کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4381891 1617787 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Isotopic characterization of sequestration and transformation of plant residue carbon in relation to soil aggregation dynamics
ترجمه فارسی عنوان
خصوصیات ایزوتوپهای ترشح و تبدیل کربن باقی مانده گیاه نسبت به پویایی تجمع خاک
کلمات کلیدی
کربن ارگانیک، کل خاک، کربن ایزوتوپیک، بقایای محصول، اسید هومیک، اسید فلوویک
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
چکیده انگلیسی


• Plant residue carbon is initially mainly stored in macroaggregates.
• Plant residue carbon is “transferred” into microaggregates with half-year retardation.
• Macroaggregates contain new humic acid carbon 57–90% more than microaggregates.
• Macroaggregates contain new fulvic acid carbon 60–84% more than microaggregates.
• Prolonged stability of macroaggregates favors carbon sequestration in microaggregates.

Soil aggregates play a key role in preserving soil organic carbon (SOC). However, the mechanisms controlling aggregate formation and SOC distribution in different sizes of aggregates remain unclear. Here, we studied the dynamics of aggregate formation and associated SOC transferring among different aggregate fractions using an isotopic tracer technique (14C-labeled wheat residues). The year-long incubation results demonstrate that the wheat residue carbon applied to soil (Typic Hapludoll) was initially mainly stored in the pores between microaggregates that were agglomerated to form macroaggregates (>250 μm). The wheat carbon started to transfer to the inside of microaggregates (250–53 μm) after six months of the incubation. The newly formed humic acid carbon (HA14C) and fulvic acid carbon (FA14C) in the macroaggregates were 57–90% and 60–84% more than in microaggregates (250–53 μm), respectively. Later, the sequestrated SOC was decomposed or chemically transformed, resulting in a decrease in the ratio of HA14C/FA14C in macroaggregates and an increase in the silt/clay fraction (<53 μm). This result indicated that the SOC in the macroaggregates was vulnerable to degradation due to less protection by soil macrostructure, while it experienced a slow degradation due to strong surface adsorption or pore protection in soil microstructure. This study suggests that macroaggregates considerably control SOC turnover and thereby their stability considerably influences how much newly introduced organic carbon could be sequestrated into stable carbon pools like microaggregates. The turnover dynamics of macroaggregates provided insights into the potential of humic carbon formation that facilitates long-term carbon preservation in soil.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Soil Ecology - Volume 96, November 2015, Pages 18–24
نویسندگان
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