Using Drip Irrigation To Make New Sustainable Growing Regions For Avocados

Healthy and in-demand fruits such as the high-margin 'green gold' avocado, primarily grown in South and Central America, are among the least tenable and environmentally-friendly crops.

According to a Rabobank report in 2021, avocados ranked high in per capita consumption growth among fruits. Avocado consumption in the US was about four pounds per person in 2010; and in 2018 it more than doubled to nearly 8.5 pounds. By 2026, avocado consumption could exceed 11 pounds per person per year by 2026. In Europe, France consumed the most avocados in 2020 at around 144 thousand metric tons. Spain, Germany and the United Kingdom consumed more than 100 thousand metric tons of the avocado in the same year.

But, the carbon footprint to export avocados to the US and Europe is twice that of a banana. And, establishing dedicated plantations to satisfy export demand causes deforestation, including the burning of trees and destruction of natural habitats.

New markets

In countries with semi-arid climates like Spain and Israel, drip irrigation, fertigation and frost protection are changing where and how avocados are grown and exported to Europe. Companies like Netafim are working to onboard new avocado regions in Turkey, Morocco, Corsica and Sicily to produce the high margin crop through continuous irrigation and fertigation and improve the size and weight of the fruit and reduce the use of chemicals required to grow the crop.

According to Danny Stern, Senior Agronomist for Tropical and Subtropical Orchards Agronomy Department at Netafim, continuous irrigation creates at least double the yield for avocados, even with no rainfall for 11 months of the year.

Stern says the main challenge for avocado cultivation in new growing regions such as Turkey, Morocco, Corsica and Sicily is that it is too cold in winter and too hot in summer.

"Avocados [..] are very sensitive to extreme climates, especially with severe temperature changes and more frequent periods of drought," said Stern. "Water availability is also a challenge. Without water, it's impossible to grow avocados commercially, so drip irrigation is especially beneficial in delivering the right amount of oxygen and water to the roots of avocados which are very close to the surface and highly sensitive."

Spain is one of the top 20 avocado-producing countries and Europe's leading supplier of avocados. Ninety-five percent of Spain's avocado production relies on drip irrigation. Israel's avocado crop, number 10 in global avocado production, is 99% reliant on drip technology.

In 2021, Israel produced around 170,000 tons of avocados production, equating to approximately €300 Million in revenue.

According to Michael Noy, Chief Advisor for Subtropical Fruit Trees, Extension Service at Israel's Ministry of Agriculture, avocado is one of the highest margin fruits.

"Avocados are grown on Israel's kibbutzim (communal settlements), and there are probably 150 kibbutzim each with avocado orchards of around 100 hectares," said Noy. "We've been growing avocados commercially since the end of the 1960s, but today we've seen a huge increase in demand over the last 20 years due to their rise in popularity."

Drip irrigation

Netafim's Stern says drip irrigation is essential for sustainable commercial avocado growth in semi-arid climates such as Southern Europe and critical for very arid regions like the Middle East.

"Avocados need a substantial amount of water to develop well and produce commercial fruit," said Stern. "Drip irrigation is far more efficient than other irrigation methods such as flood, as it majorly saves on the amount of water and fertilizer required for plant health and growth."

Stern says drip enables plants to be watered throughout dry periods, which benefits short-term growth and sustains the longer-term health of the plants for subsequent crops.

"Fertigation is the process of injecting fertilizers into an irrigation system. It is beneficial to farmers and the environment because it doesn't waste fertilizer, [..] prevents pollution of underground water and helps keep the leaves and the fruit on the trees, improving the number of fruit produced and their weight," said Stern.

Noy says that generally, from March until November, there's no rainfall in Israel, so drip is the optimal method to give the avocado trees water.

"In Israel, we've started to recycle water for other purposes, especially near the big cities. Water from sewage systems is treated and repurposed; however, recycled water can only be used for agricultural purposes if it doesn't touch the crop, said Noy. "Drip irrigation directs water straight to the soil rather than the plant, so we're using recycled water for avocado cultivation - yet another benefit of the technology."

