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\hypersetup{pdftitle={The Effect of Different Crop Residues on Soil Nitrogen},pdfauthor={Kambiz Poori, Behnam Kamkar, Seiedalireza Movahedi Naeeni},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={C/N, crop residue, soil nitrogen},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\Large{\textbf{The Effect of Different Crop Residues on Soil Nitrogen\footnote{\textbf{Contact Address:} Kambiz Poori, Gorgan University of Agricultural Sciences and Natural Resources, Dept. of Agronomy, Aghghala, Iran, \mbox{e-mail}: \email{kambizpoori@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Kambiz Poori, Behnam Kamkar, Seiedalireza Movahedi Naeeni}}
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\begin{itemize*}
\item[]{\small{\textit{Gorgan University of Agricultural Sciences and Natural Resources, Dept. of Agronomy, Iran}}}
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\index[author]{Poori, Kambiz}
\index[author]{Kamkar, Behnam}
\index[author]{Movahedi Naeeni, Seiedalireza}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Most important nitrogen source for plants, product from soil organic nitrogen mineralisation, decomposition of crop residue and chemical fertiliser. This experiment was conducted to evaluate of the effect of crop residues management on soil nitrogen with using five crop residues (cotton, maize, wheat, soybean, alfalfa), urea treatment and control with Completely Randomised Design Block four replications in number 2 land of Gorgan University of Agricultural Science and Natural Resources. Measures was conducted in wheat phenologic stages (Tillering, Stem Elongation, Booting, Anthesis, Physiological Ripening, Ripening). The results indicated that other factors are affects on nitrogen mineralisation except C/N ratio. In different crop residues with C/N ratio total nitrogen released was not significant in crop residue. also Comparison of crop residue and urea treatment was indicated that total nitrogen was not significant in this treatments. This experiment indicated that there is an extream interaction effect in rate of mineralisation of nitrogen between temperature and rain. In this measuring with increasing of temperature and rain the rate of nitrogen mineralisation was increased and with decreasing one of them nitrogen mineralisation was decreased. Also in this measuring was indicated that the least of total nitrogen was in anthesis stage and the most was in physiologic stage that plants have most and least aptake in that stages. Total nitrogen released from crop residue and urea treatments was more from control, but was not significant. In this experiment the amount of NO$_{3}^{}$ was more than NH$_{4}^{}$ because nitrificasion was higher than denitrificasion. The results indicated that crop residue can be source of nitrogen for plants.}

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\noindent \textbf{Keywords:} C/N, crop residue, soil nitrogen
\index[key]{C/N}
\index[key]{Crop!residue}
\index[key]{Soil!nitrogen}
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