African Journal Of Microbiology Research, vol.5, no.20, pp.3186-3194, 2011 (SCI-Expanded)
The effects of different soil tillage methods on rhizobial nodulation, biomass yield (root, shoot and
nodule) and nitrogen content of soybean as a second crop have been investigated. The experiment was
conducted as a field trial in Cukurova Region, Turkey in 2008. Six different tillage methods have been
studied in this research. These methods were conventional tillage with residue (CTR), conventional
tillage with burnt residue (CTBR), reduced tillage with heavy disking (RTHD), reduced tillage with rotary
tiller (RTR), no- tillage with heavy disking (NTHD) and no tillage with direct seeding (NTDS). At the stage
of inflorescence, nodulation was investigated in the root, shoot, and nodule samplings by determining
the weights of the samples and analyzing them for nitrogen contents. The results have been statically
analyzed by using MSTAT-C package programme. According to the results of the study, under the
conventional methods in which deep tillage operations are applied to soil, it has been found out that
nodule formation and plant nitrogen contents have been negatively affected. The differences among the
applications were found to be statistically significant. In general, the best nodulation has been obtained
with NTDS and RTHD plots. Moreover, the effects of other tillage methods on some parameters related
with rhizobiyal N2-fixation have caused to considerable decrease on the parameters mentined above.