Astronomy and field cultivation have many points of contact, some real, others only in popular beliefs. Traditional agriculture takes into account the “moons”. Uses vary from place to place, but a widespread habit has it that tomatoes are sown with a full moon, tubers, onions and underground vegetables with a waning moon, salads and surface vegetables with a crescent moon. The brightness of the full Moon is one six hundred thousandth of that of the Sun. This data is enough to conclude that the lunar phases are completely irrelevant to vegetation. On the other hand, the astronomical action of the seasons and circadian rhythms is obvious.
The colors of photosynthesis
Fundamental, but usually ignored, are the composition of the atmosphere and the colors of sunlight. The vegetable universe is based on photosynthesis, a wonderful chemical reaction that transforms two mineral substances into living tissues: water and carbon dioxide contained in the air. Sunlight is a mixture of colors from red to violet but not all of the light spectrum has the right energy to produce photosynthesis. The effective colors for combining carbon dioxide and water to generate sugar (glucose) are red and blue, i.e. light with a wavelength of 680 and 430 nanometers, respectively.
The line of pine forests
The amount of carbon dioxide existing in the atmosphere is less critical but in general the more abundant the better. Agricultural yield is favored by the current 420 parts per million of CO2 compared to the 290 that existed before the industrial revolution burned huge quantities of fossil fuels. The unwanted anthropogenic greenhouse effect, half due to carbon dioxide, by increasing the global temperature of the planet, pushes the vegetation to migrate to regions with a cooler climate. In the Alps, the upper line of conifers, once around 2000 meters, has risen by a few hundred, the pioneer plants are moving towards higher altitudes, in the hills the harvest season arrives early and global warming increases the alcohol content of the wines because grapes are more sugary.
With the temperature also the pests and diseases of plants of agricultural interest change. The consequences can become serious for humanity, all the more so as until the end of the century the world population will continue to grow and then settle to just over 10 billion. From this point of view, too, climate change is an issue that is receiving increasing attention. Mauro Mandrioli, a biologist who teaches genetics at the University of Modena and Reggio Emilia, has recently published “Nine billion at the table” (Zanichelli, 240 pages, 14.30 euros). One solution is to move to “precision agriculture”, which makes the best use of genomics, big data, information technology, satellites and drones. In short, agriculture 4.0.
For ten thousand years agricultural production has remained almost at a standstill, like the world population until a few centuries ago. In the last hundred years we have seen a surge of both. The economist and demographer Thomas Malthus in 1798 and then the Report on the Limits of Development of the Club of Rome (1972) made catastrophic predictions announcing a future of humanity under the banner of hunger. It did not happen because agriculture has been able to continuously update its techniques: mechanization, genetic improvement, fertilization, pesticides, pesticides. At the end of the century we will be 10 billion and agricultural production will have to increase by 50 percent. To cope with it and to reduce damage to the environment, all the most advanced technologies must join forces. At the same time, especially in richer countries, a review of eating habits is needed. For the same calories supplied, cattle farming requires 30 times more land, 10 times more water and 6 times more fertilizers than white meat and frees six times more carbon dioxide: the consumption of red meat must be reduced for the sake of ours. health and the environment.
Measure out the water
Mandrioli describes the interventions that agriculture 4.0 can already implement. Infrared remote sensing satellites, airplanes and drones make it possible to dose irrigation on a large, medium and small scale, and also to “see” plant pathologies in advance. The saving of water and the dosage of pesticides bring great savings and benefits. The margins are large, water consumption can be reduced by 30 percent with sub-irrigation, which brings only the water strictly necessary and in the right place into the subsoil. Here, too, lifestyle can go a long way. We must know that behind an apple there are 70 liters of water, 135 behind an egg and 2400 behind a hamburger.
In 15 minutes, a drone examines a 70-hectare field. The yield of the land sometimes changes on a small scale: the drones detect its characteristics on 5×5 meter “pieces”, special programs process the big data collected and in real time the automated intervention of the agro-robots follows. In Italy drones are still used little, but the Pricewaterhouse Coopers Report estimates the world market for agricultural drones at 30 billion a year. Sensors for humidity, infrared rays and chemicals are becoming more and more precise and costing less and less: precision agriculture will make more and more use of them. “Innovative sensors based on biocompatible filaments that can be inserted into the stem of plants and absorb the sap by measuring its parameters are being developed, writes Mandrioli”. The “rhizosphere”, that is the environment where roots grow in close collaboration with the microbiota of bacteria and fungi, is very promising. Personalized “medicine” is coming to the fields.
Agroinnova, the Competence Center for innovation in the agro-food field of the University of Turin is at the forefront of technological experimentation and the study of how climate change will modify agriculture. Led by Angelo Garibaldi and Maria Ludovica Gullino, in Grugliasco, where the Faculty of Agriculture is located, the Center is equipped with the most advanced equipment in Europe: biological and integrated defense laboratories against plant diseases, phytopathological diagnostics, chemical analyzes, biotechnologies, food safety, a mycoteca of pathogenic fungi cataloged from 1960 to today.
“A precious tool is the phytotron – explains Angelo Garibaldi, president of Agroinnova, professor emeritus of the University of Turin and savior of basil from the Peronospora Belbahrii fungus that was destroying it -. In Grugliasco we have six. They are climatic chambers with internal dimensions of 2x2x2.5 meters in which it is possible to vary and time the most important parameters for plant biology: the temperature (from 6 to 40 ° C), the radiation active in photosynthesis, the concentration of carbon dioxide (400 to 2000 parts per million), humidity (18 to 90 percent). For us they are real ‘time machines’, in two senses: because in the phytotrons we create the most varied meteorological conditions and because we can simulate what the Earth’s climate will be in the near and distant future, when the concentration of carbon dioxide will be greater and the planet’s temperature will rise: we are talking about a degree and a half or two at the end of the century. ”
Agroinnova employs a core of highly qualified young researchers, develops numerous European and national research programs (Emphasis, Valitest, Euclid ,, Nutriman, Excalibur, Eureka, Food Digital Monitoring), spends 70 percent of its funding in research basic and applied and 20 per cent in technology transfer, has an impressive production of publications in prestigious international journals. To give just one example, with phytotrons the reaction to the increase in temperature and carbon dioxide has been studied on plants of wide economic interest such as basil, beet leaf, bean, lettuce, pelargonium, radish, wild and cultivated rocket, courgette. The results are amazing. The increase in carbon dioxide concentration sometimes plays against, sometimes in favor, and the interaction with pathogens is important, which in turn can benefit or be limited by the change of these parameters. As for pathogenic fungi, “they are little directly influenced by the level of carbon dioxide and are much more indirectly influenced by the physiological response of the host plants to the increase in CO2”.
The deception of “nostalgic knowledge”
A conclusion? Do not be fooled by the “nostalgic knowledge” (as Mauro Mandrioli defines it) of which the “moons” are an extreme case, escape the false myths camouflaged under the adjectives natural and biological abused by advertising, be wary of ideological movements that reject a priori the scientific progress. Plotisms and ignorance not only undermine vaccines, they also hinder new agricultural technologies by playing the game of Xylella fastidiosa and many other pathogens to the detriment of the productive niches that they would like to protect.