A potato pot experiment was conducted to study the effects of potassium chloride coated by polymer (PCK) with different dosages on potato yield

quality and soil potassium (K) supply

which set six treatments: no potassium

potassium chloride

30% PCK

50% PCK

70% PCK and 100% PCK dosage (with potassium chloride dosage equivalent). The results showed that the K released by 1.2% amount average of PCK in 25 ℃ water immersion

which met the controlled-release fertilizer industry standards. The K release rate was in “S” trend in the soil and reached the maximum value at 70～90 days

which was consistent with the potato potassium uptake in tuber formation period and beneficial to yield formation. The yields of potato were increased by 13.92%～36.54% under PCK different dosages compared with potassium chloride. The potato Vc

total soluble protein and starch contents of 100% PCK were significantly higher than that of potassium chloride

and the potato total reducing sugar content of 100% PCK was significantly lower than other treatments

the decreased amplitude was 13.9%～36.2%. The PCK released K slowly

which could meet the needs of the potato K uptake at later period. After the tuber formation period

potato K uptake amount of above 50% PCK dosage treatments were significantly higher than other treatments. Compared with potassium chloride

the content of soil available K content of above 50% PCK was significantly higher after the tuber formation period. At the same time

the soil water soluble K and non-specifically adsorbed K contents were increased by 8.4%～25.1% and 9.3%～36.1% respectively

so the soil K supply adequately. In conclusion

above 50% PCK dosage was beneficial to improve potato yield

commercial potato rate and quality

and increase soil K supply.