Drought and Its Impact on Olive Groves: How Does It Affect the Quality and Flavor of Extra Virgin Olive Oil?

Introduction

Drought is a climate phenomenon that raises concerns across many areas of agriculture, and olive oil production is no exception. In this article, we'll look at how drought affects olive groves, and in particular, how it influences the quality and flavor of extra virgin olive oils. We'll also explore some of the strategies that have typically been used to combat the effects of drought on olive cultivation.

1. The olive tree and its relationship with water

The olive tree (Olea europaea) is a species native to the Mediterranean region, known for its ability to withstand harsh climate conditions such as drought and high temperatures. That said, this doesn't mean the olive tree has no need for water to grow and produce fruit.

The olive tree's water requirements

The amount of water needed for healthy olive tree development varies depending on several factors, including the growth stage, soil type, and climate. Generally speaking, a mature olive tree requires between 400 and 1,000 mm of water per year.

To give you a sense of the current situation, in the six months between October 2022 and March 2023, just 329 mm of rainfall was recorded across Andalusia — placing the region in a critical state.

On top of this, Andalusia's reservoirs in 2023 sat at just 25.7% of total capacity — a drop of 539 hm³ compared to 2022.

How does the olive tree resist drought?

The olive tree has developed a range of adaptations to cope with drought conditions, including the ability to close its stomata to reduce water loss through transpiration, and the capacity to draw water from deep soil reserves.

Furthermore, the olive tree's root system is extensive and deep-reaching, allowing it to access water sources at greater depths.

2. The impact of drought on olive groves

Despite the olive tree's natural resilience, drought can have significant negative effects on olive groves, both in terms of yield and quality.

Effects on production

Water scarcity in olive groves can lead to a decline in olive yield and, consequently, in olive oil production.

Drought can also affect flowering and fruit set, resulting in fewer olives per tree.

Effects on olive oil quality

Drought can alter the chemical composition of olive oil, which in turn affects the quality and flavor of the final product. Some of the most notable effects of drought on olive oil quality include:

• Increased polyunsaturated fatty acid content: During drought, the concentration of polyunsaturated fatty acids — such as linoleic acid — can rise in olive oil. This can affect the oil's oxidative stability, shortening its shelf life.
• Higher phenol content: Drought can lead to a higher concentration of phenolic compounds in olive oil. While these compounds are beneficial to health due to their antioxidant properties, an excess of phenols can affect the oil's taste and aroma, producing more intense bitter and peppery notes.
• Changes in sensory profile: Drought can disrupt the balance of aromatic and flavor compounds in olive oil, resulting in shifts in its sensory profile. These changes can include a greater intensity of bitter and peppery flavors, along with a reduction in sweetness and fruitiness.

3. Strategies to mitigate the impact of drought on olive groves

Since drought can affect both the yield and quality of olive oil, growers have put in place strategies to help reduce its impact on olive groves. Some of these strategies include:

3.1. Selecting drought-resistant varieties

Choosing olive varieties with greater drought tolerance can be an effective approach to managing water scarcity.

Certain olive varieties, such as Picual, Hojiblanca, and Cornicabra, are well known for their drought resistance and are widely cultivated across Andalusia, particularly in areas most prone to drought.

3.2. Efficient irrigation

Making the most of available irrigation water is essential when facing drought in olive groves. Drip irrigation is a technique that delivers water precisely and evenly to the olive tree's root zone, minimizing waste and improving overall irrigation efficiency.

In addition, monitoring soil moisture levels and using sensors to measure humidity allows irrigation to be adjusted to the trees' actual needs, preventing water stress.

That said, when drought is severe — as has been the case in recent years — irrigation restrictions become commonplace, drastically cutting water use in order to protect supplies for human consumption.

3.3. Soil management

Proper soil management is another key strategy for reducing the effects of drought on olive groves. Adding organic matter to the soil — such as compost or manure — helps improve water retention capacity and maintain moisture around the root zone.

The use of cover crops and reduced tillage also contributes to preserving soil moisture and protecting against erosion.

Conclusion

Drought is a climate phenomenon that can significantly affect both the production and quality of olive oil. Although olive trees are naturally resilient, it is essential to put strategies in place to limit drought's impact on olive groves.

Choosing drought-resistant varieties, efficient irrigation, and sound soil management are among the practices that can help growers navigate drought conditions and continue producing high-quality extra virgin olive oils with exceptional flavor.

Even so, when drought is as severe as what we experienced in 2022 and throughout 2023, its greatest impact on olive groves is an economic one — production was cut roughly in half, dealing a heavy blow to growers and driving up prices for those of us who love genuine extra virgin olive oil — the kind that comes direct from the grower, with a real name and face behind it, like Mi Oliva Gourmet.

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