Objective Distribution pattern of potassium in soils at tea plantations in northern Anxi county was surveyed to facilitate fertilization of the farming.

Method Potassium contents in the soils of 50 tea plantations in 9 townships in the region were classified by degree of abundance. Spatial distribution of the total and available potassium in soil was correlated with selected environmental factors.

Result Thirty-one plantations, accounting for 62% of the total surveyed sites, had the total potassium content in soil ranging from 5.0 g·kg⁻¹ to 42.7 g·kg⁻¹ with a mean of 18.45 g·kg⁻¹ and were classified as medium and above levels in abundance. On the other hand, 36 locations, i.e., 72% of the total, were low or deficient on available potassium with a content ranging 21.85-168.51 mg·kg⁻¹ and averaging 64.64 mg·kg⁻¹. Spatially, the areas with high total potassium in the region were northwest-to-southeast geographically distributed in a dumbbell-like shape, while those with low soil potassium bordered between the towns of Gande and Jiandou. The areas of same available potassium classification spread uniformly, except some places low on the content sporadically located in Hushang town and parts of the land close to Changqing town. The total potassium in soil was affected by the potassium oxide in the rocks as well as sand, whereas the available potassium did not significantly correlate with either the organic matter and physiochemical properties of the soil or the potassium oxide content in the rock.

Conclusion The total potassium in soil of tea plantations in northern Anxi county was relatively rich, but the available potassium generally poor. Hence, potassium fertilization might be necessary for the area tea plantations.