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\hypersetup{pdftitle={Soil Microbial Activities and its Relationship with Soil Physico Chemical Properties under Organically and Inorganically Managed Soils},pdfauthor={Adedayo Omowumi Oyedele, Adebayo Gabriel, Azarel Caldbak Oladotun Uthman, Alemeru Mayowa Olusola},pdfsubject={Tropentag 2016: Abstract},pdfkeywords={Inorganic, microbial activity. soil management. physico-chemical, organic},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 18-21, 2016, Vienna, Austria}}\\[1ex] \Large{``Solidarity in a competing world ---\\fair use of resources''\\[2ex]}}
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\Large{\textbf{Soil Microbial Activities and its Relationship with Soil Physico Chemical Properties under Organically and Inorganically Managed Soils\footnote{\textbf{Contact Address:} Adedayo Omowumi Oyedele, Institute of Agricultural Research and Training (IAR\&T), Land and Water Resources Management Programme, Moor Plantation, Ibadan, Nigeria, \mbox{e-mail}: \email{adeedii@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Adedayo Omowumi Oyedele, Adebayo Gabriel, Azarel Caldbak Oladotun Uthman, Alemeru Mayowa Olusola}}
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\begin{itemize*}
\item[]{\small{\textit{Institute of Agricultural Research and Training (IAR\&T), Land and Water Resources Management Programme, Nigeria}}}
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\index[author]{Oyedele, Adedayo Omowumi}
\index[author]{Gabriel, Adebayo}
\index[author]{Uthman, Azarel Caldbak Oladotun}
\index[author]{Olusola, Alemeru Mayowa}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Various soil management systems are employed in agriculture for sustainable soil productivity towards ensuring food security in Nigeria. Soil microbial activities which are important indicators of soil quality are affected by various soil management systems. However, most studies in agricultural soil management systems have been focused on soil physico"=chemical parameters with less on the soil microbial attributes and activities. The aim of this study was to evaluate microbial activities of soils under organic and inorganic soil management systems.  Soil samplings were carried out in year 2012 and 2015 and a total of 75 soil samples were collected each year from three established fields having different management systems. The fields assessed are Crop Residue"=managed Soils (CRS), Inorganically Managed Soils (IMS) and these were evaluated against an Abandoned Land having grass coverage (ALS). Microbial assessment carried out includes the total viable bacterial and fungal counts, Soil Microbial Respiration (SMR), Microbial Biomass Carbon (MBC), Microbial Biomass Nitrogen (MBN) and Microbial Biomass Phosphorus (MBP). Physico"=chemical parameters including soil texture, pH, organic carbon, total nitrogen, available Phosphorus and exchangeable potassium were also analyzed. The results showed a substantial difference in the microbial activities, in terms of soil management in both years. Generally, Soil microbial activities were highest in crop residue"=managed soils as observed in  SMR (11.24 $\mu$gCO$_{2}$-Cg$^{-1}$h$^{-1}$), MBC (456.20 $\mu$gCg$^{-1}$), MBN (38.21 $\mu$gNg$^{-1}$) and MBP (21.62 $\mu$gPg$^{-1}$), while the lowest microbial activities were observed in inorganically managed soils for SMR (5.54 $\mu$gCO$_{2}$-Cg$^{-1}$h$^{-1}$), MBC (219.74 $\mu$gCg$^{-1}$), MBN (21.70 $\mu$gCg$^{-1}$) and MBP (11.40 $\mu$gCg$^{-1}$) in both years. Between 2012 and 2015 there were percentage increases in the soil microbial activities under the management systems suggesting an increase in the stability of organic carbon. MBC which is one of the key indicators of soil quality had an increase of \mbox{48.9\,\%}, \mbox{29.6\,\%} and \mbox{43.5\,\%} in CRS, IMS and ALS respectively. Organically managed soils appeared to be a more sustainable soil management practice for enhancing soil microbial activities when compared to inorganically managed soils. Therefore to improve or maintain the soil microbial activities and soil quality the implementation of such sustainable agricultural practices is necessary.}

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\noindent \textbf{Keywords:} Inorganic, microbial activity. soil management. physico"=chemical, organic
\index[key]{Inorganic}
\index[key]{Microbial activity. soil management. physico"=chemical}
\index[key]{Organic}
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