Acidic soil correction lime, dolomite, pH below 5.5, aluminium toxicity.
3 Answers
Acidic soils (pH below 5.5) are common in high-rainfall and laterite areas and cause aluminium and manganese toxicity plus poor phosphorus availability. Correct by applying agricultural lime or dolomite based on the lime requirement from your soil test, broadcast 3 to 4 weeks before sowing and mix into the top soil. Dolomite is useful when magnesium is also low. Add organic matter and use phosphorus efficiently since it gets fixed in acid soils. For tea and other acid-loving crops only mild correction is needed. Re-test after one season as over-liming can push pH too high. Confirm the exact lime dose with your soil testing lab or KVK.
In our hill plots we apply lime in line with the seed furrow rather than broadcasting the whole field, which stretches a smaller quantity and still helps the root zone. It is cheaper when lime is hard to get.
Give the lime time to react before sowing. I once limed and sowed the same week and saw little effect that season. Spreading it a few weeks ahead onto moist soil made a clear difference the next time, and I re-tested to avoid over-liming.