An experiment in cement rough was conducted at Sakha Agric. Res. Station
during two successive seasons (2000 and 2001) to explore symbiotic performance of
two strains of Bradymizobium japonicum (1577 and 110) used to inoculate soybean
cultivar crowford, irrigated with high quality of tap water and low quality of sewage
and drainage water or their mixture. Results were recorded after 50 and 90 days from
planting time. Effect of inoculation on nodules formation was very clear by soybean
plants, irrigated with tap water and inoculated with any of two rhizoblal strains. Strain
1577 achieved higher values of N2-fixation parameters, as well as growth
measurement of soybean plants than strain 110. On contrary soybean plants irrigated
with sewage or drainage water didn't show any response to inoculation. While a little
improvement was observed for soybean plants received a mixture of drainage and
tap water, indicating that failure of nodule formation could be attributed to quality of
water used in irrigation. Concerning the grain yield and their total N-content, irrigation
with tap water gave the highest improvements being 105.57 for the seed yield and
156.92% for nitrogen content over control, while those received sewage and drainage
water recorded a very less improvements. In the case of irrigation with sewage water,         lower values of grain yield were obtained than the control (·1.71%). For these reasons, the research was directed towards identifying some
chemical and biological characteristic of wastewater used in irrigation, which it could
be concluded that the failure of Rhizobium-soybean symbiosis is a resultant
expression of three interacting factors: high concentration levels of heavy metals,
high density of parasltes, microbial pathogens and high amount of nitrogen especially
in sewage water.