This study was conducted to investigate Physiological changes in growth parameters under main effects of bio fertilizer EM1 and phosphorus fertilizer of two soybean varieties [Glycine max (L.) Merrill] in afield by using two concentrations of biofertilizer EM1(0 and 1.5 ml. L-1), four levels of phosphorus fertilizer (0, 40, 80 and 120 kg P2O5.ha-1) and two soybean varieties (Lee-74 and Senaia-2). The experiment was conducted in two locations in the summer Season 2011, the first in Reasreches station/Department of Field Crops/College of Agriculture and Forestry/Mosul University in Mosul City, while the second was in Tuzkhurmatu City-Salahaddin province in a Randomized Complete Block Design (RCBD) with three replicates. The results obtained can be summarized as follows:
Biofertilizer EM1 concentration (1.5 ml. L-1) was significantly superiority in relative leaf growth rate, relative stem growth rate, leaf area index , leaf area duration (leaf area index basis), absolute growth rate, pod weight percentage in both locations and yield efficiency in Mosul location, specific leaf area, leaf area ratio and stem weight percentage in Tuzkhurmatu location.
Phosphorus fertilizer level (80 kg P2O5.ha-1) in Mosul location and (40 kg P2O5.ha-1) in Tuzkhurmatu location was significantly superiority in relative leaf growth rate, leaf area index, leaf area duration (leaf area index basis), absolute growth rate, pod weight percentage in both locations and yield efficiency in Mosul location, specific leaf area, leaf area ratio, relative stem growth rate, stem weight percentage in Tuzkhurmatu location coparded with non fertilizer treatment.
Differences between varieties were not significant for all characteristics were studied in both locations.