The effects of vermikompost, farm manure and nitrogen fertilizer applications on N2 fixation and soil microbial activities in different soybean genotypes

This research was carried out to determine the effects of vermikompost, farm manure and nitrogenous mineral fertilizer applications on rhizobial nitrogen fixing potentials and some root zone soil microbial activities in different soybean genotypes. Soybean used in pot trials established with soil samples taken from Reyhanlı district of Hatay province are the Asian, Bravo, Lider and Sonya genotypes produced by Progen seed company in Hatay Region. This research, wich was established as a pot experiment in climatic room conditions, was continued until the flowering periods and then harvested and plant and soil samples were taken. In plant samples, biomass weights, nodule number and nodule weight values were determined, while soil respirations (CO2), dehydrogenase enzyme activity (DHA), microbial biomass carbon contents (MBC), pH and salt (EC) were determined in root zone soils. According to the results of the research, the nodule number values determined by control, vermikompost, farm manure, and mineral fertilizer 1-2 applications were 87,143,130,58 and 33 pieces plant-1, respectively. According to these results, vermikompost and manure applications caused significant (p<0.05) differences in soybean genotypes on the investigated parameters. Vermikompost and farm manure applications increased rhizobial nitrogen fixation values and root zone microbial activities.