The Truth about “Replenishing” Soil with Microbes
Friday June 29th 2007, 1:16 pm
Filed under: General Info
Professional growers and homeowners are inundated with new products that are promoted to “produce healthy plants.” One such type of product is microbial inoculants that can be added to the soil to “replenish” soil or create a “healthy” soil. These products typically are advertised as providing specific microbes that are somehow missing or inactive.
Soils typically are inhabited by huge numbers of a wide variety of microorganisms, and while there is little doubt that the microbial populations that inhabit the soil and colonize the roots of plants are of critical importance, the introduction of beneficial microbes by inoculating the soil is highly unlikely to lead to any significant benefit. First, it is almost impossible to make changes to the existing microbial populations by just adding an inoculum. Newly introduced microbes cannot compete with the existing populations that inhabit the soil in huge numbers. The introduced microbes are not likely to survive or grow if the nutrients and soil environment are not also modified to the degree that they will have a competitive advantage.
University research performed under controlled laboratory conditions and in field trials has clearly demonstrated that in order for any microbial inoculant to be effective the soil environment must also be controlled. In particular, years of research performed with microbial inoculants introduced to the soil to control plant pathogens has shown that the introduced microbes might grow and survive, but they were not effective unless appropriate sources of organic matter (e.g., composts) were also present. In addition, the quality of the organic amendment had a significant effect not just on the ability of the introduced microbes to grow and survive but also on the activity of the introduced microbes.
I absolutely agree!
