Annual Report 2006/07 - ETH - North-South Centre North-South ...

ZIL research projectsLivestocksystemsresearchFodder resourcesZIL research project, Phase VProject leaderEmmanuel FrossardContact personsAstrid ObersonSabine DouxchampsCollaboratorsIdupulapati Rao, Axel Schmidt,Rein van der Hoek, CIAT, Colombia /Martin Mena, INTA, Nicaragua /Andrea Mayer, Michael Kreuzer,ETH ZurichDurationJanuary 2007 – December 2009Benefits of cover crop legumesin smallholder crop-livestock systems ofthe hillsides of Central AmericaDue to population growth in poor rural areas of theNicaraguan hillsides, land use has been intensified in a waythat adversely affects soil fertility. Crop and livestock productivityhas therefore declined, leading to the decrease of incomeand to food insecurity. Cropping is limited to two shortand successive rainy seasons, and livestock suffers from forageshortages during the following five-month dry season.We will evaluate the effects of introducing Canavalia brasiliensis(canavalia), a highly drought-adapted cover legume, eitheras green manure for improving crop productivity or as foragefor improving animal productivity, into the traditional maizebean-livestockproduction system. We hypothesise that itmakes a significant N input in the soil-plant system throughsymbiotic N 2 fixation, decreases water losses and provides agood quality animal feed during the dry season.In May 2007, trials were set up on eleven smallholder farmsin the district of Condega. Green manure trials aim to comparemaize yields and the N budget of the maize-bean rotationwith the maize-canavalia rotation, where canavalia ispartially removed or not during the dry season to serve asanimal feed. Yield and quality of milk from cows grazing thetraditional maize stover versus a maize-canavalia mixturewill be compared in livestock trials. N dynamics in thesoil/plant system will be studied in depth in an on-stationfield experiment, using direct and indirect 15 N-labelling techniques.Forage quality of canavalia will be assessed in feedingtrials with sheep.The project is carried out in collaboration between twogroups of the ETH Zurich (Plant Nutrition and AnimalNutrition), the International Centre for Tropical Agriculture(CIAT) and the Nicaraguan Institute of AgriculturalTechnology (INTA).The socio-economic aspects of this work are addressed by aparallel project funded by the Systemwide LivestockProgramme of the CGIAR, and conducted by CIAT (F. Holmannet al.), INTA (M. Mena) and the University of Zurich (C. Binder).Left: Livestock in smallholder farms of Condega (Department of Esteli, Nicaragua)Right: Canavalia brasiliensis in the field trial of San Dionisio (Department of Matagalpa, Nicaragua)32