Potassium deficiency made worse by
- Acidic soils (low pH)
 - Sandy or light soils (leaching)
 - Drought conditions
 - High rainfall (leaching)
 - or heavy irrigation
 - Heavy clay (illite) soils
 - Soils with low K reserves
 - Magnesium rich soils
 
Potassium is important for
- Resistance to cold injury and drought
 - High yields through increased biomass and head weight
 - Consistent, early and evenly matured marketable crop