Sum16-19 Potassium rates and timing


This trial examines potassium (K) rates as muriate of potash (MOP) products applied by a number of methods and the effects on growth and yield of Mace wheat.

For further details contact your local Area Manager or the Summit Research Team

Table 1: Soil Analysis
Fig 1: Yield and Protein Responses to K
Fig 2: Yield response to K rates


  • Sandplain soil with Colwell K analysis lower than 30 mg/kg is highly likely to be responsive to K.
  • K applied at 13-17 kg/ha in the compound NPK+traces fertiliser, Vigour, banded below the seed improved yields compared to NP+traces compound alone, and yields were further enhanced by applying additional 12.5 kg/ha K as MOP.
  • Optimised returns will depend on fertiliser and grain prices at the time.
    In the present trial, the greatest increase in returns were seen with Vigour 140 kg/ha at seeding plus 25 kg/ha MOP applied PSPE.