Spatially Scaled and Customised Daily Light Integral Maps for Horticulture Lighting Design

In order to produce high-quality plant materials, it is necessary to consider a series of biotic and abiotic inputs. In this study, we focus on horticultural light climate mapping in Europe using earth and weather observation and information technologies. It is widely accepted that optimised light programmes and spectral recipes with dedicated wavelengths can most efficiently support the photoreceptors and the controlled plant production. By knowing the DLI (Daily Light Integral) for a particular area, growers can optimise their crop management strategies, such as selecting the most appropriate crops for the light levels, determining optimal planting times, and selecting the best location for their crops. Generating a sufficiently resolved DLI map usually demands both a spatial and spectral downscaling process. In our present research we thus focus on (i) the development of a semi-automatic DLI mapping workflow and (ii) a first exemplary visualisation of an all-season DLI map for a European country, which can easily be adapted to any other country based on the suggested approach. A special focus was put on the development of precise DLI values at a European scale, especially experiencing with 1 and 2 mol·m−2·d−1 DLI value increments. Additional purposes of DLI mapping such as the adaption to climate changes and the efficient use of energy were also addressed as the present energy crisis documents the need to adapt future horticulture engineering systems both for indoor and outdoor production. Customised DLI maps are also useful secondary information sources for solar energy mapping, especially for renewable energy sources.