12 Jun 2013

N Product Research Summary

GRDC Project Report UM00023
Flowering wheat spike

Research Summary – Altering the rate of N supply to crops – field evaluations
UM00023 GRDC Nutrient Management Initiative

Internal Project Report – not to be cited without clearance from the project team.
Mention of any product name is not an endorsement of that product. The data is presented is specific to the soils, crops and climates reported and is provided without prejudice.

R Norton1, R Christie2, P Howie1 and C Walker3
1. School of Agriculture and Food Systems, The University of Melbourne,
Private Bag 260, Horsham, Vic. 3401.
2. Incitec Pivot Limited, Horsham, Victoria
3. Incitec Pivot Limited, PO Box 54, North Geelong, Vic. 3215.

    · Nine field experiments were undertaken to compare a range of N placement and product delivery strategies for wheat grown in the Mallee, Wimmera and Western District of Victoria.

    · The experimental results were compromised by dry seasons and any responses reported here are relatively low due to those conditions.

    · The marginal nitrogen removal (MNEff) in grain was used as an arbiter of the comparative efficiency of different placement and product delivery strategies.

    · On all except one site, Deep Banding of urea at sowing was no less efficient than any of the other at-sowing strategies used.

    · For the topdressing options, the use of a urease inhibitor or zeolite on top-dressed urea was never less than normal urea applications and, in two cases each, these treatments significantly improved MNEff.

    · At Inverleigh in 2006 and 2007, the use of UAN top-dressed resulted in lower MNEff, probably due to the degree of crop damage.

    · While topdressing urea at GS30 was not as effective in the Western District, the addition of a urease inhibitor resulted in marginal nitrogen use efficiencies similar to deep banding

    · Despite these differences in efficiencies, potential savings in nitrogen use were generally small in the Western District (~10 kg N/ha) and the Mallee (~5kg N/ha).

    · The decision concerning adopting different strategies should consider potential N savings, any additional capital and operating costs, changes to sowing efficiency and the extra cost of amendments or changed fertilizers.

    A full copy of the report can be downloaded below.

    Additional Resources

    N Product Research Summary 2005-2007Size: 0.47 MB

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