**3.2 Pigeonpea yields**

Long-term yields of pigeonpea under variable and changing climate in Katumani are presented in **Figure 2**. Unlike maize, both CSIRO and CNRM models predicted decreased pigeonpea yields in Katumani in the near and far future. Yields from sole pigeonpea crop will decline by 10–20% and 4–9% under CSIRO and CNRM models, respectively, by 2100. Intercropping short and medium duration pigeonpea varieties with maize will reduce pigeonpea yields by 60–80% and 70–90% under the CSIRO and CNRM model, respectively. However, long duration varieties will yield highest under the two Global Climate Change Models (GCMs) irrespective of the cropping system, but the yields will be much lower than the potential yield of over 2 t ha−1 obtained from research experiments and large-scale commercial farms in the region. The decline in pigeonpea yields could be attributed to the projected 2°C and 11% increase in temperature and rainfall, respectively. Pigeonpea is a Carbon-3 (C3) plant and is highly sensitive to waterlogging; therefore, existing pigeonpea varieties may not thrive in the predicted hotter and wetter conditions [59, 60]. High temperatures reduce the rate of photosynthesis in legumes due to their C3 photosynthesis cycle leading to low yields [61, 62]. Waterlogging blocks oxygen supply to roots which hamper permeability [63], delays flowering and reduces vegetative growth, photosynthetic rate, biomass and grain yield in pigeonpea [64, 65]. Short duration


**241**

Kenya

**Author details**

**4. Conclusion**

that Kenya currently enjoys.

**Acknowledgements**

Kizito Musundi Kwena1,2\*, G.N. Karuku1

County for their technical support.

(LARMAT), University of Nairobi, Nairobi, Kenya

\*Address all correspondence to: kwenakizito@yahoo.com

Katumani Research Centre, Machakos, Kenya

provided the original work is properly cited.

, F.O. Ayuke1

1 Department of Land Resource Management and Agricultural Technology

3 Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Kenya Agricultural and Livestock Research Organization (KALRO),

and A.O. Esilaba3

*Impact of Climate Change on Maize and Pigeonpea Yields in Semi-Arid Kenya*

pigeonpea varieties like Mbaazi I are more prone to the risk of yield reduction due to waterlogging compared to the medium and long duration varieties such as Kat 60/8 and Mbaazi II, respectively [66]. Therefore, farmers in Katumani and similar areas in the country may have to rethink their dependence on pigeonpea going into the future. Scientists also need to start breeding for more heat and waterlogging-tolerant varieties to save the livelihoods of thousands of resource-poor households in ASALs and safeguard the huge pigeonpea export market that Kenya currently commands.

Prospects for growing maize in Katumani are high both in the near (2050) and far (2100) future. However, pigeonpea production will be negatively affected by climate change going forward due to pigeonpea's susceptibility to high temperatures and waterlogging. Therefore, farmers in the ASALs need to rethink their dependence on pigeonpea while national plant breeding programs need to start developing heat and waterlogging-tolerant varieties to help thousands of resource-poor households in ASALs to adapt to climate change and protect the huge pigeonpea export market

We are grateful to the Kenya Agricultural and Livestock Research Organization (KALRO) for allowing us to conduct this study. We also thank the Department of Land Resource Management and Agricultural Technology (LARMAT) of the University of Nairobi, KALRO's Natural Resources Management (NRM) Programme and the Kenya Meteorological Service (KMS) office in Machakos

*DOI: http://dx.doi.org/10.5772/intechopen.93321*

**Figure 2.** *Projected pigeonpea yields for Katumani in the near and far future.*

*Impact of Climate Change on Maize and Pigeonpea Yields in Semi-Arid Kenya DOI: http://dx.doi.org/10.5772/intechopen.93321*

pigeonpea varieties like Mbaazi I are more prone to the risk of yield reduction due to waterlogging compared to the medium and long duration varieties such as Kat 60/8 and Mbaazi II, respectively [66]. Therefore, farmers in Katumani and similar areas in the country may have to rethink their dependence on pigeonpea going into the future. Scientists also need to start breeding for more heat and waterlogging-tolerant varieties to save the livelihoods of thousands of resource-poor households in ASALs and safeguard the huge pigeonpea export market that Kenya currently commands.
