Using high frequency data collection to study nitrate on clear creek during high flow events

Nitrate is an important nutrient vital to row crop production of corn, but this nutrient also creates potential water quality issues when it is washed out farm fields and into surrounding surface water. Iowa is a state known for its rich agricultural history; the farm industry would not be as strong as it is without the use of synthetic fertilizers. Iowa watersheds which feed the Mississippi River deliver approximately 25% of the annual nitrate load to the Gulf of Mexico. The nitrate that reaches the Gulf has a negative impact on water quality because it leads to the formation of the summer time hypoxic zone. This project examined the feasibility of using high frequency data collection as a way to monitor the nitrate concentrations in a small Iowa stream named Clear Creek. The concentration data was used to calculate the nitrate-N flux. This project also compared high frequency sampling to hourly sampling and daily sampling to see if high frequency data collection is better at capturing the nitrate flux during a season full of high flow events. Project results show that high frequency sampling is best utilized at the "flashiest" site on Clear Creek.