Effects of Potassium Fertilizer on Tomato Yield,Quality and Potassium Cycling in Greenhouse

Potassium application effects on tomato were studied in 2007 —2009.The results showed that after the potassium application,tomato yield improved 3.5%～38.9% and net income increased 3 407.3～51 415.0 Yuan·hm-2 . Potassium fertilizer played a key role on improving VC and total sugar content.VC and total sugar content of NPK 4 treatment were 190.4 mg·kg-1 and 3.65% ,which were the highest content than the other treatments.VC and total sugar content of CK treatment in tomato were 138.5 mg·kg-1 and 2.97% ,separately,which were the lowest content than the other treatments.The potassium content in fruit and plant uptake of potassium, increased with the increment of potassium.Potassium accumulation in tomato fruit was relation with yield. Potassium fertilizer use efficiency was 43.4%～49.9%.Potassium content of CK and NPK 3 treatment in soil decreased to 25 mg·L-1 and 2 mg·L-1 compared with before planting. Potassium content of the other treatments were higher than that of before planting ,separately.