کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8487065 | 1551991 | 2018 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nitrous oxide (N2O) flux responds exponentially to nitrogen fertilizer in irrigated wheat in the Yaqui Valley, Mexico
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم زراعت و اصلاح نباتات
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چکیده انگلیسی
The Yaqui Valley, one of Mexico's major breadbaskets, includes â¼230,000â¯ha of cultivated, irrigated cropland, with two thirds of the area planted annually to spring wheat (Triticum turgidum). Nitrogen (N) fertilizer applications to wheat have doubled since the 1980s, and currently average around 300â¯kgâ¯Nâ¯haâ1. Emissions of nitrous oxide (N2O), a potent greenhouse gas, increase following soil management activities, especially irrigation when N fertilizer is applied, and particularly when N fertilizer inputs exceed crop N requirements. Here we investigate trade-offs among N fertilizer inputs, spring wheat yields, and N2O emissions to inform management strategies that can mitigate N2O emissions without compromising yields, and link this to how farmers can generate carbon credits from N management to receive payment for more precise N use. We used static chambers to measure N2O fluxes from spring wheat at five N fertilizer rates (0, 80, 160, 240, and 280â¯kgâ¯Nâ¯haâ1) during two growing seasons at CIMMYT in Ciudad Obregon, Sonora, Mexico. Average daily fluxes were between 1.9â¯Â±â¯0.5 and 13.4â¯Â±â¯2.8â¯gâ¯N2O-Nâ¯haâ1, with lower emissions at N rates below those that maximized yield, and substantially higher emissions at N rates beyond maximum yield; this exponential response is consistent with crops in temperate regions. Results suggest that current average N fertilizer rates (300â¯kgâ¯Nâ¯haâ1) are at least double economically optimum rates, resulting in low crop N use efficiency: 36-39% at higher N rates as compared to 50-57% for economically optimum rates. N fertilizer rate reductions to the economic optimum rates here (123 and 145â¯kgâ¯Nâ¯haâ1 in 2013 and 2014, respectively) could have avoided N2O emissions equivalent to 0.5 to 0.8â¯Mg CO2e haâ1 yrâ1 or, regionally, 84-138 Gg CO2e yrâ1 without harming yields. Insofar as fertilizer use in Yaqui Valley is likely similar to high-productivity irrigated cereal systems elsewhere, our results provide evidence for a global triple-win scenario: large reductions in agricultural GHG emissions, increased farmer income, and continued high productivity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agriculture, Ecosystems & Environment - Volume 261, 1 July 2018, Pages 125-132
Journal: Agriculture, Ecosystems & Environment - Volume 261, 1 July 2018, Pages 125-132
نویسندگان
Neville Millar, Abisaà Urrea, Kevin Kahmark, Iurii Shcherbak, G.Philip Robertson, Ivan Ortiz-Monasterio,