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Available nitrogen and responses to nitrogen fertilizer in Brazilian Eucalypt plantations on soils of contrasting texture
Citation
Pulito, AP and Goncalves, JLDM and Smethurst, PJ and Arthur, JC and Alvares, CA and Rocha, JHT and Hubner, A and de Morales, LF and Miranda, AC and Kamogawa, MY and Gava, JL and Chaves, R and Silva, CR, Available nitrogen and responses to nitrogen fertilizer in Brazilian Eucalypt plantations on soils of contrasting texture, Forests, 6, (4) pp. 973-991. ISSN 1999-4907 (2015) [Refereed Article]
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Copyright Statement
Copyright 2015 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
DOI: doi:10.3390/f6040973
Abstract
Eucalyptus plantations have seldom responded to N fertilization in tropical and subtropical regions of Brazil. This implies that rates of N mineralization have been adequate to supply tree needs. However, subsequent crop rotations with low N fertilization may result in declining concentrations of organic and potentially mineralizable N (N0), and consequent loss of wood productivity. This study investigated (a) in situ N mineralization and N0 in soils of eucalypt plantations in São Paulo state, Brazil; (b) tree growth responses to N fertilizer applied 6-18 months after planting; and (c) the relationships between N0, other soil attributes and tree growth. We established eleven N fertilizer trials (maximum 240 kg ha−1 of N) in E. grandis and E. grandis x urophylla plantations. The soil types at most sites were Oxisols and Quartzipsamments, with a range of organic matter (18 to 55 g kg−1) and clay contents (8% to 67%) in the 0-20 cm layer. Concentrations of N0 were measured using anaerobic incubation on soil samples collected every three months (different seasons). The samples collected in spring and summer had N0 140-400 kg ha−1 (10%–19% total soil N), which were best correlated with soil texture and organic matter content. Rates of in situ net N mineralization (0-20 cm) ranged from 100 to 200 kg ha−1 year−1 and were not correlated with clay, total N, or N0. These high N mineralization rates resulted in a low response to N fertilizer application during the early ages of stand growth, which were highest on sandy soils. At the end of the crop rotation, the response to N fertilizer was negligible and non-significant at all sites.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | forest, productivity, potentially mineralisable N, sustainability, fertiliser application, nutrition |
| Research Division: | Agricultural, Veterinary and Food Sciences |
| Research Group: | Forestry sciences |
| Research Field: | Forestry management and environment |
| Objective Division: | Plant Production and Plant Primary Products |
| Objective Group: | Forestry |
| Objective Field: | Hardwood plantations |
| UTAS Author: | Smethurst, PJ (Dr Philip Smethurst) |
| ID Code: | 117266 |
| Year Published: | 2015 |
| Web of Science® Times Cited: | 39 |
| Deposited By: | Tasmanian Institute of Agriculture |
| Deposited On: | 2017-06-06 |
| Last Modified: | 2017-09-04 |
| Downloads: | 150 View Download Statistics |
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