25] T Yamaguchi Y Harada and M Tsuiki ldquoBasic data of animalwaste compostsrdquo Miscellaneous Publication of the NationalAgriculture Research Center vol 41 pp 1ndash178 2000 (Japanese)

[26] G W Gee and J M Bauder ldquoPartical-size analysisrdquo inMethodsof Soil Analysis Part 1 A L Page R HMiller andD R KeeneyEds pp 383ndash411 American Society of Agronomy MadisonWis USA 1986

[27] L M Shuman ldquoFractionation method for soil microelementsrdquoSoil Science vol 140 no 1 pp 11ndash22 1985


[28] A Tessier P G C Campbell andM Blsson ldquoSequential extrac-tion procedure for the speciation of particulate trace metalsrdquoAnalytical Chemistry vol 51 no 7 pp 844ndash851 1979

[29] MATabatabai ldquoSoil enzymesrdquo inMethods of Soil Analysis Part2 S H Mickelson and J M Bigham Eds pp 77ndash83 AmericanSociety of Agronomy Madison Wis USA 1994

[30] E Kandeler and H Gerber ldquoShort-term assay of soil ureaseactivity using colorimetric determination of ammoniumrdquo Biol-ogy and Fertility of Soils vol 6 no 1 pp 68ndash72 1988

[31] W T Frankenberger and J B Johanson ldquoMethod of measuringinvertase activity in soilsrdquo Plant and Soil vol 74 no 3 pp 313ndash323 1983

[32] S Sauve M McBride and W Hendershot ldquoSoil solution spec-iation of lead (II) effects of organic matter and pHrdquo Soil ScienceSociety of America Journal vol 62 no 3 pp 618ndash621 1998

[33] H Wang X Shan T Liu et al ldquoOrganic acids enhance theuptake of lead by wheat rootsrdquo Planta vol 225 no 6 pp 1483ndash1494 2007

[34] M Aoyama ldquoFractionation of water-soluble organic substancesformed during plant residue decomposition and high perfor-mance size exclusion chromatography of the fractionsrdquo SoilScience and Plant Nutrition vol 42 no 1 pp 31ndash40 1996

[35] M Aoyama ldquoProperties of fine and water-soluble fractions ofseveral composts II Organic forms of nitrogen neutral sugarsandmuramic acid in fractionsrdquo Soil Science and Plant Nutritionvol 37 no 4 pp 629ndash637 1991

[36] T Pare H Dinel M Schnitzer and S Dumontet ldquoTransfor-mations of carbon and nitrogen during composting of animalmanure and shredded paperrdquo Biology and Fertility of Soils vol26 no 3 pp 173ndash178 1998

[37] D L Jones and D S Brassington ldquoSorption of organic acids inacid soils and its implications in the rhizosphere soilrdquo EuropeanJournal of Soil Science vol 49 pp 447ndash455 1998

[38] M Farrell W T Perkins P J Hobbs G W Griffith and D LJones ldquoMigration of heavy metals in soil as influenced bycompost amendmentsrdquo Environmental Pollution vol 158 no 1pp 55ndash64 2010

[39] A W Schroth B C Bostick J M Kaste and A J FriedlandldquoLead sequestration and species redistribution during soilorganic matter decompositionrdquo Environmental Science amp Tech-nology vol 42 no 10 pp 3627ndash3633 2008

[40] M Levonmaki H Hartikainen and T Kairesalo ldquoEffect oforganic amendment and plant roots on the solubility andmobilization of lead in soils at a shooting rangerdquo Journal ofEnvironmental Quality vol 35 no 4 pp 1026ndash1031 2006

[41] A Perez-de-Mora P Burgos E Madejon F Cabrera P Jaeckeland M Schloter ldquoMicrobial community structure and functionin a soil contaminated by heavy metals effects of plant growthand different amendmentsrdquo Soil Biology and Biochemistry vol38 no 2 pp 327ndash341 2006

[42] S Doni C MacCi E Peruzzi M Arenella B Ceccanti andG Masciandaro ldquoIn situ phytoremediation of a soil histori-cally contaminated by metals hydrocarbons and polychloro-biphenylsrdquo Journal of Environmental Monitoring vol 14 no 5pp 1383ndash1390 2012

[43] J Wyszkowska J Kucharski and W Lajszner ldquoThe effects ofcopper on soil biochemical properties and its interaction withother heavy metalsrdquo Polish Journal of Environmental Studiesvol 15 no 6 pp 927ndash934 2006

[44] M Farrell G W Griffith P J Hobbs W T Perkins and D LJones ldquoMicrobial diversity and activity are increased by com-post amendment of metal-contaminated soilrdquo FEMSMicrobiol-ogy Ecology vol 71 no 1 pp 94ndash105 2010

