Agriculture provides many ecosystem services such as food, fiber, clean water, and sequestration of carbon. The efficiency of such ecosystem services depends on crop composition and farmer decisions. Current knowledge on landscape changes is focused on crop allocation process at farm scale and rotations at field scale, whereas the impact of farmer decisions on the choice of crop acreages is poorly known. Therefore, we have built a method to assess the evolution of farm crop acreages in time and space and to identify factors ruling agricultural landscape changes. We use a dynamic typology, which is a multi-year classification of farmers. The seven steps of the method include three steps on farm typology, three steps on landscape changes, and then one step on change factors. We applied the method on 3,591 farms in Guadeloupe. Eight farm types were distinguished according to crop acreages. Our results show evidence of a diversification of 111 sugarcane growers toward production of vegetables and fruits. Spatial analysis revealed a relationship between diversification and water availability. Our method could be used to measure ecosystem services or disservices associated with changes in agricultural landscapes.