An artificial turf system, comprises: an artificial grass layer comprising a substrate and pile fibers upstanding from the substrate and an infill layer, disposed on the substrate and interspersed between the pile fibers. The infill layer comprises granules comprising at least 60 wt % polybutylene adipate terephthalate (PBAT) and a pigment or pigment masterbatch. Additives such as one or more fillers or additional polymers may also be used. The granules are compostable and highly flexible. The granules may e.g. be shaped as cylindrical granules. The new infill is in particularly useful as an infill material on artificial turfs for football, where it has passed the highest performance and quality tests by FIFA. The outstanding properties are correlated to a high flexibility and softness of the material, giving rise to reduced requirement of infill (