科研之友
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摘要
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.
- 出版日期2011-4
