Evaluation of Interaction of Weed Management, Bradyrhizobium Japonicum, Vesicular Arbascular Mycorrhiza and Mineral Nutrition on Quantitative and Qualitative Characteristics of Soybean Cultivar Katoul

In order to evaluate the competition of weeds with Soybean (Glycine max L.) cultivar Katoul along with the comparison of the effects of application of biological and chemical fertilizers separately and simultaneously, a factorial experiment based on randomized complete block design with three replications in a field in Ali Abad Katoul was carried out during the 2011-2012. Treatments were included weed management at two levels (non-control and full control of weed), the use of bio-fertilizer at four levels (non-usage as control group, seed inoculation by Bradyrhizobium japonicum bacteria, seed inoculation by Mycorrhizae Fungi (Glomus Mosseae) and Co-inoculation of Mycorrhizae and Rhizobium), and the use of nitrogen fertilizer (pure nitrogen from urea form) at three levels (non-usage as control group, 25 and 50 kg.ha-1). The results showed that among photosynthetic pigments just Chlorophyll a were affected by weed treatment and chlorophyll b and carotenoids were not affected, but all of them affected by biological and chemical treatments. Additionally interaction of weeds and biological fertilizers influenced plant phosphorus content and the highest content of phosphorus (0.48%) was related to weed control treatment and co-inoculation of bacteria and fungi and the least amount (0.19%) was related to weed infested and control group of biological fertilizer. Leaf potassium content was affected by triple interaction of weeds, biological fertilizer and chemical fertilizer. The results of the analysis of variance showed that Oil and Protein content was affected by weed and biological fertilizer treatments and chemical fertilizer treatment only affects protein content of the seed.