Contribution of N2O to the greenhouse gas balance of first-generation biofuels

Authors

Errata

This article corrects:

  1. Contribution of N2O to the greenhouse gas balance of first-generation biofuels Volume 15, Issue 1, 1–23, Article first published online: 19 November 2008

Edward M. W. Smeets, tel. +31 30 253 7688, fax +31 30 253 7601, e-mail: e.m.w.Smeets@uu.nl

In Table 3, the last footnote: “For deserts, no effect values are given. Instead we assumed a default N2O emission of 0.1 kg N2O-N ha−1 yr−1 based on Bouwman et al. (1999)” was missing in the printed Issue 15:1.

Table 3.   Effect values and constant for the Stehfest & Bouwman model (2006) used to calculate direct N2O emissions from agricultural fields and natural vegetation
Agricultural fieldsNatural vegetation
  • *

    The category cereals excludes maize, which is in ‘other crops’.

  • The measurements for temperate coniferous and deciduous forests stem from areas with high N deposition (≥10 kg N ha−1 yr−1). For coniferous and deciduous forests with low N deposition (< 10 kg N ha−1 yr−1) we correct the N2O emissions calculated by the model. The correction factor is the ratio of N deposition for forests with low N deposition to 10 kg N ha−1 yr−1.

  • This category includes sugar cane. Although this crop has some biological N fixation, it is not usually classified as a legume (Dobereiner et al., 2000). The rate of N fixation in sugar cane production is much lower than that in leguminous crops, but higher than that of other non-leguminous crops (see further the main text. An analysis of the results of N2O emission measurements that are included in the dataset of Stehfest & Bouwman (2006), from which the statistical model is calculated, showed that the N2O emissions are similar to those of ‘other crops’.

  • §

    For deserts, no effect values are given. Instead we assumed a default N2O emission of 0.1 kg N2O-N ha−1 yr−1 based on Bouwman et al. (1999).

Constant (c)−1.5160Constant (c)−2.8900
Effect values (ev) Effect values (ev) 
N application rate N application rate 
 Variable0.0038 × N application rate in kg N ha−1 yr−1 N/aN/a
Soil organic C content (%) Soil organic C content (%) 
 < 10 < 10
 1–30.0526 1–30.6683
 > 30.6334 > 31.0918
Soil pH Soil pH 
 < 5.50 < 5.50
 5.5–7.3–0.0693 5.5–7.3–0.2750
 > 7.3–0.4836 > 7.3–2.4179
Soil texture Soil texture 
 Coarse0 N/aN/a
 Medium–0.1583 N/aN/a
 Fine0.4312 N/aN/a
Climate Climate 
 Temperate_C0 N/aN/a
 Temperate_O0.0226 N/aN/a
 (sub)Tropical0.6117 N/aN/a
 Tropical–0.3022 N/aN/a
Crop type Vegetation type 
 Cereals*0 Coniferous0
 Grass–0.3502 Deciduous0.0115
 Legume0.3783 Grass–0.7941
 Other§0.4420 Rain forest0.4995
 Wetland rice–0.8850 Savannah–0.6881
 None0.5870 Tropical dry forest–0.5811
  DesertN/a
Soil drainage Soil drainage 
 N/aN/a Poorly drained0
 N/aN/a Well-drained–1.0462
Bulk density (g cm−3) Bulk density (g cm−3) 
 0–10.9941 N/aN/a
 1–1.25−0.3786 N/aN/a
 > 1.25–0.8597 N/aN/a
Length of experiment (year) Length of experiment (year) 
 11.9910 13.6120

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