Vegetables are a group of more than 100 species of food plants with high nutritional value, of which different parts are consumed raw, cooked or processed, depending on each species (Brainer, 2021). Olericulture is the branch of agriculture that encompasses the cultivation of vegetables and includes the production of leafy crops (lettuce, cabbage), roots (carrots and yams), bulbs (onions and garlic), tubers (potatoes) and various fruits (tomatoes, eggplants, okra). Unlike extensive activities, olericulture is an agricultural activity that extends throughout the year, regardless of the season. The Brazilian vegetable market is highly diversified and segmented, with the production volume concentrated in six species – potatoes, tomatoes, watermelons, lettuce, onions and carrots, with family farming responsible for more than half of production, as mentioned on the Embrapa website.
Vegetables are a common food on Brazilian plates and have a wide range of culinary uses, in addition to being important sources of vitamins, minerals, fiber and antioxidants that are essential for health. Regarding vitamins, the only one that vegetables do not provide is B12, as it is only present in foods of animal origin. Some vitamins and minerals, which are water-soluble, are easily eliminated after being used by our bodies, such as vitamin C, which is why it is important to consume these foods daily. In addition to providing essential nutrients for the proper functioning of the body, vegetables also help with hydration. In turn, low consumption can cause nutritional deficiencies, weakening the body and making it more susceptible to diseases. Furthermore, daily consumption of vegetables can delay or prevent degenerative diseases, in addition to increasing energy levels and reducing the risk of diseases such as hypertension and diabetes.
Economic importance of vegetables for Brazil
In Brazil, vegetable growing evolved more significantly from the 1940s onwards, during World War II, as stated by Caetano (2014). According to this author, at that time, there were only small diversified farms located in the green belts on the outskirts of cities. There was a shift towards rural areas, establishing themselves in larger and more specialized areas. From this point on, national vegetable growing evolved from small vegetable gardens to a commercial farm with well-defined characteristics.
Currently, the Brazilian vegetable market is highly diversified and segmented, with dozens of vegetables being sold and consumed in different regions of the country, although the volume of production has been concentrated in a few species, such as lettuce, potatoes, onions, carrots, watermelons and tomatoes. The production of a large part of the volume of vegetables sold in Brazil is carried out by small farmers, generally referred to as family farmers. Given the current economic scenario, family farming stands out as the segment with constant economic and social growth through the agricultural production of vegetable foods, an increase in the number of rural establishments and the generation of jobs in rural areas (Carvalho et al., 2015). The area of the main crops and producing regions is expected to increase in 2022, partially offsetting the reduction in 2020 and 2021. This increase is concentrated again in the industrial tomato and potato segment, in addition to a partial recovery in the lettuce area (main producing regions in the Southeast), according to the Hortifruti Brasil Yearbook (2021-2022).
According to the 2017 Agricultural Census and the Municipal Agricultural Survey (PAM), both from the Brazilian Institute of Geography and Statistics (IBGE), the national area occupied by the 10 main horticultural crops is 1.6 million hectares, where 30.5 million tons of vegetables were produced. The largest areas are in the Northeast (524 thousand ha), especially in the states of Bahia, Ceará, Maranhão, Pernambuco and Rio Grande do Norte. The main regional producer is the South, followed by the Southeast, North and Northeast with very similar production levels. These products are sold through different channels, such as the distribution centers (DCs) of large supermarket chains, smaller markets, fruit and vegetable markets, street markets, restaurants and/or supply centers (Ceasa, Ceagesp). The retail sector has proven to be one of the main distribution channels for vegetables, with supermarkets being the main channel in metropolitan areas.
Fertilization and management of vegetables
The response of vegetable plants to fertilization is influenced by several factors, such as the species cultivated, climate, soil type, and nutrient source used in fertilization, among others (Andrade et al., 2012). As previously mentioned, vegetables comprise a very wide variety of species, and therefore have different nutritional requirements and preferences for soil types. For this reason, the topic of fertilization and management will be divided by the parts of the plant that are consumed.
- Leafy crops
Leafy crops, such as lettuce, respond very well to nitrogen fertilization. However, this mineral requires special management, since leafy vegetables absorb larger amounts of N in the final period of the cycle. In cases of deficiency, a severe reduction in productivity is observed, with uniform yellowing of older leaves, due to their mobility to younger leaves, as cited by Yuri et al (2016). Regarding phosphorus (P), leafy vegetables have high requirements, especially during the transplanting period. Its deficiency can cause reduced development and yellowing of the edges of older leaves. Potassium (K) is the second most required element by leafy vegetables, behind only P, and its management is also done during the transplanting period.
It is important to mention that leafy crops have a rapid development cycle, requiring adequate application of fertilizers so that they are readily available to meet the plants' needs. Therefore, the correct interpretation of soil analysis and leaf diagnosis provide information to determine the appropriate doses and times for applying these nutrients.
- Roots
Tuberous roots, which are responsible for nutrient storage, generally prefer medium-textured, well-drained soils that are rich in organic matter and have a slightly acidic pH (Luz et al., 2009). Research conducted in Brazil shows that the extraction of macronutrients by tuberous roots, such as carrots, follows the following decreasing order: K, N, Ca, P, S and Mg. In general, N and K fertilization is mostly done as top dressing and the supply of Ca is credited only to the application of limestone and gypsum (Raij et al., 1997; Ribeiro et al., 1999). Luz et al. (2009) also show that the combined application of sources of N, K and Ca considerably increases the productivity of tuberous roots.
