SoilOptix® Blog

How Soil Microbes are Affected by Fertilizer Application in the USA & Commercial Cropping

Soil microbes increase soil fertility by adding air, minerals, and nitrogenous compounds. Microbes contribute to higher plant growth and better-quality crops by offering essential elements and minerals that the plants cannot use on their own. Microorganisms decompose organic matter into simple forms that can be easily taken in by the plants.

Microbes increase soil fertility through nutrient recycling, such as carbon, sulfur, nitrogen, and phosphorous. In general, we associate agricultural fertilizer applications in the USA with better plant growth. It is crucial to remember that the fertilizer nutrients are not only exposed and available to the plant, but also to all the soil microbes and organisms.

Soil microbes play a crucial role in getting nutrients to plants and improving soil fertility, which is crucial to overall plant health. Therefore, we must consider the impact of intensive fertilizer application in the USA on the activities of native microbes in the soil. A common perception is fertilizer applications in the USA have a negative effect on the soil microbes. Fertilizers, especially inorganic ones, distort the microbial balance and, therefore, hamper soil health. This can be the case in some instances (especially when there is excess fertilizer application in the USA); fertilizers are still crucial for viable cropping, including the microbes that play a pivotal role in facilitating the uptake of most of the nutrients needed by plants.

fertilizer application in USA 

Source: Freepik

Is Fertilizer a Friend or Foe?

The recent advancements in technology have allowed researchers to measure the total biomass in a much better way and identify the specific microbial families in the soil to assess the impact of fertilization on soil microbes. There is no “one-size-fits-all” when it comes to fertilizer application in the USA. All the soils, fertilizers, and microbes are unique. Different environments have different interactions between these elements. The factors that influence the relationship include:

  • Soil type
  • Native microbe population
  • Fertilizer amount, placement, and formulation

Interactions among soils, microbes, plant roots, and fertilizers in different combinations. Therefore, what works for one environment will not necessarily work for another. In particular, the microbial population in the soil, within the root hair soil interface, is highly complex.

The single most important natural process on Earth, photosynthesis, depends on the naturally available elements—water, sun, and carbon dioxide—for 95% of its function. The remaining 5% comprises nutrients taken up by the plant. In nature, these nutrients are free. However, they are added as organic and inorganic nutrients in commercial agriculture.

Fertilizers play a crucial role in farming. However, fertilizer applications in the USA need a tailored approach to what should be applied and when—all of this will depend on the condition and nature of the soil. The correct fertilizer application is not only about adding fertilizer that worked for a fellow farmer and waiting for an extraordinary yield.

Improving the Microbes in Agricultural Soil:

A healthy soil will need more than just a handful of nutrients that make up inorganic fertilizers. It is possible to improve the diversity of soil microbes by the following:

  • Cover crops
  • Green manures
  • Biochar
  • Compost

The products that have been derived from the organic raw material are fish hydrolysate (natural amino acids), Amino K (fermented molasses), and Kelp (plant hormones).

Organic products are taken up directly by the plants as foliar applications, but they are most beneficial as microbe food sources in the soil. The high concentrations of amino acids, plant hormones, fermentation metabolites, and soluble carbon act as instantly available microbial food sources. The stimulation of the soil microbial population triggers and magnifies the uptake of the more traditional nutrients and results in a much better yield.

In Conclusion:

Soil microorganisms might be tiny, but they have a significant impact on our crops. They toil silently beneath our feet, offering nutrients and protection to our crops that they need to thrive. While we embrace new technologies, sustainable farming practices, and tailored fertilizers ensure the invaluable microorganisms continue to flourish—making our fields greener and our harvests better quality. Visit to learn the benefits of tailored fertilizer application in the USA to ensure the sustainability of soil microorganisms.