Use of CAF2007, a process-based model of coffee agroforestry systems, to represent and understand the evolution of coffee productivity in two long term trials in Mesoamerica
Coffee is frequently cultivated under shade in Mesoamerica. The effects of shade trees on coffee productivity depend on the environmental conditions: mainly temperature, humidity, solar radiation and rainfall patterns. Crop models may be useful to assess current systems and modify their shade management, to improve productivity and provision of environmental services. The CAF2007 model was recently developed to simulate coffee growth and yield elaboration under shade at plot scale, under Mesoamerican environmental and technical conditions. The model was first compared with the scientific and local knowledge on coffee productivity under shade. Our results show that coffee phenology is correctly accounted for in the model, although the module that simulates the effects of light and water stress on flowering needs adjustment. The water module, carbon accumulation module and N balance module were then tested in coffee plantations, using 2 experimental data sets. When adequately parameterized, the modules did simulate correctly the variables measured, with a few exceptions. Proposals were formulated to develop or modify modules, to improve the simulations. The model was then parameterized to reproduce 2 data sets from two 7-year-old experiments of CATIE, with coffee cultivated under diverse shade trees and N management: one in Turrialba, Costa Rica, under humid conditions, with no definite dry season, and one in Masatepe, Nicaragua, with a very pronounced dry season. The model was able to reproduce the evolution of coffee bean production and the accumulation of biomass in the experiments. Functional explanations for observed evolutions, related to excessive shade and to insufficient N inputs, were proposed from the model. The implications of these results for future model improvement and applicability are discussed. (Texte intégral)
| Main Authors: | , , , , , , , , , , , |
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| Format: | conference_item biblioteca |
| Language: | eng |
| Published: |
WCA [Nairobi]
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| Subjects: | U10 - Informatique, mathématiques et statistiques, F08 - Systèmes et modes de culture, F01 - Culture des plantes, F62 - Physiologie végétale - Croissance et développement, agroforesterie, Coffea, http://aims.fao.org/aos/agrovoc/c_207, http://aims.fao.org/aos/agrovoc/c_1720, http://aims.fao.org/aos/agrovoc/c_1434, http://aims.fao.org/aos/agrovoc/c_5171, http://aims.fao.org/aos/agrovoc/c_1920, |
| Online Access: | http://agritrop.cirad.fr/553627/ http://agritrop.cirad.fr/553627/1/document_553627.pdf |
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| Summary: | Coffee is frequently cultivated under shade in Mesoamerica. The effects of shade trees on coffee productivity depend on the environmental conditions: mainly temperature, humidity, solar radiation and rainfall patterns. Crop models may be useful to assess current systems and modify their shade management, to improve productivity and provision of environmental services. The CAF2007 model was recently developed to simulate coffee growth and yield elaboration under shade at plot scale, under Mesoamerican environmental and technical conditions. The model was first compared with the scientific and local knowledge on coffee productivity under shade. Our results show that coffee phenology is correctly accounted for in the model, although the module that simulates the effects of light and water stress on flowering needs adjustment. The water module, carbon accumulation module and N balance module were then tested in coffee plantations, using 2 experimental data sets. When adequately parameterized, the modules did simulate correctly the variables measured, with a few exceptions. Proposals were formulated to develop or modify modules, to improve the simulations. The model was then parameterized to reproduce 2 data sets from two 7-year-old experiments of CATIE, with coffee cultivated under diverse shade trees and N management: one in Turrialba, Costa Rica, under humid conditions, with no definite dry season, and one in Masatepe, Nicaragua, with a very pronounced dry season. The model was able to reproduce the evolution of coffee bean production and the accumulation of biomass in the experiments. Functional explanations for observed evolutions, related to excessive shade and to insufficient N inputs, were proposed from the model. The implications of these results for future model improvement and applicability are discussed. (Texte intégral) |
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