Ecosystem C and N dynamics affected by a modified spring barley trait with increased nitrogen use - a simulation case study

Abstract

To what extent might a crop with increased plant N uptake efficiency and/or N demand increase plant biomass and soil carbon storage, decrease N leaching, and reduce the need for N fertilisation? This was assessed for a fertilised sandy loam site in central Sweden cultivated with spring barley for a four year period using a process based crop and soil simulation model (SOILN) calibrated to fit observations of field experiments with non-modified crops. Crop properties were changed in accordance with previous model applications to other crops with higher N uptake and utilisation efficiencies, to resemble potential effects of breeding. For the modified crops a doubling of daily uptake efficiency of soil mineral N and/or increase of radiation use efficiency by 30%, increased plant biomass by 3%-30%, decreased N leaching by 1%-30% and increased soil organic carbon (SOC) content by 1-12 g C m(-2) year(-1). The larger changes were mainly due to increased uptake efficiency. Fertilisation of the modified spring barley crop could be reduced while still producing the same plant biomass as the non-modified crop. The plant biomass to N leaching ratio of the modified crops increased. The simulated changes in plant biomass and SOC were sensitive to weather conditions suggesting that in situ experiments would need to cover a large range of weather conditions to evaluate the performance of new crop traits under climatic variability. The study suggests a strong need that field experiments are accompanied with model applications, when exploring the potential of the modified crops under variable conditions.

Keywords

Plant breeding; N uptake; N utilisation; N leaching; SOC; sandy loam; Sweden

Published in

Acta Agriculturae Scandinavica, Section B - Soil and Plant Science
2018, volume: 68, number: 3, pages: 230-242
Publisher: TAYLOR & FRANCIS AS

SLU Authors

• Eckersten, Henrik

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

• Marstorp, Håkan

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Collentine, Dennis

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • University of Gävle

• Johnsson, Holger

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Kätterer, Thomas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science
Soil Science

Publication identifier

• DOI: https://doi.org/10.1080/09064710.2017.1385835

Permanent link to this page (URI)

https://res.slu.se/id/publ/94663