Abstract

A large part of crop nutrient uptake occurs through the interaction of roots with symbiotic arbuscular mycorrhizal fungi (AMF). However, it is still an open question how straw management and earthworm activity affect AMF community structure and their nitrogen-transferring function in wheat. A split-plot field experiment was conducted to address this question. Three straw management regimes including different tillage treatments (notill with no straw, NTNS; rotary tillage with straw return, RTSR and ditch-buried straw return, DBSR), and two earthworm treatments (no earthworm, -E; and earthworm addition, + E) were conducted. The AMF community structure in the wheat roots was characterized with high-throughput sequencing, and its function in terms of N acquisition was measured with 15 N isotope tracing through hyphal in-growth cores. Our results showed that both the DBSR and RTSR treatments significantly changed AMF community composition and enhanced the mycorrhiza-mediated plant N uptake when compared to NTNS. The effect of earthworm activity on AMF community composition and mycorrhiza-mediated N uptake strongly depended on the straw management regimes. While earthworm presence increased AMF dominance (+32.9%) and mycorrhizal N uptake (+ 2.05-fold) under straw removal, they decreased AMF dominance (- 30.4% and -41.9% respectively) and mycorrhizal N uptake (- 37.3% and - 34.3% respectively) under both DBSR and RTSR treatments in comparison with the absence of earthworms. It is concluded that straw addition shifts the AMF community structure and increases N uptake by the host plants; and that the effect of earthworms on AMF community structure and functioning depends on the straw management regime. The results suggest that straw management and its interaction with earthworms can affect mycorrhiza-mediated plant N uptake, possibly through altering some dominant AMF taxa.

Keywords

Arbuscular mycorrhizal fungi; Crop residue incorporation; Wheat; Nitrogen uptake

Published in

Applied Soil Ecology
2020, Volume: 155, article number: 103672
Publisher: ELSEVIER

SLU Authors

• Weih, Martin

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


UKÄ Subject classification

Soil Science


Publication identifier

DOI: https://doi.org/10.1016/j.apsoil.2020.103672

Permanent link to this page (URI)

https://res.slu.se/id/publ/108213