caa a22 4500 44586480X CHVBK 20180317145454.0 cr unu---uuuuu 170323e20110401xx s 000 0 eng 10.1007/s11119-010-9174-5 doi (NATIONALLICENCE)springer-10.1007/s11119-010-9174-5 An analytical C3-crop growth model for precision farming [Elektronische Daten] [Mikko Hautala, Mikko Hakojärvi] A simple and transparent analytical model for C3-crop biomass accumulation is introduced. The model is aimed to be used as a decision tool in precision farming. It is valid when growth is limited only by radiation or water and gives the optimal (maximum) biomass. It contains 8 fixed parameters, all with a clear basis in physics, chemistry and physiology. As a function of time, the growth is divided into two phases: exponential and linear. At an early stage of growth, the growth is exponential due to the expanding leaf area of the crop. At this stage, the model needs 6 parameters. The growth becomes linear when the leaf area is adequate to use all possible radiation. The model needs 2 parameters at this later stage. Water-limited growth needs an additional set of 4 parameters to describe phenomena of water related processes. When water is a limiting factor, the root-growth model becomes critical because the daily root growth determines the crop's growth directly. The model was tested first against field data at one point where all relevant inputs and parameters of the model were measured. Despite the simplicity of the model, there was a good agreement between simulated and measured values of biomass and leaf area. A scenario is described to show how the model may be used in practice and what kind of field data is needed. In on-line precision farming the key factor is the amount of radiation used by the crop, which can be measured adequately with two sensors, one above and one below the canopy. Springer Science+Business Media, LLC, 2010 Yield variation nationallicence Spatial growth model nationallicence Precision agriculture nationallicence Hautala Mikko Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 28, 00014, Helsinki, Finland aut Hakojärvi Mikko Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 28, 00014, Helsinki, Finland aut Precision Agriculture Springer US; http://www.springer-ny.com 12/2(2011-04-01), 266-279 1385-2256 12:2<266 2011 12 11119 https://doi.org/10.1007/s11119-010-9174-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11119-010-9174-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hautala Mikko Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 28, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Hakojärvi Mikko Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 28, 00014, Helsinki, Finland aut NATIONALLICENCE 773 0- Precision Agriculture Springer US; http://www.springer-ny.com 12/2(2011-04-01), 266-279 1385-2256 12:2<266 2011 12 11119 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer