research article effects of deep tillage and straw...

Research ArticleEffects of Deep Tillage and Straw Returning on SoilMicroorganism and Enzyme Activities

Baoyi Ji12 Hao Hu3 Yali Zhao1 Xinyuan Mu1 Kui Liu4 and Chaohai Li1

1 Agronomy College Henan Agricultural Universtiy Zhengzhou 450002 China2 Institute of Horticulture Henan Academy of Agricultural Sciences Zhengzhou 450002 China3 Institute of Digital Agriculture Zhejiang Academy of Agricultural Sciences Hangzhou Zhejiang 310021 China4Department of Engineering Nova Scotia Agricultural College Truro NS Canada B2N 5E3

Correspondence should be addressed to Chaohai Li lichaohai2005163com

Received 10 November 2013 Accepted 2 February 2014 Published 26 March 2014

Academic Editors M R Simon and T Takamizo

Copyright copy 2014 Baoyi Ji et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Two field experiments were conducted for two years with the aim of studying the effects of deep tillage and straw returning on soilmicroorganism and enzyme activity in clay and loam soil Three treatments (1) conventional tillage (CT) shallow tillage and strawreturning (2) deep tillage (DT) deep tillage and straw returning and (3) deep tillage with no straw returning (DNT) were carriedout in clay and loam soil The results showed that deep tillage and straw returning increased the abundance of soil microorganismandmost enzyme activities Deep tillage was more effective for increasing enzyme activities in clay while straw returning was moreeffective in loam Soil microorganism abundance andmost enzyme activities decreased with the increase of soil depth Deep tillagemainly affected soil enzyme activities in loam at the soil depth of 20ndash30 cm and in clay at the depth of 0ndash40 cm Straw returningmainly affected soil microorganism and enzyme activities at the depths of 0ndash30 cm and 0ndash40 cm respectively

1 Introduction

In China traditional tillage in grain production areas wasshallow ploughed to the depth of about 0ndash20 cm This mayresult in soil hardpan layer and affect crop growth andproduction Farmers also had the tradition of straw returningbut recently most straws were burned for labor saving whichwas a waste of resources and caused environment pollutionIt has been accepted that deep tillage and straw returningwere significant for the improvement of soil characteristicsand agricultural sustainable development Deep tillage couldremediate subsoil compaction break up high-density soillayer [1] improve water infiltration change the soil aggregatesize distribution [2] enhance root growth and developmentand increase crop production potential [3] Crop straw inthe soil surface couldmoderate soil temperature and increasewater infiltration and soil organic carbon [4]

Soil microorganism and enzyme activity are importantindicators of soil quality [5]The change of soil physicochem-ical characters may directly influence soil microorganism

and enzyme activity As is known soil microorganism andenzyme activity could activate potential soil nutrient andincrease crop yield Bacteria actinomycetes and fungi arethe main soil microorganisms They can decompose organicresidues produce antibiotics and supply food sources fororganisms [6] Soil microorganisms help to reduce cropresidues and biochemically process nutrients to improve thesoil They are major sources of soil enzymes which seemto be related to agriculture management practices Enzymesplay an important role in the nutrients cycling Benıtez etal thought it can be used as an indicator of soil microbialactivity and fertility [7] On the other hand enzymes wereinvolved in soil mineralization processes and related to somesoil biological properties [8] Soilmicroorganism and enzymeactivity profiles reflect an important part of plants and soilwhich is in close relation to agriculture practice

Previous studies indicated that tillage and straw return-ing had great effect on soil microbial community andenzyme activity Govaerts et al found that residue applicationincreased the soil microbial community [9] In many cases

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 451493 12 pageshttpdxdoiorg1011552014451493

2 The Scientific World Journal

bacteria and fungi under no-tillage weremore abundant thanconventional tillage [10] Spedding et al found the residuein no-tillage systems was mainly decomposed by the fungalcommunity [11] Deng and Tabatabai reported that activitiesof phosphatases in no-tilldouble mulch were significantlygreater than those of other treatments studied [12]

However the influence of deep tillage on soil microbialcommunity and enzyme activity was seldom studied Soiltexture had marked influence on the structure and activityof microbial population and mineralization of carbon Thedirect effects of deep tillage and straw returning in differentsoil types on microorganism and enzyme activities werenot known This study investigated the effect of deep tillageand straw returning on soil microorganism (actinomycetebacteria and fungi) and enzyme activities (catalase phos-phatase urease and saccharase) in clay and loam soil Theobjective was to reveal the direct response of soil microbialcommunity and enzyme activity to deep tillage and strawreturning and obtain the internal function mechanism forfuture agricultural guidance

2 Materials and Methods

21 Study Sites Two field experiments were established dur-ing the maize growing seasons of 2010 and 2011 on the farmof Hebi County Academy of Agricultural Science (35∘671015840N114∘981015840 E) and Luohe County Academy of Agricultural Sci-ence (33∘571015840N 113∘981015840 E) Henan province China Both siteshave a continental monsoon type climate The soils of Hebiand Luohe were classified as loam and clay soil accordingto the USA soil taxonomy method (Soil Survey Staff USA1999) The data of monthly average temperature and rainfallduring the study periodwere collected from aweather stationadjacent to the experimental fields and were presented inFigure 1 of [13] Soil samples were collected at the beginningof experiment The main physical and chemical properties ofsoils in the two study sites were presented in Table 1 of [13]

