Green Ocean, Japan’s futuristic floating farm on the sea

Imagine growing vegetables using seawater rather than soil or plain water, and doing so on the ocean itself. This groundbreaking concept is being pursued by architectural tech startup N-ARK. Their ambitious project, called “Green Ocean,” envisions a floating ocean farm that cultivates food crops on the sea surface while also introducing soil improvement techniques and aquaculture technologies underwater to enhance the marine environment.

Seawater agriculture retains the nutrients originally present in seawater by mixing rainwater to supply essential nitrogen, phosphorus, and potassium for plant growth. Adjusting pH levels and nurturing specialized aerial roots enable plants to absorb these nutrients, resulting in functional vegetables that utilize the nutrients in seawater. Seawater agriculture has already shown success in cultivating leafy vegetables, with the establishment of tomato cultivation technology expected soon.

Multiple studies have demonstrated that vegetables grown using hydroculture can adapt to diverse environments and possess strong resistance to temperature fluctuations. Shohei Toyonaga, CEO of CULTIVERA, the company that researched and developed this farming method, asserts that these plants can withstand temperature changes of 10-15°C. Amid recent reductions in vegetable quality and yield due to abnormal weather, hydroculture emerges as a resilient cultivation method.

N-ARK is not only focused on agricultural technology but also on developing salt-resistant technologies – a critical and challenging aspect of architecture – to make floating ocean farms a reality. Green Ocean plans to utilize thinned wood for construction materials and salt-resistant carbon joints for connections. The company is also collaborating with a partner firm on a demonstration experiment scheduled for mid-year at Lake Hamana.

A United Nations report indicates that agriculture is the largest consumer of freshwater worldwide, accounting for 72% of total water usage. As the global population grows, freshwater demand is projected to increase, with a 40% shortage of freshwater resources predicted by 2030. Consequently, reducing water consumption and employing seawater for cultivation are essential for addressing the depletion of freshwater resources.

Establishing agriculture that is not land-dependent is crucial for tackling climate change, food crises, and political challenges, as 1.6 billion hectares of the world’s land are used for crop cultivation. Toyonaga, who has a background in archaeology at CULTIVERA, highlights that the collapse of food supply systems due to land-dependent agriculture led to the fall of ancient civilizations. He believes that developing non-land-dependent agriculture is vital for preventing future conflicts.

The world’s food systems are currently under threat from population growth, abnormal weather, and rising grain prices due to war. Green Ocean offers a new approach to farming that does not rely on land and instead harnesses technology. Adopting cultivation methods that minimize environmental impact by using sustainable materials will become the standard, ensuring a stable supply and ultimately contributing to the creation of a resilient society.

As we face dwindling resources, the question remains: will we continue to fight for their preservation, or will we assess our current situation and strive for improvement using technology for the sake of our future?