KTDA conducts soil testing to determine best tea fertilizer mix

A soil expert, Clive Otuoma, takes a soil sample for analysis from a smallholder tea farm in Bomet County. KTDA in partnership with IFC is conducting soil testing in tea farms to establish soil nutritional deficiencies and ascertain the best fertilizer mix for improving tea yields and quality – PHOTO BY NIKKKO TANUI

The national tea development agency has began conducting soil tests in small-scale farms to determine the best fertiliser for them

The project, a joint venture between the Kenya Tea Development Agency (KTDA) and the International Finance Corporation (IFC) aims at increasing production in smallholder tea farms through fertiliser optimisation.

Currently, the team that is doing soil testing is in Bomet County and has so far tested 30 tea catchment areas where tea supplied to KTDA-managed factories is grown.

Some 64 tea farms are picked randomly from these areas for soil testing.

Every year, KTDA purchases fertiliser in large volumes for its farmers. The fertiliser is then supplied to farmers on credit, with repayment made when they sell their tea to the company.

The current tests also include examining tea leaves.

“Once fertiliser is applied to tea bushes, we want to establish whether it has been translocated back to the leaf. We check the percentage of macro and micro nutrients in the soil and whether they are enough or not. We are also checking whether the kind of fertiliser farmers receive is the correct one,” said Clive Okioma, a soil expert with Crop Nutrition Laboratory Services who has been contracted by KTDA, said.

The fertiliser blends that KTDA has been purchasing and distributing to tea farmers have been based on soil analysis conducted years ago.

Soil changes

According to Mr Okioma, there could have been changes to the soil structure since then. The soil's chemistry may also have been altered by years of tea production and fertiliser application. This can only be ascertained through a new soil analysis using new technology.

 “The technology has changed. A new analysis technique called the Diagnosis and Recommendation Integrated System (DRIS) was developed in 1973 to identify nutritional deficiencies based on statistical correlation of soil and leaf tests. It requires computational power that was not available when the original testing was done and will provide farmers with more appropriate recommendations,” said Okioma.

Over 560,000 smallholder tea farmers have received 88,000 metric tonnes of NPK fertiliser procured by KTDA on their behalf and are applying it on their farms. Application of fertiliser is necessary to ensure consistent high quality and quantity of tea.

Importing fertiliser in bulk enables KTDA to leverage on economies of scale, enabling small-scale farmers who form the core of the agency's clients to buy the same at affordable rates.