Agriculture does not exist without sun. It will be? In fact, a correct solar incidence determines the quality of a crop. But, despite being the main source of light, it is not the only one. With the development of new technologies, artificial lighting has been attracting the attention of researchers, companies and producers. “We study the needs of the plants and provide light in the ideal quantity and with the right spectrum to grow,” said Mateus Delalibera, co-founder of Pink Farms. Among the reasons that make it an increasingly relevant tool are the possibility of extending the photoperiod, that is, increasing the length of the day and making it the only source of light supplementation for various cultures. In other words, the use of LED lamps results in increased productivity and savings in inputs for producers, in addition to making food as healthy as or more and in traditional cultivation for consumers. The professor in the plant production department at the Luiz de Queiroz School of Agriculture (Esalq) Simone da Costa Mello explains that studies in the country started in 2014 when Philips wanted to explore the impact of technology on the production of tomatoes, cucumbers and peppers in agricultural greenhouses. “We used artificial lighting in the canopy of minitomates feet and obtained a 15% higher productivity in fruit production,” said Simone. For lighting to collaborate in the supplementation process, however, it is necessary to carry out detailed studies to understand what is the composition of colors, intensity and duration suitable for the chosen crop. “Each color represents a wavelength and plants respond differently to spectral compositions,” he said. Knowing the genetic material to reveal the most efficient way to use it is the safest ways to ensure the result.
With the first successful tests, companies began to emerge focused on the development of solutions for planting in greenhouses and urban farms, as is the case with Signify, which has in its portfolio brands such as Philips Lighting. Dedicated to the topic since 2007, the company has intensified its research in recent years, obtaining numbers that prove the efficiency of LED light in vegetables. “In lettuce, the annual yield can be up to three times higher compared to production in the open field,” said Ramiro Robles, commercial manager of agriculture in Latin America at Signify. It is worth noting that in addition to the correct use of the technique, the success of the crop also depends on other factors. “The increase in productivity depends on the type of crop, variety and local circumstances, such as temperature, humidity, carbon dioxide, water and nutrition,” said Robles.
COMPOSITIONS In this cultivation model, the color of the bundles is critical. While the human eye is more sensitive to green and yellow, plants are red and blue, which are the wavelengths most absorbed by chlorophylls A and B. It is not for another reason that Pink Farms, considered the largest vertical farm America, uses these lamps to its advantage. Located in São Paulo, the company’s 750 m² warehouse is dedicated to vegetables in the aeroponic system – kept suspended in the air supported by the root colon – and hydroponic. To increase production and increase quality, the property uses 20% blue light and 80% red light, indexes that are adjusted if necessary. “The composition works very well. We have the capacity to produce around 4 tons per month ”, said Geraldo Maia, a founding partner of the company, who points out that the lighting stays on for 18 to 20 hours a day. In addition to high productivity, the controlled environment allows savings of 95% in water consumption and a reduction of 60% in the use of fertilizers, in addition to zero use of pesticides and 100% use of everything that is produced.
Even though the combination of red and blue is the most used, other alternatives can generate good results. Fazenda Cubo uses white light to produce some types of hydroponic vegetables in a space of 70 m², with a monthly volume of up to 900 kg. In its production, it uses tones that also vary between orange, yellow and green, which are received by other photoreceptors. “We maintain a peak in blue and red, which are highly absorbent, but plants also take advantage of other wavelengths that are important for their good development,” said Paulo Bressiani, the company’s founder. Contact with different tones can make the flavor and even the aroma of some plants stand out. “We were able to deliver a quality product, fresh, tasty and free from pesticides,” said Bressiani. In addition to the possibility of artificial lighting being used as the only source in the case of indoor crops, it can also be used in open environments.
The Fienile Group, formed by producers and researchers with experience in agricultural crops, has been developing for over five years a project aimed at creating the first central pivot with artificial lighting to increase the photoperiod. Two years ago, the first property received the technology for testing. Located in the Triângulo Mineiro and Alto Parnaíba region, the initiative is installed in an irrigated area of 100 hectares, where 14 crops are worked, among them sugar cane, cotton, wheat, corn, soybeans as well as flowers, tubers and vegetables . The plants receive irrigation from lighting and water at night and in cloudy periods. The innovation named Irriluce, still in the pilot phase, has already registered an average production increase of 66%, with variations according to the culture. “We need another summer to validate. So when we have the result of three summers and three winters, we will have more certain conclusions ”, said Gustavo Grossi, agronomist and partner of the group. In addition to the red and blue lights, they also study the application of yellow and green. “Each culture, in every place in Brazil, has its specificities, so we need to know which is the best light spectrum for each region”, he said.
COST BENEFIT For technology to gain scale, the path goes through efforts in research and development, in addition to reducing the necessary investment. “The value of electricity, for example, makes production more expensive, but with the popularization of LED in agriculture, the trend is to decrease,” said Simone. Like all disruptive technology, challenges exist. The secret is to put the pros and cons in the balance, because in addition to improving the harvest and the savings generated, there are also aspects of sustainability that need to be considered. “We managed to reduce the use of pesticides by 35% and the application of water depths per hectare / year in open air by 18%, in addition to using smaller amounts of water resources,” said Grossi. Just like any innovation that arrives in the field, the use of artificial lights is not a miracle solution, but an additional tool for the Brazilian producer who is looking for solutions that are good for the consumer and for the business.
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