can we reduce nitrous oxide emissions from animal production systems - kevin kelly

Can we reduce nitrous oxide emissions from animal production systems?

Kevin Kelly, Graeme Ward, Sally Officer, Tim Huggins, Richard Eckard

Agricultural soils - nitrous oxide emissions

(DCCEE 2010)

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Nit

rou

s o

xid

e (M

t C

O2e

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Background

Nitrogen excreted at grazing, major contributor to N2O emissions.

NZ research with inhibitors has demonstrated - up to 70% reduction in direct emissions, and- reduction in nitrate leaching (indirect emissions)- 0-30% increases in pasture production

Aust. research demonstrated potential for 25-50% reduction

Project FocusEmissions from urine patches

Dicyandiamide (DCD) applied to pasture/soils

Gas measurements pasture measurements

Why a dairy system? stocking intensities are high generally in high rainfall zones

TerangSW Victoria

Daily nitrous oxide flux and soil water

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Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10

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N2O

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a/d

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Urine day 1 average SW

Daily nitrous oxide flux and soil water

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Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10

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Urine day 1 Urine day 1 + DCD day 1 average SW

Daily nitrous oxide flux and soil water

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Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10

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Urine day 28 Urine day 28 + DCD day 1 average SW

Daily nitrous oxide flux and soil water

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Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Aug-10 Oct-10

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x (g

N2O

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a/d

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Urine day 1 Urine day 1 + DCD day 1 Urine day 28 Urine day 28 + DCD day 1 average SW

Summary of nitrous oxide emissions

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Day 1-30 Day 31-60 Day 61-90 Day 91-120 Day 121-150 Total (150)

Flu

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Urine 28 days after start DCD at start, Urine 28 days after start Urine at start Urine and DCD at start

August 2009 start

April 2010 start

Effects of treatment on DM yields

Urine Urine + DCD(day 1 – day 1)

DCD + Urine(day 1 – day 28)

Late winter 4 of 5 3 of 5 1 of 5

(2009) (30-160%) (10-15%) (10%)

Autumn 5 of 6 3 of 6 3 of 6

(2010) (30-120%) (10-20%) (10-15%)

Summary

• DCD application reduced emissions by 35 and 45% both when applied immediately after urine applied and when applied one month prior to urine application

• Impact of DCD on emissions likely to be at least 90 days when applied in late winter or autumn • Impact of DCD on DM production at whole of paddock scale likely to be minimal

Acknowledgements