Reduced Nitrogen, Increased Output

The use of High Sugar Grasses reduces nitrogen levels deposited on pasture: a major environmental opportunity.

There has been comprehensive research undertaken for many years on various HSGs in Wales at the Welsh Plant Breeding Station (Institute of Grasslands and Environmental Research = IGER). The environment in which these grasses have been bred is similar to Gore in the South Island.  There are no similar grasses on the market in New Zealand.

In trials in the UK, there have been the following approximate results (summary from a number of trials):

  • 6% more milk production
  • Dry matter intakes up by as much as 2 kg per head (dairy cows) 
  • 3% improvement in diet digestibility
  • 24% less feed nitrogen lost in urine
  • Lamb and beef cattle growth increased in animals grazing HSGs

How High Sugar Grass improves efficiency of nitrogen utilisation

The figure shows the partition of nitrogen in cows consuming a control ryegrass and a High Sugar Grass: (IGER data from the UK).

Nitrogen Partition

If one takes the view that methane production is vented to the air and there is not a lot we can do about that at the moment, then it is possible to do something now about the voiding of high levels of nitrogen on the pasture by using High Sugar Grasses.

This nitrogen, mostly in urine predominantly gives rise to nitrous oxide emissions and is the biggest contributor to the dangerous greenhouse gas (nitrous oxide). We suggest therefore that the use of HSGs reducing nitrogen deposition may be one of the most important strategies for farmers mitigating against climate change!

Lamb growth data from the UK is in the figure below, and similar results have been achieved with beef cattle grazing HSGs in the UK.

Lamb production comparing High Sugar Grass with an ordinary ryegrass

Lamb Production

Farmers will be able to use HSGs and expect at least as much total dry matter to be produced (the initial NZ trials suggest some advantage). Also the dry matter is also of significantly higher quality, which will result in higher animal productivity, and a meaningful reduction in the nitrogen deposition on soils, and therefore into the environment! This will certainly be of interest to regulatory authorities such as Regional Councils!

It almost seems too good to be true!