Interactive effects of Ensifer meliloti (Sinorhizobium meliloti) and phosphorus on some growth characteristics of alfalfa under soil water deficit conditions

In arid and semi-arid regions, plants frequently encounter with several stresses including drought stress during the growing season. The effects of Ensifer melilotiinoculation, soil water and P fertilizer on the growth characteristics of alfalfa (Medicago sativa cv. Ghareyonjeh), were studied by conducting an experiment at greenhouse conditions. The study was performed as a factorial experiment in a randomized complete block design (RCBD) including soil water conditions at three levels (0.5FC-0.6FC, 0.7FC-0.8Fc and 0.9FC-FC, moderate drought stress, low drought stress and no drought stress, respectively), P at three levels (0, 30 and 60 mg P per kg soil as mono-calcium phosphate, Ca(H2PO4)2.H2O) and bacterium inoculation at two levels (with and without Ensifer melilotiinoculation) with three replications. At the end of growth period, shoot and root dry matter, shoot to root dry weight ratio (S: R), plant height and root volume were measured. The results indicated that soil moisture increment, increased the dry weights of shoot and root, plant height, root volume and shoot to root dry weight ratio (p