Nitrous Oxide Emissions from Smallholders’ Cropping Systems in Sub-Saharan Africa

Table 1

In situ empirical studies on N₂O emissions from different cropping systems in Sub-Saharan Africa.

Cropping systems	Country	Sampling frequency	Sampling duration	Soil type	N2O fluxes	N2O EFs (%)	N2O YSE (g N2O kg^−1 grain)	References
Annual emissions
Sorghum, peanut, and groundnut	Burkina Faso	1–3 per week	Jun–Sep 2006	Sandy	0.19–0.67 kg ha^−1 yr^−1	∗	∗	Brummer et al. [34]
Millet-legume intercrop	Mali	Monthly	Jan 2004–Feb 2005	Alfisol	0.9–1.5 kg ha^−1 yr^−1	4.1	∗	Dick et al. [35]
Vegetable	Niger	Twice a day for 6 days	Apr 2006–Feb 2007	Sandy	48–92 kg ha^−1 yr^−1	∗	∗	Predotova et al. [36]
Vegetable	Zimbabwe	Twice a day	Mar 2008–Mar 2009	Clay	80.5–113.4 kg ha^−1 yr^−1	3–4		Lompo et al. [37]
Maize	Zimbabwe	During raining season	Jun 2006–May 2009	Clay/loam	0.8–2.5 kg ha^−1 yr^−1			Mapanda et al. [38]
Fruit	Zimbabwe	2 days–2 weeks	2011–2013	Sandy loam	2.5–112 kg ha^-1	∗	2.1–14	Nyamadzawo et al. [39]
Maize	Kenya	Daily to weekly	99 days	Clay	0.16–0.81 kg ha^−1yr^−1	∗	∗	Hickman et al. [40]
Maize	Kenya	Daily to weekly	March 2011–July 2011	Sandy-clay	0.1–0.3 kg ha^−1 yr^−1	0.11	0.27–0.8	Hickman et al. [41]
Tea, vegetable, and maize	Kenya	Weekly	Jan–Dec 2013	Sand-clay	0.4–3.9 kg ha^−1 yr^−1	0.4–0.8	∗	Rosenstock et al. [42]
Maize, beans, and sorghum	Kenya	Weekly	Aug 2013–Aug 2014	Nitisols	-0.1–1.8 kg ha^−1 yr^−1	∗	1.1–67	Pelster et al. [1]
Maize, bean, and coffee	Kenya	1-2 times a week	Feb 2015 –Feb 2016	Nitisols	1–1.9 kg ha^−1 yr^−1	<1	0.08–0.15	Ortiz-Gonzalo et al. [43]
Tea	Kenya	1-2 times per week	Aug 2015–July 2016	Humic nitisols	0.6–2.34 kg ha^−1 yr^−1	∗	∗	Wanyama et al. [44]
Maize	Ghana	Daily during fertilization, then weekly	Aug 2013–Aug 2014	Ferric luvisol	1.22–4.29 kg ha^−1 yr^−1	0.1–0.55	0.39–1.24	Atakora et al. [45]
Maize	Tanzania	Weekly to monthly	Dec 2015– Nov 2017	Alfisol/andisol	0.26–2.24 kg ha^−1 yr^−1	0.1–1.3	0.18	Zheng et al. [46]
Maize-legumes (lablab/Crotalaria	Ethiopia	Weekly	107–123 days	Clay-loam	0.17–0.33 kg ha^−1yr^−1	0.2–0.25		Raji and Dörsch [47]
Maize	Kenya	Weekly	Feb 2017–Feb 2018	Sandy loam	0.13–1.22 kg ha^−1yr^−1	0.2–0.9	0.5–2.2	Macharia et al. [28]
Maize	Kenya	Weekly	March 2018–March 2019	Humic nitisols	0.21–0.38 kg ha^−1yr^−1	0.05–1.4	0.024–0.028	Musafiri et. [48]
Seasonal fluxes
Maize	Zimbabwe	Weekly	Dec 2000–Feb 2001	Sandy loam	0.1–0.3 kg ha^-1	0.2	∗	Chikowo et al. [49]
Maize	Kenya	1-2 times per week	84 days	Sandy-clay	0.1–4.1 kg ha^-1	∗	∗	Millar et al. [50]
Maize	Kenya	Weekly	Feb–June 2002	Silt-clay-loam	0.2–0.6 kg ha^-1	∗	∗	Baggs et al. [18]
Soybeans and maize	Madagascar	Weekly	Nov 2006–Apr 2007	Ferralsol	0.3 kg ha^-1	0.46–0.47	∗	Chapuis-Lardy et al. [51]
Maize	Zimbabwe	Once every two months	Jan 2006–May 2009	Clay and sandy loam	0.1–0.5 kg ha^-1	∗	0.02–3.93	Mapanda et al. [52]
Maize	Zimbabwe		2008/2009 growing season	Sandy loam	0.26–0.52 kg ha^-1	∗	0.22–0.68	Nyamadzawo et al. [53]
Vegetable	Kenya	1–3 days per week	Sept 2015–July 2016	Humic nitisols	0.4–3.0 kg ha^−1	0.0–2.6	∗	Kurgat et al. [54]
Coffee, maize-beans	Kenya	1–3 days per week	Feb 2015– Feb 2016	Nitisols	0.18–1.9 kg ha^−1			Ortiz-Gonzalo et al. [43]
Short duration
Maize-beans	Nigeria	1–3 days to 2 weeks	21 days	Ferric lixisol	0.1–0.3 kg N ha^-1/day	1		Roing et al. [55]
Maize	Kenya	3 times per month	4 weeks	Humic nitisols	1.3–12 µg m^−2 h^−1	∗	∗	Kimetu et al. [56]
Vegetables	Zimbabwe	Biweekly	Sept 2007–Nov 2008	Loamy sandy	2.5–18.8 g N2O–N h^−1	0.3–1.0	∗	Masaka et al. [57]
Banana-coffee	Uganda	4-5 times per month	May 2018–June 2018	Sandy-clay loam	3.7–6.7 µg m^−2 h^−1		∗	Fatumah et al. [58]
Amaranth	Benin/Nigeria	Daily during planting and then after 2 weeks	21 days	Haplic lixisols/plethnic plinthosols	24.8–279.5 mgN/kg soil			Olaleye et al. [59]

N/B. All measurements were carried out using static chambers. ∗no value reported.