Corn and soybean’s season-long in-situ nitrogen mineralization in drained and undrained soils

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• 作者：Fabián G. Fernández ; Karina P. Fabrizzi…
• 关键词：Tile ; drain ; Urea fertilizer ; Nitrogen cycle ; In ; field mineralization ; Maize
• 刊名：Nutrient Cycling in Agroecosystems
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：107
• 期：1
• 页码：33-47
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Agriculture;
• 出版者：Springer Netherlands
• ISSN：1573-0867
• 卷排序：107

文摘

Many factors influence nitrogen (N) mineralization in agricultural soils. Our objective was to quantify cumulative (season-long) net N mineralization in corn (Zea mays L.) and soybean [Glycine max (L.) Merr] in a corn-soybean rotation under different N and soil drainage management (drained and undrained) in poorly-drained soils. In-situ incubations were conducted over two growing seasons using a sequential core-sampling technique to measure net N mineralization. Differential drainage was imposed three-years before this study, in which time, the soil lost 2.2 Mg C ha−1 year−1 and 0.14 Mg N ha−1 year−1 due to tile-drainage. Overall greater total soil organic carbon (TOC) and total soil nitrogen (TN) in the undrained soil resulted in 2.7 times greater net N mineralization compared to the drained soil in the unfertilized control (0N), but the effect of drainage was inconsistent across years with N fertilization. Across all variables, soils mineralized 2.89% of TN in soybean residue and 0.94% of TN in corn residue. Nitrogen fertilization increased mineralization rate, as high as 9.6 kg N ha−1 day−1, compared to <2.2 kg N ha−1 day−1 for 0N. Overall, net N mineralization was 3.4 times greater with N fertilizer than the 0N, but fertilization made mineralization more variable. The impact of fertilization on boosting mineralization under differential soil drainage needs further refinement if we are to improve decision-making tools for N application based on soil mineralization predictions.