TY - JOUR
T1 - Comparative carbon stability in surface soils and subsoils under submerged rice and upland non-rice crop ecologies
T2 - A physical fractionation study
AU - Deb, Shovik
AU - Kumar, Deo
AU - Chakraborty, Somsubhra
AU - Weindorf, David C.
AU - Choudhury, Ashok
AU - Banik, Pabitra
AU - Deb, Dibyendu
AU - De, Parijat
AU - Saha, Sushanta
AU - Patra, Alok Kumar
AU - Majhi, Munmun
AU - Naskar, Puspendu
AU - Panda, Parimal
AU - Hoque, Anarul
N1 - Funding Information:
The authors gratefully acknowledge Science and Engineering Research Board, Department of Science and Technology, Government of India for funding this research (project code: SR/FTP/ES-11/2014). Further, the authors gratefully acknowledge the BL Allen Endowment in Pedology at Texas Tech University in conducting this research.
Funding Information:
The authors gratefully acknowledge Science and Engineering Research Board , Department of Science and Technology , Government of India for funding this research (project code: SR/FTP/ES-11/2014 ). Further, the authors gratefully acknowledge the BL Allen Endowment in Pedology at Texas Tech University in conducting this research.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/4
Y1 - 2019/4
N2 - The role of subsoil to store stable carbon (C) has become an important research topic in recent decades. In doing so, pools of subsoil C are compared to surface soil. The present study identified differences in mineral associated C (as separated by density fractionation) and aggregate occluded C in surface and subsurface soils. It also considered the impact of submerged rice as well as upland non-rice ecology on soil C stability. Results indicated that subsoil had a significantly greater amount of soil microaggregates as well as microaggregates within macroaggregates compared to surface soils. Subsequently, subsoil also had higher microaggregate occluded C, inaccessible to microorganisms. The higher ‘ratio of C present in the heavy density fraction with C present in bulk soils’ suggested that more C was strongly associated with the subsoil mineral fraction. Besides, spectroscopic analysis of functional groups indicated higher stability of subsoil aggregate occluded C than the aggregate C of surface soils. Summarily, results indicated that subsoil is a potential niche for recalcitrant C storage. Contrariwise, submerged rice ecology resulted in marginally higher soil aggregation compared to upland non-rice soils. Crop ecology did not influence aggregate occluded C dynamics and mineral-C association. As soil physical and aggregation dynamics differ substantively in puddled rice soils and upland non-rice soils, more research is warranted before making a strong conclusion.
AB - The role of subsoil to store stable carbon (C) has become an important research topic in recent decades. In doing so, pools of subsoil C are compared to surface soil. The present study identified differences in mineral associated C (as separated by density fractionation) and aggregate occluded C in surface and subsurface soils. It also considered the impact of submerged rice as well as upland non-rice ecology on soil C stability. Results indicated that subsoil had a significantly greater amount of soil microaggregates as well as microaggregates within macroaggregates compared to surface soils. Subsequently, subsoil also had higher microaggregate occluded C, inaccessible to microorganisms. The higher ‘ratio of C present in the heavy density fraction with C present in bulk soils’ suggested that more C was strongly associated with the subsoil mineral fraction. Besides, spectroscopic analysis of functional groups indicated higher stability of subsoil aggregate occluded C than the aggregate C of surface soils. Summarily, results indicated that subsoil is a potential niche for recalcitrant C storage. Contrariwise, submerged rice ecology resulted in marginally higher soil aggregation compared to upland non-rice soils. Crop ecology did not influence aggregate occluded C dynamics and mineral-C association. As soil physical and aggregation dynamics differ substantively in puddled rice soils and upland non-rice soils, more research is warranted before making a strong conclusion.
KW - Functional groups
KW - Heavy density fraction of C
KW - Microaggregates
KW - Stable C
KW - Subsoil
UR - http://www.scopus.com/inward/record.url?scp=85059528846&partnerID=8YFLogxK
U2 - 10.1016/j.catena.2018.12.037
DO - 10.1016/j.catena.2018.12.037
M3 - Article
AN - SCOPUS:85059528846
SN - 0341-8162
VL - 175
SP - 400
EP - 410
JO - Catena
JF - Catena
ER -