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| Titel |
Root growth of Lotus corniculatus interacts with P distribution in young sandy soil |
| VerfasserIn |
B. Felderer, K. M. Boldt-Burisch, B. U. Schneider, R. F. J. Hüttl, R. Schulin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 3 ; Nr. 10, no. 3 (2013-03-13), S.1737-1749 |
| Datensatznummer |
250018152
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| Publikation (Nr.) |
 copernicus.org/bg-10-1737-2013.pdf |
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| Zusammenfassung |
| Large areas of land are restored with unweathered soil substrates following
mining activities in eastern Germany and elsewhere. In the initial stages of
colonization of such land by vegetation, plant roots may become key agents in
generating soil formation patterns by introducing gradients in chemical and
physical soil properties. On the other hand, such patterns may be influenced
by root growth responses to pre-existing substrate heterogeneities. In
particular, the roots of many plants were found to preferentially proliferate
into nutrient-rich patches. Phosphorus (P) is of primary interest in this
respect because its availability is often low in unweathered soils, limiting
especially the growth of leguminous plants. However, leguminous plants occur
frequently among the pioneer plant species on such soils, as they only depend
on atmospheric nitrogen (N) fixation as N source. In this study we
investigated the relationship between root growth allocation of the legume
Lotus corniculatus and soil P distribution on recently restored
land. As test sites, the experimental Chicken Creek Catchment (CCC) in eastern
Germany and a nearby experimental site (ES) with the same soil substrate were
used. We established two experiments with constructed heterogeneity, one in
the field on the experimental site and the other in a climate chamber. In
addition, we conducted high-density samplings on undisturbed soil plots
colonized by L. corniculatus on the ES and on the CCC. In the field
experiment, we installed cylindrical ingrowth soil cores
(4.5 × 10 cm) with and without P fertilization around single
two-month-old L. corniculatus plants. Roots showed preferential
growth into the P-fertilized ingrowth-cores. Preferential root allocation was
also found in the climate chamber experiment, where single
L. corniculatus plants were grown in containers filled with ES soil
and where a lateral portion of the containers was additionally supplied with
a range of different P concentrations. In the high-density samplings, we
excavated soil-cubes of 10 × 10 × 10 cm size from the
topsoil of 3 mini-plot areas (50 × 50 cm) each on the ES and the
CCC on which L. corniculatus had been planted (ES) or occurred
spontaneously (CCC) and for each cube separated the soil attached to the
roots (root-adjacent soil) from the remaining soil (root-distant soil). Root
length density was negatively correlated with labile P (resin-extractable P)
in the root-distant soil of the CCC plots and with water-soluble P in the
root-distant soil of the ES plots. The results suggest that P depletion by
root uptake during plant growth soon overrode the effect of preferential root
allocation in the relationship between root density and plant-available soil
P heterogeneity. |
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