Journal article

Predicting ammonia volatilization from fertilized pastures used for grazing

AP Smith, IR Johnson, G Schwenke, SK Lam, HC Suter, RJ Eckard

Agricultural and Forest Meteorology | ELSEVIER | Published : 2020

Abstract

Ammonia (NH3) volatilization from fertilised agricultural soils is driven by complex interactions between edaphic, climatic and plant canopy factors that can be difficult to measure or predict. We developed a simplified approach using default parameters in the DairyMod model to predict daily NH3 volatilization from urea applied to grazed dairy pastures. Several published datasets were used to validate the reliability of the model to reproduce key related soil processes in a whole farming systems framework. For the sites where monitoring for the experimental duration occurred, DairyMod simulated the main features of the observed NH3 emissions, with an overall predicted median of 4.1 kg/ha or ..

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Grants

Funding Acknowledgements

The `More Profit from Nitrogen: enhancing the nutrient use efficiency of intensive cropping and pasture systems' project was supported by funding from Dairy Australia and the Australian Government Department of Agriculture and Water Resources as part of its Rural R&D for Profit program. Author contributions: A.S. conceptualized the study, carried out the modelling and analysis, and wrote the paper; I. J. developed the model, contributed to the writing, M. B., S. K. L., G. S. and H. S. provided validation data and reviewed the manuscript; R. E. reviewed the manuscript. We also acknowledge Dr. Mei Bai, Ms. Yinghsi Li, Drs. Rachelle Meyer and Humaira Sultana for assisting with collection of some of the data files.