Model-based
optimization
of crop
management
for climate
forecast
applications.
Source: Transactions of the ASAE. 44, no. 5 (Sept/Oct 2001): p. 1319-1327.
Additional Info: St. Joseph, Mich. : American Society of Agricultural Engineers
1958- Publishing Agencies: US Imprint, not USDA
Standard No: ISSN: 0001-2351
Language: English
Abstract: Recent improvements in climate forecast technology have led to new uses of
crop models for exploring potential benefits of tailoring crop management to
expected weather conditions. However, conventional use of crop models limits
each simulation experiment to a small, predetermined subset of the possible
combinations of variables. Unfortunately, much of the potential contribution of
dynamic models is untapped when seeking optimal management parameters
under varying environmental and/or economic scenarios. This research linked a
widely used crop model, CERES-Maize, to a simulated annealing algorithm and
a partial budget calculator, to permit optimizing economic results by varying
crop management. Management was optimized by El Nino-Southern Oscillation
(ENSO) phase using a 67-year series of daily weather data from Pergamino,
Argentina. The per-hectare value of the ENSO-optimized management was
calculated. Nine management variables were included in the optimizations, at
two levels of resolution (increments or step size) for each variable. The
optimization algorithm, Adaptive Simulated Annealing (ASA), required tuning to
achieve reasonable reliability and efficiency. Although the optimizer did not
consistently find the precise optimal combination at either resolution, it did
consistently find the optimal "region", with small differences in some
management variables. A "quenching" variation of simulated annealing was
found to be much faster but considerably less reliable. Optimization by ENSO
phase leads to phase-differentiated management: earlier planting date, higher
N applications, and increased plant density lead to higher yields during El Nino,
as compared to neutral and especially La Nina years. The CERES-Maize to
ASA linkage is useful for investigating optimal combinations of management
practices using validated crop simulation models.