Impact of Different Doses of Phosphorus Fertilizer Application on Wheat Yield, Soil-Plant Nutrient Uptake and Soil Carbon and Nitrogen Dynamics

The aim of the study was to investigate the impact of phosphorus (P) dose application effects on bread wheat (Triticum aestivum) yield, mineral nutrients concentration and soil C (C) and nitrogen (N) concentration. From 1998to date, the same soil plots (200 m(2)) have been fertilized regularly with the same P fertilizer doses, namely 0 (PO), 50 (P50), 100 (P100), 200 (P200) kg P2O5 ha(-1) as triple superphosphate (TSP). For the current study, fertilization was done 1 week before seed planting in 2013. Wheat yield increased with increasing P dose applications under long-term field conditions. Compared to the control treatment, 50, 100 and 200 P2O5 ha(-1) application significantly increased wheat yield by 60%, 85% and 138%, respectively. Agronomic efficiency decreased with P-level increases. Indigenous root infection results and number of spore count decreased due to increasing P fertilizer application. With increasing fertilizer doses, soil organic C and N increased as well. It was concluded that since plants grow better with high P doses application, it may have a positive impact on organic matter (OM) remaining in the soil and increased soil C and N concentration.