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
- Internal water regulation
 - Vigorous growth and healthy foliage
 - Required in large amounts