Response Strategies among Smallholder Sweet Potato Farmers to Climate Change and Variability in Kiambu County, Kenya
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Date
2025-09
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Kenyatta University
Abstract
Climate variability could be particularly damaging to smallholder farmers who depend on
rain-fed agriculture. The study’s general objective was to assess the relationship between
smallholder sweet potato production and climate variability in Gatundu North Sub-County.
The specific objectives were to analyse temperature and rainfall trends and variability in
the study area for the 30-year period between 1993 and 2022; to examine the relationship
between climate variability and sweet potato production; to determine whether climate
variability influences varietal diversity of sweet potatoes; and to assess the coping
strategies adopted by smallholder sweet potato farmers against climate variability. The
study used descriptive survey research design with a sample size (n) of 389. Structured
questionnaires were administered on 292 randomly selected smallholder sweet potato
farmers. Key informants (agricultural and meteorological officers) were interviewed.
Monthly rainfall totals and monthly average maximum and minimum temperatures were
obtained from KMD. Annual sweet potato production data was obtained from the Gatundu
North Sub-County Agricultural Office. The Real Statistics Resource Pack was used to carry
out trend analysis on rainfall and maximum and minimum temperature data using the
Mann-Kendall Test and Sen’s Slope Estimator; and to carry out Pearson correlation on
temperature, rainfall and sweet potato production. Shannon Diversity Index (H) was
calculated to determine varietal diversity and species richness of sweet potatoes. Survey
analysis was done on data collected through structured questionnaires to isolate running
themes on the coping strategies. Results indicated that there was a decreasing but
statistically insignificant trend (slope = -2.555, p-value = 0.669) in annual rainfall totals.
Both monthly and annual rainfall was highly variable with CV>0.3. Annual average
maximum and minimum temperatures had been increasing (slope = 0.065, p-value =
7.056E-07 and slope = 0.024, p-value = 0.032 respectively) but variability was negligible
(CV < 0.3). Annual sweet potato production and annual rainfall had a weak negative
correlation (r = -0.052, p = 0.865). The correlation between annual sweet potato production
and annual average maximum and minimum temperatures was also weak and negative (r
= -0.254, p = 0.399 and r = -0.199, p = 0.512 respectively). Climate variability influenced
the choice of sweet potato varieties that smallholder farmers were growing (χ 2 =5.294
with 1 degree of freedom, p-value = 0.0214). The main coping strategies that were being
utilized by smallholder sweet potato farmers were crop diversification (42.47%), irrigation
(13.70%) and planting fast-maturing varieties (7.88%). The study concluded that there was
a statistically insignificant decreasing trend in annual rainfall totals though variability was
high on both monthly and annual time-scales; both annual average maximum and minimum
temperatures had an increasing trend though monthly and annual variability was negligible;
there was no significant relationship between changes in rainfall and temperature and sweet
potato production; climate variability influenced varietal diversity of sweet potatoes and
smallholder farmers had adopted coping strategies against climate change. It was
recommended that MoALD and DoALI - Kiambu should prioritize a climate-smart sweet
potato development program in the study area; DoALI - Kiambu should publicize the
success of smallholder sweet potato farmers in coping with climate variability; KALRO
should decentralize its services to sub-county and ward levels to enhance access to vines;
and smallholder sweet potato farmers should enhance production by hosting on-farm
demonstrations and participating in farmer field schools
Description
A Thesis Submitted in Partial Fulfilment of the Requirements for the Award of the Degree of Master of Environmental Science in the School of Agriculture and Environmental Sciences of Kenyatta University, September 2025
Supervisor:
1.Evelyn Wemali
2.Gladys Gathuru