What soil factors affect B. japonicum production and efficiency?
The soil environment can impact the ability of B. japonicum to infect soybean root hairs, develop nodules and fix nitrogen. A suitable environment for B. japonicum is obtained when multiple soil factors are positive for bacterial growth and productivity. Soil characteristics that need to be considered in terms of B. japonicum survival are pH, temperature, texture, water content and residual nitrogen levels. The optimal soil pH is between six and seven. A soil pH significantly outside this range (less than five or greater than eight) is detrimental because it disrupts the communication process that needs to occur for root hair infection, thereby limiting nodule development. Soil pH also affects the amount of nitrogen fixed. For example, in a very acidic soil (pH = 4.4), nitrogen fixation can be reduced up to 30 percent. Extreme root temperature can have a negative impact on the ability of B. japonicum to communicate with the soybean plant and infect the roots. Optimum root temperatures