22 Experiment Designs The experiment was designed asa randomized block with three replications Three treat-ments were set up (1) conventional tillage (CT) moldboardploughed to a depth of 20 cm and straw was returned(2) deep tillage (DT) moldboard ploughed to a depth of30 cm and straw was returned and (3) deep tillage andstraw removed (DNT) moldboard ploughed to a depth of30 cm and straw was removed The crop rotation consistedof winter wheat and summer maize Soil tillage was carriedout after the harvest of maize and before the winter wheatsowing Residues of postharvest winter wheat were left onthe soil surface throughout the study periods Maize residueswere ploughed into the soil with tillage in the CT and DTtreatments

Each treatment plot had 60m times 20m area The sum-mer maize hybrid Zhengdan 958 was sown at a densityof 67500 plant haminus1 on June 7 at Hebi and June 5 atLuohe during the two years Basal fertilizers of 135 kgNhaminus1as urea 135 kg P

2O5haminus1 as diammonium phosphate and

180 kgK2Ohaminus1 as potassium sulfate were applied just before

sowing according to N P and K content in the soil135 kgNhaminus1 as urea was applied at 12-leaf full expansionThe same culture practices were implemented to all theexperimental plots

23 Measurements of Soil Microbial Abundances and EnzymeActivities Soil samples were taken from selected plots withthree replications from the soil profile depths of 0ndash10 cm 10ndash20 cm 20ndash30 cm and 30ndash40 cm in the grain physiologicalmaturity stage (in October) over the 2010-2011 time periodsThe soil samples were sieved through a 2mm sieve and storedin a refrigerator at 4∘C Soil microbial functional groups wereanalyzed using the most probable number method describedby previous studies [14]

Soil urease activity was measured using indophenol col-orimetry method with urea as the substrate Briefly ammo-nium was released over 1 h and assayed colorimetricallyat 578 nm Soil urease activity was expressed as mgNH

3ndash

N gminus1 dry soil Saccharase activity was determined by 35-dinitrosalicylic acid colorimetry method using sucrose asthe substrate It was expressed as mg glucose gminus1 dry soilSoil phosphatase activity was determined with disodiumphenyl phosphate colorimetry according to Ge et al [15] andcatalase activity was determined according to Johnson andTemple [16] The enzyme activities were expressed as mg p-nitrophenol released gminus1 dry soil in the case of phosphataseand as 120583molKMnO

4gminus1 dry soil minminus1 for catalase All

determinations of enzymatic activities were performed intriplicate with values reported as means

24 Statistical Analysis Analyses were performed in threereplicates and average values were presented Analysis ofvariance (ANOVA) was conducted using SPSS 170 software(IBM SPSS Inc 2009) Differences between the two yearstillage systems and soil textures were compared by theStudent 119905-test Statistically significant differences among thedifferent soil depths were determined by Duncanrsquos testSignificant differences were accepted at 119875 le 005 level andindicated in different letters unless otherwise statedThe sameletters in the graph and columns of tables represented nosignificant difference statistically (119875 gt 05)

3 Results and Discussion

31 Effects of Deep Tillage and Straw Returning on SoilMicroorganism Tillage and straw returning had great influ-ence on soil microorganism The abundance of soil microor-ganism (actinomycetes bacteria and fungi) under CT DTandDNT conditions in loam and clay was shown in Figures 12 and 3 Seen from the above figures and Table 1 the numberof soil actinomycetes bacteria and fungi followed the orderof DT gt CT gtDNTThe difference of the three treatments allreached significant level (119875 lt 005) DT gt CT indicated thatdeep tillage increased the abundance of soil microorganismIt may be because deep tillage loosens the soil and addsthe organic matter into the soil Studies also proved thatdeep tillage could improve the soil physical characteristicsdecrease the soil penetration resistance and increase the

The Scientific World Journal 3

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Figure 1 Effects of tillage and straw returning on the number of soil actinomycetes Different small letters indicated significant difference at119875 lt 005 according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returnedDT represented deep tillage moldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillage moldboardploughed to a depth of 30 cm and straw was removed

soil porosity [17] DT gt DNT indicated that straw returningincreased the abundance of soil microorganism What ismore straw returning was proved to increase the carbonresource accelerating soil microorganism breeding and alsostraw increased the capacity of the small-sized fractions toprotect soil microorganisms [18] Govaerts et al reported thatresidue retention induced higher population counts of totalbacteria fluorescent Pseudomonas and actinomycetes com-pared to residue removal under zero tillage and conventionaltillage [19]

311 Differences of Two Soil Textures Soil microbes wereaffected by soil texture The number of soil actinomycetesbacteria and fungi in loam and clay soil was shown in Figures1 2 and 3 and Table 1The significant differences between theloam and clay soil were found (119875 lt 005) It was shown thatthe number of soil actinomycetes and fungi in clay soil was1512 and 429higher than those in loam soilMaybe it wasbecause clay soil contained more fine texture clay particlesthan loam soil Meliani et al revealed that fine-textured soilstypically contain greater quantities of organic matter and


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Figure 2 Effects of tillage and straw returning on the number of soil bacteria Different small letters indicated significant difference at119875 lt 005 according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returnedDT represented deep tillage moldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillage moldboardploughed to a depth of 30 cm and straw was removed

microbial biomass than coarse-textured soils [20] Clay-sizedparticles were thought to shelter soil microorganisms frompredation [21] According to the study of Alvarez et al thefine-textured soil (lt50 microns) has a protective effect ontotal microbial biomass [22]

312 Differences ofThreeMicrobe Species For actinomycetesbacteria and fungi the DTCT values were calculated from(1) DT treatment in loam was higher than CT by 523164 and 146 while in clay DT treatmentwas higher thanthose of CT by 243 145 and 313 These indicated that

deep tillage had the greatest effect on soil actinomycete inloam and on the soil fungi in clay For soil bacteria effect ofdeep tillage in clay was a bit higher than in loam

