The present invention enables the acquisition of plant information at a lower cost than a chlorophyll meter or a spectroscopic analysis device, as a result of being configured so as to obtain information about a plant from image data of the plant, on the basis of the color of the surface of the plant. A plant information acquisition system, a plant information acquisition device, a plant information acquisition method, a crop management system, and a crop management method are provided in order to support fertility management via a smart phone, etc., as a user terminal, during production of rice plants and other crops on the basis of observed data such as converted leaf color value etc., calculated from image data of the crop, said fertility management including fertilization management, such as determining the amount of fertilizer, and other farm work. A camera 30 is connected to a smart phone 1. A converted leaf color value can be obtained from image data obtained by capturing images of rice plant leaves using the camera 30. By sending this converted leaf color value to a management server 10, information about, for example, fertilizer amounts required when the converted leaf color value is lower than a reference value can be obtained as management information for fertilization management.La présente invention permet l'acquisition d'informations concernant une plante à un coût moindre que celui d'un chlorophylle-mètre ou d'un dispositif d'analyse spectroscopique, en conséquence de sa configuration qui permet d'obtenir des informations concernant une plante à partir de données d'imagerie de la plante, sur la base de la couleur de la surface de la plante. Un système d'acquisition d'informations concernant une plante, un dispositif d'acquisition d'informations concernant une plante, un procédé d'acquisition d'informations concernant une plante, un système de gestion de culture et un procédé de gestion de culture sont utilisés afin d'accompagner la gestion de fertilit
