Introduction: Net primary productivity (NPP) plays a key role in the knowledge of the functioning, production and C sequestration of ecosystems. The part of C allocated to belowground organs is non-negligible and amounts to 33% of total NPP for fine roots (Jackson et al. 1997). Fine root turnover is rather high, particularly in tropical ecosystems (Jourdan et al. 2008). Nevertheless, belowground NPP (bNPP) was usually estimated from shallow soil samplings whereas it is now well-known that fine roots can grow deep into the soil and reach several meters in depth (Maeght et al. 2013). Agroforestry systems are often said to exhibit root competition which leads to deep rooting ecosystems. Coffee trees associated to native shade trees don't escape to this assumption. They are pruned every 5th year and resprout biomass represents a relatively small contribution to overall plant biomass, due to accumulation in perennial parts only (stumps, coarse roots). Our objectives here were to assess coffee root biomass and bNPP along the whole rooting profile (0-4.5 m) in coffee tree plantations as a function of distance to shade tree, between coffee trees and soil depth. Method: In this study, root biomass by root category was assessed on ten coffee plants, distributed according to an inventory of diameter at collar via 10 Voronoi trenches down to 1.5 m and 2 deep trenches along the full rooting profiles, down to 4.5 m. Fine root NPP was assessed by sequential coring with 8-cm-diameter cylindrical auger during 16 consecutive months in Costa Rica within the 0-30 cm soil horizon. We then extrapolated to the complete rooting profile of coffee trees using the Voronoi and deep trenches. Fine root bNPP calculations were performed using “decision matrix” (including fine root decomposition rate; Fairley and Alexander 1985) and “Max-Min” (McClaugherty et al. 1982) methods. Coarse root bNPP calculations were performed by allometry with the diameter at collar and annual growth rate. Results and