In:
Biology and Fertility of Soils, Springer Science and Business Media LLC, Vol. 56, No. 7 ( 2020-10), p. 1047-1061
Abstract:
We conducted a 15 N tracer experiment in laboratory microcosms with field-fresh soil samples from a biodiversity experiment to evaluate the relationship between grassland biodiversity and N cycling. To embrace the complexity of the N cycle, we determined N exchange between five soil N pools (labile and recalcitrant organic N, dissolved NH 4 + and NO 3 − in soil solution, and exchangeable NH 4 + ) and eight N transformations (gross N mineralization from labile and recalcitrant organic N, NH 4 + immobilization into labile and recalcitrant organic N, autotrophic nitrification, heterotrophic nitrification, NO 3 − immobilization, adsorption of NH 4 + ) expected in aerobic soils with the help of the N-cycle model Ntrace . We used grassland soil of the Jena Experiment, which includes plant mixtures with 1 to 60 species and 1 to 4 functional groups (legumes, grasses, tall herbs, small herbs). The 19 soil samples of one block of the Jena Experiment were labeled with either 15 NH 4 + or 15 NO 3 - or both. In the presence of legumes, gross N mineralization and autotrophic nitrification increased significantly because of higher soil N concentrations in legume-containing plots and high microbial activity. Similarly, the presence of grasses significantly increased the soil NH 4 + pool, gross N mineralization, and NH 4 + immobilization, likely because of enhanced microbial biomass and activity by providing large amounts of rhizodeposits through their dense root systems. In our experiment, previously reported plant species richness effects on the N cycle, observed in a larger-scale field experiment within the Jena Experiment, were not seen. However, specific plant functional groups had a significant positive impact on the N cycling in the incubated soil samples.
Type of Medium:
Online Resource
ISSN:
0178-2762
,
1432-0789
DOI:
10.1007/s00374-020-01480-x
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
1473419-9
detail.hit.zdb_id:
742137-0
SSG:
12
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