Abstract
Soils of Pakistan are generally alkaline and calcareous and usually contain low amounts of available micronutrients. Zinc (Zn) is an essential micronutrient for plant growth and its deficiency is common in cultivated soils of Pakistan. A field experiment was conducted for two years, at Government Adaptive Research Farm Karor Lal Eason, District-Layyah, to study the effect of added zinc on growth and yield parameters, zinc uptake, soil zinc status and also the effect of added zinc in soil. Wheat variety Bhakkar- 2002 was sown during Rabi season, 2005-2006 and 2006-2007 with recommended inputs. The recommended doses of N, P and K were applied @ 150: 100: 60 kg N: P2O5: K2O ha(-1) in all treatments. Zn was applied @, 4, 8, 12 and 16 kg ha(-1) as zinc sulphate at the time of sowing in the all treatments except control (recommended NPK). Combined Zn and NPK application significantly improved growth and yield parameters of wheat. Application of Zn increased its total uptake by wheat crop and also resulted in a built-up of Zn in the upper 15 cm layer to be available for next crop. Increasing the dose of Zn showed a little increase in the uptake of Manganese (Mn). The uptake of iron (Fe) increased by applying Zn upto 8 kg ha(-1), while high Zn doses resulted in reduced Fe uptake. Applying Zn upto 12 kg Zn ha(-1) increased net return, however value cost ratio (VCR) decreased by increasing Zn doses beyond 4 kg Zn ha(-1).