- Bulbs
Onions and garlic are among the vegetables most sensitive to soil acidity, with an optimum pH close to 6.0 (5.5 > pH > 6.5). They are plants that require N, P and K; however, in situations of excess N, they may present pseudotillering, compromising final productivity. In general, the recommendation is to apply pre-planting fertilization, which should be incorporated between 7 and 10 days before sowing, and to use organic fertilizers. Regarding topdressing, the amounts of N, P and K will depend on the evaluation of the previous crop, previous organic fertilization, plant stand and desired or expected productivity, as cited by Trani et al. (2014). Other factors to consider are: the vegetative state of the plants in the field, the nutritional requirements of the cultivars used and the planting system used.
- Tubers
According to Embrapa Vegetables, approximately 78 % of P, 68 % of K, 65 % of N, 65 % of sulfur (S), 33 % of magnesium (Mg) and 9 % of calcium (Ca) absorbed by this group of vegetables are accumulated in the tubers. The appropriate time of application, as well as the period and dose of each nutrient, is also important for the nutritional balance of the plant to obtain high productivity. Considering a cycle of 90 to 110 days, the maximum absorption of N, P, Ca, Mg and S occurs in the initial phase of tuber filling (45 to 70 days after planting - DAP). K, on the other hand, has its most concentrated absorption between 40 and 60 DAP.
According to Embrapa, there is a critical period in which tuber crops need practically all available nutrients in relatively high quantities, which ranges from the beginning of tuber formation, three to four weeks after emergence, until near the end of the cycle. The tuber filling phase is a critical phase in which the availability of nutrients and water in the soil must be high, since, during this period, the accumulation of dry matter and the absorption of nutrients are very rapid.
- Fruits
Regarding tomatoes – one of the main vegetables produced in Brazil – nutrient absorption is low until the first flowers appear. From then on, absorption increases and reaches its maximum during the fruit setting and growth phase (between 40 and 70 days after planting), decreasing again during fruit ripening. The amount of nutrients extracted by the tomato plant is relatively small, but the need for fertilization is very high, since the plant's nutrient absorption efficiency is low. In this sense, they are considered plants with high N, P and K requirements, especially during the fruiting period – as already mentioned.
Another vegetable that is also important for the Brazilian market is watermelon, which, according to Andrade Jr. et al. (2007), is considered a crop that is relatively tolerant to soil acidity when compared to other cucurbits, with the most suitable pH for the crop being between 5.0 and 7.0. The distribution and absorption of nutrients in this crop depends on its development stage. In the first 30 days after planting, absorption and accumulation are relatively small, intensifying and reaching a maximum between 40 and 50 days. Nutrient absorption during the fruiting period tends to be linear between fruit emergence and physiological maturity (45 to 65 days), increasing the requirement for top dressing, especially N and K after the first 30 days after planting. After 50 days, absorption efficiency decreases drastically, making top dressing inadequate.
Fertilization management of vegetables is quite complex, since this group comprises a large number of species and is a crop with high nutritional requirements. Follow the next blog on the fertilization management of ILSA BRASIL vegetables.
Bibliographic references
ANDRADE, EMG; SILVA, HS; SILVA, NS; SOUSA JR., JR; FURTADO, GV Organomineral fertilization in leafy vegetables, fruits and roots. Green Journal of Agroecology and Sustainable Development, v. 7, n. 3, 2012.
ANDRADE JR., AS; et al. Watermelon cultivation. Plantar Collection, Embrapa Technological Information, Brasília, n. 57, ed. 2, 2007. 85 p.
Hortifruti Brasil Yearbook 2021-2022. Available at: www.hfbrasil.org.br
BRAINER, MSCP Vegetable production in the BNB area of operation. ETENE Sectoral Notebook – Year 6, n. 180, 2021. 14 p.
CAETANO, AC Olericultura. Federal Institute of Education, Science and Technology, Manaus Campus, Manaus, ed. 1, 2014. 130 p.
CARVALHO, CO; SANTOS, AC; CARVALHO, GR Rede Brasil Rural: innovation in the context of family farming. Journal of Agribusiness and Environment, Maringá, v.8, n.1, p.79-94, 2015.
IBGE – BRAZILIAN INSTITUTE OF GEOGRAPHY AND STATISTICS. Cider. Agricultural Census 2017.
IBGE – BRAZILIAN INSTITUTE OF GEOGRAPHY AND STATISTICS. Cider. Municipal Agricultural Production (PAM).
LUZ, JMQ; FILHO, AZ; RODRIGUES, WL; RODRIGUES, CR; QUEIROZ, AA Topdressing fertilization with nitrogen, potassium and calcium in commercial carrot production. Horticultura Brasileira, Brasília, v. 27, n. 4, 2009.
Embrapa Portal – Available at: https://www.embrapa.br/
Embrapa Vegetables Portal – Available at: https://www.embrapa.br/hortalicas
RAIJ B; CANTARELLA H; QUAGGIO JA; FURLANI AMC. 1997. Fertilization and liming recommendations for the state of São Paulo. 2nd ed. Campinas: IAC. 285 p.
RIBEIRO AC; GUIMARÃES PTG; ALVAREZ VVH. 1999. Recommendations for the use of correctives and fertilizers in Minas Gerais, 5th Approach. Viçosa: UFV. 359 p.
TRANI, PE; BREDA JR., JM; FACTOR, TL Liming and fertilization of onion (Allium cepa L.). Agronomic Institute of Campinas, 2014. 35 p.
YURI, JE; MOTA, JH; RESENDE, GM; SOUZA, RJ Nutrition and fertilization of lettuce crops. Nutrition and fertilization of vegetables, Jaboticabal, p. 559-577, 2016.
Authors
- Agricultural Eng. Msc. Aline Tramontini dos Santos
- Agricultural Eng. Msc. Carolina Custodio Pinto
- Agricultural Eng. Msc. Thiago Stella de Freitas
