The effects of biofertilizers on physiological traits and biomass accumulation of red beans (Phaseolus vulgaris cv.Goli) under water stress

This field experiment was executed as the split plot in a randomized complete block design with three replications in 2014. In a red bean irrigated farm, halt irrigation was implemented in main plots and the treatments included the control (full irrigation) and halt irrigation at vegetation, flowering, and pod development stages. In subplots utilization of biofertilizers were applied at four cases of control, phosphorus solubilizing bacteria, potassium solubilizing bacteria, and combined application of these bacteria in soil. Results showed that halt irrigation and biofertilizers had significant interaction on red bean biomass. Normally, to achieve the highest biomass full irrigation and application of phosphorus and potassium solubilizing bacteria (8023 and 7978 kg ha-1) are suggested. But the use of biofertilizers instead of chemical fertilizers led to more water efficiency under low water condition. Finally, our results showed that maximum biomass in red bean (about 7985 kg. ha-1) was recorded in ecological nutrition management under limited water resources. In other words, halt irrigation at flowering stage was compensated by Bio-P and Bio-K fertilizer application as a logical method to mitigate and moderate biomass losses about 37%.