Soil biodiversity reflects the variability among living organisms including a myriad of organisms not visible with the naked eye, such as micro-organisms (e.g. bacteria, fungi, protozoa and nematodes) and meso-fauna (e.g. acari and springtails), as well as the more familiar macro-fauna (e.g. earthworms and termites). Plant roots can also be considered as soil organisms in view of their symbiotic relationships and interactions with other soil components.
These diverse organisms interact with one another and with the various plants and animals in the ecosystem forming a complex web of biological activity. Soil organisms contribute a wide range of essential services to the sustainable function of all ecosystems. They act as the primary driving agents of nutrient cycling, regulating the dynamics of soil organic matter, soil carbon sequestration and greenhouse gas emission, modifying soil physical structure and water regimes, enhancing the amount and efficiency of nutrient acquisition by the vegetation and enhancing plant health. These services are not only essential to the functioning of natural ecosystems but constitute an important resource for the sustainable management of agricultural systems.
The settlement of Indiana brought agriculture, which resulted in the polyculture perennial landscape of forest and plains being replaced by a monoculture annual landscape. Where the soil food web use to receive carbon exudates (food) from a diversity of perennial plants harvesting sunlight and carbon dioxide; it now receives carbon exudates from only one annual plant at a time.
We can start to mimic the original plant community by using crop rotations which include all four major crop types:
Warm Season Grass – corn, sudan, and millet.
Warm Season Broadleaf – sunflower, and soybean.
Cool Season Grass – wheat, oat, barley, and rye.
Cool Season Broadleaf – flax, pea, and lentil.
Diverse crop/cover crop rotations provide more biodiversity, benefiting the soil food web; which in turn improves rainfall infiltration and nutrient cycling, while reducing disease and pests. Crop rotations can also be designed to include crops which are; high water users, low water users, tap root, fibrous root, high carbon crops, low carbon crops, legumes, and non-legumes to name a few.
Diverse crop rotations mimic our original plant diversity landscapes. They are important to the long term sustainability of our soil resource and food security.