The invention relates to a plant (1) of the primary industry, having a number of plant components (2). A target value optimizer (4) of a control system (3) of the plant (1) determines threshold values (X*) for the individual plant components (2) based on predetermined target variables (Z) utilizing an optimizer-internal model (5) of the plant (1). The target value optimizer (4) supplies the respective target values (X*) to a model-based controller (8) of the control system (3) controlling the respective plant component (2), at least for part of the plant components (2). The respective model-based controllers (8) receive current values (X) at least from the respective plant component (2). They determine controlled variables (Y) for the respective plant component (2) based on the target values (X*) fed to them, and based on actual values (X) received by them, utilizing a controller-internal model (9) of the plant component (2) regulated by them, and output the controlled variables (Y) determined by them to the respective plant component (2). A model identifier (11) associated with the respective model-based controller (8) receives the controlled variables (Y) output to the respective plant component (2) by the respective model-based controller (8) and the actual values (X) fed to the respective model-based controller (8), determines parameters (P) based on the controlled variables (Y) and actual values (X) received, and optimizes the controller-internal model (9) of the respective plant component (2) based on the parameters (P). The target value optimizer (4) receives the parameters (P) determined by the model identifiers (11) from the same, and optimizes the optimizer-internal model (5) of the plant (1) utilizing the parameters (P).