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ARS Home » Midwest Area » Columbus, Ohio » Soil Drainage Research » Research » Publications at this Location » Publication #392103
Research Project: Agricultural Water Management in Poorly Drained Midwestern Agroecosystems

Location: Soil Drainage Research

Title: Effect of alfalfa on subsurface (tile) Nitrogen and phosphorus loss in Ohio, USA

Author
item ARRUETA, L - The Ohio State University
item Hanrahan, Brittany
item King, Kevin
item KALCIC, MARGARET - University Of Wisconsin

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2022
Publication Date: 11/2/2022
Citation: Arrueta, L.D., Hanrahan, B.R., King, K.W., Kalcic, M. 2022. Effect of alfalfa on subsurface (tile) Nitrogen and phosphorus loss in Ohio, USA. Journal of Environmental Quality. 51(6):1181-1197. https://doi.org/10.1002/jeq2.20414.
DOI: https://doi.org/10.1002/jeq2.20414

Interpretive Summary: Water quality problems originating from systematic subsurface drainage continue to be a focus of conservation practices in the tile drained regions of the world. Adopting conservation practices has been identified as a means to address excess nutrient loss, specifically altering the typical corn-soybean crop rotation to include perennials. Using a before-after-control-impact design on two sets of paired fields located in Northwest Ohio, perennial crops were shown to reduce tile drainage discharge and nutrient loss when compared to typical row crop agriculture. These findings are important for conservation policy makers, educators and practitioners seeking ways to improve water quality in tile drained landscapes.

Technical Abstract: Perennial crops are expected to reduce nutrient losses to waterbodies compared to annual row crops. However, more comprehensive data are needed on the nutrient loss effect of introducing perennial crops into row crop agriculture. We examined the effect of alfalfa (Medicago sativa L.) using a Before-After-Control-Impact experimental design with one control site (no alfalfa) and one impact site (with alfalfa) each on two farms located in northwest Ohio to (1) quantify the influence of alfalfa on nitrate (NO3--N), total nitrogen (TN), dissolved reactive phosphorus (DRP), and total phosphorus (TP) from subsurface drainage and (2) evaluate seasonal nutrient load reductions. Alfalfa reduced subsurface discharge and subsurface nutrient loads in both study fields. Although reductions in the mean monthly discharge (9%) and loads of NO3--N (108%), TN (101%), DRP (22%), and TP (78%) were significant at site A, the only significant change at site B was a 103% reduction in the mean monthly TP load. Nutrient load reductions were most apparent during the spring season, with significant reductions in NO3--N and TN loads at site A. Alfalfa also reduced the variability of nutrients and water loss through tile drainage. Our findings suggest that introducing alfalfa into row crop rotations could improve water quality in waterbodies by reducing nutrient losses and increasing the resiliency of agricultural systems.