23˝˜>v No. 3.,p..+.3 ,**- CO O - js-soilphysics.comCO, O, * BehaviorsofCO, andO,...

9
腆腍腄腎腀腃腌腈腊腇腉腂 CO , O , 腂腅腋 * Behaviors of CO , and O , Gases in a Field Soil with a Hard Pan Tomonori FUJIKAWA* Department of Biological and Environmental Engineering, The University of Tokyo, +++ Yayoi, Bunkyo-ku, Tokyo ++-20/1, Japan Abstract Gas concentration in the soil air is di#erent from that in atmosphere, because it is a#ected by activity of microorganisms, gas di#usion and chemical reaction. Under the field condition for cultivation, large changes in soil physical properties by human operations may a#ect the gas behavior in the soil. The objective of this study is to clear gases behaviors in the soil from field measurements, column experiments and simulations. Under field condition, CO, and O, gas concentrations in the deeper layer than the hard pan changed remarkably with seasons, whereas those concentrations in the top layer changed little. From the column experiments, CO, gas concentrations in the top layer increased with infiltration, whereas CO, gas concentrations decreased both in the other layers and in the atmosphere. The changes of O, gas concentrations after infiltrations are opposite to those of CO, gas. Simulation with measured gas CO, gas concentration of column experiment suggested that the activity of microorganisms at the hard pan might be larger, and also, prevention of gas movement above the hard pan or large flux of gas through the top layer might be keep CO, gas concentration low in the top layer. It was concluded that gas concentrations changes above and below the hard pan, because the hard pan a#ects the activity of microorganisms and gas di#usion. Key words : soil gas, field soil, hard pan +腇腅腈腆 膐臒膂膎臫臀腙腒腗膦腧腑腔腐腩腗腇腨臄膊腹臂腺 腝膔腵臡膥腙腒腗 膿膇臇腝腹膤膖腼腫腬 CO,N, OCH. 腛腚腋臈自腐腩腗腌腔臎膮臇腊腦膿膇腠腝腫腬 臤膩臲腞臎膮腝臯臮膃臰臥臦腜腥腕腗膿腌腍臣腺腓腨 腔腢臎膮腝膰膽腙臎膮臇腝腫腬膌臑腝膄膑腪膴膀腜臕 腰腓腨腏腙腞腹膤膖腼腫腬腝膲膕腜腣臛膯腜臬膖腘腆 腏腩腡腘腝膓膋腘臎膮臇腝 CO, 腫腬臓臍腞膿膇腥腧 腣膚腍O, 腫腬臓臍腞膿膇腥腧腣臉腇腏腙腋臩腦腊腜 腛腕腔腋腫腬臓臍腝膿腌腐腤臓臍臢臠腝膒膰腞膓膋 腝膼膬腙腛腕腔膭膪膢膆臎臄臯臮膒膽膜臟腎臞自 腜腥腕腗膿腌腍腲腛腕腗腇腨 Pyatt and Smith, +32- ; Osozawa and Hasegawa, +33/ ; Sierra and Renault, +332 ; Sotomayor and Rice, +333腄腀 腏腩腦腝膓膋腘腞膜自腤膻臊膭膪腜腥腨腫腬膌臑腝臣腺腪膜臡膧腤臎膮 臡臰膳腊腦臊膳臌腜膙膝腒腗腇腨腋腫腬膌臑腝膅膹臥 臋膣腜膅腖腇腔腫腬臓臍臢臠腝臊臲臌腛腽膶腜腞膠腕腗 腇腛腇臎膮臇腝腫腬膌臑腞臎膮膵臡腤膱臡膛臎膮臜膵臡 腜腥腨臗膵腉腥腟膫臚腫腬臓臍膗臖腜膅腖腍腾膞腳 CO, 腫腬腝臭腽腜膾臝腐腩腨腺膁臘腸膸腱膗臖腜 膅腖腍腮腬腭腯腂臎臱膟腙腝膉臁臆腜腷膏腪膨腎腨腙 膙腈腦腩腨腋CO,O, 腫腬腜膄腒腗腞腮腬腭腯腂腤 膉臁臆腋臧膡腘腌腨腏腙腋臃腦腩腗腇腨腴臥腫腬臗 * 臏膍膿膁膿膁腶臔膁膵臨腻膁膓膋腻 ++-20/1 腉腁腋腁腊 : 臎膮腫腬臔臄臎膮膘臙膺 J. Jpn. Soc. Soil Phys. 臎膮腝臡臰膳 No. 3., p. .+.3 ,**-腎腍腏腌

Transcript of 23˝˜>v No. 3.,p..+.3 ,**- CO O - js-soilphysics.comCO, O, * BehaviorsofCO, andO,...

