Abstract:
The main challenges facing smallholder farmers in sub-Saharan Africa (SSA) are soil fertility decline and climate
change, culminating in increased food insecurity. The double effect of climate change and soil fertility decline
could be devastating among the poor rural smallholder farmers, who solely depend on rain-fed agriculture with
little investment in adaptive mechanisms. Using inorganic fertilizers and careful selection of climate-resilient
crops such as sorghum could improve the livelihoods of smallholder farmers through improved soil health
and crop yields. However, information on the effects of inorganic fertilizer on sorghum production remains
uncertain, especially in SSA. We evaluated the effects of inorganic fertilizers on sorghum yields among small-
holder farmers in Western Kenya. We conducted a cross-sectional survey and collected data from 300 smallholder
sorghum farmers. We employed a multi-stage sampling procedure to collect data from the specific smallholder
farmers from the target population. We employed endogenous switching regression (ESR) modeling to control
observed and unobserved bias in predicting the effects of inorganic fertilizer use on productivity. Smallholder
farmers applied a limited amount of inorganic fertilizer. We established that hired labor, agricultural training,
and farmers’ perception of soil erosion were significant positive determinants of inorganic fertilizer use. Location
and access to weather forecast information were key negative determinants of inorganic fertilizer use. The use of
inorganic fertilizer increased crop yields by 14%. The findings suggested that inorganic amendments could
promote food security and improve purchasing power, thus enhancing smallholder farmers’ capacity to cope
with declining soil fertility and climate change-related challenges. Therefore, agricultural policies targeting
improved productivity of smallholder sorghum farmers could enhance inorganic fertilizer use while considering
the determinants