For high potato yields, proper fertilization is key!

Potatoes yield highly and require substantial fertilizer application; to achieve high yields, it’s essential to appropriately increase the amount of fertilizer applied. So, how should potatoes be fertilized to maximize productivity? Let’s take a look!
Potatoes thrive in cool, temperate climates and prefer well‑drained, sandy soils. With a relatively short growing season, they benefit from a base application of organic fertilizer combined with chemical fertilizers, which helps improve soil physical properties and promotes both vegetative growth and tuber formation. Base fertilizer should account for more than 70% of the total fertilizer application; supplementing this with appropriate amounts of nitrogen, phosphorus, potassium, and micronutrient fertilizers can boost yield and enhance quality. Therefore, for potato base fertilization, it is recommended to prioritize a bio‑organic fertilizer as the primary component, supplemented by a humic‑acid‑based compound fertilizer such as 17‑17‑17 or 16‑9‑20S, along with medium‑ and micro‑element fertilizers rich in calcium, potassium, and magnesium.

The types and amounts of nutrients required by potatoes vary at different growth stages. From germination through the seedling stage, potatoes primarily rely on the nutrients stored in the tubers, so their nutritional needs are relatively low. In high-altitude, cold‑climate regions where early‑season temperatures remain low, excessive topdressing can easily lead to seedling burn.
With the arrival of summer rains, potato topdressing enters a critical phase, which is carried out in two applications: First, the seedling‑maintenance fertilizer, applied when the seedlings have emerged and reached about 15 cm in height, combined with intertillage and hilling; use 5–8 kg per mu of a high‑nitrogen foliar fertilizer along with microbial biofertilizer “Gui Gen Dao Di” to promote stem and leaf growth and help prevent soilborne diseases. Second, the tuber‑promoting fertilizer, applied during the vegetative growth stage and the tuber‑setting stage, to supply the nutrients needed for tuber formation, encouraging early and abundant tuberization. The second topdressing and accompanying intertillage and weeding should be done when the plants are around 40 cm tall and beginning to form flower buds. Of the total nitrogen applied, two-thirds should be incorporated as the seedling‑maintenance fertilizer, while the remaining one-third is applied as the tuber‑promoting fertilizer, adjusted according to the plants’ growth condition.
Potatoes are a high-yielding, potassium‑loving crop. Their optimal N:P:K ratio is 2:1:4, indicating that potassium is their most critical nutrient requirement. During the tuber‑formation stage, topdress with humic acid‑based nitrate‑sulfur fertilizers such as 15‑5‑23 or 15‑5‑20, or with water‑soluble formulations like 20‑20‑20 or 16‑6‑36. At the same time, apply the soil‑conditioning amendment “Soil Loosener No. 1” via irrigation; it not only replenishes nutrients but also improves soil structure and promotes tuber enlargement. Potassium application significantly boosts yield, with potassium sulfate delivering the best results. Magnesium fertilizer also markedly increases potato yields; typically, begin foliar spraying with “Golden Dew” at the onset of flowering, repeating every seven days for three consecutive applications. The calcium component in this product further enhances tuber surface luster and improves storage and transport durability.

After potatoes flower, root-zone topdressing is generally avoided; in particular, nitrogen fertilizer should not be applied near the roots. Improper fertilization can lead to excessive vegetative growth, inhibit tuber formation, delay development, and increase the incidence of small and misshapen tubers, while reducing dry matter content and making the crop more susceptible to late blight and common scab.