Page 1: 23˝˜>v No. 3.,p..+.3 ,**- CO O - js-soilphysics.comCO, O, * BehaviorsofCO, andO, GasesinaFieldSoilwithaHardPan TomonoriFUJIKAWA* DepartmentofBiologicalandEnvironmentalEngineering,TheUniversityofTokyo,+

���������� CO, O,���

� � � �*

Behaviors of CO, and O, Gases in a Field Soil with a Hard Pan

Tomonori FUJIKAWA*

Department of Biological and Environmental Engineering, The University of Tokyo, +�+�+ Yayoi,Bunkyo-ku, Tokyo ++-�20/1, Japan

Abstract

Gas concentration in the soil air is di#erent from that in atmosphere, because it is a#ected by

activity of microorganisms, gas di#usion and chemical reaction. Under the field condition for

cultivation, large changes in soil physical properties by human operations may a#ect the gas

behavior in the soil. The objective of this study is to clear gases behaviors in the soil from field

measurements, column experiments and simulations.

Under field condition, CO, and O, gas concentrations in the deeper layer than the hard pan

changed remarkably with seasons, whereas those concentrations in the top layer changed little.

From the column experiments, CO, gas concentrations in the top layer increased with infiltration,

whereas CO, gas concentrations decreased both in the other layers and in the atmosphere. The

changes of O, gas concentrations after infiltrations are opposite to those of CO, gas. Simulation

with measured gas CO, gas concentration of column experiment suggested that the activity of

microorganisms at the hard pan might be larger, and also, prevention of gas movement above the

hard pan or large flux of gas through the top layer might be keep CO, gas concentration low in the

top layer. It was concluded that gas concentrations changes above and below the hard pan,

because the hard pan a#ects the activity of microorganisms and gas di#usion.

Key words : soil gas, field soil, hard pan

+� � � � �

��� ��� ������������������� � � !"#��$%&'( )CO,� N,O�CH.*+, -./���0�1 23#45!"6�'(789:23�;<�=>?@ABC�!0DE�F��G� 23�HI�23#�'(JK�LMNOPAQRF�S�:�$%&'(�TUAVWXAY%Z[�1S�\Z�]^Z23#� CO,'(_`:!"B�

VaD� O,'(_`:!"B�Vb�S�-c54A*C�-� '(_`�!0�d_`ef�gH:� ]^�hi�*C�jk� lm� 2�;<gI� nopq/

ABC�!0Dr*C��� )Pyatt and Smith, +32- ;

Osozawa and Hasegawa, +33/ ; Sierra and Renault,

+332 ; Sotomayor and Rice, +333,1 S�5�]^Z:�n/dstjkAB�'(JK�E�N� n�ud23�>v45tvwAxy ���-� '(JK�z{?|}Az~��'(_`ef�t9w*��A:�C��*�123#�'(JK:� 23��d���� 23���AB����B���� '(_`��Az~D���K� CO,'(���A���������� ����Az~D�(���� 2������ A¡¢N£p��x¤5��-� CO,� O,'(AL �:� �(���d�� -¥¦Z0�S�-§5����¨?� '(�

*©ª!�!�«¬��­®�]^® ¯++-�20/1

���� : 23'(� ¬�23� °±²

J. Jpn. Soc. Soil Phys.

23��>vNo. 3., p. .+.3 �,**-�

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K� ���;������L����!�$�M�7N� OPQ�R +332� /S 9TU /S�):� VWX�Y +332� +*S 9+*S�):� ��� 92Z�:WX�Y +333� -S 9-S�): -[�)$���67� >�)$���67�(�\]$^ +�� _7��`�^$^ ,�a%� �bcde b � ��fLgh!��"`I7�i#j� � CO,� O,���� ��� !�kl$�m�&nm�o������p� q 9�q:� r�� 9gh!� st$� u$v��wx:� �����kl$�m�&nm�o�����yp�z�� ���� � pit�%{I7�|���}~�$&�I�}~I7� '�����7��}~�$^ -�a%� �(� Rolston 9+320: $�n���I� /S�)���7��)� � ��52����$v�7��� �(��

