A stable, robust and reproducible data-driven strategy for maximizing yields

The principles of Het Nieuwe Telen (‘Next Generation Growing’) have been tested and proved around the world ever since first being developed in the Netherlands by P.A.M Geelen, J.O. Voogt, and P.A.M. van Weel in 2005. In 2016, the founders renamed the cultivation method ‘Growing by Plant Empowerment’ and wrote a book explaining this integrated approach, which is based on physics and plant physiology and focuses on keeping all the plant balances in equilibrium. Data is continuously collected and analyzed during the cultivation process to monitor how the greenhouse conditions are affecting crop performance as the basis for decision-making.

BASF Vegetable Seeds' ambition is to make healthy eating enjoyable by offering vegetable solutions that are in line with consumers’ needs. By exchanging knowledge and collaborating with partners along the entire vegetable value chain it aims to provide innovation, expert advice, reliable varieties, profitable and consumer-oriented concepts, and sustainable solutions.

“That’s why collaborative partnerships are an important part of our strategy,” states Martin Voorberg, R&D Capital Investment Venture Manager and Project Manager at BASF Vegetable Seeds.

“Together with Hoogendoorn Growth Management, one of the GPE Implementation Partners, we previously ran a hydroponic lettuce trial at our site in ’s-Gravenzande, the Netherlands, based on autonomous and data-driven growing. The results were so impressive that we decided to try it for tomatoes too, so in October 2019 we set up a GPE trial on around 500m2 with a broader team.”

Multidisciplinary project team

In addition to Hoogendoorn Growth Management, the multidisciplinary team comprised five other GPE Implementation Partners: Koppert Biological Systems for pollination and pest management, Hortilux/PL Light Systems for lighting, the LetsGrow.com data platform, Ludvig Svensson for the screening strategy, and stone wool specialist Saint-Gobain Cultilene.

“We wanted to develop a proactive rather than a reactive approach to the crop strategy and explore the possibilities for maximizing production by taking all aspects of the climate and plant health into account. That meant ‘switching off’ our emotions and allowing ourselves to be led by the data, even if it went against our natural instincts. On our side, the project was managed by a grower with a lot of experience who is also open to innovation and not afraid of stepping out of his comfort zone,” adds Martin.

“We were keen to try working with higher temperatures, and another thing we wanted to explore was increased light levels and different light regimes,” he explains.

No holding back

“What was great about the team at BASF was that even though the growing method didn’t feel ‘normal’, they put their trust in the figures and just did it,” says Mark van der Werf, a nutrition and climate consultant working with the GPE-concept.

“If you want to get the most out of GPE, you have to do what the data tells you – no holding back. The human aspect is the most unstable factor in crop production. GPE makes it all about physics and mathematics; once you know the right formula for your crop, you can run it all year round. The initial results were amazing, with a 20-25% increase in yield in the winter. But then the crop weakened and lost vigor as we headed into spring.”

This decline in plant performance was discussed in one of the regular GPE meetings.

“The general consensus was that the overall strategy was promising, but we had some practical issues,” recalls Mark.

“The trial area was exposed to quite a lot of external influences due to aisles and gables, which made it difficult to maintain a uniform climate. We also suspected that the increased light levels – based on 100% high-pressure sodium (HPS) lamps – had generated too much heat for the plants to cope with.”

Lighting solution

Hans de Vries, a consultant from Hortilux, rapidly set about finding a solution.

“HPS lamps typically generate a lot of heat and, especially when the screens were closed for energy saving and CO2, the temperature in the greenhouse sometimes rose too high. We also identified some other issues, such as that the ceiling of the greenhouse was a little lower than ideal, meaning that the plants were too close to the lamps. That affected the uniformity of light and hence crop growth,” explains Hans.

“LEDs are the best option to solve the heat problem, so we’ve installed a hybrid system of 65% LEDs and 35% HPS for the second season. We now have 262μmol PAR instead of 180μmol PAR in the old system – but thanks to the energy-savings of LEDs this doesn’t translate into higher energy costs. By reducing the heat, we give the grower more flexibility in the lighting strategy. For example, he can leave the lights on for longer even when it’s warm outside, and he doesn’t need to open the windows to ventilate so soon, which means he can keep the CO2 inside – and that’s better for photosynthesis and for the plant’s ability to regulate its temperature. Additionally, the LED fittings have enabled us to create a bit more space between the tops of the plants and the ceiling so the light can be distributed more evenly. All of these factors improve plant health and performance.”

Data-driven growth is not a new concept for Hortilux.

“We’ve developed a tool that helps to monitor the efficiency of photosynthesis based on the climate and light data from the existing sensors. That’s another useful piece in the data puzzle in this project to help the customer achieve an even stronger crop and a higher yield,” he comments.

Unique collaborative support

At BASF Vegetable Seeds, Martin is very positive about the combined approach of all the GPE Implementation Partners.

“The whole sector is professionalizing very quickly and it’s increasingly important to be part of an ecosystem. Ultimately, we all share the common goal of helping our customers – the crop production companies – to tackle their challenges. Skilled growers with traditional ‘green fingers’ are getting harder to find but the younger generation is interested in data, so we see GPE as one of the solutions – mainly for our customers, but also for us – to recruit and retain good crop managers. In terms of scalability, autonomous, data-driven growth has the potential to make it possible for growers to manage larger production areas in the future. So GPE ticks several boxes for us and, in my view, it is definitely a case of one plus one equals three,” he says.

Hugely enthusiastic

“In terms of concrete results, we didn’t completely achieve the objectives we had set for ourselves last year,” admits Martin. “But despite that, everyone is hugely enthusiastic about the potential. Above all, it has been a very steep learning curve. I myself have 20 years of experience as a grower but GPE has given me a whole new perspective on crop production. By focusing on the data, you can question all the previously held ‘truths’ about temperatures, light, photosynthesis, and do so much more than you realize.”

BASF has just planted the tomato crop for its second trial season of GPE.

“The strategy for the whole year was prepared and entered into the computer around six weeks ago, so now it’s just a matter of executing it. Also, nutrition is now data-driven with biweekly plant sap analyses to monitor and steer the composition of the plant. It was good to experiment last year, but this year our strategy is less about pushing things beyond the limits and more about maximizing the yield of our main truss variety, Provine, over the entire season, and to create a positive business case for growers. The beauty of data-driven growth is that it makes things more predictable and easier to explain. If we can develop a stable, robust, and reproducible strategy based on GPE principles, we can recommend it to our customers to help them get the very best out of this variety. And then we can hopefully do the same for our other varieties and crops in the near future too,” he concludes