CARICE: A Rice Model for Scheduling and Evaluating Management Actions
- Baird C. Miller ,
- Theodore C. Foin and
- James E. Hill
Crop growth modeling can be useful in crop management, but previous rice crop models lack the morphologically accurate phenological detail needed for practical application. We designed a rice crop management model, CARICE, for scheduling management actions on the farm and evaluating consequences of alternative management strategies. A simple rice crop productivity model was expanded to include (i) phenology, based on leaf stage; (ii) tiller development, to establish yield components (iii) assimilate partitioning by developmental stage, (iv) assimilate partitioning patterns of California cultivars; and (v) direct-seeded cultural system. The key phenological events were accurately simulated: leaf stage development followed the expected pattern; predicted 50% heading was within 6 d of the actual heading dates; and grain filling predictions were within 1 to 11 d of field observations. Cultural management strategies simulated included delayed planting, and managing barnyardgrass (Echinochla spp.; BYG) competition by increasing water depth and seeding tale. Simulated yield results were within the range of field observations, although total aboveground biomass was overestimated. The model simulated a 27% loss in grain yield from a 21-d delay in planting, which is close to the 21% loss measured in the field. At 11 and 54 BYG plants m−2, the model simulated 20.6 and 54.6% yield reductions relative to the control, as compared with 32.5 and 57.5% reported in the literature. The model predicted the interactive effect of rice seeding rate and water depth management or reducing barnyardgrass competition. The morphologically accurate phenology submodel and the yield-component approach to calculating yield are keys to using CARICE for scheduling and evaluating management actions and strategies.
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