'Living labs' to tackle emissions
Living labs that bring together expertise at locations around New Zealand are among potential solutions identified by researchers to help the country move towards a more climate resilient future.
“I seem to have more than my share this year,” admits the Invermay, Otago, scientist. While he won’t be presenting all the papers he’s had an input on, the lucerne-for-lambs work is one he will. “It’s a project we’ve been running in conjunction with the Central Otago Beef + Lamb monitor farm project.”
The aim was to work out how best to integrate a crop well-known for the quality of its feed and potential to produce more drymatter, particularly in a dryland situation, into the farming systems of that area.
Some were already using it, but not necessarily in the optimum way, and in many cases on not nearly the area they could be, says Stevens.
“There was a feeling that you had to have a certain microclimate for it to work, but when we had a good look at it, those microclimates are everywhere in Central.
“Quite often farmers were coming unstuck with it because they were using too little too.” As a minimum, he suggests 10% of the grazed area needs to go into the crop so there’s sufficient area to keep a mob of stock on it continuously on a rotation around at least six blocks.
Grazing the crop in spring, then letting it grow later in the season, is proving a better strategy than traditional practice where it tended to be cut first for conserved feed, and only grazed if or when the haybarn was full.
“Grazing it in the spring does have real benefit. You get the lambs off the farm faster, so there’s less need for that
conserved feed in summer, or later in the year.”
For stands to persist, they do need to be allowed to grow out at least once a season, but that can be done in the autumn once lambs have gone. Such growth can then be cut, or used as a standing feed into early winter.
Where regular pastures in the area might carry 2-4 ewes/ha in spring, on lucerne up to 10 ewes/ha might be possible on the same land with lambs finished 30% faster. “The problem is that’s only spring. If you increased your stocking rate 2.5 times you’d be dead come winter, hence the need to work out how the crop is going to fit into the whole farm system.”
Lambing a week or two later to coincide with the slightly later growth curve of lucerne might be necessary. “Moving lambing later is counter-intuitive but because the lambs grow faster they can reach the same liveweight by the same date, if not earlier, than off ryegrass.”
Lucerne’s greater persistence on summer-dry country can also make it worthwhile renovating paddocks with the crop, where it would be a waste of time doing so with ryegrass.
“If you renewed with ryegrass it might last three-five years at best, so there’s not a lot of point in that, but lucerne might last 15 years and produce two-four times what you had.
On big, extensive properties, that can make a massive difference. Money just drops out the bottom.”
Cattle can be grazed on lucerne but providing salt and a fibrous feed such as straw is essential in spring, and advisable at other times. “It may pay to use a bloat capsule. It’s so much easier to use if you do.
“The other beauty of lucerne with cattle is it provides a bulk of feed that they can easily eat. Often there’s not enough really long feed for cattle on these properties.”