[45] P Miretzky and A Fernandez-Cirelli ldquoPhosphates for Pbimmobilization in soils a reviewrdquo Environmental ChemistryLetters vol 6 no 3 pp 121ndash133 2008

[46] K G Scheckel J A Ryan D Allen and N V Lescano ldquoDeter-mining speciation of Pb in phosphate-amended soils methodlimitationsrdquo Science of the Total Environment vol 350 no 1-3pp 261ndash272 2005

[47] P Castaldi L Santona and P Melis ldquoHeavy metal immobiliza-tion by chemical amendments in a polluted soil and influenceonwhite lupin growthrdquoChemosphere vol 60 no 3 pp 365ndash3712005

[48] A Ruttens M Mench J V Colpaert J Boisson R Carleer andJ Vangronsveld ldquoPhytostabilization of a metal contaminatedsandy soil I influence of compost andor inorganic metalimmobilizing soil amendments on phytotoxicity and plantavailability of metalsrdquo Environmental Pollution vol 144 no 2pp 524ndash532 2006

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


Table 1 Physicochemical properties of contaminated soil used in this study (on the basis of air-dried weight)

Sand Silt Clay pH TC TN WSOCa WS-Pbb Total Amorphous Fe() () () (g kgminus1) (g kgminus1) (mg kgminus1) (mg kgminus1) Pb (g kgminus1) P (g kgminus1) Al (g kgminus1) Fe (g kgminus1) (g kgminus1)815 95 90 73 60 00 139 35 440 040 131 338 13aWater-soluble organic carbonbWater-soluble lead

Lead immobilization by AMC can be separated into indi-rect and direct mechanismsThe typical indirect mechanismsof lead immobilization are explained by the pH increaseowing to the alkalinity of the inorganic component in AMCthis pH increase can promote the precipitation of leadcarbonate and hydroxide minerals resulting in a reductionof lead mobility and bioavailability [1 20] The direct mecha-nisms of lead immobilization by AMC have been consideredto be the reaction of the lead with the inorganic and organiccomponents in AMC Phosphorus sulfate and iron in theinorganic component and humic substances in the organiccomponent in AMC seem to be the sources responsible forthe reaction with lead [10 18 21ndash23] Katoh et al [24] applieda specific method for the fractionation of the inorganic andacid-insoluble organic components from AMC to elucidatetheir separate contributions to lead immobilization Theyindicated that the inorganic component in AMC couldimmobilize leadmore effectively than its organic components[24] These results imply that the inorganic component inAMC has a crucial role in lead immobilization and AMCwith a higher inorganic content is more suitable Howeverto rehabilitate microbial activity the organic component inAMC is also required since it supplies sufficient nutrientsto soil microorganisms [17] This component however maynegatively affect lead mobility water-soluble organic matterin AMC reacts and forms complexes with lead ions resultingin enhancements in lead mobility Therefore a suitable ratioof inorganic and organic components in AMC should beclarified to reduce themobility and bioavailability of lead andenhance the microbial activities in the soil AMC has a widerange of the inorganic-to-organic component ratios [25]however to our knowledge the optimal ratio of inorganic-to-organic components in AMC for lead immobilization andthe rehabilitation of microbial activity have not been studied

We investigated the mobility and bioavailability of thelead lead phases and microbial activities in soil amendedwith the AMCs of various inorganic-to-organic componentratiosThe inorganic fractionwas derived from swinemanurecompost and the acid-insoluble organic fraction was derivedfrom cattle manure compost These fractions can immobilizelead more effectively than other AMCs owing to the highcontent of phosphorus and mature organic matter in theinorganic and acid-insoluble organic fractions respectively[24] We aimed to identify how the ratio of inorganic-to-organic components in AMC affected the mobility andbioavailability of lead lead phase and microbial activity Onthe basis of the obtained results we discuss the optimalratio of the inorganic and organic components in AMC toimmobilize lead and rehabilitate microbial activity in soil

Table 2 Chemical properties of inorganic and acid-insolubleorganic fractions used in this study (on the basis of air-dried weightmg gminus1) [24]

Characteristic Inorganic fraction Acid-insolubleorganic fraction

Total calcium 152 NDlowast1

Total magnesium 44 NDTotal potassium 53 NDTotal iron 7 NDTotal phosphorus 131 NDTotal carbon ND 452ADF-Clowast2 ND 344Humic acid carbon ND 25Fulvic acid carbon ND 52lowast1Not determinedlowast2Acid detergent fiber carbon

