Unbalanced nutrient levels can result from the over use of chemical fertilizers, especially those based on nitrogen. High nitrogen concentrations can promote the growth of nitrophilic microbes, which proliferate quickly, while suppressing the growth of other microbial life species. The composition of the microbial community may change as a result, which may have detrimental effects on the variety and functionality of soil microorganisms.
Changes in pH: Chemical fertilizers, particularly those that are very acidic or alkaline, can change the pH of the soil. Microbial activity and community composition are directly influenced by the pH of the soil. Different microbial life communities react differently to pH variations. Alkaline fertilizers can raise the pH of the soil, thereby decreasing the activity of acidophilic microbes, whereas acidic fertilizers can drop the pH of the soil, encouraging acid-tolerant microorganisms.
Reduced Organic Matter Inputs: While chemical fertilizers do not add organic matter to the soil, they do supply a majority of inorganic nutrients. For soil microbes, organic matter is an essential source of energy and nutrients. Over time, the amount of organic matter in the soil may decrease as a result of ongoing usage of chemical fertilizers without organic matter additions. The biomass, diversity, and activity of microorganisms may be significantly impacted by this decrease in the availability of organic materials.
Nitrogen-Fixing Bacteria’s Effect: Some chemical fertilizers, especially nitrogen fertilizers, can stop microbes from fixing nitrogen in the environment. High concentrations of easily available nitrogen can prevent nitrogen-fixing bacteria from cooperating with plant roots, such as rhizobia in legumes.