DTCT = DT minus CTCT (1)

Compared with DNT from the DTDNT value (2) thenumber of actinomycetes bacteria and fungi of DT treat-ment was greatly increased by 770 500 and 1582 inloam while those of DNT treatment in clay were increasedby 1775 627 and 540 These suggested that straw


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Figure 3 Effects of tillage and straw returning on the number of soil fungi Different small letters indicated significant difference at 119875 lt 005according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returned DTrepresented deep tillagemoldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillagemoldboard ploughedto a depth of 30 cm and straw was removed

returning increased the number of soil fungi bacteria andactinomycetesThe effect of straw returning on actinomyceteand bacteria in clay was greater than that in loam Effect ofstraw returning on soil fungi abundance in clay was lowerthan that in loam soil

DTDNT = DT minus DNTDNT

(2)

313 Differences of Soil Depth Figures 1 2 and 3 showedthat no matter clay or loam soil with the soil samplingdepth increasing the number of soil actinomycetes bacteria

and fungi decreased constantly This agreed with the resultof Qiao et al [23] And Zhao also found that bacteriafungi and actinomycetes mainly distribute in the layer of 0ndash40 cm being gradually decreased with the increasing depthof soil layers [24] The surface soil contained more soilmicroorganisms than the deep soil Maybe there were moreorganic matter or organic carbon and dissolved organiccarbon providing good living condition and food for soilmicroorganism in the surface soil [25]

Tillage management greatly affected the distributionof soil microorganism in different soil depths Seen from


Table 1 Differences of tillage year soil depth and soil texture on soil microorganism and enzyme activities

Soil texture Factor Actinomycete Bacteria Fungi Urease Phosphatase Saccharase Catalase

Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b

T (tillage)CT 086b 317b 151b 289b 211b 121a 153c

DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a

10ndash20 cm 117b 358b 143b 290b 272b 145b 162ab

20ndash30 cm 075c 297c 057c 282c 192c 097c 165ab

30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b

T (tillage)CT 288b 324b 176b 268a 268b 111b 175c

DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a

Note different small letters in the column indicated significant difference at 119875 lt 005 Differences between 2010 and 2011 were compared by the Student 119905-test(2-tailed test) Differences among the different soil depths and soil tillage were determined by Duncanrsquos test CT represented conventional tillage moldboardploughed to a depth of 20 cm and straw was returned DT represented deep tillage moldboard ploughed to a depth of 30 cm and straw was returned DNTrepresented deep tillage moldboard ploughed to a depth of 30 cm and straw was removed

Table 2 DTCT and DTDNT values of soil microorganism in the loam and clay soil

Depth Actinomycete Bacteria FungiLoam Clay Loam Clay Loam Clay

DTCT

0ndash10 cm 0447 0251 0041 0003 0057 009910ndash20 cm 0628 0241 minus0024 0062 0197 020120ndash30 cm 0797 0301 0707 0671 0613 198730ndash40 cm 0030 0064 0428 0423 0203 0401

DTDNT

0ndash10 cm 0648 1660 0749 0366 2342 024810ndash20 cm 1032 1663 0785 0839 1702 104520ndash30 cm 1111 3038 0198 0998 0486 084130ndash40 cm 0008 0973 0106 0686 0058 0587

Bold numbers in the column represented the maximal value

Table 2 DT treatment had the greatest effect on actinomycetein the depth of 20ndash30 cm which can be obtained from thevalue of DTDNT in different depths Similarly in the depthof 20ndash30 cm DT treatment contained higher bacteria andfungi numbers than CT These data all suggested that soilmicroorganism at the soil depth of 20ndash30 cm was moreeasily affected by deep tillage Egamberdiyeva et al alsoreported that microbial population was different in differentsoil depths The abundance of bacteria was found higher at20ndash30 cm depth after tomato and wheat tillage [26]

Straw returning was another factor affecting the soilmicroorganism in different soil depths Seen from Table 2actinomycete numbers in the depth of 20ndash30 cm were easierto be influenced by straw returning This could be indicated

by the highest DTDNT values which were 1111 and 3083higher in loam and clay respectively For bacteria the depthsof 10ndash20 cm in loam and 20ndash30 cm in clay were the easiestaffected layer with the highest DTDNT of 785 and 998And for fungi the depths of 0ndash10 cm in loam and 10ndash20 cm in clay were the easiest affected layer with the highestDTDNT of 2342 and 1045These results showed that soilmicroorganisms in the depth of 0ndash30 were the most easilyaffected layer by straw returning

32 Effects of Deep Tillage and StrawReturning on Soil EnzymeActivities Tillage and straw returning had great effects onsoil enzyme activities The soil enzymes activities (urease


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Figure 4 Effects of tillage and straw returning on soil urease activity Different small letters indicated significant difference at 119875 lt 005according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returned DTrepresented deep tillagemoldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillagemoldboard ploughedto a depth of 30 cm and straw was removed

phosphatase saccharase and catalase) of CT DT and DNTtreatments in loam and clay were shown in Figures 4 56 and 7 Seen from the figures and Table 1 the activitiesof urease phosphatase and saccharase generally followedthe order of DT gt CT gt DNT For the four soil enzymeactivities it had the tendency of DT gt CT which indicatedthat deep tillage increased the soil enzyme activities It maybe because deep tillage loosens the soil and adds the organicmatter into the soil which increased the abundance of soilmicroorganismThemore soilmicroorganism the higher soilenzyme activities It was consistent with our results of deeptillage on soil microorganism On the other hand urease

phosphatase and saccharase activities ofDTwere higher thanDNTThis suggested that straw returning increased most soilenzyme activities Jin et al also reported that subsoiling withmulch consistently had higher enzyme activities comparedwith no-till with mulch [27]

