Survival of the Fittest

The recent drought in North Canterbury has highlighted the need to build resilience into east coast dryland farming systems. Early-season subterranean clover has the potential to drive early season production and with the help of funding from B+LNZ, Lincoln University are running a trial programme to find the best management package to help farmers make the most of this valuable legume. This two-part series looks at how sub clover performed on a drought-ravaged North Canterbury trial site.
Tuesday, 7 November 2017

There is nothing like drought to test the resilience of plants and a trial in North Canterbury has highlighted subterranean clover’s ability to persist in harsh conditions.

The trial on Hugh and Lucy Dampier-Crossley’s Hurunui farm “Koromiko”, is one of seven being run throughout both islands as part of Lincoln University’s and the Sustainable Farming Fund’s Sub4Spring programme.  Lincoln University plant scientist Professor Derrick Moot is leading the programme.

The focus on the 12ha Koromiko trial site, which has a mix of north and south facing country, is the establishment of subterranean (sub) clover into steep, uncultivable hill country.

In some ways, the trial could not have been set up at a better time. The drought that ravaged North Canterbury for three years desiccated soils and plants, but following Darwinian principles, the emergence of subterranean clover going into spring has proved it is one of the fittest forage species around.

Hugh admits to being very surprised at the number of sub seedlings that have emerged post-drought and says the plants that did appear last summer obviously set more seeds than he had anticipated

This feed was used for ewes over lambing before being shut up again in late spring to allow seed-set.

He has been particularly impressed with the clovers’ performance because the trial block is one of the worst on the farm in terms of fertility and feed value.

With a soil pH of 5.2-5.3 which is sub-optimal for legumes-the block, which sits at about 460m above sea level, was always going to be a tough testing-ground for forages and drought made it even more challenging.

Trial set up

The Sub4Spring trial on Koromiko was sown down in April 2016 following three spray treatments of three different chemical applications.

The seed mix of Antas, Monti and Denmark-3.3kg/ha of each- which was flown on with 250kg/ha of Sulphur Super 20 fertiliser. All the seed was inoculated.

Following seed application, a mob of ewes was run over the area to ensure seed to soil contact.

Andrew Johnston from Luisetti Seeds – who supplied the seeds for the trial- recommends sowing a mix of sub clovers, as different cultivars have different physiological characteristics and environmental preferences.

Because of the drought, these seeds didn’t strike until June but still generated enough feed for Hugh to lamb ewes on the area.

The block was shut-up for re-seeding in mid-October and then, says Hugh, it got really dry.  This lack of moisture meant that very few seeds appeared to have struck in late summer.

“There were very few plants-it did not look like a great strike.”

Despite what appeared to be a poor seed strike in the drought year, there were obviously a lot more plants than Hugh and the trial team had thought. In late August of this year, there was a good covering of clover throughout the trial area which was used for lambing ewes.