While the quake, described as the ‘most complex ever studied’, prompted seismologists to rethink many assumptions about earthquake processes, something that can’t be questioned is the extraordinary landscape changes that resulted.
On the coast, a massive shoreline shelf was thrust upwards by several metres, while inland the geographical contours of many upper South Island farms were totally changed, leaving some areas unfarmable.
Groundwater levels were also severely affected by the quake. Land that was previously dry is now too wet and vice versa, drains were destroyed, waterways changed course or ceased to exist and some wells and bores had either dried up or been plugged with tonnes of sediment.
But help is at hand. The Kaikōura Plains Recovery Project was launched late last year to assist farmers manage damaged farmland and water use.
The three-year project, primarily funded by $600,000 from MPI’s Earthquake Recovery Fund, is being led by Jodie Hoggard and supported by Environment Canterbury, Kaikōura District Council, Fonterra, DairyNZ and local iwi and farmers.
The Recovery Project wanted a way to help farmers better understand their post-quake soils and make more informed decisions about irrigating effluent and water. Fonterra’s NxtGen Farms team had previously investigated and trialled soil moisture sensor technology (see more about this here) and provided support around what could be achieved. The Recovery Project Governance group decided that funding the purchase of soil moisture sensors for the 21 farms was the best way to help. The Fonterra Farm Source team supported with the installation of the sensors alongside farmers with help also from ECan staff and James Riddell from Wild Eye.
The sensors operate at multiple depths, picking up the variation in soil moisture and temperature at different levels. The data is then sent to the farmer’s online device, telling them how wet their soil is, if drainage is occurring and if there is enough moisture, or too much, for optimal grass growth. This data, combined with weather forecasts, can help farmers make more informed decisions about when and how much effluent or water to irrigate or whether to apply fertiliser on a particular day or not. While identifying the sweet spot for pasture growth, the information can also help limit the risk of nutrient run-off into waterways.
Mark Hislop, a Kaikōura farmer and member of the Recovery Project Governance group, says it’s that dual advantage of the sensors that prove their value.
“From an on-farm management perspective, to have the data from the sensors readily available makes a big difference. We want to use water wisely and only irrigate when the soil and pasture needs it. The same goes for irrigating effluent because we want to keep it out of the waterways by only spreading it when and where it can be absorbed.”
James Caygill, Fonterra’s Regional Engagement Manager (South Island), says it’s been great to see farmers embracing the technology.
“I’ve been really impressed with how onboard they are with the project and how easily the new data the sensors provide can be used to modify their management decisions. Kaikōura’s farmers have been actively seeking ways to improve water quality for some time, and this initiative provides a tangible way of limiting the impact their activity has on local waterways.”