Soybean response to different levels of nano-potassium under cutting irrigation conditions in Moghan plain

In order to investigate the effect of potassium nano fertilizer on soybean growth under cutting irrigation condition, an experiment was carried out as split plots arrangement based on completely randomized block design with three replications in Moghan plain at 2015 and 2016 cropping seasons. The main factor included four levels of irrigation normal irrigation, cutting irrigation during vegetative phase, cutting irrigation during flowering phase and cutting irrigation during grain filling phase and a sub factor included three levels of potassium nano fertilizer five, 10 and 15 kg per hectare. The results showed that at all stages of irrigation, the use of potassium nano fertilizer reduced the effect of drought stress. So that the greatest seed yield and yield components under normal irrigation and off-irrigation conditions were obtained with use of 15 kg / ha of potassium nano fertilizer. Also, the highest plant height (66 cm), the distance between the first pod of ground (20 cm), number of leaves per plant (345) and the number of lateral branches (19.66) in normal irrigation treatment with consumption 15 kg of potassium nano fertilizer was obtained and the least of them was obtained in irrigation cut during vegetative phase with use of 5 kg/ha of potassium nano fertilizer. According to the results, it can be concluded that using 15 kg / ha of potassium nano fertilizer can reduce the effects of drought stress on yield, especially in seed filling stage in soybean plant, by 15%.