Analysis of soybean cultivars in response to different forms of inoculation

Biological Nitrogen Fixation (BNF) is essential for soybeans in Brazil, eliminating the use of mineral nitrogen and reducing the cost of production. This study aimed to analyse the soybean cultivars in response to different ways of seed inoculation. The experiment was conducted at the Federal University of Mato Grosso in the municipality of Sinop-MT, implemented in the 2014/15 crop. A randomized block design with four replicates was used and four treatments were tested: 1) peat inoculant; 2) liquid inoculant; 3) control (without inoculation and without nitrogen fertilizer); 4) fertilization with mineral N (240 kg ha-1 N), and 120 kg ha-1 of N were applied at sowing and the same rate 35 days after emergence. All seeds were treated with Fipronil insecticide + Pyraclostrobin and Methyl Thiophanate fungicides. The parameters evaluated were plant height, leaf chlorophyll and at the end of soybean cycle, the number of pods per plant, grain yield, weight of 1000 seeds, and productivity. Overall, no significant differences were found between treatments, this may have occurred due to the fact that the soil already has an established population of rhizobia, which are capable of forming a symbiosis with soybeans