Effects of Inga densiflora on the Microclimate of Coffee (Coffea arabica L.) and Overall Biomass under Optimal Growing Conditions in Costa Rica

background

This article compares a coffee agroforestry system shaded with Inga densiflora to a coffee monoculture in optimal coffee growing conditions in Costa Rica. The two systems were investigated to determine differences in microclimate, coffee yield, and vegetative development of the coffee plants.

Goals & Methods

Two experimental design plots were used in this study, both following the same coffee monoculture for 15 years but with one shaded with an agroforestry system and one without any shade. Both sites were planted and managed similarly. Over the two years of the study, the following were measured at regular intervals: radiation transmission and interception, leaf temperature, soil water content, tree growth leaf area index and biomass monitoring, yield, and fine root biomass. 

Conclusions & Takeaways

 Air temperatures were moderated in the shaded system, with temperatures up to 5°C lower during the day and 0.5°C higher during the night in the shaded system. Coffee leaf temperature extremes were also moderated as a result. During the early years of shade tree establishment, no significant difference was found in coffee yields between the two systems. However, as shade levels passed 60% in later years, a yield decrease of 30% was observed in the shaded plot due to inadequate shade tree pruning. Aerial biomass accumulation was 3 times as great in the shaded system.