321 Differences of Two Soil Textures Soil texture had greateffect on soil enzyme activities The activities of soil ureasephosphatase saccharase and catalase in loam and clay soilwere shown in Figures 4 5 6 and 7 and Table 1 It couldbe found that the activities of urease in loam soil were


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Figure 5 Effects of tillage and straw returning on soil phosphatase activity Different small letters indicated significant difference at 119875 lt 005according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returned DTrepresented deep tillagemoldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillagemoldboard ploughedto a depth of 30 cm and straw was removed

937 higher than those in clay soil Phosphatase and catalaseactivities of clay soil were 985 and 960 higher than thoseof loam soil Urease and catalase activities were significantlydifferent between loam and clay soil There was no obviousdifference of saccharase activities between loam and clay soilIt suggested that most soil enzyme activities were higher inclay soil Maybe it was because clay soil contains more finetexture clay particles inhabiting more soil microorganismswhich were the resources of soil enzymes [21 22]

Seen from Table 3 DTNT values of urease phosphataseand saccharase activities in loam were lower than those inclay It indicated that effect of deep tillage onmost soil enzyme

activities in the loam was lower than that in the clay soilSimilarly DTDNT values of studied enzyme activities in theloamwere higher than in clay It suggested that effect of strawreturning on the soil enzyme activities in the loamwas higherthan in the clay

322 Differences of Four Enzyme Species Seen from theaverage values of each enzyme activity in clay and loamsoil the four enzyme activities followed the order of ureasegt phosphatase gt catalase gt saccharase Of the average ofall soil depths urease activity of clay was lower than that


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Figure 6 Effects of tillage and straw returning on soil saccharase activity Different small letters indicated significant difference at 119875 lt 005according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returned DTrepresented deep tillagemoldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillagemoldboard ploughedto a depth of 30 cm and straw was removed

of loam by 86 and the difference reached significantlevel (119875 lt 005) Activities of phosphatase and catalasein clay soil were higher than those of loam soil by 109and 106 respectively The difference of catalase activitybetween clay and loam reached significant level (119875 lt001) Saccharase activity in clay was lower than in loamby 46 Almost no difference was found between theloam and clay for the saccharase activity It indicated thatphosphatase and catalase enzyme activities were higher andurease had lower activities in clay Small and no significantdifference of saccharase activities was found between theloam and clay soil Activities of enzyme speciesmay be related

to organic matter mineralization and humification in thesoil

For the four soil enzyme activities regardless of soiltexture they had the similar tendency of DT gt CT Ureasephosphatase and saccharase activities of DT were higherthan DNT But catalase activity of DT in the loam and claywas lower than DNT They suggested that straw returningincreased the activities of urease phosphatase and saccharasebut decreased the catalase activities The effect of strawreturning on urease was in agreement with Lu et al [28]which showed that the treatments incorporated with strawwere higher in urease and phosphatase activities


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Figure 7 Effects of tillage and straw returning on soil catalase activity Different small letters indicated significant difference at 119875 lt 005according to Duncanrsquos test CT represented conventional tillage moldboard ploughed to a depth of 20 cm and straw was returned DTrepresented deep tillagemoldboard ploughed to a depth of 30 cm and straw was returned DNT represented deep tillagemoldboard ploughedto a depth of 30 cm and straw was removed

323 Differences of Soil Depth Effect of tillage on soil enzymeactivities was affected by soil depth With the increasing ofsoil depth urease saccharase and phosphatase activities alldecreased (Figures 4 5 and 6) Kheyrodin et al [29] alsoreported that urease activity decreased markedly with soildepth Deng and Tabatabai [12] found that phosphatasesactivities decreased with increasing soil depth They thoughtthis decrease may be associated with the decrease in organiccarbon content Most enzyme activities in the surface soilwere higher than deep soil This may be because there weremore soil microorganism and plant residues in the surfacesoil which were the main parts of soil enzymes

For urease deep tillage in loam was most effective in thedepth of 20ndash30 cm (Figure 4 and Table 3) At this soil depthurease of DT had the highest DTCT value and was 695higher than CT For urease in clay soil deep tillage was mosteffective in 0ndash10 cm At this depth urease activities of DTwere 135 higher than CT Similarly deep tillage had thegreatest effect on the activities of phosphatase saccharaseand catalase at the depth of 20ndash30 cm in loam For the clayat the depth of 20ndash30 cm deep tillage had the greatest effecton phosphatase and catalase activities For saccharase in clayit was at the depth of 30ndash40 cm where DT was 3504 higherthan CT It suggested that deep tillage mainly affected the


Table 3 DTCT and DTDNT values of urease phosphatase saccharase and catalase activities in loam and clay soil

Urease Phosphatase Saccharase CatalaseLoam Clay Loam Clay Loam Clay Loam Clay

DTCT

0ndash10 cm 0031 0135 0051 0182 minus0012 0077 0076 009110ndash20 cm 0058 0021 0132 0273 minus0131 0047 0197 012720ndash30 cm 0070 0045 0144 0159 0321 0030 0305 007930ndash40 cm 0062 0070 0031 0659 0123 0183 0171 0107

