Drainage water recycling is a conservation practice during which subsurface drainage water is captured for use as supplemental irrigation water in the summer. In addition to the irrigation benefit, drainage water recycling reduces nitrogen and phosphorus loss by reusing the water in the field.
Hay described drainage water recycling as a multiple “win-win” scenario, where the farmer is able to address excess water in the spring and fall through drainage, but also during dry periods in the summer by using the captured drainage water as supplemental irrigation. The practice can also prevent loss of nutrients downstream and captures water containing both nitrogen and phosphorus, while many other other conservation practices only address one nutrient of concern. The practice can also lead to a flood peak reduction and have positive impacts on downstream water quantity.
Current research projects at sites around the Midwest have been looking at yield increases with the supplemental irrigation that drainage water recycling supplies and have found that during dry years they saw a 50% corn yield increase and a 29% soybean yield increase. Hay stated that although the idea of drainage water recycling is not new, it is an emerging conservation practice that has attracted more attention recently and that more research is needed to understand the benefits and economics. To learn more the ongoing research, visit the Transforming Drainage website.
To learn more about this topic, watch the full webinar here!
Join us next month, on Wednesday, July 17 at noon, when Laurie Nowatzke, Measurement Coordinator for the Iowa Nutrient Reduction Strategy at Iowa State University, will present an Iowa Learning Farms webinar titled “The Iowa Nutrient Reduction Strategy Measurement Project: Tracking Progress Towards Iowa’s Water Quality Goals”.