Syed Manzar-ul-Alam, Syed Azam Shah, and Mohammad Mohsin Iqbal

pp. 457 - 463

Abstract

Most of the Pakistani soils are alkaline and calcareous and the efficiency of P-uptake by wheat is
low. To improve the efficiency, post emergence application of P in split dose was evaluated against the
recommended broadcast and incorporation method of fertilizer application at seeding. Three field experiments were laid-out during 2001-2003 on wheat following randomized complete block design with four
replications. The results showed that P applied through fertigation or top-dressing methods in split dose at
first and second irrigation were equally effective for production of wheat grain and straw. However, application of full P dose at first irrigation and split application of N at first and second irrigation times by fertigation was superior to top-dressing. Fertigation applied N and P fertilizer increased wheat grain yield by 16%,
P-uptake by 13%, P-fertilizer efficiency by 74%, and agronomic efficiency by 240% over top-dressed N and
P at the same times.