Potato Nutritional Summary

A correct balance between macronutrients and micronutrients is essential to obtain the best results possible from potato crops.

Macronutrients

Nutrient uptake varies with the growth stage of the crop (See slideshow above). While removal differs from field to field and depends on yield, potato crops can utilize 50% more potassium than nitrogen. A 15.6t/ac crop can remove over 178lb/ac of potassium and 103lb/ac of nitrogen. Both potassium and nitrogen are needed throughout vegetative growth, tuber formation and bulking.

Nitrogen

Nitrogen is important for leaf and tuber growth. Like potassium, a lot of nitrogen is recycled from the leaf to the tuber during bulking.

Phosphate

Phosphate is also needed in relatively large quantities, particularly during early growth, to encourage rooting and tuber set, and then again during late season for bulking.

Potassium

Potassium is particularly important for high yields but also for maintaining tuber integrity. "Luxury uptake" of potassium is typical in potatoes.

Calcium

A regular supply of calcium is critical to ensure stress-free leaf growth. Relatively high rates of calcium fertilizer are needed to achieve the small amounts in the tuber that are critical for crop quality.

Magnesium

Magnesium is more important at later stages of growth, particularly during bulking (See slide show), where it has a major role to play in maintaining tuber quality

Sulphur

Sulphur is needed for all growth stages and is particularly important in reducing common scab.

Micronutrients

While much lower amounts of micronutrients are needed, the correct balance is essential for quality crop production.

Boron

Boron is needed in greatest quantities in order to ensure several key growth processes proceed unchecked. It is also important in optimizing calcium utilization.

Copper

While significant quantities of copper are used, deficiencies are rarely seen, with most soils providing adequate long-term supplies.

Manganese and zinc

Manganese and zinc are important for yield. Zinc plays a key role in N-assimilation and metabolism and starch formation.

Molybdenum

Molybdenum can be important in low pH soils.