Climate Change and Tropicalization: Strategies for Our Olive Growing and Viticulture

It is now part of the common imagination—and clearly tangible—the effect of tropicalization in our territories, both urban and agricultural.

More and more frequently, we witness extreme events that, unfortunately, often cause damage far beyond material losses, affecting people, families, and entire communities.

The term climate change, now commonly used, does not in fact fully convey the severity of the situation or the reality we are witnessing.

It certainly falls to our generation, which is experiencing a phenomenon that is new in itself, to provide answers and solutions—because this is what is needed today.

Clearly, agriculture is heavily affected, with damage and repercussions to crops that are often severe and tangible.

But how can all of this be addressed in our territories—specifically, what approach should be taken not at a broad territorial level, but at the strictly local level of the individual vineyard and olive-growing enterprise?

The soil–plant–air ecosystem is a very fragile mechanism, based on a delicate balance. It is precisely this balance that is being disrupted by scorching climates, persistent rainfall, and extreme temperature fluctuations.

Today, technology and knowledge make it possible to mitigate extreme phenomena, and our task will be to enable our crops to adapt to the new climate.

Compared to short-rotation cereal crops (with a short growing cycle), grapevines and olive trees have a medium- to long-term cycle (once planted, from 25 years onward). Therefore, we must focus our actions on everything that surrounds them, since those are now the varieties and types that have been planted.

In a rational vademecum, soil management is the first factor to be considered.

During winter, soil aeration becomes increasingly important through the use of a subsoiler plough. Creating vertical cuts in the soil near the roots loosens it, allows excellent winter aeration, and enables water to penetrate deeply, preventing surface waterlogging. The soil essentially “breathes” and naturally becomes softer; the fine root system is renewed, preserving its vitality, explores a larger soil volume, and provides the plant with greater resistance to summer droughts or prolonged spring rains.
If we wish to be even more virtuous, no-till seeding of cover crops (green manure crops, sown in September or in spring) significantly enhances resilience. These annual herbaceous plants (of all species and types) are left to grow until flowering and, once flowering is complete, are either incorporated into the soil or “rolled down” using crimper rollers. Lodging (laying the plants horizontally) creates a mulching layer on the soil, which becomes an extraordinary tool for protection against high summer temperatures. It has now been proven that vegetative cover can reduce soil temperature by up to 10 degrees Celsius during summer periods, reducing water loss from the soil, lowering root temperature, and ultimately creating a less extreme environment for the ecosystem to thrive.

To support the actions described above, it is essential to enrich the soil with organic matter which, by generating humus, makes it more friable and richer in beneficial bacterial microflora.

This goal can be achieved by manuring the soil (with cow or horse manure), and in the absence of readily available raw material, high-quality organic pelleted fertilizers are now available on the market, offering excellent performance and largely replacing the effects of manure. Moreover, application is very fast, as it only requires the use of fertilizer spreaders.

Depending on rainfall, humidity, and leaf wetness, conditions change, and so do the treatments required for grapevines and olive trees. From this perspective, staying connected to local phytosanitary bulletins helps guide crop protection practices, as does collaboration among farms and the flow of information between them. Today, more than ever, information networks, cooperation, and knowledge sharing form the foundation of an effective defense strategy.
Compared to the past, such strategies clearly require greater timeliness, higher-performing application equipment (sprayers), and a different mindset toward intervention. In essence, the professionalism of the overall approach has evolved, demanding more advanced mechanization and better-trained personnel.

In this regard, a foliar treatment that has been increasingly used in recent years is the application of kaolin, a white rock powder that, when spread on the leaves, reflects solar radiation, reduces surface temperature, and prevents sudden evapotranspiration and excessive water consumption by plants—an essential practice in more arid climates.

Even harvesting practices are adapting to the new climatic conditions. Grape harvests and olive picking now take place in months that are still considered summer, making a clear advance compared to the past likely (even by several days), along with the simultaneity of the two operations (requiring virtually doubled logistical organization) and faster transfer from field to winery to prevent product deterioration due to high temperatures—therefore requiring greater human resources.

But it is through technology and science that important prospects for the future are opening up.

Thanks to genetic crossbreeding among cultivated plants, it is possible to obtain varieties that are more resistant to extreme climates, more tolerant of fungal diseases and insect attacks—in essence, plants that are more easily adaptable to altered climatic conditions. There are already examples of new grapevine and olive varieties; suffice it to think of the selected Xylella-resistant olive varieties, which will offer a new future to olive growing that has been damaged and almost wiped out in those areas. These varieties are already commercially available and suitable for planting, providing a concrete example of how varietal selection, supported by today’s knowledge, can remedy disastrous situations within just a few years.

In essence, the response to tropicalization lies in a series of coordinated actions, carried out throughout the seasons and, if we wish, logically connected to one another. Undoubtedly, the approach and the role of the farmer are changing: the farmer becomes an agricultural entrepreneur, managing their activity not only by physically cultivating the land, but by running it in an entrepreneurial way, with continuous updates and ongoing study to be applied in the field.

From this perspective, the contribution of new generations—young people—is essential, as they can support agricultural entrepreneurs in applying new knowledge developed at a theoretical level and transferable to the field. A historic opportunity not to be missed.

Marco Penitenti