Abstract:
Kenya’s tea industry depends predominantly on imported compound NPK fertilizers to replenish nutrients removed through
plucking. 'ese fertilizers cannot be easily manipulated for specific soils and tea clones. 'ey also frequently become
hazardous within tea-growing environments. In this respect, two fertilizer blends containing NPKS 25 : 5 : 5 : 4 + 9Ca + 2.62Mg
and NPKS 23 : 5 : 5 : 4 + 10Ca + 3Mg with trace elements have been produced commercially in the country. However, the extent
to which the blended fertilizers may contribute to optimal economic gains without degrading the environment has not been
determined. 'is was the knowledge gap that this study seeks to address. 'e goal of this study was to evaluate the economic
efficacy of fertilizer blends with the aim of identifying optimal levels of application which would maximize tea productivity
with minimal negative impacts on the environment. 'e study hypothesized that blended fertilizers maximize productivity of
tea clones with minimal environmental damage. 'e fertilizer blends were evaluated in two study sites, i.e., Timbilil Estate in
Kericho and Kagochi farm in Nyeri. 'e sites were selected purposefully, one in the eastern and the other in the western
tea-growing areas. 'e trial was laid out in randomized complete block design with two fertilizer blends and the standard NPK
26 : 5 : 5 as control. 'e treatments were applied at four fertilizer rates (0 (control), 75, 150, and 225 kg·N·ha−1
·yr−1
), replicated
thrice. Leaf samples were collected and analyzed for nutrient uptake as well as associated yields and economic trends.
'e economic optimum nitrogen rate (EONR) was achieved at 75 kg·N·ha−1
·yr−1 at Kagochi with all fertilizers, while at
Timbilil, EONR was variable, between 75 and 225 kg·N·ha−1
·yr−1 with fertilizer types. 'is study has shown that, based on the
economic point of view, Blend “A” was the most efficient and consistent fertilizer in production and economic returns across
the two sites.
