NZJA system_append PDF_proof_hi.pdf (441.99 kB)

Can alternative forages substantially reduce N leaching? Findings from a review and associated modelling

Download (441.99 kB)
journal contribution
posted on 2023-05-03, 21:50 authored by Racheal Bryant, Val SnowVal Snow, Paul ShortenPaul Shorten, Brendon WeltenBrendon Welten
Nitrogen (N) leaching losses from grazed pasture systems pose a risk to the environment with mitigation strategies urgently required to achieve regulatory limits. There has been increased interest in alternative forages to manipulate excretion of urinary-N of livestock. This review summarises research on key forage attributes which affect the pattern of urine-N excretion. The literature showed an opportunity to alter both N concentration and moisture concentration of forages to reduce urine patch N loading. Complementary mitigations of extending the grazing rotation and reducing fertiliser were tested in simulations in addition to a diuresis effect on nitrate leaching in pastoral dairy systems. Findings suggested that forage species alone could not substantially reduce (by more than 20%) nitrate leaching. Combining all forage, management and systems-based solutions led to the greatest reductions in nitrate leaching, 59 and 31% for Waikato and Canterbury. Nonetheless, reductions in N loss came at the expense of pasture productivity which will likely affect profitability and farmer adoption of this suite of solutions in the absence of other drivers. The role of plant secondary metabolites in microbial dynamics has implications on N recycling in soil and rumen environments and this was identified as an area for further research.


Rights statement

© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.


  • English

Does this contain Māori information or data?

  • No


Taylor & Francis Group

Journal title

New Zealand Journal of Agricultural Research




Bryant, R. H., Snow, V. O., Shorten, P. R., & Welten, B. G. (2020). Can alternative forages substantially reduce N leaching? Findings from a review and associated modelling. New Zealand Journal of Agricultural Research, 63(1), 3–28. doi:10.1080/00288233.2019.1680395

Contract number


Job code


Usage metrics


    Ref. manager