Dutch Entrepreneur Creates First Seaweed Refinery to Combat Agricultural Nitrogen Crisis
Netherlands, Thursday, 12 February 2026.
Nikki Spil’s groundbreaking seaweed refinery in Beverwijk produces biostimulants that increase crop yields while reducing artificial fertilizer dependency. Field tests show remarkable results, with tomato yields jumping 18 percent and grassland production rising by 0.75 tonnes per hectare. The innovation addresses the Netherlands’ strict nitrogen emission regulations by helping crops absorb soil nutrients more efficiently, potentially revolutionizing sustainable agriculture and creating circular solutions for environmental challenges.
From Architecture to Marine Innovation
Nikki Spil’s journey into seaweed refining began far from the agricultural sector. After studying interior architecture at Willem de Kooning Academy, where she researched emission-free building materials, Spil worked several years as an architect and designer before pivoting to marine agriculture [2]. Her environmental awakening came from her childhood in Castricum, where she witnessed firsthand the polluting effects of local industry. “I grew up in Castricum, was always on the beach. There you can see the polluting effects of the industry in the area very clearly. Extreme algae blooms, mussels just washing up on the beach… You feel: that’s not how it should be,” Spil explained [1]. In 2016, she launched Zeeboerderij IJmond, renting a dock in IJmuiden harbor to cultivate seaweed for water purification [2]. The small operation created “a kind of mini-ecosystem,” with schools of fish gathering around the seaweed and attracting numerous birds, despite being a tiny farm [2].
Scaling Challenges Lead to Strategic Pivot
The initial seaweed farming venture faced significant operational hurdles that ultimately shaped Spil’s current approach. While the potential was evident, space constraints and permitting difficulties made scaling impossible [1][2]. “Seaweed cultivation turned out to be difficult. The potential was there, but there was too little space. Getting permits was difficult,” Spil explained [2]. The 2016 operation used seaweed fibers for construction materials, lamps, and soap, but discovered that the remaining nutrients were suitable for agricultural land [1]. Rather than abandon the venture entirely, Spil made a strategic decision in 2023 to focus exclusively on seaweed refining, partnering with Roy Wormsbecher to establish Holdfast and Stipe [2]. “I decided to stop growing and focus only on seaweed refining. I knew that focus was necessary. If I continued to do everything halfway, it wouldn’t make any difference,” she stated [4].
Revolutionary Biostimulant Technology
The seaweed refinery, now operating in Beverwijk, represents the Netherlands’ first facility dedicated to processing seaweed into agricultural biostimulants [3][4]. The production process creates what Spil describes as a “tea” from seaweed, containing all the nutrients naturally present in the marine plant [4]. This concentrate is then sold as a biostimulant that farmers and growers can add to their spray systems, enabling crops to better absorb existing nutrients in the soil [3][4]. The technology addresses a fundamental inefficiency in traditional agriculture: rather than adding more artificial fertilizers, the biostimulant optimizes nutrient uptake from what’s already present in the soil [GPT]. “Ultimately, it’s about closing the loop for me. Now it’s the case that fertilizers like phosphate and nitrogen leach from the soil into our surface water. You can think of all kinds of complex solutions for that, like filters in waterways. But if you look at the cause of the problem, the solution turns out to be much simpler. We need to bring the nutrients from the water back to the land. And actually they should stay there. Nature has already figured it all out for us,” Spil explained [2][3].
Impressive Field Test Results and Production Capacity
Field testing has demonstrated the commercial viability of Spil’s biostimulant technology across multiple crop types. Tomato yields increased by 18 percent in trials, while grassland production rose by 0.75 tonnes per hectare [1]. The improved grass quality also reduces farmers’ need to purchase concentrated feed, providing additional economic benefits [1]. The current refinery can produce approximately 1,000 liters of concentrate per week, with leftover seaweed fibers supplied to SeaWood for sheet materials, creating a fully circular production process [1][4]. Beyond the immediate results, Spil and Wormsbecher plan to expand through technology licensing, offering their refinery blueprint to other operators [4]. Additional field test reports for potatoes, cabbage, ornamental flowers, and tropical houseplants are expected by the end of 2026, with the goal of achieving stable sales [1]. The entrepreneur also aims to engage major agricultural companies, stating: “I would like to sit down with the Campina’s of this world about the sustainability of livestock farming” [1].