Fertilization requirements of grapevines

Although grapes are vine‑type fruit trees, they possess a well‑developed root system, prolific vines with large leaves, vigorous growth, high yields, and long lifespans; consequently, they have relatively high nutrient requirements.

As the primary source of nutrients for grapevines, fertilizer is indispensable in production and forms the foundation for the trees’ healthy growth and the yield of high‑quality fruit.

Fertilization requirements of grapevines

• It has the characteristic of storing nutrients.

Grapes are perennial vines that store substantial reserves of nutrients in their roots and canes. During late summer and early autumn, these stored reserves are translocated from the leaves back into the stems and root system; in early spring, they are remobilized from the storage organs to the emerging growth points, supplying the needs of bud differentiation, bud break, and the development of shoots and leaves during the early growth phase. Consequently, these stored nutrients play a crucial role in ensuring vigorous tree health and consistent, high yields.

• Fertilizer demand is relatively high.

Grapes exhibit vigorous growth, with lush foliage and abundant fruit production, thus demanding substantial soil nutrients. Data indicate that for every 100 kg of fruit produced, a grapevine absorbs from the soil approximately 0.3–0.6 kg of pure nitrogen, 0.1–0.3 kg of phosphorus pentoxide, 0.3–0.65 kg of potassium oxide, 0.1 kg of magnesium, and 0.05 kg of sulfur.

• Potash fertilizer demand is substantial.

Grapes are a quintessential potassium‑loving fruit tree, requiring substantial amounts of potassium throughout their entire growing season. Their potassium demand ranks first among the three major nutrients, far exceeding that of other fruit trees—1.7 times that of pears and 2.25 times that of apples. Under typical production conditions, the optimal N:P:K ratio for grapes is 1:0.5:1.2.

• Relatively sensitive to calcium.

When calcium is deficient, grape leaves turn pale, with interveinal and marginal chlorosis in young leaves; the growing point at the tip of new shoots dies back, flowers shrivel, fruit accumulates less sugar, loses firmness, becomes less transport‑resistant, exhibits increased cracking, and suffers from poor quality. Additionally, new roots become short and stout, plant growth slows, and yields decline. Therefore, in production it is essential to apply calcium fertilizer appropriately and in a timely manner to enhance both grape yield and quality.

• Stage-specific fertilizer requirements

During the course of a year, grapevines undergo distinct growth and developmental stages, each with varying nutrient requirements. For instance, from bud break to flowering, they demand substantial nitrogen; during flowering, an adequate supply of boron is essential; in the berry‑development and flower‑bud differentiation phases, high levels of phosphorus and potassium are needed; at fruit ripening, calcium becomes critical; and even after harvest, a supplemental nitrogen application remains beneficial.