Effects of Land Management Changes on Soil Microbial Communities in Eastern Montana.

To what extent the soil microbial community changes in response to different land uses or management strategies remains an important question. As soil microbial communities play an important role in keeping soils healthy and functional, the research community recognizes that diverse microbial ecology improves soil structure, nutrient availability, and helps facilitate air and water movement in the soil; thus, it is imperative to further understand the diversity of soil microbial communities under different conditions. For example, an increased ratio of soil predators to prey may indicate active communities, abundant resources, and the ability to support higher trophic level organisms. In this study, three different land management strategies are compared to determine how the microbial communities are responding to these different conditions and how these different microbial communities affect basic physical and chemical soil properties and overall soil health. The current study is being conducted in Dawson County in Eastern Montana, USA. The first management site was previously enrolled in the Conservation Reserve Program for over thirty years, has been untouched over that time period, and represents long-term perennial cover. The second site has history similar to site 1, but was converted to no-till production agriculture starting in fall of 2015. The third site also has similar history, but was converted to no-till agriculture beginning in the fall of 2014 and is grazed by livestock over the winter months following crop harvest. Herein we report the results of our first year of our study (spring and fall samples). Samples underwent Phospholipid Fatty Acid Analysis at three soil depths (0-5cm, 5-15cm and 15-30cm). In year one of the study, total biomass and diversity appear to increase in the no-till management sites. Over the next two years of the study, we expect increasing changes to the soil microbial communities under these conditions.