Phosphorus Runoff and Cover Crops after Undergoing Freeze-Thaw Cycles
Soils in northern climates (like Minnesota) undergo what is known as freeze-thaw cycles. During the fall and spring seasons, as the climate transitions from or to colder temperatures, soils may freeze overnight when the temperature drops, and thaw during the day. These freeze-thaw cycles may cause nutrient mobility in soils, and with heavy rainfall, this nutrient mobility contributes to issues such as eutrophication. The usage of cover crops acts as an additional variable, possibly impacting nutrient mobilization and runoff rates in a variety of ways. This research project’s goal was to test this hypothesis of nutrient mobility after soils have undergone freeze-thaw cycles. Cover crops were added to this incubation study to see if there were variations amongst the usage of different cover crops. Amongst the three cover crops used, it was found that radish had the highest concentration of phosphate in its runoff. Out of four runoff events, it was found that runoff event 3 had the highest concentrations of phosphate in all four treatments.