CEES research affiliate, Dr. Pierre-Andre Jacinthe (Associate Professor, Earth Sciences, IUPUI), recently received funding as lead-PI from the USDA to examine the impact of drought on water quality in Indiana. The project team includes Dr. Lixin Wang, Dr. Lin Li, and Dr. Pamela Martin (all faculty in Earth Sciences at IUPUI); Indiana state climatologist Dr. Dev Niyogi; and, Dr. Juan Sesmero (Purdue University).
By investigating the influence of agricultural practices on this issue, Dr. Jacinthe and the team hope to be able to educate Indiana farmers on best environmental and economic decisions for their farms.
Due to climate change, models predict the Midwest will experience frequent stretches of dry periods followed by periods of excessive rainfall within the next 20 years. If these rainfall periods occur during the growing season, crops will not be able utilize all the fertilizer applied during the growing season, and there will be an excessive amount of nutrient in the ground during the dormant season that could end up in the waterways. Evidence of this efflux of nitrate has been seen in key periods such as: (1) in December when the ground is still warm but there are no plants to utilize the nutrients and (2) during mid-March thaw events.
There are two types of tillage management styles used on farms that can impact the amount of nutrient that ends up in the waterways. In the conventional tillage practice, farmers plow about 12 inches into the soil every fall. Conversely, no-till agricultural practices allow the land to go for a number of years without being plowed. In a no-till field, there is a high amount of crop residue on the soil surface that prevents evaporation of soil moisture. No-till fields also allow crops to utilize nutrients more efficiently, leading to lesser amounts of nutrients in the ground capable of ending up in streams. Dr. Jacinthe hypothesizes that if no-till practices are used more widely in watersheds, there will be a smaller agricultural impact on water quality, particularly at the end of the drought season.
This project will take place in the Eagle Creek watershed over a three-year period. There will be two agricultural fields used: one where conventional tillage practices are employed, and one with no-till. In each field, a series of small plots will be established for a rainfall manipulation study where rain will be blocked in one area (no rain), diverted to another (double rain), or experience normal rainfall (normal rain). In each plot, the crop yield and water quality will be measured. Once data has been collected and analyzed, results will be extrapolated to the entire Eagle Creek watershed using satellite images. An economic analysis of the two practices will be conducted to determine which tillage management style is more profitable for the farmer. This information will then be packaged and provided to farmers, students, and educators in Indiana.
