手法を比較

	Nitrogen Use Efficiency Analysis	Crop Simulation Modeling
分野	Food Agriculture Studies	Food Agriculture Studies
系統	Process / pipeline	Process / pipeline
提唱年	2005	2003
提唱者	Jagdish K. Ladha and colleagues (synthesis of agronomic NUE indicators)	James W. Jones et al. (DSSAT); Dean Holzworth et al. (APSIM)
種類	Descriptive indicator pipeline for nitrogen-use efficiency	Process-based dynamic simulation pipeline for crop growth and yield
原典	Ladha, J. K., Pathak, H., Krupnik, T. J., Six, J., & van Kessel, C. (2005). Efficiency of Fertilizer Nitrogen in Cereal Production: Retrospects and Prospects. Advances in Agronomy, 87, 85-156.	Jones, J. W., Hoogenboom, G., Porter, C. H., Boote, K. J., Batchelor, W. D., Hunt, L. A., Wilkens, P. W., Singh, U., Gijsman, A. J., & Ritchie, J. T. (2003). The DSSAT cropping system model. European Journal of Agronomy, 18(3-4), 235-265.
別名	NUE Analysis, Nitrogen Use Efficiency, Fertilizer Nitrogen Efficiency Analysis, Nitrogen Recovery Efficiency Analysis	Crop Growth Simulation, Process-Based Crop Modeling, Crop Systems Modeling, Dynamic Crop Modeling
関連	4	4
概要	Nitrogen use efficiency (NUE) analysis is the set of agronomic indicators used to quantify how effectively applied nitrogen is converted into harvested yield and nutrient uptake, and how much escapes to the environment. Synthesized authoritatively by Jagdish Ladha and colleagues in 2005, the family includes agronomic efficiency (extra yield per unit of nitrogen applied), recovery efficiency (the fraction of applied nitrogen the crop takes up), physiological efficiency (yield produced per unit of nitrogen taken up), partial factor productivity (total yield per unit of nitrogen applied), and the partial nutrient balance of nitrogen out in harvest versus nitrogen in from inputs. Because nitrogen is the most yield-limiting and environmentally costly nutrient in cereal systems, these indicators are central to diagnosing fertilizer performance, guiding the right rate, source, timing, and placement, and benchmarking the sustainability of cropping systems.	Crop simulation modeling uses process-based, dynamic computer models to predict how a crop grows and yields under specified weather, soil, and management, by numerically integrating mechanistic equations for development, photosynthesis, and water and nutrient balances on a daily time step. The two most widely used platforms are DSSAT, documented by James Jones and colleagues in 2003, and APSIM, whose modern architecture was described by Dean Holzworth and colleagues in 2014. Rather than fitting a statistical curve to yield data, these models encode the underlying biophysics — temperature-driven phenology, radiation-use efficiency, soil water and nitrogen dynamics — so they can extrapolate to weather, soils, and management combinations never directly observed. This makes crop models powerful tools for in silico experimentation, scenario analysis, and climate-change and management impact assessment where field trials alone would be impossibly slow or costly.