Precision control of soil nitrogen cycling via soil functional zone management

Academic Article

Abstract

  • Managing the soil nitrogen (N) cycle is a major component of agricultural sustainability. Soil functional zone management (zonal management) is a novel agroecological strategy for managing row-crop agroecosystems. It may improve the efficiency of soil N cycling compared with conventional and no-tillage approaches, by managing the timing and location (crop row vs inter-row) of key soil N cycling processes. We compared N mineralization and availability during the period of maize peak N demand in crop rows and inter-rows in zonal management and conventional chisel plow tillage systems at four sites across the US Corn Belt over three growing seasons. Under zonal management, potential N mineralization and N availability during crop peak N demand were significantly greater in crop rows, where the majority of crop roots are found, compared with inter-rows. Averaged across all site-years, plant-available N in zonal management crop rows was 46mgkg−1 compared with 21mgkg−1 in inter-rows. In contrast, in conventional tillage, potential N mineralization and N availability were greater in inter-rows compared with crop rows; averaged across all site-years, plant-available N in conventional tillage crop rows was 24mgkg−1 compared with 51mgkg−1 in inter-rows. The results demonstrate that the active management of crop residues under zonal management can enhance the spatiotemporal efficiency of soil N cycling processes, by concentrating N mineralization and availability close to crop roots in synchrony with crop developmental needs. Zonal management therefore has potential to increase crop N-use efficiency compared with conventional tillage, and thereby reduce the impacts of row-crop agricultural production on water resources and greenhouse gas emissions that result from N leaching and denitrification.
  • Authors

  • Williams, Alwyn
  • Davis, Adam S
  • Ewing, Patrick M
  • Grandy, A. Stuart
  • Jordan, Nicholas R
  • Kane, Daniel A
  • Koide, Roger T
  • Mortensen, David
  • Smith, Richard
  • Snapp, Sieglinde S
  • Spokas, Kurt A
  • Yannarell, Anthony C
  • Status

    Publication Date

  • September 2016
  • Has Subject Area

    Keywords

  • Agriculture
  • Agroecology
  • Ecological intensification
  • Microbial processes
  • Tillage
  • Zonal management
  • Digital Object Identifier (doi)

    Start Page

  • 291
  • End Page

  • 295
  • Volume

  • 231