Preliminary investigation of effects of rhodic lixisol soil and biochar types on Soybean inoculated with Bradyrhizobium japonicum: A field trial study

In our previous study, biochars derived from poultry manure (PMB) and rice husk (RHB) where shown to be promising sources of nutrients to the soybean crops that were grown in the ferric acrisol soils. Furthermore Bradyrhizobium japonicum inoculated soybean seeds were concluded to be advantageous. However, no field study was found for the rhodic lixisol soil types. Here we report effects of such biochars on soybean crops grown in rhodic lixisol soils were examined in terms of root dry weight (unit), shoot dry weight (g plant-1), total plant dry weight (g plant-1), seed weight (g), grain yield (Mg ha-1), number of nodules (nodule number plant-1), nodule dry weight (g plant-1) and harvest index (unit). Our results showed 4 kg Mg ha-1 PM had a superior effect on the grain yield of the soybeans coated with B. japonicum. In this study B. japonicum coated seeds produced both high numbers as well as dry weights of nodules in response to PM and biochars either alone or in combinations. The harvest index of the un-inoculated soybeans upon treatment with 5 kg Mg ha-1 RHB + 2 kg Mg ha-1 PMB was found to be the highest. We successfully conclude rhodic lixisol soils to be well suited for PM and RHB applications on both inoculated and un-inoculated soybean crops.