As with other tree crops, vines and vineyards need adequate nutrient supply. Fertilizing the vineyard is not a simple practice and requires specific precautions in the various vegetative phases. In addition to the preparation of the soil with organic fertilizers, the vineyard must be fertilized both in the resting phase, when it does not produce, and after the harvest. Fertilization is also essential to prepare the soil to adequately accommodate the vineyards. To improve quality and production, and to allow winemakers to respond to market needs, the fruit of the vineyard must be mature and healthy, so a lot of attention is paid to these procedures from which the half of the wine production work follows. Fertilization has three main objectives, to improve the production cycle, make the plants more resistant to pests and climatic difficulties, improve the quality of the fruit and therefore of the wine. The nutrients that are administered are Nitrogen, Phosphorus, Potassium and Iron, their distribution depends on several factors, first of all the quality of the soil and the organic substances that are present in it.
Fertilize the vineyard
The first phase consists in preparing the soil, generally the bottom is prepared with organic fertilizers, especially manure manure. The second phase involves two fertilizations to improve the production cycle, they are performed in spring and autumn. Finally, as a third step, a foliar fertilization is performed, this is carried out especially with soluble solutions in water, even during irrigation. To prepare the soil for the planting of a vineyard, the manure must be spread with a "broadcaster" technique, the manure fertilizer must be carefully distributed over the entire soil. In this phase it is also advised to dig, or spread the manure by furrow or holes. If manure is used, easily available from agricultural consortia and farms, the quantity required for each hectare of land is at least 15 quintals. It is advisable to carry out this operation in the autumn before the plant, if for example the vineyard is planted in March or early spring, the manure must be distributed in September of the previous year.
After the planting, a balanced fertilization is carried out, with nitrogen, phosphorus and potassium, before this phase it is advisable to carry out an analysis of the soil, an operation that should actually be performed even before choosing the types of vines to cultivate. In this phase, generally 2 to 4 quintals of fertilizer per hectare are distributed. The most important phase, as mentioned, is the vegetative fertilization, when the plants are in production we proceed to fertilize with phosphorus and potassium, just this last substance is fundamental to give the fruit sugar quality in order to make a wine of higher quality. The periods of the year in which to perform it are the months of January / February and the end of May beginning of June. Finally, although covering a marginal role, we point out foliar fertilization. It is an integrative solution and it proceeds through fertigation, that is with nutrients that are administered together with water. This is done in case of nutritional problems and deficiencies, the cases may be different. If there is a poor production quality, the vineyard will be deficient in iron, whereas if the soil is not optimal, phosphorus and potassium are added.
Fertilizers for the vineyard
Since about 40 years, manure fertilizer has been supplemented by the use of synthetic fertilizers. On the market there are mineral and chemical fertilizers, natural organic substances called amendants, secondary microelements. Mainly, organic nitrogen fertilizers are used, such as diammonium phosphate, urea and other mineral compounds, and recently, mixed compounds consisting of organic elements and chemical or mineral elements are also spreading. Nitrogen-based fertilizers generally contain elements such as dried blood and meat meal, there are also products that are distributed in pellets and generally contain humus and soluble extracts. In choosing the most suitable product for the needs of the vineyard, it must also be taken into account in a fertilization plan, that is, the internal process must be organized both with regard to the fertilizers to be used and with regard to the periods of execution. In this phase the climatic conditions are also taken into account. Fertilizers are generally distributed on the rows, this avoids dispersion of the fertilizer where it is not needed. If modern techniques are used, such as fertigation, for example, a plant is created in the vineyard, usually always along the rows. In this case the elements that are distributed are biostimulant substances that can also be distributed in a localized manner, for example if there are parts of the vineyard that have not reached the desired maturity.