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Elevated CO 2 increases nitrogen rhizodeposition and microbial immobilization of root‐derived nitrogen
Author(s) -
De Graaff MarieAnne,
Six Johan,
Van Kessel Chris
Publication year - 2007
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2006.01974.x
Subject(s) - nitrogen , cycling , agronomy , biomass (ecology) , nitrogen cycle , triticum turgidum , chemistry , legume , biology , poaceae , history , archaeology , organic chemistry
Summary• With this study, we aimed to determine how elevated CO 2 affects rhizodeposition and the cycling of rhizodeposited nitrogen (N) in the soil under C 3 and C 4 plants. In addition, we examined how cultivated genotypes of wheat ( Triticum turgidum ) and maize ( Zea mays ) responded to elevated CO 2 in comparison with their wild relatives. • By constructing an N‐transfer experiment we could directly assess cycling of the rhizodeposited N and trace the fate of rhizodeposited N in the soil and in receiver plants. • Biomass production, rhizodeposition and cycling of root‐borne N in maize genotypes were not affected by elevated CO 2 . Elevated CO 2 stimulated above‐ and below‐ground biomass production of the wheat genotypes on average by 38%, and increased rhizodeposition and immobilization of root‐derived N on average by 30%. Concurrently, elevated CO 2 reduced mineral 15 N and re‐uptake of the root‐derived N by 50% in wheat. • This study shows that elevated CO 2 may enhance N limitation by increasing N rhizodeposition and subsequent immobilization of the root‐derived N.