$M� }~%���\]� ��I7����$�!��#%��&��Q�� ��}~�&�Y� ,.��T�*]I� �����+���I�����$}~I7�

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CO,� O,��� � �� *�,* cm_� � ���&� ,-�z67�� e bz� ,* cm¡.�� ¢£�CO,�����¤I� O,����/UI7� e b;¥��0����� �Q¦�I7� e b���� CO,���§¨© +0�� O,���§/© ,� 9+*S�)�� 2* cm: �z67�>JK���$ª��� 1b *�,* cm��� � «�$2¬�3­�I���AI�� e bT���� �®�;¥�Q¦�%��&������67�4��t�5�Y +*S�)e bT�� � ¯�®;¥¨� CO,���� /� O,����e bT��i#�o7� �����p� �q�r��i#�� � �q� t�6�JK����;¥�%��AI� ���p�«�$2¬�3­�I���&������67 9^ /�1:� _7������yp � �7��kl$°�� +*S1b� � ±�¦�6��7 9^ 2:� ¯�)�$M� e bT�� +*S�) CO,����¨¦� O,����/¦�67²«³´&I�� ¨��q&t�6�;���� !�¤�µ¶�o�� �o � �qLt�6&����8�·��¤%��&$9¸I7 Roch-

ette and Gregorich 9+303: �;� Joshi et al. 9+33+:¹º&�«»%�� ²:³´&I�� �1;¡�

��+ �)\]Fig .+ Locations of each research area in the

field.

��, ��`�^Fig. , Soil profiles.

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��- ��������Fig. - Schematic diagrams of gas sampling pipes.

��. ���� ��Fig. . Gas concentration distributions in the field.

��/ ������Fig. / The distribution of the number of

microorganisms.

��0 ����Fig. 0 Soil temperature profiles.

���� : ������ �!"#� CO,$ O,�%& 43

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mm�h�� ���� +*��c� ��s� +*t+/ mm�����!���;���" �\�R�Q]jc�ru

��1 ��56Fig. 1 Solid, liquid and gaseous phases of soil.

��2 ����56Fig. 2 The distributions of gas di#usion

coe$cient.

��3 ?@ABC��JFig. 3 Schematic diagram of apparatus of

column experiments.

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-�+�, ������� +1��������� CO,� O,���� � �!"# +*�$%� ����&� '( *)+* cm*&+, ��*-./�0�� 12��/3456( 7+*),/ cm8 *9:� CO,����;<=�� O,����;>?%.@ ;�AB�� �� ,* cm���4( 7�(8 *&����&CDE�*-B�� FGHIJ*��������� � KL*���������"MN��OP 7# ++8� FGHIJ/�����!&� Q��'(R�S56(*&KL/����"�TUK�� 56(/VW���XYZ/ CO,����;<=�� O,

����;>?%.@ ;�AB�� �A�� 56([�*&KL/�����!;���\�+]T�^%./�0�� FGHIJ*���������&CDE� _B�� 56(���4(�R`.KL FGH/�����!/a4/bc �d� �KL*&���\�efg;hi%./�0�� FGHXY/efg&���\��jkl� �4(/efmn;o_.@ � �KL*&��pqrg/s�t];+]T� Lu���vwE_pqx^;fyd4.@ � �FGHXY&?�"�����z{|}~*����d4���� ��/?�x^; ���d4./�0�� KL*&�?�/���� �?A�/���fyd4.@ _�;������ ?�/����;�������.��"��.���&� ���4FGH"�4�IJ;��*-.�E�� 56([�/ CO,���� O,����/�

&� KL��� '(��>T_B�� @/bc �d�������.N,����/<= XYZ�/ CO,

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-�,�+ ���IJ 7[?��IJ8 &<�/IJ� ]¡4dR@_B�� <¢/IJ��� ,*��"��IJ *�� �� *� -� 0� +,� +.��/ /£��� ¤&¥� +.+)+.- mm�h* +,�¦*-.� IJ���/FGH§/¨©ª«¬�j"# +,�$%�

