Hawkes Bay Case Study
Based on a representation of a Hawke’s Bay, Tararua or Wairarapa farm this 570 ha sheep and cattle breeding and finishing farm is on easy to medium hill country, with some steeper aspects (on which lower intensive farming practices are undertaken). In 1990 the stocking rate was expected to have been 10 stock units per hectare shifting to 9.7 in 2040.
Under both the low and high emission scenarios, temperatures increased 0.7°C and 1°C respectively. The farm was likely to be exposed to a further 6 days per year at temperatures exceeding 28°C and at the other end of the spectrum 16 less days per year where temperatures would drop below 2°C.
Under the low emission scenario, the level of annual rainfall decreased from 883mm/y to 857 mm/y while at the high emission level rainfall decreases by only 7mm from the 1990 base records.
Under the low emission scenario total annual pasture production decreased slightly by 200 kg DM ha-1y-1 from 1990 levels of 6500 kg DM ha-1y-1 while in the high emission scenario total annual pasture production dropped by 300 kg DM ha-1y-1.
There will be changes in monthly growth rates: for example, it is predicted that by 2040 the late winter-early spring pasture growth rates will have increased overall by 15% compared to 1990. Further, under the high emissions scenario, growth rates in November through to January may decrease by up to 30%.
From a financial point of view, if management practices from 1990 remain unchanged, i.e. business as usual, then a reduced gross margin will be achieved. However, if adaptations to the changing climate are incorporated into farm management, a greater gross margin will remain at existing levels. This suggests great incentive for farmers to put in place tactical and strategic adaptations to build their farms resilience to changing climate on their farm business.