Phosphorus and tillage management for maize under irrigated and dryland conditions

Deficiencies of phosphorous (P) and soil moisture are the main limiting factors under semiarid climates throughout the world. Proper tillage management could increase P and water availability and therefore crop productivity under semiaraid climates. The objective of this study was to investigate proper P and tillage management practices for improving growth, yield and yield components of maize (Zea mays L. cv Azam). The experiment was conducted under, irrigated (no moisture stress) and dryland (moisture stress) conditions at the Agronomy Research Farm of The University of Agriculture, Peshawar Pakistan during summer 2012. Experiment was laid out in randomized complete block design with split-plot arrangement having three replications under both irrigated and dryland conditions. Tillage depths (15, 30 and 45 cm) were assigned to main-plots while P levels (0, 30, 60 and 90 kg ha-1) allotted to sub-plots. Better growth and higher yield components and grain yield (3535 kg ha-1) was obtained when P was applied at the highest rate of 90 kg P ha-1 (90 > 60 > 30 > 0 kg P ha-1). Increase in tillage depths showed positive relationship with grain yield and yield components. The deep tillage depth (45 cm) produced the highest grain yield (3323 kg ha-1) while the shallow depth (15 cm) resulted in the lowest grain yield (2894 kg ha-1). Maize planted under irrigated condition had better growth, higher yield components and therefore resulted in the higher grain yield (3621 kg ha-1) as compared with maize under dryland (water stress) condition. We concluded from this study that increase in P level and tillage depth had positive effect on growth, yield components and grain yield of maize under both irrigated and dryland conditions.