Incentives based on extrinsic motivations such as Payments for Environmental Services (PES) could negatively affect intrinsic motivations (i.e., motivational crowding-out). This effect occurs when conservation levels after the intervention decline relative to those existing before the PES implementation. However, few experimental studies have assessed PES effects on motivations once financial incentives are missing. Moreover, experimental research still lacks insights on PES designs that may prevent motivational crowding-out. This research aims to i) provide a classification of plural motivations and values; ii) assess the motivational crowding effects associated to a PES design based merely on monetary incentives; and iii) assess the motivational crowding effect of integrating plural motivations and values in PES design via environmental awareness and social recognition. We conducted a lab-in-the-field experiment followed by a questionnaire involving 120 participants in rural Cali, Colombia. We use a difference in differences (DiD) approach to show that while PES had a crowding-out effect, integrating plural motivations and values via environmental awareness had a crowding-in effect on conservation. We also found that irrespectively of the PES treatment women were more prone to conservation. We conclude that conservation instruments such as PES could be more effective if they integrate plural motivations and values, rather than only emphasize extrinsic motivations and instrumental values.