THE EFFECTS OF NK INTERACTION ON YIELD, QUALITY AND UPTAKE OF NITROGEN, PHOSPHORUS AND POTASSIUM IN POTATO (Solanum tuberosum L. )

The effects of four NK treatments on growth, tuber yield and quality, and uptake of nitrogen, phosphorus and potassium in potato (Solaxmn tuberosum L. cv. Gloden-crown) were studies. The results showed that high nitrogen treatments inhibited plant growth and decreased tuber yield as compared with low nitrogen treatments when potassium treatments were the same. Increased potassium fertilizers enhanced markedly plant growth and increased tuber yield in low nitrogen treatments, while inhibited plant growth and decreased tuber yield in high nitrogen treatments. Low N+ high K treatment gave best yield, quality and commodity rate of tuber among treatments. NK interaction caused marked effects on content of nitrogen and potassium, while no on that of phosphorus in plants. The correlation coefficient between nitrogen or phosphorus content in plants and tuber yield was not over the level of negative significance, and that significant corrlativity existed between potassium content in plants and tuber yield, as well as between N/K ratio and tuber yield, the correlation coefficients were 0. 9670 and -0. 9649, respectively.