Document Type : Research Paper


Department of Agronomy and Plant Breeding, Faculty of Agriculture, Kurdistan University, Sanandaj, Iran


In order to investigate the effects of integrated management of chemical and biological fertilizers on physiological traits, and grain yield of black cumin (Nigella sativa L.) under different irrigation levels, a split-plot experiment was conducted based on a randomized complete block design with four replications at research farm University of Kurdistan during 2016 spring. Two irrigation levels (irrigation at 100 percent and 70 percent of plant water requirement) were randomized on the main plot. Five fertilizer levels (including 100 percent chemical fertilizers, 80 percent chemical fertilizers + biofertilizers, 60 percent chemical fertilizers + biofertilizers, 40 percent chemical fertilizers + biofertilizers, and non-fertilizer application) were randomized on a sub-plot. The results revealed that under irrigation at 70 percent of the plant water requirement conditions, proline concentration, soluble carbohydrates concentration and lipid peroxidation increased, but the values of other physiological parameters were studied, and grain yield decreased. The combination of biological and chemical fertilizers positively affected the studied physiological traits and grain yield, such that the highest grain yield belonged to the combined treatment of 60 percent chemical fertilizers + biofertilizers (798.18 kg ha-1), which showed an increase of 37.22% compared to the control treatment (without fertilizer). Due to the positive effects of combining bio-chemical fertilizers on physiological parameters and grain yield, it is recommended to replace the combination of bio-chemical fertilizers instead of using only chemical fertilizers.