Monitoreo de servicios ecosistémicos en un observatorio de cafetales agroforestales. Recomendaciones para el sector cafetalero

Ocho años de estudio de la ecofisiología del café, a través de experimentación y de modelación y el monitoreo de los servicios del ecosistema (SE) en una gran finca cafetalera en Costa Rica, revelaron varias recomendaciones prácticas para los agricultores y los formuladores de políticas. El sistema de cultivo estudiado dentro de nuestro observatorio colaborativo (Coffee-Flux), corresponde a un sistema agroforestal (SAF) a base de café bajo la sombra de grandes árboles de Erythrina poeppigiana (16% de la cubierta del dosel). Una gran cantidad de SE y limitantes dependen de las propiedades locales del suelo (en este caso Andisoles), especialmente de la erosión/infiltración, el agua/carbono y la capacidad de almacenamiento de nutrientes. Por lo tanto, para la evaluación de SE, el tipo de suelo es crucial. Una densidad adecuada de árboles de sombra (bastante baja aquí por la condición de libre crecimiento), redujo la severidad de las enfermedades de las hojas con la posibilidad de reducir el uso de plaguicidas y fungicidas. Un inventario simple del área basal en el collar de las plantas de café permitió estimar la biomasa subterránea y la edad promedio de la plantación, para juzgar su valor de mercado y decidir cuándo reemplazarla. Las fincas de café probablemente estén mucho más cerca de la neutralidad de C que lo indicado en el protocolo actual de C-neutralidad, que solo considera árboles de sombra, no los cafetos ni el suelo. Se proponen evaluaciones más completas, que ncluyen árboles, café, hojarasca, suelo y raíces en el balance C del SAF. Los árboles de sombra ofrecen muchos SE si se gestionan adecuadamente en el contexto local. En comparación con las condiciones a pleno sol, los árboles de sombra pueden (i) reducir la erosión laminar en un factor de 2; (ii) aumentar la fijación de N y el % de N reciclado en el sistema, reduciendo así los requisitos de fertilizantes; (iii) reducir la severidad de enfermedades de las hojas; (iv) aumentar el secuestro de C; (v) mejorar el microclima y (vi) reducir sustancialmente los efectos del cambio climático. En nuestro estudio de caso, no se encontró ningún efecto negativo sobre el rendimiento del café

Spatial-temporal variations of nitrous oxide emissions in coffee agroforestry systems in Costa Rica

International audienceThis study investigates spatial-temporal trends in N2O emissions from coffee production systems in Costa Rica with a focus on the effects of nitrogen fertilisation, topography and soil type. This is done by combining (i) multiyear continuous dynamic chamber measurements from sites with different fertilisation levels, (ii) static chamber measurements taken along a typical sloping coffee field and (iii) measurements from a laboratory incubation experiment with nutrient addition to different soil types. In the field and in the laboratory, additions included standard NPK fertiliser, ammonium nitrate (NH4NO3) as well as potassium nitrate (KNO3). Soils in a laboratory experiment were incubated under both drained and flooded conditions. Continuous measurements from automatic chambers show that annual N2O fluxes were dominated by bursts over few weeks following N-fertilisation with peak emissions up to 60 g N-N2O ha(-1) day(-1). A two-month slope experiment with static chambers after KNO3-fertilisation with 90 kg N ha 1 showed N2O significant differences between the highest daily emission rates from the top and the bottom of the slope (134 +/- 20 g N-N2O ha(-1) and 336 +/- 104 g N-N2O ha(-1), respectively) which can be explained by NO3- transport downhill and flooded conditions favouring denitrification at the bottom of the slope. Incubation experiments indicate that denitrification is the main process controlling N2O emissions but also that nitrification can result in low N2O emission rates under drained conditions. It can be concluded that the reported N2O emissions from the coffee agroforestry systems are generally low, but may be underestimated, as both poorly drained depressions functioning as N2O hotspots as well as temporal N2O bursts need to be taken into account

The "Coffee-flux collaborative observatory": measuring and modeling carbon, nutrients, water and sediment Ecosystem services in a coffee agroforestry watershed (Costa Rica)

il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : REPORTCoffee-flux is a platform where collaborative research on coffee agroforestry is promoted: data are being shared between collaborators and positive interactions are enhanced. The philosophy is to concentrate several investigations on one specific site and for several years, to share a useful common experimental database, to develop modelling and to publish results in highly-ranked scientific journals. Applied research is also highly encouraged (e.g. C-Neutral certification, NAMA, Agronomy, etc.). Coffee-Flux benefits from infrastructure, easy access from CATIE and very good security, ready to welcome complementary scientific investigations and collaborations. The project is wide open to complementary projects, scientists and of course to students. The core data base is for sharing. The aim of Coffee-Flux is to assess carbon, nutrients, water and sediment Ecosystem Services (ES) at the scale of a coffee agroforestry watershed. Observation, experimentation, modelling and remote-sensing are combined, collecting data and calibrating models locally, then upscaling to larger regions. The project has been running continuously since 2009, in order to encompass seasonal and inter-annual fluctuations of coffee productivity and ecosystem services