Biological and Chemical Phosphorus Fertilizers Effect on Yield and P Accumulation in Rapeseed (Brassica napus L.)

A field experiment was conducted for investigation of different phosphorus fertilizer sources and their importance in rapeseed farms on 2007 at Arak, Iran. Ammonium phosphate fertilizer with 50% P2O5 (APF) was as chemical phosphorus sources with 3 rates of application and Phosphor solublizing bacteria (PSB) was as biological phosphorus surcease in 4 levels. Experiment was factorial arrangement in randomized complete block design with 3 replications. APF levels were control (AP0), 125kg/ha APF (AP1) and 250kg/ha (AP2) application and PSB levels were, control (PSB0), PSB at sowing time only (PSB1), PSB as top dress fertilizer after over wintering only (PSB2) and PSB at dual fertilizing in sowing time and also after over wintering (PSB3). The statistical analyses were showed that the PSB3 treatment was a great treatment for increasing seed yield. The heist rate of seed yield was recorded at 9.9t/ha under dual fertilizing in sowing time and after rosette over wintering stage. The interaction effects of phosphorus solublizing bacteria and ammonium phosphate fertilizer application had not significant effect on plant height, biomass yield, number of silique per plant, seed oil percent and seed yield. Interaction effects of phosphorus solublizing bacteria and ammonium phosphate fertilizer application were significant for plant tissues phosphorus content.