Journal article

Which multispectral indices robustly measure canopy nitrogen across seasons: Lessons from an irrigated pasture crop

Manish Kumar Patel, Dongryeol Ryu, Andrew W Western, Helen Suter, Iain M Young

Computers and Electronics in Agriculture | ELSEVIER SCI LTD | Published : 2021

Abstract

In precision farming, accurate estimation of canopy nitrogen concentration (CNC) is valuable for effective crop growth monitoring and nitrogen (N) fertiliser management. To date, many canopy multispectral indices have been proposed as indicators for CNC; however, many of these indices have also shown sensitivity to biomass and their performance drops at high biomass levels. Dependence on growth stage, season, or other environmental conditions limits their efficacy as generalized CNC indices. The objectives of this study were to assess the robustness of popular CNC indices across a wide range of biomass levels and fertiliser application levels; and for two contrasting seasons – winter and sum..

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Grants

Awarded by Australian Government Department of Agriculture, Water and the Environment as part of its Rural R&D for Profit program


Awarded by AustraliaChina Joint Research Centre for Healthy Soils for Sustainable Food Production and Environmental Quality


Funding Acknowledgements

This work was supported by the Australian Government Department of Agriculture, Water and the Environment as part of its Rural R&D for Profit program (grant No. RRDP1715) ; the AustraliaChina Joint Research Centre for Healthy Soils for Sustainable Food Production and Environmental Quality (grant No. ACSRF48165) ; and Dairy Australia. We are thankful to Dr. Alexis Pang, Mr. Graeme Ward and Dr. Oxana Belyaeva who helped in maintaining the crop condition and organising the ground data collection. The authors would also like to acknowledge the timely services provided by TrACEES platform in chemical analysis at the University of Melbourne.