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Mechanisms of nitrogen transfer in a model clover-ryegrass pasture: a 15N-tracer approach.
- Source :
-
Plant & Soil . Nov2022, Vol. 480 Issue 1/2, p369-389. 21p. 3 Diagrams, 6 Charts, 2 Graphs. - Publication Year :
- 2022
-
Abstract
- Purpose : Nitrogen (N) transfer from white clover (Trifolium repens cv.) to ryegrass (Lolium perenne cv.) has the potential to meet ryegrass N requirements. This study aimed to quantify N transfer in a mixed pasture and investigate the influence of the microbial community and land management on N transfer. Methods: Split root 15N-labelling of clover quantified N transfer to ryegrass via exudation, microbial assimilation, decomposition, defoliation and soil biota. Incorporation into the microbial protein pool was determined using compound-specific 15N-stable isotope probing approaches. Results: N transfer to ryegrass and soil microbial protein in the model system was relatively small, with one-third arising from root exudation. N transfer to ryegrass increased with no microbial competition but soil microbes also increased N transfer via shoot decomposition. Addition of mycorrhizal fungi did not alter N transfer, due to the source-sink nature of this pathway, whilst weevil grazing on roots decreased microbial N transfer. N transfer was bidirectional, and comparable on a short-term scale. Conclusions: N transfer was low in a model young pasture established from soil from a permanent grassland with long-term N fertilisation. Root exudation and decomposition were major N transfer pathways. N transfer was influenced by soil biota (weevils, mycorrhizae) and land management (e.g. grazing). Previous land management and the role of the microbial community in N transfer must be considered when determining the potential for N transfer to ryegrass. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0032079X
- Volume :
- 480
- Issue :
- 1/2
- Database :
- Academic Search Index
- Journal :
- Plant & Soil
- Publication Type :
- Academic Journal
- Accession number :
- 160458913
- Full Text :
- https://doi.org/10.1007/s11104-022-05585-0