New Zealand
February 25, 2008
Source:
Massey University
With much of New Zealand suffering drought conditions and more
dry predicted, farmers who have not yet made plans for the
drying climate would be wise to do so, ruminant animal nutrition
expert Professor Tom Barry says.
Professor Barry heads a team working on drought-resistant plants
and alternate food sources.
"A lot of farmers think drought is something that will happen to
somebody else," Professor Barry says, "and of course drought
does mean different things to different individuals. Using the
scientific definition from Niwa (National Institute of Water and
Atmospheric Research) in the last 31 years there were nine
droughts. The East Coast is a lot drier and the projection is
that the frequency and severity of drought is going to increase
between now and 2080 and they are going to affect a larger area
of New Zealand and areas that have not previously been
affected."
Professor Barry, of the University's Institute of Veterinary,
Animal and Biomedical Sciences, has been working on drought
issues and animal nutrition for several years. Much of his
research is trialled at the University's Riverside Farm, in the
Wairarapa drought area near Masterton.
"Simply, if you have a drought the farmer has got to have some
plans for that," he says, "otherwise the farmer will lose a huge
amount of income. Our research is around what are the best
solutions available for farmers to be able to feed their stock
throughout drought."
Niwa says severe soil moisture deficits have persisted in
Marlborough, Canterbury, North and central Otago, with
significant soil moisture deficits in Auckland, Bay of Plenty,
Taranaki, Manawatu, Wairarapa, and Nelson.
Professor Barry says that traditionally farmers have addressed
drought by altering their stocking policy. "Beef and sheep farms
producing a lot of stock will lamb or calve as early as possible
and get lambs and calves off the farm early, de-stocking. Others
consider bringing in bull calves from dairy farms, fattening
them for meat production and selling only if drought occurs.
"However there are other strategies, including using plants that
can resist drought - those with extra-deep root structures that
can reach deeper into the soil.
"Chicory is a herb that has traditionally been used
internationally as a coffee substitute but in the mid-80s the
then DSIR produced forage chicory. It can be grazed by sheep or
cows but it does need specialised management - you need to sow
it either alone or with a legume such as clover; it needs
specialised management which is different to that for normal
perennial ryegrass or white clover pasture.
"Benefits are that is does provide superior animal growth
through high nutritive value, and better control of parasites
because it contains anti-parasitic compounds."
A well-managed stand of chicory could last for four or five
years, Professor Barry says. "But you can't get to the drought
and say 'well now we need chicory' - it needs to be sown in
spring."
Another alternative is the use of trees as feed, which has an
additional benefit of stabilising land. Riverside Farm has been
trialling use of willow and poplar supplement to ewes grazing
drought pasture, with studies showing that the sheep fed trees
just prior to or while the ram is out had an increase in
reproductivity by 20 to 25 per cent, producing more but not
heavier lambs. Dr Eileen McWilliam completed her PhD on the
willow supplementation of ewes grazing drought pasture during
mating. She now lectures on nutritional problems in dryland
farming, teaching nutritional science and vet students.
Other projects underway at Riverside include use of fescue
grass, which will be planted in strips along the roadside
paddock, enabling passers-by to see its growth.
"Fescue contains a fungus, referred to as the endophyte.
"This grows in symbiosis with the plant, the fungus in this case
containing a plant defence system of alkoids which deter animals
or insects - in the case if fescue deterring only insects and
non-toxic to livestock. AgResearch has selected a fescue
endophyte which is used a lot in the US and is believed to be
drought resistant."
Fescue will be sown in two paddocks in the next few weeks,
Professor Barry says, in the two stoniest, driest paddocks
available to see how well it copes. The experiment will be done
in conjunction with the plan improvement group of AgResearch. |
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