Impact of controlled drainage on corn yield under varying precipitation patterns: A synthesis of studies across the U.S. Midwest and Southeast

Authors: YOUSSEF, MOHAMED - North Carolina State University; STROCK, JEFF - University Of Minnesota; BAGHERI, EHSAN - North Carolina State University; REINHART, BENJAMIN - Purdue University; Abendroth, Lori; CHIGHLADZE, GIORGI - Iowa State University; GHANE, EHSAN - Michigan State University; SHEDEKAR, VINAYAK - The Ohio State University; FAUSEY, NORMAN - Retired ARS Employee; FRANKENBERGER, JANE - Purdue University; HELMERS, MATTHEW - Iowa State University; JAYNES, DAN - Retired ARS Employee; KLADIVKO, EILEEN - Purdue University; NEGM, LAMYAA - North Carolina State University; NELSON, KELLY - University Of Missouri; PEASE, LINDSAY - University Of Minnesota

Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2022
Publication Date: 11/4/2022
Citation: Youssef, M., Strock, J., Bagheri, E., Reinhart, B.D., Abendroth, L.J., Chighladze, G., Ghane, E., Shedekar, V., Fausey, N., Frankenberger, J., Helmers, M.J., Jaynes, D.B., Kladivko, E., Negm, L., Nelson, K., Pease, L. 2022. Impact of controlled drainage on corn yield under varying precipitation patterns: A synthesis of studies across the U.S. Midwest and Southeast. Agricultural Water Management. 275. Article 107993. https://doi.org/10.1016/j.agwat.2022.107993
DOI: https://doi.org/10.1016/j.agwat.2022.107993

Interpretive Summary: Controlled drainage (CD) is a conservation practice used in artificially drained agriculture in the Midwest. Artificial drainage is used on a significant amount of this area to reduce waterlogged and overly saturated soils. Controlled drainage can decrease the amount of drainage outflow and subsequent nutrient loss to nearby water bodies. The CD infrastructure can be managed to limit the drainage outflow and retain water for use by the crop later in the season when moisture shortages may occur; however, the impact of CD on corn production is not completely understood. This research investigated if a consistent yield response was identified when the drainage infrastructure was controlled rather than allowed to freely drain year-round. Research was carried out across thirteen (13) experiments in six Midwestern states and North Carolina between 2006-2017. On average, corn grain yields were not different between the two practices. However, about half of the time, there was a yield difference and these cases were further examined. Under moderate drought stress, CD plots had up to 14% greater corn yields than freely drained plots. The availability of water in the deep root zone was of benefit during these drought periods. However, during a few wet growing seasons, grain yield was reduced by up to 10% under CD because the soils were too wet and could not drain quickly enough. This variability in seasonal precipitation is a key factor in the performance of CD systems and subsequently, the productivity of corn. This research identified the necessity for farmers to actively manage their CD systems rather than leaving them unchanged for the entire growing season. Research showing positive yield responses in years with moderate drought stress will provide motivation for implementing this conservation practice more widely.

Technical Abstract: Controlled drainage (CD) is a valuable management practice for reducing drainage volume and nutrient loss, but its impact on corn (Zea mays L.) production is not completely understood. The objectives of this study were to investigate the regional effect of CD on corn grain yield compared to free drainage (FD), investigate the factors influencing corn yield response to CD, provide management recommendations for optimizing corn yield under CD, and identify future research needs for corn production on poorly drained soils with subsurface drainage systems. This synthesis included data collected from 13 field sites with FD and CD in six Midwestern states and North Carolina totaling 55 site-years of FD and CD systems from 2006-2017. On average, there was no statistically significant difference in corn grain yield between CD (10.62 Mg/ha) and FD (10.53 Mg/ha). However, 42% of the dataset indicated that CD either increased or decreased corn yield by 4% or more compared to FD. Further analysis was conducted on this subset of data in order to evaluate underlying factors (i.e., weather conditions during the season, soil type, and drainage system design and management) influencing corn yield response to CD. Results of this analysis showed that CD was effective in alleviating mild to moderate drought stress conditions and increased corn grain yield by 4% to 14% in 12 site-years. In contrast, CD reduced corn grain yield by 4% to 10% during wet growing seasons (6 site-years). Variability in growing season precipitation has been identified as a key factor influencing corn grain yield under CD, and more active management or automation is recommended. General recommendations are provided for managing manually operated CD systems in the Midwest to improve growing season water management and corn yield. Additional research to develop technologically advanced water management systems for crop production on poorly drained soils is needed in order to adapt to changing weather patterns.