Adapting Agriculture to Heat Waves & Water Shortages

As summer arrives, bringing with it scorching heat waves and looming water shortages, the urgency to rethink our agricultural practices becomes undeniable.

Traditional farming methods are increasingly strained by these environmental challenges, prompting a shift towards innovative solutions. In this edition, we delve into the transformative potential of Controlled Environment Agriculture (CEA) — a beacon of hope for sustainable farming in an era of climate uncertainty.

Special thanks to Ben Crowther, CTO of LettUs Grow, for his valuable input.

What We Are Covering Today:

• Water Savings in Controlled Environment Agriculture

• Ferti-Irrigation Efficiency in Controlled Environment Agriculture

• Comparing Aeroponics and Hydroponics: Insights from LettUs Grow

• A Case Study in The Caribbean

• Complementary Sources

Water Savings in Controlled Environment Agriculture

In a nutshell, Controlled Environment Agriculture (CEA) is changing the way we think about water usage in farming. One of the key features of CEA systems is its ability to recirculate water. Unlike open-field farming, where a substantial amount of water is lost to evaporation and runoff, CEA systems can capture and reuse water. In a typical hydroponic system, water is circulated through the plant roots and then collected, filtered, and reused. This closed-loop system can reduce water usage by up to 90% compared to conventional farming methods.

CEA's water use efficiency is further enhanced by precise control over the growing environment. By maintaining optimal temperature and humidity levels, CEA systems minimize water loss through evaporation. Technologies like fog systems and misting can also provide plants with the exact amount of moisture they need without oversaturating the growing medium.

Hydroponics is a prime example of plants growing in nutrient-rich water without soil. Real-world applications of CEA demonstrate its water-saving capabilities. For instance, a study by the University of Arizona found that hydroponic lettuce production used only 10% of the water required for field-grown lettuce (Barbosa and al,. 2015).

Greenhouse farming offers long-term benefits despite initial costs, lowering expenses and increasing returns on investment.

Ferti-Irrigation Efficiency in Controlled Environment Agriculture

Controlled environment agriculture (CEA) reduces water consumption and provides significant advantages in nutrient management. Ferti-irrigation, which involves applying fertilizers through irrigation systems, demonstrates how CEA outperforms open-field cultivation by delivering precise nutrient doses directly to plants, enhancing efficiency and sustainability.

In CEA, precise control over the growing environment extends to nutrient delivery, allowing for optimized plant nutrition with minimal waste. In traditional open-field farming, fertilizers are often applied broadly, leading to inefficient use and potential environmental issues such as nutrient runoff. CEA, however, allows for the exact measurement and application of nutrients directly to the plant roots. This precision ensures that plants receive the optimal amount of nutrients at the right time, enhancing growth while minimizing excess. Nutrient use efficiency in CEA systems is remarkable compared to open-field farming.

Studies have shown that CEA can achieve up to 95% nutrient use efficiencies, compared to as low as 50% in conventional agriculture. This means that nearly all of the nutrients provided in a CEA system are utilized by the plants, with minimal loss to the environment (Abishkar and al., 2024). Advanced technologies are crucial in optimizing fertigation in controlled environment agriculture (CEA). Sensors continuously monitor nutrient levels in the growing solution, while automated systems adjust the nutrient mix in real-time based on plant needs. Machine learning algorithms can even predict plant nutrient requirements based on growth stage, environmental conditions, and other factors, further refining the fertigation process.

The implications of this improved fertigation efficiency are far-reaching. In fact, it reduces input costs for farmers and minimizes agriculture's environmental impact by reducing nutrient pollution in waterways—a major issue associated with traditional farming methods.

Comparing Aeroponics and Hydroponics: Insights from LettUs Grow

Aeroponics, a technique where plants are grown with their roots suspended in the air and misted with nutrient-rich water, presents a notable advancement in CEA methods. According to Ben Crowther, CTO of LettUs Grow, "In theory, aeroponics can significantly reduce the water used to grow crops compared to NFT. Some companies have put out very bold statements about this. In reality, water usage is very closely linked to the complete system design and is a key element that we work very closely with our customers to optimize for their needs."

In terms of fertilizer recycling, aeroponics can enhance the efficiency of gas, water, and nutrient uptake when correctly implemented. This efficiency stems from the precise delivery of nutrients directly to the plant roots, ensuring minimal waste and optimal growth conditions. Crowther highlights that "achieving greater savings with aeroponics depends on various factors, including crop type, target specifications, and system design." He also references a scientific article published in collaboration with Professor Anthony Dodd from the John Innes Centre, which delves into the principles and fundamentals of aeroponics.

Looking towards the future, Crowther envisions a diversified agricultural landscape. He suggests that "tomorrow's agricultural landscape will undoubtedly differ from what we know today. However, I do not foresee this being purely based on vertical and greenhouse farms. As with all systems, a considered, hybrid approach tends to provide the greatest efficiency, diversity, and resilience." He adds, "I expect we will still see broadacre arable farming and livestock production, but complemented by a much larger network of greenhouses and vertical farms, which are specialized for the crops that get the most benefit and protection from the different grades of CEA."

A Case Study in The Caribbean

In water-scarce regions like Bermuda, where freshwater storage is limited and water importation may be necessary, agricultural efficiency in water usage is paramount. Bermuda's unique geographical constraints and potential for water shortages necessitate innovative approaches to farming. However, Bermuda’s residents have ingeniously adapted by using white-painted roofs to collect rainwater. This centuries-old system channels rainfall into storage tanks beneath houses, providing the island's primary source of fresh water.

In this case, greenhouse farming emerges as a crucial solution, offering significant advantages in water conservation and management. The modern ferti-irrigation system allows for precise irrigation, reducing water waste and optimizing plant uptake. Additionally, greenhouses can be designed to capture and store rainfall, creating a sustainable water cycle within the agricultural system.

By implementing advanced irrigation techniques such as drip systems or hydroponics, greenhouse farming can dramatically decrease water consumption compared to traditional open-field agriculture. This approach not only conserves precious water resources but also enhances crop yields and quality. Furthermore, the controlled climate of greenhouses extends growing seasons and protects crops from extreme weather events, further contributing to agricultural sustainability and food security in Bermuda's challenging environment.

Cardinal Farms has launched hydroponic lettuce and tomato production in Bermuda to supply local supermarkets. Since the pandemic, demand has increased and the local price of imported fruit and vegetables has risen. Recycling water and fertilizers was mandatory for the owners to be able to produce and generate profits.

In addition to water-related issues, the increasing number of tropical hurricanes in the Caribbean region thas forced these growers to opt for Canadian quality greenhouse structures (Harnois) that are strong and tall enough to provide adequate growing conditions in a hot and humid environment (Horti-Generation, 2024).

This concrete example, set in a unique context dictated by water scarcity, points the way to what could be the future of agriculture. A closer relationship with the environment and the technologies available to produce better and, above all, minimize the need for water and fertilizers to preserve our planet.

Complementary Sources

💦Special Thanks To LettUs Grow’s CTO, Ben Crowther, discover their website and work here.

🌿Greenhouse cultivation: plant protection and water saving, we will see how greenhouse production allows for crop protection and significant water savings. (Horti-Generation, 2022)

💧Hydroponic paradox: Saving water with water (Food Future, 2022)

🥬Mid-tech hydroponic greenhouse in Bermuda, leafy greens and vine-crops for the local island market. (Horti-Generation, 2023)

🧪Aerofarms, how we grow: Cutting-Edge Vertical Farming Technology Plateform