eCite Digital Repository
Nitrogen use efficiency, allocation, and remobilization in apple trees: uptake Is optimized with pre-harvest N supply
Citation
Tan, BZ and Close, DC and Quin, PR and Swarts, ND, Nitrogen use efficiency, allocation, and remobilization in apple trees: uptake Is optimized with pre-harvest N supply, Frontiers in Plant Science, 12 Article 657070. ISSN 1664-462X (2021) [Refereed Article]
 | PDF (Published version) 2Mb |
Copyright Statement
Copyright © 2021 Tan, Close, Quin and Swarts. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License (https://creativecommons.org/licenses/by/4.0/).
DOI: doi:10.3389/fpls.2021.657070
Abstract
Optimizing the utilization of applied nitrogen (N) in fruit trees requires N supply that is temporally matched to tree demand. We investigated how the timing of N application affected uptake, allocation, and remobilization within 14-year-old "Gala"/M26 apple trees (Malus domestica Borkh) over two seasons. In the 2017–2018 season, 30 g N tree-1 of 5.5 atom% 15N-calcium nitrate was applied by weekly fertigation in four equal doses, commencing either 4 weeks after full bloom (WAFB) (pre-harvest) or 1-week post-harvest, or fortnightly, divided between pre- and post-harvest (50:50 split). Nitrogen uptake derived from fertilizer (NDF) was monitored by leaf sampling before whole trees were destructively harvested at dormancy of the first season to quantify N uptake and allocation and at fruit harvest of the second season to quantify the remobilization of NDF. The uptake efficiency of applied N fertilizer (NUpE) was significantly higher from pre-harvest (32.0%) than from the other treatments (-17%). The leaf NDF concentration, an indicator of N uptake, increased concomitantly only when pre-harvest N was applied. Pre-harvest treated trees allocated more than half of the NDF into fruit and leaves and stored the same amount of NDF into perennial organs as the post-harvest treatment. Subsequent spring remobilization of NDF was not affected by the timing of N fertigation from the previous season. A seasonal effect of remobilization was observed with a decrease in root N status and a reciprocal increase in branch N status at fruit harvest of season two. These findings represent a shift in the understanding of dynamics of N use in mature deciduous trees and indicate that current fertilizer strategies need to be adjusted from post-harvest to primarily pre-harvest N application to optimize N use efficiency. This approach can provide adequate storage N to support early spring growth the following season with no detriment to fruit quality.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | nitrogen use efficiency, 15N, remobilization (nitrogen), partitioning (nitrogen), application timing, storage (nitrogen), nitrogen uptake |
| Research Division: | Agricultural, Veterinary and Food Sciences |
| Research Group: | Horticultural production |
| Research Field: | Horticultural crop growth and development |
| Objective Division: | Plant Production and Plant Primary Products |
| Objective Group: | Horticultural crops |
| Objective Field: | Pome fruit, pip fruit |
| UTAS Author: | Tan, BZ (Mr Bi Tan) |
| UTAS Author: | Close, DC (Professor Dugald Close) |
| UTAS Author: | Quin, PR (Mr Peter Quin) |
| UTAS Author: | Swarts, ND (Dr Nigel Swarts) |
| ID Code: | 144639 |
| Year Published: | 2021 |
| Deposited By: | TIA - Research Institute |
| Deposited On: | 2021-06-01 |
| Last Modified: | 2021-09-08 |
| Downloads: | 0 |
Repository Staff Only: item control page