Agricultural greenhouse gases & the New Zealand beef & sheep sectors

Quick facts

  • Forty-nine percent of New Zealand's greenhouse gas emissions come from agriculture.
  • At the same time, more than 38% of New Zealand's merchandisable exports come from agriculture. 
  • New Zealand's beef, wool and sheep meat industries contribute eight, 27 and 75% respectively, to their world marketplaces.

What's changed in the beef & sheep sectors since 1990 in on farm practices?

Beef

  • Reduction in breeding herd numbers
  • Increased number of finishing cattle - use of dairy origin animals for finishing
  • Feed management strategies
  • Pasture management strategies

Sheep

  • Breeding and flock testing for animals with improved genetic merit (gorwth, reproduction)
  • Use of pregnancy scanning
  • Hogget mating
  • Pasture management (growth quality)
  • Optimisation of stock numbers to pasture growth

What's the impact of these on farm changes on productivity?

Beef

  • Faster growth rates
  • Increased finished weight of animal
  • Increased meat yield per hectare (kg meat/ha) 

Sheep

  • Increased lambing percentage
  • Increased number of offspring per ewe
  • Increased finished weight of animal (lamb)
  • Increased meat yield per hectare (kg meat/ha)

What's the effect of these changes on emissions intensity? 

Emissions intensity of New Zealand beef and sheep sector is lower.  For the beef sector, a great proportion of feed goes to production rather than maintenance and for the sheep sector, a lower ewe population is producing the equivalent lamb meat.

What's the latest from industry?

Beef+Lamb New Zealand Read more

On farm practice change summary tables

Beef

On farm practice Effect on farm productivity Effect on emissions intensity (net)

Reduction in breeding herd numbers

 

Increased number of finishing cattle - use of dairy origin animals for finishing 

 

Feed management strategies

 

Pasture management strategies 

Faster growth rates

 

Increased finished weight of animal

 

Increased meat yield per hectare (kg meat/ha) 

Lower

 

* A greater proportion of feed going to production rather than maintenance *


Sheep

On farm practice Effect on farm productivity Effect on emissions intensity (net)

Breeding and flock testing for animals with improved genetic merit (gorwth, reproduction)

 

Use of pregnancy scanning

 

Hogget mating

 

Pasture management (growth quality)

 

Optimisation of stock numbers to pasture growth

Increased lambing percentage 

 

Increased number of offspring per ewe

 

Increased finished weight of animal (lamb)

 

Increased meat yield per hectare (kg meat/ha) 

 

Lower

 

* Lower ewe population needed to produce equivalent lamb meat *

 

What else is being done to lower emissions on farm?

The NZAGRC is working in partnership with the PGgRc to explore options to mitigate GHGs on New Zealand farms.  An overview publication is available for download

pdf NZAGRC_PGgRC_What are we doing_ed2.pdf (17.12MB)

or you can read about our research programme

More information

The potential of using alternative pastures, forage crops and gibberellic acid to mitigate nitrous oxide emissions

Di, H. J., Cameron, K. C., Podolyan, A., Edwards, G. R., de Klein, C. A. M., Dynes, R., & Woods, R. (2016). The potential of using alternative pastures, forage crops and gibberellic acid to mitigate nitrous oxide emissions. [Article]. Journal of Soils and Sediments, 16(9), 2252-2262.

Purpose

In grazed pastures, nitrous oxide (N2O), a powerful greenhouse gas and an ozone depletion substance, is mostly emitted from animal excreta, particularly animal urine-N returned to the soil during grazing. We conducted a series of four field lysimeter and plot experiments to assess the potential of using gibberellic acid (GA) and/or alternative pastures or forage crops to mitigate N2O emissions from outdoor dairy farming systems.

Materials and methods

Pasture and forage plants assessed in the experiments included Italian ryegrass (Lolium multiflorum L.), lucerne (Medicago sativa L.), diverse pastures (including plantain (Plantago lanceolata L.), chicory (Cichorium intybus L.), perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.)), fodder beet (Beta vulgaris L.), kale (Brassica oleracea L.), as well as the standard perennial ryegrass and white clover (RG/WC) pastures. N2O was determined using a standard static chamber method in the field either on top of lysimeters or field plots.

Results and discussion

The results showed that the application of GA to urine-treated lysimeters with Italian ryegrass, lucerne or RG/WC pastures did not result in lower N2O emissions. However, the use of diverse pastures which included plantain with a lower urine-N loading rate at about 500 kg N ha−1significantly decreased N2O emissions by 46 % compared with standard RG/WC with a urine-N loading rate at 700 kg N ha−1. However, when urine-N was applied at the same rates (at 500 or 700 kg N ha−1), the N2O emissions were similar between the diverse and the standard RG/WC pastures. This would indicate that it is the N-loading rate in the urine from the different pastures that determines the N2O emissions from different pastures or forages, rather than the plants per se. The N2O emissions from cow urine from fodder beet were 39 % lower than from kale with the same urine-N application rate (300 kg N ha−1).

Conclusions
These results suggest that N2O emissions can potentially be reduced by incorporating diverse pastures and fodder beet into the grazed pasture farm system. Further studies on possible mechanisms for the lower N2O emissions from the different pastures or forages would be useful.

Read more (external link)


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