Evaluation of the STICS model for simulating vineyard water balance under two different water management strategies

International audienceWater is an important factor to be considered for its contribution to yield and product quality of grapevine. Recently, the STICS model has been adapted to simulate grapevine crops. The present work aimed to evaluate its ability to represent the vineyard water balance in two situations differing in annual rainfall and in water management policies. To this end, an irrigated vineyard in Chile and an irrigated and a non-irrigated vineyard in France were used to assess the model. The crop model gave a good estimation of the main stages of grapevine phenology. Soil water content was well estimated in both situations (model efficiency (EF) approximate to 0.8), as well as total dry matter production and yield (EF >= 0.8). The fraction of transpirable soil water (FTSW) calculated from variables simulated by the model were compared with FTSW measurements in each situation. The time of occurrence and duration of the vine water stress simulated by the model were close to the ones calculated on the basis of FTSW values. Thus, it is possible to identify critical periods concerning the vine water status thanks to the model. Then, vineyard water management could be adjusted. However, in situations where surface runoff would be significant, the present approach of water balance modelling in STICS could be inappropriate. Moreover, some imprecisions still remain, notably in the simulation of the surface soil layer humidity. Although these deficiencies have few consequences on global water balance modelling, they could have a significant impact on the quality of nitrogen balance simulation