Energy balance in the DSSAT-CSM-CROPGRO model

One potential way to improve crop growth models is for the predict energy balance and evapotranspiration (ET) from first principles, thus serving as a check on “engineered” ET methodology. In this paper, we present new implementations results of an model (EBL) developed by Jagtap Jones (1989) then implemented in DSSAT's CROPGRO (CG-EBL) Pickering et al. (1995) linked balance-photosynthesis that has not been field-tested until now. The code computes other components, well canopy air temperature, based three sources (sunlit leaves, shaded soil surface). Model performance was evaluated with measured biomass fluxes two sites Nebraska, namely, US-Ne2 irrigated maize-soybean rotation field US-Ne3 rainfed field, which are part Ameriflux eddy covariance network (https://ameriflux.lbl.gov/sites). After implementing aerodynamic resistances stomatal conductance Ball–Berry–Leuning, growth, temperature were simulated EBL model. improved predictions slightly over often-used FAO56 method [Penman–Monteith (Allen al., 1998)] 4 5 years both conditions. Further, significant improvement achieved using simulation at various depths compared STEMP, original subroutine DSSAT simulating temperature. Compared available methods, explicitly simulates impacts morphology, physiology management crop's environment mass exchange, turn directly affect water use irrigation requirements, phenology, photosynthesis, sterility, yield crop.