Rehabilitation will be greatly influenced by the time of year of the ashfall and the nature of the ash.
- Pastures can be re-established either through conventional cultivation or undersowing.
- Where ash is up to 25 mm thick, incorporation of the ash through ploughing is the most suitable method.
- Hill country rehabilitation will be slower, as material cannot be incorporated into the soil profile.
- Rainfall will improve the rate of recovery as the ash is eroded.
- Oversowing with fertilizer will be necessary, due to the inherent lower fertility of the soils and also where pastures are weakened/destroyed by the ash.
- Extra supplements are required to maintain stock numbers until pastures recover.
- Greenfeed crops and high producing annual ryegrasses could be established where the eruption occurred late summer, to provide increased feed in the winter until permanent pastures could be established.
- It is important to maintain farm operations, especially in terms of providing good quality water and maintaining farm machinery.
- The costs of re-establishing pastures after an eruption are similar to a severe drought.
Late Winter/Early Spring in Temperate Climates
- Most critical period for dairy, sheep, and beef (pasture covers are low and supplementary feed has largely been used).
- Management options will be to gather stock and move them through longer pasture areas of the farm to shake/remove ash off the plants. These areas can then be grazed with some brought supplementary feed such as meal and hay if available.
- It will be difficult to procure sufficient grazing to de-stock affected farms at this time of the year. However, some de-stocking of the farm may be possible by sending stock to the works or for grazing in other parts of the country.
- Paddocks that had been intended for cropping or pasture renewal could be cultivated and sown in fast growing annual crops, including annual ryegrasses, feed oats and barley.
- Soil fertility is likely to decrease in the short term, requiring higher fertilizer inputs but not necessarily for all elements.
Summer/Autumn in Temperate Climates
- Management options are eased by the ability to de-stock lambs and prime cattle, and cull dairy cows to the works. Reserves of hay or silage are at the greatest and greenfeed crops such as corn, choumollier or swedes will be of sufficient maturity to supply a substantial amount of feed.
- Good quality water is essential, increased water pump maintenance and cleaning of troughs will be required for farms on deep well bores and reticulated systems.
- Farms taking supplies from streams or dams, provision of good quality water for both human and stock consumption will be more difficult. Outside assistance may be required in the short-term (until streams clear and dam water can be tested clear of toxic chemicals).
- Rehabilitation of any farm will be dependent on the financial resources of the farmer and the robustness of the farm business.