Noy says climate change plays a huge factor in the growth of sub-tropical fruits in Israel.

"Not only is the weather getting warmer, but weirder and extreme conditions are becoming much more common," said Noy. "May is a key month for fruit production in Israel, and if we get heatwaves, we lose all the fruit. The only way to counter this is with drip irrigation because it ensures strong, healthy trees throughout our Spring."

Spain's new green crop

Gil María Campos Alabau, an agriculture engineer and MIT Sloan Fellow in Innovation and project of the Avocado Innovation Operative Group, says that avocados can be grown using different irrigation systems, including surface, micro-sprinklers and drip irrigation.

"In Spain, drip is the most suitable system because it accurately reduces the water flow and allows the application of fertilizers," said Alabau. "It's the optimal way to distribute water and fertilizers, delivering all the precise and smart agriculture benefits."

Alabau says that a study by the Valencian Institute of Agrarian Research showed that half the amount of water with low and ultra-low flow irrigation could achieve the same production levels.

"This significantly reduces the hydric water footprint of avocados," said Alabau. "With both this method and drip, we have discovered how to produce avocados with the optimal water footprint, providing the country with a great competitive advantage from a sustainability point of view."

There are two traditional avocado-growing areas in Spain: Axarquia in Malaga and Granada and the Canary Islands and several hectares of production in Callosa d'En Sarrià.

"In recent years, cultivation of avocados has been expanding in other suitable places for production such as other parts of the Valencian Community and the southwest of Spain," said Alabau. "To help with this expansion, our group has developed a tool to help the farmers assess if their land plot is suitable to grow the crop that considers climate, quality and quantity of water and edaphological features."

In 2020, around 15.849 hectares (39 acres) were cultivated for avocados across Spain, with a total production of 100,000 tons.

Alabau says that avocados are helping increase biodiversity in places where the citrus crop was once queen. "At the same time, while the production costs for all crops have risen and the prices have fallen for citrus, avocado has appeared as a new opportunity for farmers," said Alabau.

"Spanish avocado production is growing due to European consumers who are concerned about sustainability and climate change," said Alabau. "In comparison to other countries, the Spanish avocado has the lowest carbon footprint for European customers and we have the best technology to produce avocado with the lowest hydric footprint."

Alabau says that the Spanish crops are more resistant to disease, providing growers with an excellent opportunity to produce organic avocados without shipment or other treatment when distributing to Europe.

"The consumption of avocados is relatively new in Spain and other countries in Europe, so we're experiencing a growth in demand," as there is a limit to where avocados can be grown in Spain. Demand is much higher than the speed at which farmers can produce them."

Alabau says that the avocado crop is replacing where citrus is being grown, and there has been a long tradition of mastering the usage of drip irrigation. "The Spanish regulation system controls the amount of water used in a river basin to distribute water across the different usages. "Drip irrigation allows farmers to make the best usage of water independently of the amount endowed by the government," said Alabau. "Smart agriculture is based on using water and fertilizers when needed by the plant, and drip irrigation in avocados is the main opening for this type of agriculture."

Sensors and UAVs

Netafim's Stern says that soil and plant sensors are also important and beneficial for irrigating the right amount of time to maximize the use efficiency of water and fertilizers.

"Other challenges to growing in these areas include water supply, labor, and soil; however, they're not unique; the climate is by far the most problematic for these regions," said Stern. "In addition to reducing the carbon miles of tropical fruit, cultivating this type of crop in semi-arid climates such as Israel, Morocco and southern Europe means it is less prone to disease or pests when compared with other regions."

Over the last five years, for some crops like avocados, satellites and Unmanned Aerial Vehicles (UAV) have started to help farmers increase the uniformity of productivity in their fields.

Alabau says this also helps to predict the final production at the end of the year and adapt fertilization to the required amount.

"Currently, we are working on adapting this technology for avocados," said Alabau. "In the Operational Group for Avocados Innovation, we have boosted the usage of tele-detection and artificial intelligence (AI) and machine learning in the production of avocados."