Luxury Absorption of Potassium by Potato Plants

Pot and field experiments were conducted to test whether excessive potassium (K) uptake by potato plants occurs under conditions with or without irrigation at different sites. The results from both pot and field experiments showed that potato biomass and tuber yield peaked at a certain level of external K, and did not increase further with additional K supply. However, K absorption by potato plants continued to increase within the range of K used. It was concluded that luxury absorption of K by potato plants occurred with high K availability in the media. This suggests that K fertilizer recommendation based on the index “K requirement per tuber production” may be unreliable, because the optimum crop need varies with production conditions.