Timing and Rate of Phosphorus Application Influence Maize Phenology, Yield and Profitability in Northwest Pakistan

Phosphorus (P) is the second most important crop nutrient after nitrogen that increases productivity and profitability of maize (Zea mays L.) on P deficient soils in Northwest Pakistan. The objective of this study was to find the best level and time of P application for higher maize (cv. Azam) productivity and profitability. Field experiment was conducted at the Research Farm of Khyber Pakhtunkhwa Agricultural University, Peshawar during summer 2005, comprising of six P application timings [40, 30, 20 and 10 days before sowing (DBS), at sowing and 15 days after sowing (DAS)] as main plots, and three P levels (30, 60 and 90 kg P ha-1) as subplots. The highest level of P enhanced phenological development, and increased ear length, number of rows and grains ear-1, grain weight, economic yield, shelling percentage, and net returns. Application of P at 10 DBS had marked increase in ear length, grain weight, grain yield, shelling percentage and net returns; while plots that received P at sowing time produced the highest number of rows and grains ear-1. There was no much difference in the net returns when P was applied at 10 DBS (22, 560 PKR ha-1) or at sowing (21, 883 PKR ha-1). It could be concluded from the study that application of 90 kg P ha-1 either at 10 DBS or at sowing time is necessary for profitable maize production in the study area.