A paper by ERG group member Konrad Krogstad published in Frontiers in Environmental Science examines the effects of freeze-thaw cycles on nitrogen, sulfate, and chloride leaching from fertilized and unfertilized soil columns. Experiment and model results show that freeze-thaw cycles promote nitrifying conditions in the upper oxidized portion of the fertilized soil columns. The findings indicate that unwanted nitrogen enrichment in agroecosystems caused by pre-winter nitrogen fertilizer application may be exacerbated by changing freeze-thaw activity. Co-authors include Mehdi Gharasoo, Grant Jensen, Laura Hug, David Rudolph, Phillippe Van Cappellen, and Fereidoun Rezanezhad. The article can be accessed here.
Another related paper by Grant Jensen exploring the impact of freeze-thaw cycles on the microbial community composition in this soil column system was also published concurrently in the same journal. The results indicate that microbial community composition remains stable independent of nutrient availability despite the nitrification observed in fertilized soil columns. The response of temperate soil microbial communities to freeze-thaw and nutrient stressors may than controlled at the level of gene expression rather than population turn-over. Co-authors of this study include Konrad Krogstad, Fereidoun Rezanezhad, and Laura Hug. The article can be accessed here.