Soil Biology
Growing up on a small dairy farm in the Thumb of MI in the 1960’s, my first introduction to biology was that bacteria in the milk house was something that the milk inspector did not want, so you needed to keep things ‘clean’ and disinfected. Over the years of looking at farming from different viewpoints we have found that in respect to soil bacteria, the beneficial type is something that a farms want, for the soil decay systems to work properly and to produce nitrogen for crops. Soil fungal organisms are also very important to the carbon or organic matter cycle in the soil, along with water management in general, disease suppression and phosphate utilization. So these two organisms are very important to dairy farmers of today, along with other organisms such as the earthworm, but in actuality they are more bacterial and fungal organisms, in good soil by weight, then there are earth worms, many times more in good soil.
In the growing of crops to feed the animals it is important to understand that there is a balance in good soil of bacterial and fungal organisms which is more of a 1 to 1 ratio on a weight basis, which may run in weight as much a 2.5 tons per acre of each organism or 5 tons total in healthy soil. What has been learned in recent years is that cash crop farms tend to be more bacterial dominated, where dairy farms that have sod for hay or pasture in their rotation have a better balance. One of the keys to long term soil building is broadleaf plants, versus just grasses and legumes, which a diverse pasture would have.
Some farms are experiencing more fungal disease, which could be thought of as having too much fungi in the soil but actually it is because they are not enough, when beneficial fungal soil organisms are also considered. In nature when ever soil biology decreases you have more disease organisms, where as when you have more soil biology the unbeneficial numbers decrease, so the key is managing the beneficial organisms to keep a healthy soil environment, which in turn tend to keep the unbeneficial organism in check. So it is not only important that dairy farms have hay/pastures in there longer rotations, but they also have manure to feed the soil organisms, which is very beneficial to the soil when it is managed properly.
Some groups talk about the soil food web, which is made up of much more than just bacterial and fungal organisms, such as actinomyceties, which are a type of bacteria that produce compounds that give good soil its distinctive musty ammonia or ‘woodsy’ smell are very important to soil health. Nematodes are also part of the decay and nutrient cycles of a proper working soil, along with protozoa and anthropods. In total these organisms may make up 7-8 tons per acre of biological life under the surface of the soil. So in the last 60 years we have gone from worrying about bad bacterial to having a better understand of good overall biology and how it helps farmers with managing the so called bad organisms, while improving nutrient and water cycles, along with the overall health on farms of today.
Written by
Joe Scrimger
Bio-Systems II
Independent Food and Farm Consulting
Battle Creek, MI 49014
989-295-6773
We have the honor of working with Joe to improve the biology of the soil we have on the farm. He is helping us steward our land well. He is also a valued herdshare owner. We appreciate him and all he does!
