كليدواژه :
Irrigation , Nitrogen , Rapeseed , كشاورزي , روغن كلزا , رژيم آبياري , كودنيتروژنه
چكيده لاتين :
Improvement of water use efficiency through the optimum use of water and fertilizer, especially nitrogen, is considered as one of the main objectives of scientists. A split plot experiment was conducted in three replications in Tikmehdash station on 1998-1999. The irrigation regime arranged in main plots in three levels including rainfed, supplemental irrigation and traditional or normal irrigation and nitrogen at five levels (0, 60, 120, 180 and 240 kg /ha) in subplots. The results showed
that the effect of irrigation on yield and yield components such as pod number per plant, seed number per pod and 1000 kernel weight and the effect of nitrogen on yield and pod number per plant was significant. Therefore, yield could be increased in rapseed via increasing in pod number per plant. It seems that the rainfed cultivation of rapeseed in Tikmehdash is impossible, because of high temperature and low precipitation in september. Supplemental irrigation and normal irrigation. (3733 and 6045 m3/ha respectively together) with 180 kg N/ha produced the highest oil yield (1049 and 1754 kg/ha, respectively). Application of 60 kg N/ha increased seed oil percent (44.28%) but applying more nitrogen decreased the seed oil percentage (40.77%). Nitrogen use efficiency in normal irrigation condition was higher than the supplemental irrigation regime. In normal irrigation condition, the increass in nitrogen led to yield increase. However, in supplemental irrigation regime, nitrogen application of more than 180 kg decreased the yield.