DTDNT

0ndash10 cm 0137 0169 0524 0274 0087 0175 0066 007010ndash20 cm 0124 0099 0622 0533 0119 0122 0145 005620ndash30 cm 0148 0136 0472 0388 0488 0144 0188 007630ndash40 cm 0188 0164 0405 minus0025 0322 0350 0160 0058


loam soil at the soil depth of 20ndash30 cm and the clay soil atalmost all the studied soil depths from 0 to 40 cm

Seen from Table 3 in loam the greatly affected depth ofthe activities of urease phosphatase saccharase and catalaseby straw returning was 30ndash40 cm 10ndash20 cm 20ndash30 cm and20ndash30 cm In clay the greatest affected depth for ureasephosphatase saccharase and catalase activities was 0ndash10 cm20ndash30 cm 30ndash40 cm and 20ndash30 cm It suggested that strawreturning affected soil enzyme activities at almost all the soildepths (0ndash40 cm)

4 Conclusions

In conclusion deep tillage and straw returning increasedthe abundance of soil microorganism and most enzymeactivities Deep tillage was more effective for increasingenzyme activities in clay while straw returning was moreeffective in loam Soil microorganism abundance and mostenzyme activities decreased with the increase of soil depthDeep tillage mainly affected soil enzyme activities in loam atthe soil depth of 20ndash30 cm and in clay soil at the depth of 0ndash40 cm Straw returning mainly affected soil microorganismand soil enzyme activities at the depths of 0ndash30 cm and 0ndash40 cm respectively

Disclosure

Hao Hu is co-first author

Conflict of Interests

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

References

[1] P P Motavalli W E Stevens and G Hartwig ldquoRemediationof subsoil compaction and compaction effects on corn Navailability by deep tillage and application of poultry manurein a sandy-textured soilrdquo Soil and Tillage Research vol 71 no 2pp 121ndash131 2003

[2] R L Baumhardt and O R Jones ldquoLong term benefits of deeptillage on soil physical properties and crop yieldrdquo in Proceedings

of the 27th Southern Conservation Tillage Systems Conferencepp 95ndash101 Florence Ky USA 2005

[3] A T P Bennie and F J P Botha ldquoEffect of deep tillage andcontrolled traffic on root growth water-use efficiency and yieldof irrigated maize and wheatrdquo Soil and Tillage Research vol 7no 1-2 pp 85ndash95 1986

[4] S M Dabney J A Delgado and D W Reeves ldquoUsing wintercover crops to improve soil and water qualityrdquo Communicationsin Soil Science and Plant Analysis vol 32 no 7-8 pp 1221ndash12502001

[5] S Pajares J F Gallardo G Masciandaro B Ceccanti and JD Etchevers ldquoEnzyme activity as an indicator of soil qualitychanges in degraded cultivated Acrisols in the Mexican Trans-volcanic Beltrdquo Land Degradation and Development vol 22 no3 pp 373ndash381 2011

[6] G B Mahajan and L Balachandran ldquoAntibacterial agents fromactinomycetesmdasha reviewrdquo Frontiers in Bioscience vol 4 pp240ndash253 2012

[7] E Benıtez R Melgar H Sainz M Gomez and R NogalesldquoEnzyme activities in the rhizosphere of pepper (Capsicumannuum L) grown with olive cake mulchesrdquo Soil Biology andBiochemistry vol 32 no 13 pp 1829ndash1835 2000

[8] W T Frankenberger Jr andW A Dick ldquoRelationships betweenenzyme activity and microbial growth and activity indices insoilrdquo Soil Science Society of America Journal vol 47 no 5 pp945ndash951 1983

[9] B Govaerts M Mezzalama Y Unno et al ldquoInfluence oftillage residuemanagement and crop rotation on soilmicrobialbiomass and catabolic diversityrdquoApplied Soil Ecology vol 37 no1-2 pp 18ndash30 2007

[10] B L Helgason F L Walley and J J Germida ldquoFungal andbacterial abundance in long-term no-till and intensive-till soilsof the Northern Great Plainsrdquo Soil Science Society of AmericaJournal vol 73 no 1 pp 120ndash127 2009

[11] T A Spedding C Hamel G R Mehuys and C AMadramootoo ldquoSoil microbial dynamics in maize-growing soilunder different tillage and residue management systemsrdquo SoilBiology and Biochemistry vol 36 no 3 pp 499ndash512 2004

[12] S P Deng and M A Tabatabai ldquoEffect of tillage and residuemanagement on enzyme activities in soils III Phosphatases andarylsulfataserdquoBiology and Fertility of Soils vol 24 no 2 pp 141ndash146 1997

[13] B Ji Y Zhao X Mu et al ldquoEffects of tillage on soil physicalproperties and root growth of maize in loam and clay in centralChinardquo Plant Soil and Environment vol 59 no 7 pp 295ndash3022013


[14] M Alexander ldquoMost-probable number method of microbialpopulationrdquo inMethods of Soil Analysis Part 2 A L Page Edvol 9 of Agronomy pp 815ndash820 2nd edition 1982

[15] G F Ge Z J Li J Zhang et al ldquoGeographical and climaticdifferences in long-term effect of organic and inorganic amend-ments on soil enzymatic activities and respiration in fieldexperimental stations of Chinardquo Ecological Complexity vol 6no 4 pp 421ndash431 2009

[16] J L Johnson and K L Temple ldquoSome variables affecting themeasurement of ldquocatalase activityrdquo in soilrdquo Soil Science Societyof America Processes vol 28 no 2 pp 207ndash209 1964

[17] H M R Javed M S I Zamir A Tanveer et al ldquoSoil physicalproperties and spring maize yield as influenced by differenttillage practices and integrated use of poultry manure withsynthetic fertilizersrdquo Journal of Agricultural Research vol 51 no3 pp 277ndash287 2013