-�,�, �����������¤��/ CO,� O,�����j"# +-�$%� ���­4� CO,����&�<�®S56([�*&>?��/�0�� '(*&<=��� O,����& CO,���� &�0/¯\"$�� �<� 7+,Z8 ®S56([�*&<=��/�0�� '(*&>?��� �/ CO,����/�j&�� ,* cm 756(8 *°+ ,.3�� �� / cm 7'(8 *°+ *..0�*-B�� ����.� �<�R�S'(�/�����j/bc �d� '(/, �/>?��.��pqx^/hi;��*-. 4�.� ���­4'(/��pqx^;±�T_�� XYZ*²f�� CO,��&XYZ�³´�� '(/ CO,����;<=� µ�+,Z/ CO,����;>?�� ����.� E�� 56([�/ CO,�����j/bc �d� ��/¶fy

��+* FGHXYZ/�����!Fig. +* Gas concentration distributions in the column.

·¸¹º : 56"�%.»�XYZ/ CO, O,/¼^ 45

Page 6: 23˝˜>v No. 3.,p..+.3 ,**- CO O - js-soilphysics.comCO, O, * BehaviorsofCO, andO, GasesinaFieldSoilwithaHardPan TomonoriFUJIKAWA* DepartmentofBiologicalandEnvironmentalEngineering,TheUniversityofTokyo,+

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.� �������� �� ,**-�

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U?@)VW<2 34567���>�XYZ�[\<�% VW)]^@+��_�2 ����`- ab�c<�de���>�?@)VW<�% ��f ab�c<=S��SghYi#2 jkl2 ��mnop�TU?@H�q��rs��)tu+�/� vw��_2 ��,-�MNOPQLx���g�I�%

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��++ 34567��d�����>���Fig. ++ Comparison of gas concentrations

between in column and in field soils.

��+, ��AFG?@Fig. +, Changes of suction with time.

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;+33.> 3��� %�&+� *#�� � *.-~+.+

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��+. CDEFGCHIMNFig. +. Simulated CO, gas concentrations.

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Boeckx, P. and van Cleemput (+330) : Methane oxida-

tion in a neutral landfill cover soil : Influence of

moisture content, temperature and nitrogen-

turn over, J. Environ. Qual., ,/ : +12�+2-.

ghij�k� l�mnop q,**-r : ���5s8�tuv� CO,� O,!"VH�wk8�xy� zt{|� ,,/ : +++�++2.

ghij�k� l�w }~�mnop q,***r : �����^����tu���&BL� CO,� O,!",-BL��w���?� zt{|� ,*2 : +3�,2.

Joshi, M., Mer, G.S., Singh, S.P. and Rawat, Y.S. (+33+) :

Seasonal pattern of total soil respiration in un-

saturated and disturbed ecosystem of Central

Himalaya, Biol. Fertil. Soils, ++ : ,01�,1,.

Osozawa, S. and Hasegawa, S. (+33/) : Diel and sea-

sonal changes of carbon dioxide concentration

and flux in an andisol, Soil Sci., // : //�0,.

Pyatt, D.G. and Smith, K.A. (+32-) : Water and oxygen

regime of four soil types at Newcastle Forest,

south Scotland, J. Soil Sci., -. : .0/�.2,.

Rochette, P and Gregorich, E.G (+332) : Dynamics of

soil microbial biomass C, soluble organic C and

CO,, evolution after three years of manure appli-

cation, Can. J. Soil Sci., 12 : ,2-�,3*.

Rolston, D.E. (+320) : Gas Flax, Klute, A. ed., Method

of soil analysis, Part +, No. 3, Am. Soc. Agron. :

pp. ++*-�++*3.

Ross, D.J. and Tate, K.R. (+33-) : Microbial C and N,

and respiratory activity, in litter and soil of a

southern beech (Nothofagus) forest : distribu-

tion and properties, Soil Biol. Biochem., ,/ (.) :

.11�.2-.

Sakamoto, K. and Oba, Y. (+33.) : E#ect of fungal to

bacterial biomass ratio on the relationship be-

tween CO, evolution and total soil microbial bio-

mass, Biol. Fertil. Soils, +1 : -3�...

Sierra, J. and Renault, P. (+332) : Temporal pattern of

oxygen concentration in a hydromorphic soil,

Soil Sci. Soc. Am. J., 0, : +-32�+.*/.

Sotomayor, D. and Rice, C.W. (+333) : Soil air carbon

dioxide and nitrous oxide concentrations in pro-

files under tallgrass prairie and cultivation, J.

Environ. Qual., ,2 : 12.�13-.

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