Effect of Inoculation Time on Yield Components of Soybean in Some Khuzestan Calcareous Soils

In nowadays modern agriculture، economic aspects and environmental protection in a sense of preventing anomalous chemical fertilizers usage and soil pollution are two undeniable principles that must be considered. Utilizing biotechnology and biological fertilizer is a proper and cheap method for crop production. Soybean is one of the crops that have a facility in usage of biological fertilizers and inoculation. Field study was conducted for determining the effect of Brady-Rhizobium Japonicum inoculation time on components of soybean yield this investigation in Behbehan confines. The experimental design was a complete randomized block with three replications and four inoculation time; Control، one week، two weeks and four weeks. Correlation between yield components، analysis of variance and means were performed with SPSS software. Results showed that treatments have a significant effect on all the yield components and nitrogen contents except number of soybean pod and all of them except leaf nitrogen content before flowering have 1% significant level. Correlations analysis showed a positive significance relation between harvest index and all of yield components except leaf nitrogen content before flowering. Results also showing maximum positive significant correlation between number of active nodules and oil and protein yield. Results corroborate that with time lapse from planting inoculation caused increasing in number of active nodules and presence of this nodules incrementing the yield of soybean. Changing inoculation time can be considered as a management factor for decreasing environmental limitations on inoculation efficiency.