In a nutshell...
- Good drainage is the basis of a healthy productive soil.
- Drains are needed to remove excess water from the air spaces in the soil.
- Blocked drains and saturated soils lead to long term damage and lowered pasture production.
- Drainage is always expensive, so farmers try to manage as far as possible to avoid the high capital cost.
- The benefits of drainage are long term.
- Drains need to be regularly maintained to reap the benefits.
- Because drains cannot be easily seen, it's easy to neglect their maintenance.
How can you tell if you have a problem?
- Water standing in pools on the soil surface (ponding) after rain.
- These pools not draining away for very long periods.
- Where drain outlets can be seen, eg. into main open drains, they are not running.
- Paddocks that pug easily during grazing in wet weather.
- Bad smells (rotten eggs) from soils in some areas of the paddock.
- Poor pasture growth in certain areas of the farm.
- No documented plan of where any drains are on the farm.
How can you tell if you're doing well?
- Highly productive pastures all year round.
- No ponding on paddocks after rain.
- After very heavy rain, pools do not last long and drain away effectively.
- Very little of no pugging when grazing wet paddocks.
- Any visible drain outlets running well after rain.
What can you do to improve things?
- First decide how important drainage is in restricting farm production and profit.
- If it is a major problem, review the farm's total drainage programme with a consultant. Beware of non-qualified enthusiasts!
- Local knowledge can be valuable.
- Remember your drains may affect your neighbour's property. Talk to them before you do anything.
- Draw up an accurate plan of the drains on the property - if they are known.
- Identify soil types on the farm and their need for drainage.
- Decide what type of drainage will meet your farm's needs and their cost/benefits.
- Make sure you use an approved drainage contractor.
- Document any new drains put on the farm.
Where can you go for help?
- Regional Councils
- County Councils
- Federated Farmers of NZ
- Ministry of Agriculture and Forestry
- Department of Conservation