Greenhouse in Agriculture - Mixed Farming Systems
Decreasing Nitrous Oxide Emissions from High Rainfall Cropping Systems
Project Leader: John Graham
Other Scientists: Sally Officer, Kevin Kelly, Penny Riffkin
Objectives: To Measure the effects of:
- Conventional and minimal tillage and
- Nitrogen inhibitors on N2O emissions from a
legume crop rotation system. and:
- Provide information that will enable an improved
understanding of the impact of different management and
mitigation options on the N2O emissions, N cycling
and productivity of legume/ pasture - cropping system in the HRZ
of Victoria
Nitrous oxide (N2O) is a powerful
greenhouse gas with a global warming potential 310 times that of
carbon dioxide (CO2). Agriculture accounts for 84% of N2O
emissions due to cultivation (38%), fertilizer (32%) and animal
waste (30%). Cropping in the high rainfall zone (HRZ) is rapidly
expanding, where N2O emissions in excess of 3 kg N2O-N
ha-1 yr-1 (930kg CO2 equivalents) have been measured when a high
fertility legume pasture was cropped with wheat.
The project will (i) evaluate methods of
mitigating N2O emissions from direct and conventionally
sown legume/wheat rotations and (ii) the efficacy N inhibitors (such
as DCD) in such rotations, using automated chambers connected to a
tunable diode laser (TDL) to constantly monitor N2O
emissions.
The project will result in options for practice
change in the farming community that reduce emissions and
information to inform models such as NCAS for industry and
government decision makers.
A tunable Diode Laser (TDL) and a Licor in
conjunction with 12 automated chambers will measure N2O
and CO2 emissions respectively from treatments described
below.A permanent mixed ryegrass/phalaris/sub-clover pasture will be
sprayed to eradicate the grass and promote legume dominance.
Minimum and conventional tillage as well as a
nitrification inhibitor will be examined, giving 4 treatments,
replicated 3 times.
The treatments are:-
-
Conventional full tillage without
nitrification inhibitor
-
Conventional full tillage with
nitrification inhibitor
-
Minimal tillage using direct drilling
without nitrification inhibitor
-
Minimal tillage using direct drilling with
nitrification inhibitor
Commencement date: April 2009 Completion
date: June 2012
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