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Tea: acid soil, steady feeding, and where organics fit.
Tea is different from most crops on this site. It grows best in acidic soil, so the advice for maize, such as liming, can harm it. This guide explains what the Tea Research Foundation of Kenya recommends, and says plainly where organic inputs fit and where the research does not yet give figures.
The numbers that matter
All figures on this page are from the Tea Research Foundation of Kenya (TRFK), Fertilizer User Guide for Tea, first edition, 2012.
Tea likes acid, so be careful with lime
- The right pH. Tea grows best at pH 4.5 to 5.6. Higher pH is harder to manage and many clones grow poorly in it.
- Nursery soil. Keep nursery soil between pH 4.0 and 5.8, and do not let seedling nursery soil rise above 5.8.
- Lime only before planting. On very acidic sites, TRFK suggests 2 to 6 tonnes per hectare of dolomitic lime before replanting, depending on the starting pH. Do not lime mature tea directly.
- Avoid CAN. TRFK does not recommend calcium ammonium nitrate for tea in Kenya.
- Test, then decide. Soil and leaf analysis can show your fertiliser needs and flag deficiency risks.
Why this matters for compost.
Advice that suits other crops, such as using lime alongside manure on acidic maize soil, does not carry over to tea. Always check a recommendation is for tea before you apply it.
SOURCE: TRFK, FERTILIZER USER GUIDE FOR TEA (2012)
Fertiliser by age
TRFK sets rates by nitrogen (N), with the equivalent amount of NPK 25:5:5 beside it.
| Stage | Nitrogen | NPK 25:5:5 equivalent |
|---|---|---|
| Year 1, stumped plants | 2 g N per plant, starting 6 months after transplanting, about every 8 weeks | 8 g per plant |
| Year 1, sleeved plants | 1.5 g N per plant, 6 weeks after planting and every 8 weeks | 12 g per plant |
| Year 2 | 120 kg N per hectare per year | 480 kg per hectare |
| Year 3 | 150 kg N per hectare | 600 kg per hectare |
| Year 4 | about 180 kg N per hectare | 720 kg per hectare |
| Year 5, clonal tea | 180 kg N per hectare | – |
| Mature, high-yielding | TRFK advises trialling 100, 150 and 200 kg N per hectare per year | – |
Timing
Apply fertiliser when the soil is moist enough to avoid root damage. With one rainy season, apply once at the start of the rains. With two, apply two half doses, one at the start of each. Avoid prolonged cold or wet spells, and in dry weather wait until rain is certain.
SOURCE: TRFK, FERTILIZER USER GUIDE FOR TEA (2012)
Compost, manure and mulch on tea
TRFK recommends integrated nutrient management, which means combining fertiliser with organic sources to improve the soil’s physical, chemical, biological and water properties. It lists organic manures as one way to manage soil acidity.
What the guide does not say.
TRFK gives no rates for manure, compost or mulch on tea. We have not made any up. Until you have advice for your own soil, use organic inputs to support the fertiliser programme, not to replace it, and ask TRFK or your factory extension officer before changing rates.
- Test before you change anything. Check soil pH first. Tea prefers it low, so don’t assume a rule from another crop applies.
- Think about the nursery. Nursery soil needs to stay acidic, below pH 5.8.
- Mother bushes. TRFK gives mother bushes twice the normal fertiliser rate, split after each prune. Their prunings are removed for cuttings, and the guide does not say how much organic matter to return.
SOURCE: TRFK, FERTILIZER USER GUIDE FOR TEA (2012)
Questions people ask
Can I use compost on tea?
Yes, as part of integrated nutrient management. TRFK lists organic manures as an option for managing acidity but gives no rates, so treat compost as a supplement to your fertiliser programme.
Should I lime my tea field?
Not mature tea. Liming can suppress potassium uptake and reduce yields. TRFK suggests lime only before planting or replanting on very acidic sites.
What soil pH should I aim for?
4.5 to 5.6. Nursery soil should stay between 4.0 and 5.8.
Which fertiliser do I use?
NPK 25:5:5 or 26:5:5 for mature tea. For young tea, TRFK advises a compound with N:P:K of about 5:1:1, or richer in P and K.
Where can I get a soil or leaf test?
Ask TRFK or your factory’s extension service. The test form asks for soil pH, nutrients, leaf nutrients and your fertiliser history.
Want to make your tea soil healthier?
We can help you plan compost and mulch for nurseries and fields, and check it against your tea programme.