Residual Effect of Potassium and Zinc on Growth, Yield and Nutrient Uptake by Groundnut in Medium Black Calcareous Soils

A field experiment was carried out on medium black calcareous soil for four years (2001-2004) on fixed plots at Vegetable Research Station, JAU, Junagadh with two levels of Zn (0 and 25 kg ZnSO4 ha^-1), three levels of K (0, 50 and 75 kg K₂O ha^-1 as muriate of potash) and their combinations (T₁ to T₆) and T₇ as FYM 20 t ha 1 in RBD with four replications. The pod and haulm yields of groundnut were significantly affected by the residual effect of Zn, K and FYM applied in individual years as well as in pooled, except haulm yield during 2002,2003 and in pooled. The average highest pod (2874 kg ha-1) yield was recorded with treatment combinations of Zn₂₅K₇₅ (T₆),which was 27 per cent higher pod yield over control (T₁). The significantly higher shelling percentage, test weight and oil content were recorded with treatment T₃, T₆ and T₇, respectively. Uptake of Zn and K by pod and haulm were significantly affected by the different treatments and were recorded highest with treatment T₆. Soil available K and Zn progressively increased with increasing levels of respective elements and found highest with treatment T₆.