Package net.simplace.sim.components.models.lintul
package net.simplace.sim.components.models.lintul
Crop model based on Lintul2 with additional changes
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== Overview ==
The sim components of this model are based on Lintul2, but include
some changes
- nitrogen limitation from Lintul3
- addition of drought tolerance parameter
- optional use of reference evapotranspiration
- etc.
The initial implementation comes from LintulFAST (written in C#).
For implementation of original versions of Lintul2 and Lintul5, as well as
LintulFAST see the corresponding sim components below.
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ClassDescriptionEvapTran.java estimates the potential actual crop transpiration and soil evaporation WIKI_START EvapTran.java estimates the potential actual crop transpiration and soil evaporation based on the potential values considering the crop available soil water content and the crop water demand at a given day as a function of LAI .EvapTranDemand.java estimates the potential crop transpiration and potential soil evaporation WIKI_START `EvapTranDemand.java` estimates the potential crop transpiration and potential soil evaporation either from daily reference ET (REFET) measurements which are specified by the user or by a modified PENMAN approach. === Reference ET measurements (Citation to this section not found) === This approach assumes that daily observations of a reference ET (r.g.WIKI_START LintulBiomass.java calculates daily increase in crop total biomass and LAI depending on intercepted radiation and the occurrence of nitrogen or water stress === Light interception === Incoming radiation (input variable DTR in MJ m-2) is intercepted by the crop canopy depending on the extinction coefficient kc and the actual LAI assuming that photosynthetically active radiation is 50% of the global radiation Intercepted photosynthetically active radiation (PARINT in MJ m-2) is then calculated as: WIKI_END \[ \begin{eqnarray} PARINT & = & 0.5 \cdot DRT (1 - e^{-k LAI}) \end{eqnarray} \] WIKI_START === Daily increase in total biomass === Daily increase in total crop biomass is calculated based on the intercepted photosynthetically active radiation (PARINT) depending on the crop specific light use efficiency (LUE) and on the major stress occuring at the same day.WIKI_START Soil water balance calculation during crop growth for a one layer soil profile including canopy interception, Drainage, RUNoff and IRrigation routines from LINTUL.WIKI_START !WIKI_START LintulPhenology.java calculates the development stage (DevStage) of a crop based on the ratio between accumulated degree days and the a user-defined, crop and cultivar specific temperature sum requirement .Root depth growth calculation (only root depth, no root biomass) WIKI_START LintulRoot.java The SimComponent LintulRoot.java calculates the daily increase in root depth (RROOTD in m d-1) depending on the crop development stage (DevStage) and the actual volumetric soil water content (WC).WIKI_START LintulWaterStress calculates the transpiration reduction factor (TRANRF) based on the ratio between actual crop transpiration (TRAN in mm) and potential crop transpiration (PTRAN in mm): WIKI_END \[ \begin{eqnarray} TRANRF &=& MIN(1,\frac{TRAN}{PTRAN} \cdot \frac{1}{DroughtTolerance}); \end{eqnarray} \] WIKI_START TRAN and PTRAN are provided by the SimComponent EvapTran.java.The SimComponent NitrogenDemand calculates crop specific nitrogen demand as a function of crop development stage WIKI_START The routines for this SimComponent are taken from Lintul 3 (Shibu et al. 2010).Calculates effective temperature sums for anthesis and maturity based on daily temperature and base temperatures WIKI_START == Daily rates of temperature sums == The model takes daily mean temperature `iAirTemperatureMean` and the parameters `cBaseTempBeforeAnt` and `cBaseTempAfterAnt` and calculates the coresponding `EffectiveTempRateBeforeAnt` and `EffectiveTempRateAfterAnt` by subtracting the base temperatures from the mean temperatures.