Understanding soil nitrogen processes in diversified vegetable systems through agroecosystem modelling

Debendra Shrestha, Krista Jacobsen, Wei Ren, Ole Wendroth

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Vegetable production systems are typically tillage- and input-intensive, though they may vary widely in production practices utilized. Improved understanding of soil water and nitrogen (N) processes with the use of agroecosystem models may aid in the optimization of crop yields and reduction of N losses. The objectives of this study were to (1) apply the RZ-SHAW model to diversified vegetable systems of varying production intensity, and (2) to elucidate soil N processes key loss pathways to inform opportunities for improving N cycling and sustainable intensification in these systems. The systems included conventional (CONV), low input organic (LI), and organic high tunnel (HT) vegetable systems. Soil water content and temperature were simulated well (rRMSE < 0.30) in all systems. Simulated soil NO3¯-N content was closer to measured values in the CONV than other systems. On average, the soil NO3¯-N content was underpredicted by 8 kg N ha−1 in the 0–0.15 m, and 5 kg N ha−1 in the 0.30–0.50 m soil layer in the LI system. In all systems, simulated daily N2O flux followed the trends in the measured values, but model predicted greater peaks than measured. Nitrate leaching was the greatest N loss pathway in all systems, though timing and driving factors varied by system. Asynchrony between N mineralization and crop uptake was observed throughout the LI rotation, indicating opportunities for targeted N and irrigation inputs to increase crop yields. Simulation results indicate the need for additional study of soil microbial and N processes in HT systems.

Original languageEnglish
Pages (from-to)49-68
Number of pages20
JournalNutrient Cycling in Agroecosystems
Volume120
Issue number1
DOIs
StatePublished - May 2021

Bibliographical note

Funding Information:
This work was supported by the US Department of Agriculture AFRI program [grant No.2013-67019-21403]. The authors thank the University of Kentucky Horticulture Research Farm staff, Elmwood Stock Farm, Dr. Alexandra Williams, Jennifer Taylor, Brett Wolff, Ann Freytag, Riley Walton, Sapana Shrestha, and David Smith for laboratory and field assistance on this project, as well as the input from anonymous reviewers that greatly strengthened the manuscript. Authors also thank Dr. Saadi Shahadha, Dr. Liwang Ma for giving feedback on model calibration.

Funding Information:
This work was supported by the US Department of Agriculture AFRI program [grant No.2013-67019-21403]. The authors thank the University of Kentucky Horticulture Research Farm staff, Elmwood Stock Farm, Dr. Alexandra Williams, Jennifer Taylor, Brett Wolff, Ann Freytag, Riley Walton, Sapana Shrestha, and David Smith for laboratory and field assistance on this project, as well as the input from anonymous reviewers that greatly strengthened the manuscript. Authors also thank Dr. Saadi Shahadha, Dr. Liwang Ma for giving feedback on model calibration.

Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature B.V.

Keywords

  • Compost
  • Cropping systems
  • High tunnels
  • NO
  • Organic agriculture
  • RZ-SHAW

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Soil Science

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