Stimulating effect of N on the uptake of P and K compared with P and K fertilization*

A field experiment was conducted on alluvial soil (Ustochrept) of Jalandhar (Punjab) during 1985–86 with four rates of application each of N, P and K with four potato cultivars (Badshah, Bahar, Lalima and Jyoti) to examine the effects of N on the nutrient uptake when compared with P and K application. Application of N increased not only the uptake of N but also that of P and K by tubers and the increase varied with cultivars. On the other hand, application of P and K did not affect N, P and K uptake of Badshah, Bahar and Lalima but increased the uptake of Jyoti marginally. The contribution of N to P and K uptake (averaged over cultivars) was 80 and 75% respectively wheareas the contribution of P to P uptake was 2.5% and that of K to K uptake was 2.8%.