Literature Review Draft
Have you ever thought about organic wine?
Overview of Organic Viticulture
Introduction
Four countries produce half of all the wine in the world and five countries drink most of it. Italy, France, Spain and the USA led the world production in 2017. In the list of the main consumers, in addition to Italy, France and the USA are Germany and China. Spain is in seventh place. (Castellucci, 2013)
Worldwide, 250 million hectoliters of wine were produced in 2017, 8.4% less than the previous year. The OIV attributes the figure to the unfavorable weather conditions that affected production, especially in Europe. Italy is positioned as the leading producer of wine in the world. Proportionally, the greatest decrease among the main producers occurred in Spain (19.8% less) and the highest increase, in Argentina (25.5% more). (Soto, 2016)
Viticulture is a business that is on the rise, the number of consumers increases day by day and the demand for wines of higher quality also grows. The viticulture is an annual production business; therefore, it is complicated and also limited by the climatic factors but at the same time it is an elegant and prestigious business.
In this literature review, I will make known the basic knowledge of viticulture as for example; the management of nutrients in the soil, micronutrients, healthy soil, optimal climate, pest management among other issues. Also, I will talk about how the production of wine and the different key processes for the production of good wine is.
Soil fertility & Microbial Activity
The first foundation of organic viticulture is that soil fertility is maintained or improved, feeding the soil and not the plant. The methods used are the production and application of compost, the sowing and the incorporation of cover crop or plant cover and the incorporation of pruning remains. With these practices, the viticulturist increases the organic matter of the soil that serves as food to microflora and micro-fauna of soils, responsible for many important processes in nutrient cycles, such as mineralization, fixation, and decomposition. Another important practice is the development and application of compost tea that enriches soils with microbes while releasing nutrients available for crops. All these practices are essential to improve biodiversity and soil fertility. (Belda, 2017)
Soil nutrient management
In agricultural production, it is very important to know the cation exchange capacity (CEC) of the soil since it allows to determine analytically the concentration and proportion of the cations and to predict some potential problems in the structure and availability of nutrients. The CIC corresponds to the total amount of cations (positively charged ions) that the soil can absorb by attraction. (Wei, 2014) The cation exchange sites occur in clays and organic matter (loaded with negative ions). High CICs indicate high soil fertility and moisture retention capacity, provided that the soil has a good structure (no compaction in clay soils or disaggregation in sandy soils). (Wei, 2014)
On the other hand, base saturation corresponds to the percentage of the total CIC occupied by positively charged cations, such as calcium (Ca + 2), magnesium (Mg + 2), potassium (K +), ammonium (NH4 +), sodium (Na + ) and in pH acidic proton (H +) and aluminum (Al + 3) soils. (Wei, 2014)
In order not to negatively affect the dynamics of nutrient absorption by the root system of vines, it is necessary to have neutral levels of acidity (pH 7). Therefore, in acid soils, it is necessary to correct with applications of calcium carbonate (agricultural lime), while in basic soils calcium sulfate (gypsum) is applied. (Abbona, 2007)
Organic matter in the soil
Strictly speaking, organic matter corresponds to all the organic components that accumulate in the soil and is composed of three fractions, 1-8% by living organisms (biomass), 10-25% remains of plants and animals in different states of origin. decomposition and 60-70% stable fraction of already decomposed waste (humus). It is considered that soil with 2-3% organic matter is ideal for the production of organic vineyards. (Koller, 2013)
Application of organic nutrients
To meet the nitrogen requirements can be fertilized with red guano, blood meal and various inputs of animal origin in solid and liquid formulations that have up to 13 UN, usually at a high cost compared to sources of synthetic nitrogen fertilizers. For the national and European market, the use of natural saltpeter (sodium nitrate) is prohibited, while for the North American market it is feasible to use up to 20% of the crop requirement. Nitrogenated foliar fertilization, with commercial and self-manufactured inputs, can be applied at the beginning of spring, if necessary, according to the results of the previous year’s foliar analysis. (Jhiane, 1999)