[18] E Kandeler M Stemmer and E-M Klimanek ldquoResponse ofsoil microbial biomass urease and xylanase within particlesize fractions to long-term soil managementrdquo Soil Biology andBiochemistry vol 31 no 2 pp 261ndash273 1999

[19] B Govaerts M Mezzalama K D Sayre et al ldquoLong-term con-sequences of tillage residue management and crop rotation onselected soil micro-flora groups in the subtropical highlandsrdquoApplied Soil Ecology vol 38 no 3 pp 197ndash210 2008

[20] A Meliani A Bensoltane and K Mederbel ldquoMicrobial diver-sity and abundance in soil related to plant and soil typerdquoAmer-ican Journal of Plant Nutrition and Fertilization Technology vol2 no 1 pp 10ndash18 2012

[21] E T Elliott R V Anderson D C Coleman et al ldquoHabitablepore space and microbial trophic interactionsrdquo Oikos vol 35no 3 pp 327ndash335 1980

[22] G Alvarez R Chaussod D Cluzeau et al Biological Activitiesand Soil Fertility Interest and Limitations of Analytical MethodsAvailable Itab London UK 1st edition 2002

[23] H Qiao C Tian Y Luo J Sun and X Feng ldquoDiversity ofsoil microorganisms in natural Populus euphratica forests inXinjiang northwestern Chinardquo Frontiers of Forestry in Chinavol 3 no 3 pp 347ndash351 2008

[24] G D ZhaoThe growth and declining of soil microbe amount inroot zone and their influence to the plant replantation in the appleorchard of Loess Plateau [MS thesis] Northwest University ofScience and Technology 2008 (Chinese)

[25] B Sun P D Hallett S Caul T J Daniell and D W HopkinsldquoDistribution of soil carbon and microbial biomass in arablesoils under different tillage regimesrdquo Plant and Soil vol 338 no1 pp 17ndash25 2011

[26] D Egamberdiyeva D Juraeva B Haitov et al ldquoMicrobialand biochemical changes induced by rotation and tillage ina calcareous soil under melon tomato wheat and cottonproductionrdquo in Proceedings of the 26th Southern ConservationTillage Conference for Sustainable Agriculture pp 224ndash228Raleigh NC USA 2004

[27] K Jin S Sleutel D Buchan et al ldquoChanges of soil enzymeactivities under different tillage practices in the Chinese LoessPlateaurdquo Soil and Tillage Research vol 104 no 1 pp 115ndash1202009

[28] Y Q Lu A N Zhu J B Zhang et al ldquoEffects of no-tillageand straw incorporation on soil enzyme activity during wheatgrowthrdquo Journal of Ecology and Rural Environment vol 29 no3 pp 329ndash334 2013 (Chinese)

[29] H Kheyrodin K Ghazvinian and M Taherian ldquoTillage andmanure effect on soil microbial biomass and respiration and

on enzyme activitiesrdquo African Journal of Biotechnology vol 11no 81 pp 14652ndash14659 2012

Submit your manuscripts athttpwwwhindawicom

Nutrition and Metabolism

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Food ScienceInternational Journal of

Agronomy


International Journal of



Microbiology

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

AgricultureAdvances in


PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

GenomicsInternational Journal of


Plant GenomicsInternational Journal of


Biotechnology Research International


Forestry ResearchInternational Journal of


Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EcologyInternational Journal of


Veterinary Medicine International


Cell BiologyInternational Journal of


Evolutionary BiologyInternational Journal of



bacteria and fungi under no-tillage weremore abundant thanconventional tillage [10] Spedding et al found the residuein no-tillage systems was mainly decomposed by the fungalcommunity [11] Deng and Tabatabai reported that activitiesof phosphatases in no-tilldouble mulch were significantlygreater than those of other treatments studied [12]

However the influence of deep tillage on soil microbialcommunity and enzyme activity was seldom studied Soiltexture had marked influence on the structure and activityof microbial population and mineralization of carbon Thedirect effects of deep tillage and straw returning in differentsoil types on microorganism and enzyme activities werenot known This study investigated the effect of deep tillageand straw returning on soil microorganism (actinomycetebacteria and fungi) and enzyme activities (catalase phos-phatase urease and saccharase) in clay and loam soil Theobjective was to reveal the direct response of soil microbialcommunity and enzyme activity to deep tillage and strawreturning and obtain the internal function mechanism forfuture agricultural guidance

2 Materials and Methods

21 Study Sites Two field experiments were established dur-ing the maize growing seasons of 2010 and 2011 on the farmof Hebi County Academy of Agricultural Science (35∘671015840N114∘981015840 E) and Luohe County Academy of Agricultural Sci-ence (33∘571015840N 113∘981015840 E) Henan province China Both siteshave a continental monsoon type climate The soils of Hebiand Luohe were classified as loam and clay soil accordingto the USA soil taxonomy method (Soil Survey Staff USA1999) The data of monthly average temperature and rainfallduring the study periodwere collected from aweather stationadjacent to the experimental fields and were presented inFigure 1 of [13] Soil samples were collected at the beginningof experiment The main physical and chemical properties ofsoils in the two study sites were presented in Table 1 of [13]

