Potato nutrient requirements
The potato crop requires potassium in large quantities, 50% more, in fact, than nitrogen. A 38.5t/ha crop can remove more than 120kg/ha of nitrogen whereas it can remove over 200kg/ha of potassium. Both of these macronutrients are important throughout vegetative growth, tuber formation and bulking.
Nitrogen is important for leaf and tuber growth and is recycled from lead to the tuber during bulking, the same can be said for potassium. When thinking of potassium then as you can see from the removal values that it is key for high yields and maintaining tuber integrity.
Phosphate is also required in relatively large quantities during early growth due to its importance in root and shoot development and tuber set but also later on in the season for bulking.
Calcium is a crucial nutrient as it plays a role in important quality parameters. Potatoes need calcium to strengthen the skins of the tubers; providing better resistance to many diseases (black scurf, silver scurf and common and powdery scab) and also a better skin finish. Calcium deficiency also causes internal rust spot so it’s essential to apply calcium at the right time but also ensure the correct source of calcium is used. For example, liming materials won’t supply plant-available calcium to the crop therefore it won’t supply sufficient supply to meet the demand.
Magnesium is important during tuber bulking where it plays a major role in maintaining tuber quality and is therefore a key nutrient.
Micronutrients are also important to ensure the crop has all it needs to produce a good, quality yield. Zinc and manganese are key to help the crop’s defence against powdery and common scab as well as maintaining skin finish.
