کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2414644 1552109 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Roots contribute more to refractory soil organic matter than above-ground crop residues, as revealed by a long-term field experiment
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
Roots contribute more to refractory soil organic matter than above-ground crop residues, as revealed by a long-term field experiment
چکیده انگلیسی

We revisited the well documented and ongoing long-term ‘Ultuna continuous soil organic matter field experiment’ which started in 1956 at the Swedish University of Agricultural Sciences. The objective of the experiment is to quantify effects of six organic amendments and mineral N fertilizers on the crop and soil. We used the ‘equivalent soil mass’ concept for estimating changes in the topsoil carbon stocks in all 15 treatments. C inputs from amendments were measured and those from crops were calculated using allometric functions and crop yields. Clustering C inputs into seven categories by quality allowed us to calculate a ‘humification’ coefficient for each category. Here, these coefficients were simply based on the fraction of total C input that still remains in the topsoil after about 50 years. As indicated by previous studies, this coefficient was highest for peat, followed by sewage sludge, manure, sawdust and above-ground crop residues. The most interesting result from the current investigation is that the optimized coefficient for root-derived carbon was about 2.3 times higher than that for above-ground plant residues. The calculated results were found to be robust in a sensitivity analysis. Our findings strongly support the hypothesis that root-derived carbon contributes more to relatively stable soil C pools than the same amount of above-crop residue-derived C.

Figure optionsDownload as PowerPoint slideHighlights▶ Roots contribute relatively more to SOM than above-ground crop residues. ▶ Humification coefficient of roots may be higher than that of farmyard manure. ▶ The calculated results were found to be robust in a sensitivity analysis.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agriculture, Ecosystems & Environment - Volume 141, Issues 1–2, April 2011, Pages 184–192
نویسندگان
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