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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #422373

Research Project: Sustainable Intensification in Agricultural Watersheds through Optimized Management and Technology

Location: Agroecosystems Management Research

Title: Temporal dynamics of nitrate concentration and leaching losses under artificially drained Mollisol

Author
item Rogovska, Natalia
item Emmett, Bryan
item Malone, Robert
item O'Brien, Peter
item Ruis, Sabrina
item Kovar, John

Submitted to: Soil and Water Conservation Society International Annual Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Understanding the temporal distribution of NO3-N leaching losses from subsurface drained fields can help develop strategies for its mitigation. A replicated plot experiment was utilized to investigate the effect of various management systems on fine-scale temporal variation in leaching of NO3-N during the 2024 Corn (Zea mays L.) growing season under six different treatments: 1) BP: basic practice with fall chisel plow; 2) NT: no-till crop production; 3) RC: no-till with a winter rye (Secale cereale L.) cover crop; 4) RB: no-till with a winter rye for biomass harvest; 5) DW: no-till with woodchip denitrification walls parallel to both sides of the tile; 6) WP: winter pennycress (Thlapsi arvense) relay cropping. Each plot was equipped with separate tile drainage collection system enabling hourly measurements of drainage flow and corresponding nitrate concentrations. High frequency nitrate concentration measurements from in-situ nitrate sensors were compared to weekly concentration measurements of composite flow-weighted drainage samples. Overall, there was good agreement between both sampling frequencies on nitrate concentrations with mean absolute error (MAE) and root mean square error (RMSE) of ~1 mg/L NO3-N. Nitrate-N losses in drainage during 2024 growing season ranged from 4 to 26 kg ha-1 depending on the management practice, with 35% to 47% of total NO3-N lost to drainage occurring during five days in May primarily driven by high precipitation-induced drainage flow. This study shows that most of the NO3-N loss occurred in a relatively brief timeframe rather than gradually over the growing season.