کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8487213 | 1551998 | 2018 | 17 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Fluxes of nitrous oxide and nitrate from agricultural fields on the Delmarva Peninsula: N biogeochemistry and economics of field management
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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 effects of two agricultural conservation practices on nitrous oxide (N2O) fluxes to the atmosphere and nitrate (NO3â) fluxes to groundwater were compared to conventional practices. The conservation practices were application of 80% of recommended nitrogen (N) and planting of winter cover crops. N2O fluxes were measured by static chambers, and NO3â fluxes were calculated using measured NO3â concentrations from tile lines and estimated groundwater yields. During the growing season, one of the five 80% N treatments showed significantly reduced N2O fluxes compared to the 100% N control, whereas three of the five 80% N treatments showed significantly reduced NO3â concentrations compared to the 100% N application. The 80% N treatment resulted in reduced crop yields of 5-26% and average economic losses of US$366 haâ1 for corn and US$153 haâ1 for winter wheat. In three winter cover-crop treatments there were two significant reductions in fall N2O fluxes compared to no-cover-crop controls, and tile drain NO3â concentrations were also significantly lower in autumn. The N2O fluxes were a function of soil temperature, moisture, and fertilizer applications (r2 = 0.49, p < 0.001). Integrating N2O and NO3â fluxes to the annual time scale without conservation measures resulted in mean export of 15 ± 8 kg N2O-N haâ1 yâ1 and 36 ± 6 kg NO3-N haâ1 yâ1. Adding an 80% N conservation treatment reduced N2O fluxes by 79% and NO3â fluxes by 22%, whereas adding cover crops had smaller effects (11% for N2O, 9% for NO3â). However, cover crops were more cost-effective, averaging US$53 (kg N)â1 compared to the 80% fertilizer treatment (US$77 (kg N)â1) due to large economic losses for corn. The state of Maryland (MD) subsidizes cover crops, making the practice even more cost-effective at US$15 (kg N)â1, emphasizing the importance of farmer-friendly policies.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agriculture, Ecosystems & Environment - Volume 254, 15 February 2018, Pages 162-178
Journal: Agriculture, Ecosystems & Environment - Volume 254, 15 February 2018, Pages 162-178
نویسندگان
Thomas R. Fisher, Rebecca J. Fox, Anne B. Gustafson, James Lewis, Neville Millar, Jonathan R. Winsten,