22 Experiment Designs The experiment was designed asa randomized block with three replications Three treat-ments were set up (1) conventional tillage (CT) moldboardploughed to a depth of 20 cm and straw was returned(2) deep tillage (DT) moldboard ploughed to a depth of30 cm and straw was returned and (3) deep tillage andstraw removed (DNT) moldboard ploughed to a depth of30 cm and straw was removed The crop rotation consistedof winter wheat and summer maize Soil tillage was carriedout after the harvest of maize and before the winter wheatsowing Residues of postharvest winter wheat were left onthe soil surface throughout the study periods Maize residueswere ploughed into the soil with tillage in the CT and DTtreatments

Each treatment plot had 60m times 20m area The sum-mer maize hybrid Zhengdan 958 was sown at a densityof 67500 plant haminus1 on June 7 at Hebi and June 5 atLuohe during the two years Basal fertilizers of 135 kgNhaminus1as urea 135 kg P

2O5haminus1 as diammonium phosphate and

180 kgK2Ohaminus1 as potassium sulfate were applied just before

sowing according to N P and K content in the soil135 kgNhaminus1 as urea was applied at 12-leaf full expansionThe same culture practices were implemented to all theexperimental plots

23 Measurements of Soil Microbial Abundances and EnzymeActivities Soil samples were taken from selected plots withthree replications from the soil profile depths of 0ndash10 cm 10ndash20 cm 20ndash30 cm and 30ndash40 cm in the grain physiologicalmaturity stage (in October) over the 2010-2011 time periodsThe soil samples were sieved through a 2mm sieve and storedin a refrigerator at 4∘C Soil microbial functional groups wereanalyzed using the most probable number method describedby previous studies [14]

Soil urease activity was measured using indophenol col-orimetry method with urea as the substrate Briefly ammo-nium was released over 1 h and assayed colorimetricallyat 578 nm Soil urease activity was expressed as mgNH

3ndash

N gminus1 dry soil Saccharase activity was determined by 35-dinitrosalicylic acid colorimetry method using sucrose asthe substrate It was expressed as mg glucose gminus1 dry soilSoil phosphatase activity was determined with disodiumphenyl phosphate colorimetry according to Ge et al [15] andcatalase activity was determined according to Johnson andTemple [16] The enzyme activities were expressed as mg p-nitrophenol released gminus1 dry soil in the case of phosphataseand as 120583molKMnO

4gminus1 dry soil minminus1 for catalase All

determinations of enzymatic activities were performed intriplicate with values reported as means

24 Statistical Analysis Analyses were performed in threereplicates and average values were presented Analysis ofvariance (ANOVA) was conducted using SPSS 170 software(IBM SPSS Inc 2009) Differences between the two yearstillage systems and soil textures were compared by theStudent 119905-test Statistically significant differences among thedifferent soil depths were determined by Duncanrsquos testSignificant differences were accepted at 119875 le 005 level andindicated in different letters unless otherwise statedThe sameletters in the graph and columns of tables represented nosignificant difference statistically (119875 gt 05)

3 Results and Discussion

31 Effects of Deep Tillage and Straw Returning on SoilMicroorganism Tillage and straw returning had great influ-ence on soil microorganism The abundance of soil microor-ganism (actinomycetes bacteria and fungi) under CT DTandDNT conditions in loam and clay was shown in Figures 12 and 3 Seen from the above figures and Table 1 the numberof soil actinomycetes bacteria and fungi followed the orderof DT gt CT gtDNTThe difference of the three treatments allreached significant level (119875 lt 005) DT gt CT indicated thatdeep tillage increased the abundance of soil microorganismIt may be because deep tillage loosens the soil and addsthe organic matter into the soil Studies also proved thatdeep tillage could improve the soil physical characteristicsdecrease the soil penetration resistance and increase the


LoamSo

il de

pth

(cm

)0

10

20

30

402010

c

a

a

d

b

h

fg

ef

de

g

h

h

0 1 2 3 4 5 6 7 8 910


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

c

f

bc

f

e

de

b

ff

e

d

a

0 1 2 3 4 5 6 7 8 910


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

f

cd

a

f

f

e

bc

bc

b

d

f

f

0 1 2 3 4 5 6 7 8 9

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

f

f

e

f

c

e

b

de

f

a

a

d

0 1 2 3 4 5 6 7 8 9

CTDTDNT


(d)





LoamSo

il de

pth

(cm

)0

10

20

30

40

2010

d

h

f

f

eaa

gg

bb

c

0 2 4 6 8 10 12


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

e

f

d

b

c

dc

aa

ab

ff

0 2 4 6 8 10 12


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

bd

fef

b

a

d

a

f

cde

0 2 4 6 8 10 12

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

b

c

d

c

aa

e

f

g

g

f

f

0 2 4 6 8 10 12

CTDTDNT


(d)








LoamSo

il de

pth

(cm

)0

10

20

30

402010

d

g

e

g

b

c

a

g

fg

fgf

f


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010g

c

g

a

e

d

a

g

f

ef

b

g


(b)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011e

a

d

a

de

de

b

b

c

c

e

e


(c)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011

c

dd

fe

f

a

f

b

fg

fg

g


(d)




(2)







Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b


DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a



30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b


DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a




DTCT


DTDNT








LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010

c

a

a

d

b

h

fg

ef

de

g

h

h

0 1 2 3 4 5 6 7 8 910


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

c

f

bc

f

e

de

b

ff

e

d

a

0 1 2 3 4 5 6 7 8 910


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

f

cd

a

f

f

e

bc

bc

b

d

f

f

0 1 2 3 4 5 6 7 8 9

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

f

f

e

f

c

e

b

de

f

a

a

d

0 1 2 3 4 5 6 7 8 9

CTDTDNT


(d)