Nutrients such as phosphorus (P2O5), potassium (K2O), calcium (CaO), magnesium (MgO), are present in compost, phosphate rock, red guano, dolomite, lime, gypsum, among others, the form of application depends on the state and the source of the fertilizer. Phosphorus is normally applied up to 50 U P2O5 / ha per year as phosphate rock, incorporated between 30 and 40 cm deep in mixture with compost, considering an annual release to the soil of approximately 30% P2O5. while the application of K2O and MgO is recommended between 30 and 100 U K2O / ha per year and between 10-30 U MgO / ha per year. In the case of existing pressurized irrigation systems, it is advisable to perform fertigation with sources such as potassium sulfate and magnesium sulfate, applying magnesium at the beginning of the season until curd and potassium from after curdling and up to 90 days after full bloom. (Abbona, 2007)
Pest management
To avoid damage by pests on the vine it is viable to use resistant varieties and rootstocks. Interspecific rootstocks, such as 3309C, 420A, SO4 or 1103P, are used in the world because they are resistant to phylloxera and in some cases to nematodes. For the control of other pests, it is necessary to favor the work of predators and parasitoids of the plagues that attack the vineyard, for this, it is very important to know the biology of both the natural enemies and the plague. The use of sexual disruption or organic pesticides, such as neem oil, chili and nettle extracts, and mineral oils, are alternatives allowed in organic production. (Batillani, 2003)
Cryptogamic diseases (caused by a fungus or other filamentous organism) of grapevine such as powdery mildew, botrytis and mildew can be prevented by preventive applications of organic fungicides such as sulfur, citrus extracts, copper, compost tea, serum or biological fungicides ( Trichoderma sp., Bacillus subtilis). Among the cultural practices that can be used are the defoliation, Andreja and Chapada that are used to avoid favorable conditions for the development of diseases. (Batillani, 2003)
Harvest
The harvest must be done when the grapes are ripe. The maturity of this fruit depends, among many things, on the number of sun hours received. In the northern hemisphere, this happens around the months of August and September, depending on their location, the type of grape and the sun received.
These three compounds must be at their optimum to guarantee the best grape. The sugar is the one that later will be transformed into alcohol. The acids will bring that rich and fresh consistency to the wine, which translates into elegance and awakens the taste buds, enhancing the flavors of the food. And the tannins, provide texture to the drink, giving it that touch of astringency and bitterness. If the tannins are green at the time of harvest, that greenness will be reflected in the taste of the wine. (Bunescu, 2014)
The weather also plays an important role in determining harvest times. Preferably, the grapes should be harvested when it is freshest, at dawn, to preserve its aromas. If it is done when exposed to high temperatures, when it is milled, it volatilizes and is lost. (Bunescu, 2014)
The process of winemaking
Wine is the beverage obtained from the total or partial alcoholic fermentation of the grape must or the grapes themselves. The main process by which the must is transformed into wine is alcoholic fermentation: it consists of the transformation of the sugars (glucose and fructose) contained in the grape into ethyl alcohol and carbon dioxide. Approximately 1 alcoholic degree is produced for every 17 grams of sugar contained in the must: thus a must with 221 grams/liter would result in a wine with 13 degrees (13 °). (Grainger, 2016)
This process also produces carbon dioxide in the gaseous state, which causes bubbling, boiling and the characteristic aroma of a must vat in fermentation. This carbon formation will be important for the extraction of substances contained in the skins and in providing a protective atmosphere for the oxidation of grapes that is beneficial for obtaining quality wines, especially in the case of red wines. (Grainger, 2005)
Yeasts adhere to grape skins (using a waxy layer calledPruinescence) which, to satisfy their growing needs, favor the process. The yeasts of the genus Saccharomyces are the ones that usually play the most important part of the process. The end of the fermentative process is when almost all the sugars have already been doubled and the boiling ceases. In wineries, this is determined with the classic pesamostos hydrometer or densimeters.
