Why biological ???
Farmers , apply chemical fertilizer assuming that all the quantity that they have applied is utilized by the plants. In reality , the major amount of chemical fertilizer is get volatilized and wasted in the process of application to assimilation. Say for example , urea is a highly volatilized in nature and for conversion of nitrate to nitrite there in involvment of bacteria that act as catalyst to that process.
If soil have adequate soil microflora , then the availabiltiy of nutrients to the plant is higher. The beneficial microbes , performs the processes like mineralization fixation so that the dispersed nutrients get centralized at rhizosphere of plants. There is symbiosis of microoraganism in plant rhizosphere . The efficiency of chemical fertiliser is improved only if there is abundant soil microflora is present.
Elements like phosphorous, which is easily fixed and immobile in soil. For such cases , the process of solubilization is necessary and which is solely done by beneficial bacteria like Pseudomonas species. For Potassium , it is fraturia aurentia. However, the presence of these organisms is nonnegotiable in maintaining soil health.
The key takeaway is , presence of beneficial soil microorganisms, i.e. biological richness of soil is very important for soil health and nutrient availability to plants, And So Why, We Must Go Biological !!!

