عملکرد و کارآیی مصرف نیتروژن کلزا (Brassica napus L.) تحت تاثیر نیتروژن و رژیم های آبیاری

This research was carried out during two years ۱۳۹۴ and ۱۳۹۲ in order to investigate the effect of nitrogen rates on quantitative yield and nitrogen use efficiency of rapeseed in different irrigation regimes in Qazvin. The factorial experiment was conducted as randomized complete block design with three replications. The irrigation factor at three levels , normal irrigation, cut off irrigation at stem elongation and cut off irrigation at flowering stage) and nitrogen rates in five levels (۰, ۴۰, ۸۰, ۱۲۰ and ۱۶۰ kg N.ha-۱) were considered in experimental blocks. The results of combined analysis showed that the effect of irrigation levels, nitrogen and their interaction were significant on grain yield. The results of the mean comparison indicated that the highest grain yield in normal irrigation regimes and the lowest grain yield related to irrigation cut at flowering stage. Treatments of ۱۲۰ and ۱۶۰ kg.ha-۱ pure nitrogen in normal irrigation conditions had the highest seed yield (۳۷۸۰ and ۴۰۵۴ kg.ha-۱), respectively. The results showed that increasing nitrogen up to ۱۶۰ kg N. ha-۱ caused to increase grain yield significantly under normal irrigation regime. However, in these conditions, a significant increase in grain yield was observed up to ۱۲۰ kg N. ha-۱, and there was no statistically significant difference between treatments of ۱۲۰ and ۱۶۰ N. ha-۱. In terms of irrigation interruption in flowering and stemming stages, increase in nitrogen consumption up to ۱۲۰ N. ha-۱increased grain yield and then decreased somewhat. In general, in the absence of water during flowering and stemming, consumption of ۱۲۰ ۱۶۰ N. ha-۱ and in the presence of sufficient water, consumption of ۱۶۰ N. ha-۱ is recommended.

Keywords:

رژیم آبیاری , عملکرد دانه , کارآیی مصرف نیتروژن , کلزا , نیتروژن