Potassium (K)

Potassium for grazing at stocking rate 170kg/ha Org N¹

Soil K Index K Advice (kg/ha)²
Dairy Drystock
1 90 75
2 60 45
3 30 15
4 0 0
  1. For stocking rates above 170kg/ha Org N increase rates by 5 kg/ha for each increase in stocking rate of 40 kg/ha. For each decrease in stocking rate of 40 kg/ha below 170kg/ha Org N decrease rates by 5kg/ha.
  2. Chemical K application rates can be calculated by deducting the quantity of K applied in organic fertilisers.

*Unless the soil is at K index 1, fertiliser K can be applied in autumn to reduce the risk of hypomagnesia.

Typical K levels in organic fertilisers¹

Organic fertiliser type Total K contained in 1 tonne² (kg/t)
Cattle slurry 4.3
Pig slurry 2.2
Sheep slurry 5.4
Dungstead manure (cattle) 4.0
Farmyard manure 6.0
Slurry (layers 30% dry matter) 6.0
Broilers/deep litter 12.0
Layers (55%) dry matter 12.0
Turkeys 12.0
  1. Dry matter and nutrient contents can vary widely between farms
  2. 1 tonne of slurry=1m³. 1000 gallons=4.5tonnes. 1000gallons/acre=11tonnes/ha

For Potassium advice for silage and hay, see the silage section.