| in order to research the effects of potassium (K) fertilizer application and rice straw (S) application on soil potassium in southern winter potato, a pot experiment was conducted with different combinations of S and K fertilizer on the basis of nitrogen (N) and phosphate (P) fertilizer application. The main results showed that added K fertilization and S could increase the contents of soil available K, effective K and slowly available K compared to
only appling N and P fertilizer, and increment effects of combination NPKS were better than those of combination NP with K or S. In potato maturation stage, compared to NP, soil available K, effective K and slowly available K of NPKS treatment, average increased by 180.13%, 125.16% and 10.62% respectively, and soil available K increased by 33.33% compared to before cultivating potato. T5(K3S2) and T8(K2S3) treatments had significant influence on soil K status, soil available K and slowly available K respectively increased by 69.69%, 14.09% and 81.98%, 10.76% compared to before cultivating potato. To conserve resource and improve soil K status, it was better to appling K with 199.7 kg/hm2 and S fertilizer 9 000 kg/hm2 under early rice-late rice-winter potato cropping pattern. |
