Synergism of nitrogen uptake from soil and symbiotic nitrogen fixation increasing nitrogen in soybean plant glycine max
Ruschel, A.P.; Ruschel, R.
Pesquisa Agropecuaria Brasileira Serie Agronomia 10(11): 37-40
1975
Accession: 006558128
The effect of [Rhizobium] inoculation and different sources of N (KNO3, (NH4)2SO4, NH4NO3 and urea) on nodulation, i.e., the number and weight of nodules, symbiotic N fixation and the amount of N, in G. max (L.) Merr. was studied. Nodular weight decreased with addition of NH4)2SO4, NH4NO3 and KNO3 to soil. This effect was not observed with urea. Although the number of nodules decreased with addition of these N sources, no inhibition of nitrogenase activity was noted. The plant dry weight measured at 45 days indicated no differences due to inoculation; however, inoculation proved effective as far as increase in total and percentage N in plant tops in all treatments under study. The increase in total N indicated a synergism of inoculation and N fertilization. Inoculation maintained a constant level of N in the plant throughout plant growth.