*4.2.4 Seed inoculation*

Seed inoculation is a cheap and beneficial tool to grow healthy plants, considering that each plant has a group of bacteria or fungi that work in association with the plant roots. The colonization of plants roots by associated bacteria and fungi result in better performance than plants colonized by the wild population of microorganisms [58]. Inoculations have to be performed for both the main crop and cover crop. Inside the cover crop, there have to be various legume seeds that can be inoculated with nitrogen-fixing bacteria. No need to fertilize the soil with nitrogen if seeds are inoculated with these types of bacteria [59, 60]. Biological control agents protect seedlings from disease as fusarium, pythium, etc. [61]. Arbuscular mycorrhizal fungi play an important role in plant growth. Corn inoculated with arbuscular mycorrhizal have a higher phosphorus absorption, increases vegetative biomass and grain yield, especially in low or medium available phosphorus [62].
