What is Soil Microbiology? 

Soil microbiology is the study of microorganisms within the soil, their specific functions, and how they influence varies soil properties. Microbiology focuses on microorganisms and microbes that are too small to be seen with the naked eye but have a crucial role in soil health. Research has shown that microbes aid in nutrient processing and cycling, the decomposition of organic matter, soil acidity, along with many other factors that influence overall soil fertility. You may be familiar with terms like fungi and bacteria, which represent two major families of microbes. A common bacterium in agriculture is Rhizobia, which forms a symbiotic relationship with legume crops to fix nitrogen. making it available to the plant. Other positive microbes like Azotobacter, convert atmospheric nitrogen to ammonia or actinobacteria which break down organic compounds into more simple complexes that can be utilized by plants.  

How can agriculture influence soil microbiology? 

The presence of microbial communities in soil can influence a range of soil properties, including soil structure, carbon storage, and nutrient cycling, which all impact plant health and growth. Soils with regular organic matter inputs tend to sustain higher microbial populations due to a consistent food source. In addition to organic matter, maintaining soil cover and ensuring a diverse supply of residues can increase microbial populations. Agricultural practices that cause greater soil disturbances are typically associated with lower microbial populations. This is due to the disruption to soil through breaking up and mixing of the soil structure, that can lead to homogenization of microbial communities. In contrast to conventional tillage methods, no-till or minimal tillage systems have shown increases in both microbial diversity and abundance with the constant supply of organic matter to the soil. However, when it comes to pesticide application and influences on the soil microbial community, more research needs to be done to have a better understanding of impacts both long and short term.  

What can you do to increase your microbial population? 

Like many things in agriculture, there is no quick fix for increasing your microbial population. Committing to making the necessary changes to your operation on a long-term scale is where you are going to likely reap those benefits. Implementing diverse crop rotations, if not already in place, provides variety in residues and root systems beneath the soil. Crop rotations also have the potential to increase microbial diversity, as different crops require different nutrients, and microbes to make those nutrients available. Alongside cover crops, applying organic matter in the form of manure can further support microbial populations, ensuring a consistent food source. When it comes to tillage practices, studies suggest that minimal or no-till systems allow microbes to function undisturbed. However, the ability to implement diverse crop rotations, apply organic amendments, and limit tillage depends upon the type of operation you have and what is feasible for you. Assessing how your current methods influence microbial populations, and where potential changes could be made to enhance those communities is a valuable first step when considering enhancing the benefits provided by microbial populations.