عنوان مقاله [English]
In order to determine the appropriate amounts of potassium and nitrogen fertilizers to achieve high grain and oil yields of rapeseed (Hyola 401) in paddy fields, a field experiment was conducted at Rice Research Institute of Iran (Rasht) in a factorial experiment based on the complete randomized block design with
3 replications in 2008-2010. The first factor was the amounts of potassium fertilizer in three levels (100, 150 and 200 kg.ha-1) and the second factor was nitrogen fertilizer values in the four levels (zero, 180, 240 and 300 kg.ha-1 from urea resource). The results of the combined analysis of variance showed that significant difference between potassium levels, according as application of 150 and 200 kg.ha-1 potassium had the highest of grain yield. Between the levels of nitrogen, application of 240 and 300 kg.ha-1 produced the highest grain yield. The control treatment with average of 43.92%, showed the maximum oil precent. In general, 150 kg.ha-1 of potassium and 240 kg.ha-1 nitrogen level are recomended due to less fertilizer consumption and prevention of destroying effect on the environment.