What type of fertilizer is good for grapevines
Article Guide: Knowledge on the best fertilizer for grapevines and the optimal formula for applying base fertilizer for grape cultivation. The following is an introduction for you.
Grape friends, good afternoon! With the harvest of grapes, we are soon approaching the time to apply base fertilizer. Base fertilizer, also known as root fertilizer, is a very important source of nutrients for grapevines after fruit picking. Because from the time when grapevines sprout in spring to the period before flowering, almost all the nutrients required for plant growth come from the reserves of the previous year, which is the base fertilizer.
Therefore, whether the development, separation, and fruit-setting stages of the grape inflorescence can transition smoothly after germination is closely related to the application of base fertilizer. Understanding the importance of grape base fertilizer, we will next discuss the application time, method, and type of fertilizer from these three aspects.
First, the application time of grape base fertilizer
There is a saying: "September is gold, October is silver, and November is copper for grape base fertilizer." This actually illustrates the significant difference in effectiveness of base fertilizer applied at different times. How to understand this? It's simple, we apply fertilizer to fruit trees, but what the trees need is nutrients, and fertilizer is not equal to nutrients. After the fertilizer is applied, the roots first absorb it and send it to the leaves, and finally, the leaves convert the fertilizer into nutrients through photosynthesis. Therefore, what kind of effect the base fertilizer can have depends on the vitality of the grapevine roots and the quality of the leaves. Considering these two factors, we can roughly determine the earliest and latest times for applying base fertilizer.
1. The earliest time to apply base fertilizerAutumn is the active period for the development of grape roots. Because when the temperature is between 15~25°C, the capillary roots grow most vigorously and have the highest quality of growth. Therefore, the earliest time to apply base fertilizer is when the soil temperature reaches slightly below 25°C.
Base fertilizer is generally applied by the method of digging trenches and burying soil. Then, during the process of digging trenches, it is inevitable to cut some roots. If the base fertilizer is applied too early, the wounds formed on the roots due to root cutting are easily prone to root rot under high temperatures; if the fertilizer is applied too late, a large number of capillary roots have already formed, and at this time, if we cut off the new roots, it greatly reduces the absorption efficiency of the roots to the base fertilizer.
The method to measure soil temperature is simple: at a distance of 50 centimeters from the tree, insert a soil thermometer 20~40 centimeters below the soil surface. If the soil temperature is found to be below 25°C for several consecutive days, you can start digging trenches and applying fertilizer. Some fruit friends may find this method cumbersome, so the simplest method is to apply fertilizer when the average daily temperature reaches about 22°C.
2. The latest time to apply base fertilizerAs we have already learned, the fertilizer absorbed by the roots needs to be converted into nutrients through photosynthesis in the leaves and then returned to the roots before it can be considered stored. This process takes at least a month, so the latest time to apply base fertilizer is one month before the local grapevines shed their leaves. If there isn't a month to ensure this, the effect of the base fertilizer is usually difficult to achieve.
Some early-ripening grape varieties have only a dozen leaves on each branch after harvest, or even have severely aging leaves. If we do not take measures to grow new leaves at this time, then applying more base fertilizer is in vain. In response to this situation, we need to apply "postpartum fertilizer," which involves giving the tree an additional application of a nitrogen-predominant fertilizer after fruit harvest to encourage the growth of several new lateral branches, thus ensuring the effect of the base fertilizer. As for late-ripening varieties, there is only about a month between their harvest period and defoliation period, so we can directly apply the base fertilizer.
Second, the application method of grape base fertilizer
When applying base fertilizer to grapes, we should adopt the method of digging trenches to apply the fertilizer. Many fruit farmers believe that root cutting will cause damage to the grapevine, which is actually a misconception. It should be known that cutting old roots when the root growth is most vigorous will instead promote the growth of more new roots, which is beneficial for maximizing fertilizer efficiency.
Moreover, the function of grape roots is not as simple as many fruit friends think, just taking on the role of absorbing water and fertilizer. They are also the storage and distribution centers for nutrients. If the root quality is poor and the growth rate is low, then even if there are a lot of nutrients, there is no place to store them. More importantly, the root tips, especially the capillary root tips, can secrete a large amount of very important cytokinins and endogenous hormones including amino acids. Without cytokinins, the differentiation of flower buds, the extension of leaves, and the swelling of fruits would not be possible. Therefore, it is very necessary to apply base fertilizer by the method of digging trenches and cutting roots.
What type of fertilizer is good for grapevines
The specific method of applying base fertilizer in trenches is to dig a single-sided trench 30~40 centimeters away from the young trees and 50~60 centimeters away from the production trees, with a depth of 40~50 centimeters, then fill in the fertilizer and cover it with soil. When applying base fertilizer the following year, dig from the other side.
In order to provide a truly suitable environment for root growth, fruit friends should ensure the humidity and looseness of the soil before applying fertilizer in trenches. Generally speaking, we require the soil moisture content to reach 60%. This standard is easy to grasp: if you can grip a handful of soil tightly in your hand without water coming out, and the soil clump can remain intact when you relax your hand, it indicates that the soil moisture is fine.
Everybody knows that during fruit picking, pickers and agricultural machinery sometimes compact the soil, so if the soil quality of the orchard is poor and has been severely trampled and compacted during picking, we need to use a rotary tiller to shallowly till the soil in advance to break up the soil compaction.
Third, the choice of grape base fertilizer
Research shows that after harvest, the absorption of nitrogen, phosphorus, and potassium by grapes accounts for about 35%, 30%, and 15% of the total annual absorption, respectively. This actually determines the ratio of nitrogen, phosphorus, and potassium in the base fertilizer, which is to focus on nitrogen and phosphorus. In addition, calcium and magnesium are both macronutrients for grapes, and the demand for calcium is even higher than that for nitrogen, phosphorus, and potassium. Therefore, in addition to focusing on nitrogen and phosphorus in the base fertilizer, we also need to emphasize calcium and magnesium. The calcium content in northern soils is higher, so the further south you go, the more attention you need to pay to calcium supplementation.
Soil organic matter is also crucial for the growth of grape roots and the maintenance of the orchard. A high content of organic matter means the soil has strong water and fertilizer retention capabilities and good breathability. Therefore, it is best to choose organic fertilizers to increase the content of organic matter in the soil.
Organic fertilizers are divided into decomposed manure and commercial organic fertilizers. The best manure for grapes is decomposed cattle and sheep dung. Among them, sheep dung has a higher nutrient content and is easier to decompose, requiring only simple stacking, while cattle dung needs to be mixed with straw and nitrogen fertilizers like urea to decompose effectively. In terms of dosage, for an orchard with a yield of 3000~4000 jin per mu, it is recommended to use 4 cubic meters of decomposed cattle and sheep dung, combined with 50~80 jin of compound fertilizer and about 100 jin of calcium-magnesium-phosphorus fertilizer.
Although the cost of commercial organic fertilizers is relatively high, they have been industrially processed, so their organic matter content is relatively high, reaching about 45%, while the organic matter content of decomposed cattle and sheep dung is only about 20%. Therefore, when using commercial organic fertilizers, you can follow the principle of "one jin of fruit, one jin of fertilizer," with a dosage of about one to one and a half tons per mu.
The above is [www.lvzhimi.com]'s introduction to the best fertilizer for grapevines and the optimal formula for applying base fertilizer, which can be used as a reference suggestion.