Climate Variability and Response Strategies among Smallholder Sweet Potato Farmers in Gatundu North Sub-County, Kiambu County, Kenya

Sweet potato (Ipomoea batatas) is a perennial creeping vine that is mainly grown for its leaves and storage roots. Its origins can be traced back to Latin America and it currently presents in various colours including orange, purple, white and yellow. The plant is a significant source of vitamin E, B and C aside from being used as a livestock feed. Sweet potato is ranked as the 5 th most important food crop in developing countries (International Potato Center2019). Sweet potatoes are grown in many parts of Kenya where average minimum temperatures are above 12 0 C and average maximum temperatures are below 35 0 C. Annual rainfall during the growing season is well distributed and ranges from 600mm to 1600mm annually. Moreover, soils are sandy-loam, well-drained and light. (Infonet-Biovision2019). In Kenya, sweet potatoes have historically been neglected and underutilized in the country's efforts to attain food sufficiency. Unlike maize and other staple foods, they have not been aggressively championed as commercially viable crops (Ministry of Agriculture & Livestock Development2019). This is however changing as the Kenyan Government and other stakeholders implement measures to boost sweet potato production. There is therefore urgent need to understand the impact of climate variability on the crop if these measures are to succeed. The impacts of climate variability on sweet potato farming cannot be fully appreciated without an indepth evaluation of climatic patterns in the area of interest. Rainfall and temperature patterns in Kiambu County have previously been investigated (Kiptum 2017, Macharia 2017). Nevertheless, there is need to expand this pool of knowledge viaanalysis of recent data as was done in this study. Moreover, smallholder farmers' perceptions on climate change and variability determine their Abstract: Climate change and climate variability as manifested in prolonged droughts and frequent floods among other effects is a challenge world over, affecting climate sensitive sectors such as agriculture. Climate variability could be particularly damaging to smallholder farmers that are dependent on rain-fed agriculture including those that grow sweet potatoes in many parts of Kenya such as Gatundu North Sub-County of Kiambu County. The aim of this research was therefore to assess the relationship between smallholder sweet potato production and climate variability in Gatundu North Sub-County. The study used monthly rainfall totals, monthly average maximum and minimum temperatures, annual sweet potato production and responses fromselected smallholder sweet potato farmers. There was a decreasing trend in annual rainfall totals, this trend was however not significantbut the rainfall was highly variable. Annual average maximum and minimum temperatures had an upward trendbut variability was negligible. There was a downward trend in annual sweet potato production. Annual sweet potato production and annual rainfall/annual average maximum and minimum temperatures had a weak negative correlation. The coping strategies being utilized by smallholder sweet potato farmers included crop diversification, irrigation, planting fast-maturing varieties, cultivating in swampy areas, cultivating under other plants to provide shade and adjustment of planting dates. It was concluded that there was no significant relationship between changes in rainfall and temperature and sweet potato production in the study area implying that the coping strategies being used by surveyed farmers were effective in mitigating the deleterious effects of climate variability on the crop and should therefore be strengthened.