How to manage fertilization well when planting Red Globe grapes?

Red Globe grapes are resistant to storage and transport, high-yielding, with firm and crisp flesh, sweet without being sour, and are deeply loved by consumers in large and medium-sized cities. However, most Red Globe grape growers manage Red Globe grapes according to conventional grape fertilization and management methods, resulting in a large quality gap between domestic Red Globe and imported Red Globe. The fertilization techniques for Red Globe grapes are introduced as follows.

1. Land preparation and fertilization. Similar to other grape varieties, Red Globe also prefers soil with good aeration, so the soil should be fertile, deep sandy loam or loose soil, with a pH of around 6.5-7.5, and good irrigation and drainage conditions. If the soil is too heavy or too sandy, consider increasing the amount of organic fertilizer applied; before planting, 2000-3000 kg of decomposed organic fertilizer should be applied per mu.

2. Base fertilizer. Base fertilizer is mainly organic fertilizer. Generally, every 1-2 months, deep digging and turning of the soil is carried out to expand the holes, with holes 60-80 cm deep and 30-40 cm wide, using alternate-row or two-side rotational fertilization. Base fertilizer is best applied after fruit harvest and before the soil freezes, with an application rate of 1000-1500 kg per mu. Applying it appropriately early helps the decomposition of organic fertilizer and the healing of root wounds, and helps restore tree vigor and improve cold and drought resistance.

3. Topdressing. Quick-acting fertilizers are mainly used. Depending on the size of the tree, a ditch 50 cm deep and 20 cm wide can be opened near the root ends (for a 5-year-old tree, about 40 cm from the trunk), and chemical fertilizers mixed with soil can be buried in the ditch. For grapevines in full fruit-bearing stage, topdressing can be carried out before bud break, before flowering, during fruit enlargement, during coloring, and after harvest. From early spring when the vines are uncovered to around bud break, carry out the first topdressing, mainly nitrogen and potassium, with a small amount of phosphorus fertilizer, called bud-promoting fertilizer; at about seven days during the flowering period, carry out the second topdressing, mainly nitrogen and potassium, called flower-promoting fertilizer. In addition, during this period, 0.3% borax can be sprayed on the leaves as needed to increase the fruit-setting rate; during the berry growth period, that is, when the berries grow to the size of soybeans, in order to promote fruit enlargement and promote branch growth, carry out the third topdressing, mainly nitrogen and potassium fertilizer, namely fruit-promoting fertilizer; from fruit harvest to the early frost period, this is an important stage for grape branches to mature, restore tree vigor, and accumulate nutrients for the next year's growth, and at this time carry out the fourth topdressing, mainly nitrogen and potassium.

4. Topdressing amount. The specific amount and frequency of topdressing should be determined according to the soil fertility status, the growth vigor of the grapevine, and the yield target. For example, if the new shoots grow moderately and the leaves are dark green, it indicates that the nutrients in the soil are relatively balanced and sufficient. If the new shoots grow too vigorously and show excessive vegetative growth, then the use of quick-acting nitrogen fertilizer and irrigation should be appropriately controlled; on the contrary, if the new shoots are thin and weak and the leaves are pale yellow, it indicates that the soil is lacking nutrients.