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Ann. For. Sci. 66 (2009) Available online at:c© INRA, EDP Sciences, 2009 www.afs-journal.org

Book review

Conceptual basis, formalisations and parameterizationof the STICS crop model

Nadine Brisson, Marie Launay, Bruno Mary, Nicolas Beaudoin

Obviously STICS, “Simulateur mulTIdisciplinaire pour les Cultures Standards”, which could be translated as “multidisciplinarysimulator for standard crops”, is one of the most famous models in the scientific community. It has been developed since 1996 byINRA in collaboration with many other research or professional institutes. For many scientists STICS is a reference model. Atfirst developed for agronomic purposes it is now used by a larger community. It has been applied to plants as different as cereals,rape, lettuce, strawberry, sugar beet, grassland, tomato, vine. . . and more recently to intercropping. To my knowledge, it has notyet been used for forest purposes, what would probably require some adjustment, whereas the basis for woody plants is availablewith developments on vine for instance. STICS simulates, in one dimension, at a daily time-step, the growth, development andproduction of the crop according to resource availability (mainly light, water, and nitrogen), physical variables (mainly radiation,temperature, and air moisture) and technical operations of crop management. The book (297 p.) exhaustively develops thesedifferent topics in 11 chapters, introduction, development, shoot growth, yield formation, root growth, management and cropenvironment, water balance, nitrogen transformations, transfers of heat, water and nitrate, cropping systems, involvement of theuser in the model operation.

Each chapter first develops the conceptual basis bearing the considered module which is very useful to understand the formali-sation of the different processes. Perhaps this conceptual framework would even have required further development, in particularfor teaching purposes, whereas it is true that one can refer to more detailed publications exhaustively referenced at the end of thebook (more than 300 references). The process formalisation is then developed in full details. Obviously, the book is a referencefor all model users from that point of view. It provides both an updated vision on how processes could be integrated in a modeland how the knowledge is used in STICS. Reading of these sections is not always easy due to the extensive use of shortenednames or symbols for parameters and variables, which are of course plentiful (more than 600 for the whole model, whereas notnecessarily all used for a given simulation). Fortunately, a table at the end of the book provides the definition and units of symbolsand short names that help greatly to follow the equations. Each chapter is illustrated up by schemes, flow diagrams and numerousillustrations giving the effect of parameters with also examples of potential applications of the model on different crops.

STICS simulates not only the crop growth but also the whole cropping system as illustrated and developed in chapter 10. Thisrequires that the user has data to fill out the numerous parameters, or at least ideas on the parameter values, linked to the dailyweather throughout the simulation, the soil characteristics, the phenology and the ecophysiological features of the crop, and alltechniques (fertilisation, irrigation, harvest, pruning. . . ) applied during one or several crop cycles. As for all complex models,this raises concerns about potential incorrect results or conclusions coming from the use of wrong parameters and how can wesecure the parameterization phase in using the model. The sub-chapter 11.4 is dedicated to such a problem, as a conclusion tothe book, with examples of methodology and values of parameters for a few crops. This certainly allows starting with the model,whereas one would have liked to know more on that aspect. Finally a full simulation would have been welcome at the end of thebook as a practical example of the potential use of STICS but we recognise that such examples can be found in the referencedarticles.

Definitely this reference book is of course recommended to all users or potential users of the model but also, as an updatedsynthesis of knowledge in modelling and formalisation of crop growth and development processes, to anyone (researcher, student,professional) wanting to know more on modelling or simply crop science.

Philippe Balandier

2009, 304 pages, 52 e – ISBN 978-2-7592-0169-3Editions QUAE c/o INRA RD 10, 78023 Versailles Cedex, FranceTel. 01.30.83.34.06 – Fax : 01.30.83.34.49serivceclients@quae.frCatalogue en ligne : http://www.quae.com