During Wageningen University’s Autonomous Greenhouse Challenge team AuTomatoes applied the principles of Plant Empowerment in their winning AI strategy. Thus, the team’s strategy was focused on the plant and its balances, in order to create a balanced and empowered crop. So how did they do this? Hoogendoorn explains all about the water balance and how team AuTomatoes kept it in balance at all times.
The water balance is the balance between the input to and output of water from the plants. Output of water is mainly caused by evaporation. Only a little portion of the total water uptake is stored in the plant and the fruits. Plants need to evaporate and thus take up water from the root zone for three reasons: the uptake of nutrients, for growth, and for cooling. In order to keep the water balance in balance, the uptake of water from the root zone must equal at least the evaporation rate. Thus, to ensure sufficient water availability, irrigation needs to be aligned with the plant’s evaporation rate.
Various algorithms were developed to support the tomato crop’s water balance in order to optimize the tomato yields. For example, some of these algorithms made use of a plant temperature sensor and pyrgeo sensor to calculate the net radiation on plant level. Based on this calculation the algorithms decided on the optimal screen position for the crop to receive the right amount of radiation to keep a steady evaporation rate.
In addition, as part of their AI strategy the team developed algorithms that closely monitored the dry-back of the slab. During the day the crop needs to receive a sufficient amount of water, and during the night there needs be enough oxygen available in the slab. For this team AuTomatoes developed the Irrigation Optimization algorithm that stops irrigation in time to reach the desired amount of dry-back after a certain amount of time. The AI model makes sure that the crop receives the optimal amount of water, while at the same time it avoids saturation of the slab during periods with little or no light, to maintain all beneficial parameters, such as oxygen and microorganisms.