In the elaboration of each type of wine, in particular, it is very important to control the temperature of fermentation continuously throughout the process: each wine requires certain temperature ranges. (Grainger, 2016)
Once the alcoholic fermentation is finished, we have the new wine, which after a period of a few months finishes fermenting the few sugars that always remain after the main fermentation. Finally, this new wine is finished with the development of a second fermentation: malolactic fermentation. Malolactic fermentation is essential for the quality of a wine, especially in red wines. It basically consists of the transformation of all or part of the malic acid from the grape into lactic acid and carbon dioxide. (Jackson, 2000)
The wine should be stored at a stable temperature of about 15 ° C (never below 10 ° C or above 18 ° C), in a dark place (the light oxidizes the wine), lying down, and not moving it. The humidity of the home cellar should have a humidity of between 60-80%. It closes under vacuum and with a cork stopper so it can expand, although young wines also use a plastic stopper. The wine absorbs everything around, so it must be stored in places that are not very humid and without strong odors. All bottles must lie flat and horizontal so that the cork is permanently moist. (Jackson, 2000)
For a wine to last a long time in the bottle, it requires alcohol and color. On the other hand, each wine has a relative duration. While some should be drunk at the moment, others age favorably in the bottle and it is advisable to keep some years to drink them at their optimum moment. White and rosé wines usually have a maximum of one year of life. Most young reds (without barrels) should be drunk in the same year. The aging reds with 12 months in oak. Reserva wines can be consumed up to ten years after harvest, and large reserves can improve up to 15 years. In no case is it recommended to exceed this time because the chances of the wine spoiling are very large. Therefore, although it is seldom specified on the labels of the bottles, the wine has an expiration date, which depends on the type of wine (mainly its degree of acidity, a degree of alcohol and content of tannins) and the conditions in what is stored. If it is not consumed at the right time, the wine will oxidize, even turning into vinegar. (Grainger, 2005)
Discussion
In this literary summary, we talked about the different processes in which they are carried out for the creation of a bottle of wine. The process was analyzed from the management of the land to how wine is stored. my nutrition classes helped me understand the importance of having a strong and healthy soil based on a good nutrient base and microfauna. One of the most important factors is the microfauna. In my personal experience, I did not take into account this factor simply because I did not have knowledge of them or could easily see them, I thought that the only solution was to add fertilizers to the soil and that I would do it healthy. Chemistry also helped me to understand why is that the ability to exchange cations in the soil is also a very important factor and it is the flow of water and also the nutrients become useful for the absorption of nutrients in plants. I found very interesting the process by which the combination of different organic agents helps the production of organic wine.
Something that also seemed impressive to me is that the grapes must be harvested at a certain temperature to avoid losing their nutrients or reach the desired flavor for wine, if this process it’s not being done in the right way, this may cause the grape to lose flavor at the moment of wine elaboration.
Finally, I decided to investigate about the winemaking process since for me this is a very elegant business and always aspired to have my own vineyard apart from my hydroponic greenhouse.
References
Soto, Lana. Red Wine Consumption and Health. 2016.
Food and Beverage Consumption and Health Ser. Web.
Castellucci, Federico. “World Vitiviniculture situation in 2012.” Proceedings of the XXXVIth
World Congress of Vine and Wine, Bucarest, Romanni. Vol. 27. 2013.
Belda Ignacio, et al. “WineSeq®: A New Tool for the Study of the Functional Biodiversity of Soils, and Its Use as a Biomarker and Guide for Vitiviniculture Practices.” BIO Web of Conferences, vol. 9, 2017, p. 01012.
Battilani, Paola, Paola Giorni, and Amedeo Pietri. “Epidemiology of toxin-producing fungi and ochratoxin A occurrence in grape.” Epidemiology of mycotoxin-producing fungi. Springer, Dordrecht, 2003. 715-722.
Abbona, Esteban A., et al. “Ecological sustainability evaluation of traditional management in
different vineyard systems in Berisso, Argentina.” Agriculture, Ecosystems & Environment 119.3-4 (2007): 335-345.
Jianhe, Li, et al. “Relationship Between Nitrogen and Potassium Nutrition and the Yield, Quality,
and Growth of Grape [J].” JOURNAL OF FUJIAN AGRICULTURAL UNIVERSITY 1 (1995).
Wei, et al. “Effect of Cationic Exchange Capacity of Soil on Strength of Stabilized Soil.”
Procedia – Social and Behavioral Sciences, vol. 141, no. C, 2014, pp. 399–406.
Koller, Robert, et al. “Protozoa Enhance Foraging Efficiency of Arbuscular Mycorrhizal Fungi
For Mineral Nitrogen from Organic Matter in Soil to the Benefit of Host Plants.” New Phytologist, vol. 199, no. 1, 2013, pp. 203–211.
Cristina Bunescu. “THE IMPACT OF FERTILIZATION AND FOLIAR STIMULATION PRODUCTS BOTH ON INCREASING THE RESISTANCE TO MAJOR PHYTOPATHOGENS ATTACKS AND ON INCREASING THE QUANTITY AND QUALITY OF WINE GRAPES HARVEST.” Scientific Papers Series: Management, Economic Engineering in Agriculture and Rural Development, vol. 14, no. 4, 2014, pp. 35–38.
Grainger, Keith, and Hazel Tattersall. Wine Production and Quality. Second ed., 2016.
Jackson, Ron S. Wine Science Principles, Practice, Perception. 2nd ed., Academic Press, 2000.
Grainger, Keith., and Hazel. Tattersall. Wine Production Vine to Bottle. Blackwell Pub., 2005.