A large-scale Mid Canterbury dairy farming operation has managed to save thousands of dollars in fertiliser costs by using effluent to create healthy soil and promote pasture growth.
The operation, Klondyke Dairies, milks over 2500 cows through three rotary sheds, meaning a lot of effluent is created in the process.
Effluent is a key part of the farm’s fertiliser plan, farm manager Simon Ferguson says.
Everything at the cowshed and feed pads is collected and goes through a stone trap. From there, it flows into a solids separator and then into a lined pond.
Each of the three farms is equipped with these separators, which consist of a small sump with a pump in it.
The effluent is pumped through a kind of mechanical sieve, separating the solids out. The liquid flows through into a bigger, lined holding pond.
From there, it is spread on the paddocks through centre pivots.
“We try to spread over as much of the farm as possible, avoiding critical source areas and makes sure we do best practice,” Ferguson says.
Non-effluent areas are targeted by Ferguson to spread out the solids, which is carried out by contracting firm, Central Injection Agri.
“We test every paddock for nutrients every three years – one farmlet per year – and the paddocks that are low in certain nutrients, we use our solids to lift the potassium and phosphorus (the nitrogen is mainly in the liquid and the solids are mainly potassium and phosphorus).
“Generally, we try to target our crop paddocks so just before we sow our crops we put our solids on those paddocks just to give our crops the best start possible and make the most out of nutrients.”
Crops have deeper root systems than pasture and are more efficient at using nutrients.
The paddocks are regularly soil tested with the aim of getting the soil to an optimum, efficient range.
If the testing shows the soils are above, maintenance is withheld, and any treatment is put on paddocks that have tested lower.
“We have to be very careful where we put our effluent and solids because once calving time comes around we don’t want to put our colostrums or sensitive cows in any of those paddocks that have been treated with effluent because the potassium throws out their metabolic and you have a lot of down cows if that happens.
“Our soil testing helps – so we put our colostrums in low K paddocks and that’s really helped minimise down cow issues in the spring.”
This article first appeared in the October edition of our sister publication, Dairy Farmer.