کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8893965 | 1629391 | 2018 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Link between paddy soil mineral nitrogen release and iron and manganese reduction examined in a rice pot growth experiment
ترجمه فارسی عنوان
پیوند بین انتشار نیتروژن معدنی خاک خرد شده و کاهش آهن و منگنز در آزمایش رشد گلدان برنج مورد بررسی قرار
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فرآیندهای سطح زمین
چکیده انگلیسی
Paddy soil indigenous N supply is often poorly related to N status and our aim was to assess its linkage to reduction of Fe3+ and Mn4+, primary terminal electron acceptors in submerged soils. Transplanted rice was grown in the greenhouse in four Bangladeshi paddy soils with distinct SOC to Feox ratio (1.6 to 4.9) for 72â¯days firstly under continuous and then intermittent flooding. Solution buildup rates of Fe2+ and Mn2+ in the first 2-3â¯weeks of flooding correlated negatively with soil organic carbon (SOC) to NH4-oxalate extractable Fe (Feox) and Mn (Mnox) ratios (pâ¯<â¯0.01). Mössbauer analysis detected ferrihydrite and goethite in all soils and with Mn3O4 these are the likely source minerals. An electron (eâ) balance calculated from soil C-emission rates suggested reductive Fe and Mn dissolution to relevant eâ-accepting processes, probably responsible for no >50% of eâ capture, though. Reduction of abundantly present octahedral Fe3+ in chlorites and vermiculite and their interstratified forms in these floodplain silty Inceptisols is hypothesized to also support microbial activity. Notwithstanding, a close temporal synergy existed between solution Fe and soil mineral N and their build-up rates were correlated (r: 0.77 to 0.90; pâ¯<â¯0.01) and with that of dissolved OC (DOC) (r: 0.84 to 0.96; pâ¯<â¯0.01), C emission rate (r: 0.99; pâ¯<â¯0.01) and SOC:Feox (r: â0.71; pâ¯<â¯0.01). These correlations suggest Fe3+ reduction to be a relevant intermediary step in soil N mineralization, possibly through release of associated DOC, N or both. After switching to intermittent flooding dissolution of Fe, Mn and DOC were decoupled from mineral N release but since Eh remained in the Fe3+-reduction range in three out of four soils, possibly clay-Fe3+ alternated with O2 as eâ-acceptor. Most importantly, in all soils N release slowed or halted after only 2â¯weeks of flooding but recommenced with intermittent flooding. As a next step, field experiments could verify if indigenous soil N supply also benefits from non-continuous irrigation management. Lastly, experimental proof is pending for release of clay-bound N and interlayer NH4+ following reduction of octahedral Fe3+ with consequent increased negative charge or structural destabilization, possibly an important process in floodplain paddy soils in Bangladesh.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geoderma - Volume 326, 15 September 2018, Pages 9-21
Journal: Geoderma - Volume 326, 15 September 2018, Pages 9-21
نویسندگان
Masuda Akter, Heleen Deroo, Eddy De Grave, Toon Van Alboom, Mohammed Abdul Kader, Sofie Pierreux, Mili Amena Begum, Pascal Boeckx, Steven Sleutel,