Fossil free strawberry cultivation

The increasing acreage of strawberry under protected conditions has to be cultivated fossil free and sustainably, certainly given the recent rise in energy prices. With the KasproIntkam greenhouse crop model, options for further energy saving options have been quantified. Computations are performed for three situations, viz., cultivating a notilluminated everbearing cultivar, an illuminated everbearing cultivar, and a lowchill fresh cultivar. Optimizing setpoints already leads to considerable energy saving, resulting in gas use of 5.7, 5.9 and 7.9 m3 m2 per cultivation season, respectively, which is substantially lower than gas use so far. Total electricity use was simulated at 5.5, 202.2 and 1.4 kWh m2 per cultivation season, respectively, and the total amount of applied CO2 was simulated at 13.1, 18.7 and 9.2 kg m2 per cultivation season, respectively. Subsequently, the energy saving potential of lowering temperature setpoints, increasing relative air humidity setpoints, longer lighting and higher light intensities were simulated. Some findings are: Lowering air temperature, increasing relative air humidity, and in case of an illuminated everbearing cultivar longer illumination or higher light intensity all result in lower gas use. A lower air temperature leads to reduced heating, a higher relative air humidity lead to less ventilation and less heat loss, and longer illumination and higher light levels to more energy supply by the lamps. Lowering air temperature and increasing relative air humidity also leads to lower CO2 supply. But longer illumination of higher light levels lead to longer CO2 shortages and therefore to more CO2 supply. CO2 levels are on the whole similar, as the CO2 regulation aims for a certain minimum value. Longer illumination or higher light levels required electricity in case of an illuminated crop. Other energy costs are much lower. Longer illumination results in higher production levels just as higher light levels.