Location: Livestock Bio-Systems
Title: Nitrate leaching potential under continuous corn and alfalfa-based cropping system in NebraskaAuthor
SINGH, ARSHDEEP - University Of Nebraska | |
IQBAL, JAVED - University Of Nebraska | |
Woodbury, Bryan | |
WORTMANN, CHARLES - University Of Nebraska |
Submitted to: American Society of Agronomy Meetings
Publication Type: Proceedings Publication Acceptance Date: 6/6/2022 Publication Date: 11/7/2022 Citation: Singh, A., Iqbal, J., Woodbury, B.L., Wortmann, C. 2022. Nitrate leaching potential under continuous corn and alfalfa-based cropping system in Nebraska [abstract]. In proceedings: American Society of Agronomy-Crop Science Society of America-Soil Science Society of America International Meetings. Baltimore, MD. 6-9Nov2022. Paper 143825. Interpretive Summary: Technical Abstract: Rotation of perennial alfalfa (Medicago sativa L.) with annual crops has the potential to reduce nitrate-nitrogen (NO3-N) in the vadose zone and increase soil organic carbon (SOC) sequestration. The objective of this study was to determine the long-term effects on soil C, nitrate (NO3)-N, ammonium (NH4)-N, and soil water in the 7.2 m depth with an alfalfa rotation compared with continuous corn (Zea mays L.). Soils from six pairs of alfalfa rotation versus continuous corn observation points were sampled to 7.2 m depth in 0.3 m increments. The upper-most 0.3 m was divided into 0 – 0.15 and 0.15 – 0.30 m. For the 0-7.2 m depth, the alfalfa rotation compared with continuous corn had 36% less soil water, 457 kg ha-1 less NO3-N with 368 compared with 824 kg ha-1, 490 compared with 413 Mg ha-1 SOC, and 59.0 compared with 53.0 Mg ha-1 soil total N (STN). Cropping system and NO3-N concentration did not affect NH4-N in the vadose zone. The SOC in the 0–0.15 m depth was 7.61 Mg ha-1 more with the alfalfa rotation than with continuous corn. The greater depletion of soil water and NO3-N with alfalfa rotation was primarily below the rooting zone of corn suggesting no negative implications for corn following alfalfa but greatly reduced potential of NO3-N leaching to the aquifer with the alfalfa rotation. Alfalfa rotation compared with continuous corn is a means to greatly reduce leaching of NO3-N to the aquifer and improve the surface soil with potential to increase SOC sequestration. |