Soil Repair | Wairoa Recovery

SOIL REPAIR AFTER CYCLONE GABRIELLE

LandWISE have a collection of resources to help growers make decisions about repairing, rebuilding or developing their soils following the flood events.

One of the best things to do is get plants growing. Growers are good at that. Plants will help draw water out of the soil, stabilise it and prevent dust blowing, and start to turn raw sediment into living soil.

Each situation is unique but principles apply

Take time to breathe – plan, prepare, act for best results
Know what the flood has done in your paddocks or blocks
- Did water cover the site for more than 3 days?
- Was the site scoured?
- Has sediment been deposited?
Check your drainage – poor drainage will slow recovery
Flood sediment is typically unstructured, with varying depths and textures
Sandier where water moves quicker, clay where water ponds
Nutrient status and pH variable, so soil testing and amendment helpful
Soil drying rate depends largely on texture – plan around that for sowing drier first, wet last
Anaerobic soil not good for seed, but cultivation will rapidly help
Medium depth sediment (5 – 20cm) best cultivated to mix with topsoil below
Deeper silt deposits (>20 cm) appear best cultivated when dried enough – lighter tractors preferred
Surveys showed annual crops e.g. oats, ryecorn, annual ryegrass grew well
Legumes can be beneficial especially in ongoing fertiliser applications not intended
Mulching cover crops when mature may help build soil organic matter
Think about the crops likely to planted when selecting species for covers
Get something going as soon as sensible to avoid dry soil blowing and to start rebuilding soil structure.

RESOURCES

Horticulture NZ Info for Growers

Apple & Pears - Orchard Info

HBRC Website Regional Info