According to the European Water Framework Directive, as of 2027, no emissions from greenhouses may reach surface water. At the same time, horticulture is working towards autonomous cultivation. Starting next year, Wageningen University & Research, BU Greenhouse Horticulture will research how sensors and models for water and fertilizers can contribute to this goal. Researcher Francisco Mondaca Duarte explains: "The question is, how can we further optimize fertigation application in substrates?"
For emission-free cultivation, the grower—or the computer—must know how much water and fertilizer the crop uses. To make this decision, the grower needs a support system combined with experience. There are two main support methods to determine this: sensors and models. Starting with the latter, models are representations of reality based on a number of assumptions, for instance, about the composition of the substrate used in cultivation. The actual composition may vary, causing the model to provide inaccurate output.
With sensors, it's possible to measure the actual amounts of water and fertilizer present in a substrate. There are, for instance, sensors for phosphorus or nitrogen levels. However, as Mondaca Duarte points out, these sensors do not necessarily reflect reality. For example, the presence of the crop itself can cause a sensor to measure an incorrect level. This means that a sensor must be checked regularly and recalibrated if necessary.
Fully autonomous cultivation
Both models and sensors introduce uncertainties in predictions or measurements. "By combining models and sensors, we can significantly reduce this uncertainty." This year, WUR will research this combination, including in WUR's Greenhouse2030 and with cultivation companies. "This way, we are working towards the next step for fully autonomous cultivation: automatic water application and fertilizer administration without emissions," says Mondaca Duarte, who is finalizing his Ph.D. on water irrigation models. "It's great to apply my PhD topic in my work towards making horticulture more sustainable."
Source: Wageningen University & Research