We all know that many people in the Hawke’s Bay, Gisborne and Northland Regions were hit hard by Cyclone Gabrielle. For many it came on top of a very difficult spring and summer, and some have little left. Houses, sheds, machinery and crops were damaged or destroyed. Some blocks have metres of sediment deposited, others have been severely scoured. There is a huge job ahead and it is going to be years before we can say things are recovered.
Our response was to help bring resources together and provide what advice we could on remediating impacted sites. When we put a call out for advice to share, we were quickly deluged with high quality information from crown research institutes, universities and industry. That is what underpins the advice note we put out to members and the wider community. We put information together at our page Soil Repair After Cyclone Gabrielle. The page also includes links to others’ websites and has downloadable information to help do a stock-take, make decisions, and prioritise actions.
For the last few weeks, we have been out in the field, assessing sediments and collecting samples for nutrient and in some cases contaminant assessment. We are grateful to Horticulture New Zealand, Vegetables New Zealand and the Ministry for Primary Industries for providing funding to collect samples and pay for lab testing.
We are also grateful to Massey University’s Farmed Landscapes Research Centre, AgResearch and Plant and Food Research for making soil science staff available to help at their own cost. The job became much larger than we had anticipated, and without these willing advisors and helpers, we would have been overwhelmed. Among the testing done is Visual Soil Assessment. Below are two examples; one from a paddock with less than 10 cm sediment, the other with almost 20 cm sediment deposited. Interestingly, even some severely affected sites still show reasonable work activity both in the soil below the sediment, and with channels through the dense sediment itself.
We have been sampling representative sites across most of the key affected areas in Hawke’s Bay, but still have a lot more to do. Along with Horticulture NZ, Gisborne District Council and Northland Regional Council, and our research partners, we are helping coordinate similar activities in the other affected regions. Information about those activities and results as they arrive will be put on the Gabrielle webpage.
We have benefitted from work done after historic flood events, including in Gisborne in 1948, and in the Southern North Island in 2004. We hope to track some of our Cyclone Gabrielle sites over the next few months and years, so we know more about the effects of different management choices on paddocks with various types and depths of sediment.