Today’s guest blog post comes from water resources intern Ritwik Chakrabarti, a junior in Environmental Engineering at Iowa State University, raised in the bustling city of Kolkata, India
Back in India, the presence of clean and safe drinking water is a priced commodity, so reading the job description for the Water Resource Internship at Water Rocks! and Iowa Learning Farms, I found an excellent opportunity for me to make an impact by studying water quality all around Iowa, and that bubbled me up with joy to learn more about such an essential resource in our daily lives.
Studying the water quality in a field is extremely important as farmers apply various chemicals, such as fertilizers, pesticides, herbicides, etc., to help crop yields, but it can also lead to potential water quality challenges. For a research project exploring relay intercropping, we installed field lysimeters three feet deep to study nitrate levels in the soil water in this relatively new-to-Iowa cropping system. For two farms in the project, one lysimeter was installed for each end of the eight replications for sixteen lysimeters.
The installation started with an earth auger drill to make a hole three feet deep. While the hole was being made, the soil being dug out was used to make a soil sludge. The field lysimeters had a ceramic bottom that would absorb water due to a pressure difference but were also sensitive to other liquids; thus, the ceramic bottom was dipped into the sludge before it was put inside the hole. After putting in the lysimeter, the sludge was poured all around it in the hole to make an air-tight seal to prevent air or water pockets. After the hole was filled with the sludge and soil, a layer of bentonite clay was put on top of it as a protective layer to make it an insulated system.
Mitch Harting drilling the hole with the Earth Auger and Ann Staudt making the soil sludge (left). Ann Staudt rocking a lysimeter (upper right). Ritwik hammering the housing for the protective cover in the soil. (lower right).
Then, we hammered a protective PVC cup holder around the top of the lysimeter and created a state of vacuum with a hand pump to help the water percolate into the suction tube through the ceramic bottom. The water samples are collected every two weeks from the lysimeters and sent to the water quality research laboratory at Sukup Hall at Iowa State University.
Seeing that such a simple instrument could collect water through the soil was terrific and helped me realize the importance of the harmful effects of nitrates in the soil and water. Thus, one lysimeter at a time, we can get closer to keeping our beautiful home, Earth, safe and healthy.
-Ritwik Chakrabarti
Iowa Learning Farms 