LoamSo

il de

pth

(cm

)0

10

20

30

40

2010

d

h

f

f

eaa

gg

bb

c

0 2 4 6 8 10 12


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

e

f

d

b

c

dc

aa

ab

ff

0 2 4 6 8 10 12


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

bd

fef

b

a

d

a

f

cde

0 2 4 6 8 10 12

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

b

c

d

c

aa

e

f

g

g

f

f

0 2 4 6 8 10 12

CTDTDNT


(d)








LoamSo

il de

pth

(cm

)0

10

20

30

402010

d

g

e

g

b

c

a

g

fg

fgf

f


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010g

c

g

a

e

d

a

g

f

ef

b

g


(b)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011e

a

d

a

de

de

b

b

c

c

e

e


(c)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011

c

dd

fe

f

a

f

b

fg

fg

g


(d)




(2)







Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b


DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a



30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b


DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a




DTCT


DTDNT








LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

40

2010

d

h

f

f

eaa

gg

bb

c

0 2 4 6 8 10 12


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

e

f

d

b

c

dc

aa

ab

ff

0 2 4 6 8 10 12


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

bd

fef

b

a

d

a

f

cde

0 2 4 6 8 10 12

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

b

c

d

c

aa

e

f

g

g

f

f

0 2 4 6 8 10 12

CTDTDNT


(d)








LoamSo

il de

pth

(cm

)0

10

20

30

402010

d

g

e

g

b

c

a

g

fg

fgf

f


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010g

c

g

a

e

d

a

g

f

ef

b

g


(b)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011e

a

d

a

de

de

b

b

c

c

e

e


(c)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011

c

dd

fe

f

a

f

b

fg

fg

g


(d)




(2)







Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b


DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a



30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b


DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a




DTCT


DTDNT








LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010

d

g

e

g

b

c

a

g

fg

fgf

f


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010g

c

g

a

e

d

a

g

f

ef

b

g


(b)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011e

a

d

a

de

de

b

b

c

c

e

e


(c)

Soil

dept

h (c

m)

0

10

20

30

40

CTDTDNT

2011

c

dd

fe

f

a

f

b

fg

fg

g


(d)




(2)







Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b


DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a



30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b


DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a




DTCT


DTDNT








LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014



























Loam

Y (year) 2010 102 464a 155a 291a 254 119a 221a

2011 092 156b 106b 281b 249 113b 109b


DT 131a 369a 173a 305a 265a 124a 158b

DNT 074c 246c 067c 265c 203b 103b 183a

D (soil depth)

0ndash10 cm 171a 462a 292a 304a 304a 165a 164a



30ndash40 cm 026d 124d 028d 268d 138d 058d 168b

Clay

Y (year) 2010 233b 279b 188 265a 225 116a 251a

2011 283a 336a 183 258b 228 107b 113b


DT 358a 371a 231a 272a 292a 119a 179b

DNT 129c 228c 150c 244b 193c 104c 193a

D (soil depth)

0ndash10 cm 419a 546a 373a 296a 307a 126a 180b

10ndash20 cm 376b 376b 209b 267b 252b 124a 179b

20ndash30 cm 173c 227c 116c 252c 236c 105b 185a

30ndash40 cm 064d 082d 045d 231d 210d 089c 185a




DTCT


DTDNT








LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010

ab

aa

debc

cd

cd

de

g

f

ef

ef


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

f

de

de

cd

bc

bca

f

g

b

bc

ef


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

b

fc

c

cd

b

de

acd

de

e

b

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

cde

e

e

de

bcdbc

abc

b

g

f

f

0 1 2 3 4 5 6Urease (NH3-N mg

CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010

a

f

f

e

bcd

bc

e

de

f

a

e


)gminus1 hminus1

(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

c

2010

cd

c

e

b

b

dd

b

a

a


)gminus1 hminus1

(b)

Soil

dept

h (c

m)

0

10

20

30

402011

cdef

bc

f

ab

f

a

g

g

f

g

de


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

402011

bc

de

b

ac

a

f

f

g

f

efd


CTDTDNT

)gminus1 hminus1

(d)







LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010g

f

ab

a

dc

bc

a

e

ed

fg


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010

def

fg

bcd

b

cde

ef

a

bc

ab

ab

g

h


(b)

Soil

dept

h (c

m)

00 04 08 12 16 20 24 28

0

10

20

30

402011g

de

fg

c

a

a

bbc

d

aa

ef


CTDTDNT

)gminus1 hminus1

(c)

Soil

dept

h (c

m)

0

10

20

30

4000 04 08 12 16 20 24 28

2011hef

cde

bcd

a

ab

abc

gh

ef

def

bcde

fg


CTDTDNT

)gminus1 hminus1

(d)






LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014

























LoamSo

il de

pth

(cm

)0

10

20

30

402010c

a

c

a

c

c

c

b

c

b

c

c

0 1 2 3 4


(a)

Soil

dept

h (c

m)

0

10

20

30

40

Clay

2010cd

de

a

ab

ab

de

de

de

cde

cd

bc

e

0 1 2 3 4


(b)

Soil

dept

h (c

m)

0

10

20

30

402011

abc

a

a

abc

abc

ab

abca

d

abc

cda

0 1 2 3 4

CTDTDNT


(c)

Soil

dept

h (c

m)

0

10

20

30

402011

a

ab

ab

ab

bcd

bcd

abcd

abc

ab

abc

d

c

0 1 2 3 4

Catalase (KMnO4mL

CTDTDNT

)gminus1 hminus1

(d)







DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014



























DTCT


DTDNT





4 Conclusions


Disclosure




References



































Journal of




Agronomy





Microbiology




Volume 2014












































Journal of




Agronomy





Microbiology




Volume 2014
























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