2 Materials and Methods

21 Preparation of Soil The lead-contaminated soil usedherein was collected from depths of 5ndash15 cm at a shootingrange located at 35∘281015840610158401015840N and 137∘291015840210158401015840E in Gifu JapanThe soil sample was air-dried passed through a 2mm sieveand was used for chemical analysis and incubation testsThe selected physicochemical properties of the soil used areshown in Table 1The soil had a sandy loam textureThe totallead content of the soil was 440 g kgminus1 and the soil pH was73

22 Preparation of Animal Manure Compost Commercialswine and cattle manure composts were used herein toobtain the inorganic and acid-insoluble organic fractionsrespectively We selected these composts since each fractionof the compost can immobilize lead more effectively thanother composts [24] The fractionation followed the methoddescribed by Katoh et al [24] In brief the swine manurecompost was combusted at 600∘C for 2 h the residue aftercombustion was used as the inorganic fraction The cattlemanure compost was subjected to extraction with 1M HClfor 1 h to remove almost all inorganic components and theresidue after extractionwas used as the acid-insoluble organicfraction The pH of each fraction was adjusted to 7 to matchthat of the soil Table 2 shows the selected chemical propertiesof each fraction [24] The calcium magnesium potassiumiron and phosphorus contents in the inorganic fraction were152 44 53 7 and 131mg gminus1 respectively moreover thetotal acid-detergent fiber humic acid and fulvic acid carbon





2


2

SO4


2


119862119904

=119881 times 119865 minus 119862

119887

119878 (1)

where 119862119904



2

mLminus1) 119862119887



2





3


2



3

solution 5mL 30 H2

O2


3





3 Results






0

20

40

60

80

100


Wat

er-s

olub

le le

ad (m

g kgminus

1)

75255050

25750100

1000

Control(a)

0

600

1200

1800


Wat

er-s

olub

le o

rgan

ic ca

rbon

(mg

kgminus1)

75255050

25750100

1000

Control(b)




2


2


2




0

200

400

600

800


100050500100

CO2

emiss

ion

deriv

ed fr

om co

mpo

st (m

g kgminus

1)



1000 7525 5050 2575 0100 Control0

20

40

60

80

100

Lead

frac

tion

of su

m to

tal (

)







4 Discussion


2


2



00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)










5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics


















2


2

SO4


2


119862119904

=119881 times 119865 minus 119862

119887

119878 (1)

where 119862119904



2

mLminus1) 119862119887



2





3


2



3

solution 5mL 30 H2

O2


3





3 Results






0

20

40

60

80

100


Wat

er-s

olub

le le

ad (m

g kgminus

1)

75255050

25750100

1000

Control(a)

0

600

1200

1800


Wat

er-s

olub

le o

rgan

ic ca

rbon

(mg

kgminus1)

75255050

25750100

1000

Control(b)




2


2


2




0

200

400

600

800


100050500100

CO2

emiss

ion

deriv

ed fr

om co

mpo

st (m

g kgminus

1)



1000 7525 5050 2575 0100 Control0

20

40

60

80

100

Lead

frac

tion

of su

m to

tal (

)







4 Discussion


2


2



00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)










5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics

















0

20

40

60

80

100


Wat

er-s

olub

le le

ad (m

g kgminus

1)

75255050

25750100

1000

Control(a)

0

600

1200

1800


Wat

er-s

olub

le o

rgan

ic ca

rbon

(mg

kgminus1)

75255050

25750100

1000

Control(b)




2


2


2




0

200

400

600

800


100050500100

CO2

emiss

ion

deriv

ed fr

om co

mpo

st (m

g kgminus

1)



1000 7525 5050 2575 0100 Control0

20

40

60

80

100

Lead

frac

tion

of su

m to

tal (

)







4 Discussion


2


2



00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)










5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics















0

200

400

600

800


100050500100

CO2

emiss

ion

deriv

ed fr

om co

mpo

st (m

g kgminus

1)



1000 7525 5050 2575 0100 Control0

20

40

60

80

100

Lead

frac

tion

of su

m to

tal (

)







4 Discussion


2


2



00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)










5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics















00

05

10

15

20

1000 7525 5050 2575 0100 Control

C

B

B

B

AA

Deh

ydro

gena

se(120583

g TP

F g

soil

dwminus1

hminus1)

(a)

0

20

40

60

80

100

1000 7525 5050 2575 0100 Control

ABAB

B

A AA

Ure

ase

(120583g

NH

4-N

g so

ildw

minus1

hminus1)

(b)

0

5

10

15

20

1000 7525 5050 2575 0100 Control

B

B

B

AB

AB

A

Sacc

hara

se(n

g gl

ucos

e g so

ildw

minus1

hminus1)

(c)










5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics



















5 Conclusion





Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics

















Acknowledgments


References























































Journal of












Volume 2014

Advances in









Geophysics








































Journal of












Volume 2014

Advances in









Geophysics














research article role of inorganic and organic fractions...

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