Determining the optimal irrigation interval for canola plant in surface and subsurface drip irrigation methods in Hajiabad region

In order to investigate the effect of different intervals and irrigation methods on the growth characteristics of canola, an experiment was conducted in the form of split strip plots based on a randomized complete block design with three replications during 2009-2010 at Hajiabad Agricultural Research Center. In this regard, three irrigation intervals including irrigation after 20, 40 and 60 mm of evaporation from the surface of the evaporation pan (I1, I2 and I3, respectively) and two drip irrigation methods (surface and subsurface) were considered as the main and secondary factors, respectively. The results indicated the lowest and highest yield (1.97-3.15 t/ ha), 1000-seed weight (3.38-4.82 g) and number of seeds per pod (14.5-24.5) at the I1 and I3 irrigation intervals, respectively. However, the I2 irrigation interval treatment resulted in a 9.6% increase in water use efficiency compared to the I1 irrigation interval. Also, the use of subsurface drip irrigation compared to surface drip irrigation method increased crop yield, water use efficiency and number of pods per plant by 29.8%, 32.2% and 33.1%, respectively. The findings of this study showed that in general, in case of water insufficiency in the study area, the irrigation cycle after 40 mm of evaporation from the pan applied in the subsurface drip irrigation method can be suggested as a superior treatment. With this approach, we can take steps to deal with the water crisis based on sustainable agriculture in canola cultivation in Hajiabad region.