Niger: Agriculture

Smallholder farmers in Niger are increasingly challenged by the uncertainty and variability of weather that climate change causes [23]. Since crops are predominantly rainfed, yields highly depend on water availability from precipitation and are prone to drought. However, the length and intensity of the rainy season is becoming increasingly unpredictable and the use of irrigation facilities remains limited: In 2010, less than 33 % of the estimated irrigation potential of 270 000 ha (0.6 % of total national crop land) were irrigated [8]. Irrigated crops include onions, sesame and cow peas [24]. Large parts of Niger’s soils are severely degraded due to unsustainable farming techniques and grazing practices, limiting opportunities for crop production [25].

Crop land exposure to drought

Figure 10: Projections of crop land area exposed to drought at least once a year for Niger for different GHG emissions scenarios.

Currently, the high uncertainty of projections regarding water availability (Figure 9) translates into high uncertainty of drought projections (Figure 10). According to the median over all models employed for this analysis, the national crop land area exposed to at least one drought per year will hardly change in response to global warming. However, there are models that project an increase in drought exposure. Under RCP6.0, the likely range of drought exposure of the national crop land area per year widens from 0.4-6.0 % in 2000 to 0.5–12.1 % in 2080. The very likely range widens from 0.1-18.0 % in 2000 to 0.1–40.6 % in 2080. This means that some models project a doubling of drought exposure over this time period, while others project no change.

Crop yield projections

Figure 11: Projections of crop yield changes for major staple crops in Niger for different GHG emissions scenarios assuming constant land use and agricultural management, relative to the year 2000.

In terms of yield projections, model results indicate a negative yield trend for maize under either RCP (Figure 11). Compared to the year 2000, maize yields are projected to decline by 5.3 % under RCP2.6 and by 2.7 % under RCP6.0 by 2080. However, yields of millet and sorghum, cow peas and groundnuts are projected to gain from climate change. Under RCP6.0, crop yields are projected to increase by 3.8 % for millet and sorghum, 54 % for cow peas and 52 % for groundnuts by 2080 relative to the year 2000. A possible explanation for the positive results under RCP6.0 is that cow peas and groundnuts are so-called C3 plants, which follow a different metabolic pathway than maize, millet and sorghum (C4 plants), and benefit more from the CO2 fertilisation effect under higher concentration pathways. Although yield changes of maize, millet and sorghum appear to be small at the national level, they will likely increase more strongly in some areas and, conversely, decrease more strongly in other areas as a result of climate change impacts.

Overall, adaptation strategies such as switching to improved varieties in climate change sensitive crops need to be considered, yet should be carefully weighed against adverse outcomes, such as a resulting decline of agro-biodiversity and loss of local crop types.

References

[23] O. Mertz, S. D’haen, A. Maiga, I. B. Moussa, B. Barbier, A. Diouf, D. Diallo, E. D. Da, and D. Dabi, “Climate Variability and Environmental Stress in the Sudan-Sahel Zone of West Africa,” Ambio, vol. 41, no. 4, pp. 380–392, 2012.
[24] FAO, “Adapting Irrigation to Climate Change (Aicca): Background,” 2020. Online available: http://www.fao.org/in-action/ aicca/country-activities/niger/background/en [Accessed: 16-Jan-2020].
[25] I. Soumana and T. Abasse, “Effects of Physical and Biological Treatments in Restoring Degraded Crusted Soil in Niger,” Res. J. Agric. Environ. Manag., vol. 3, no. 10, pp. 560–568, 2014.