Livestock intensification and use of natural resources in smallholder mixed farming systems of Bhutan

摘要

Bhutanaimstointensifylivestockproductionnotonlytoimprovelivelihoodsoffarminghouseholdsandtomeettheincreasingdemandsoflivestockproducts,butalsotosustainablyusenaturalresources.ThispaperassessestheimpactandtrendsoflivestockintensificationontheuseofCommonPropertyResources(CPR),andhowthisaffectsthecattlenumbersthatcanbemaintainedandthenitrogen(N)andphosphorus(P)flowsatthefarm.Dataonhousehold,croppingandlivestockactivitieswerecollectedthroughinterviewing183householdsinextensive,semi-intensive,intensive,andintensiveperi-urbanareasintheyears2000and2004.Intheextensiveandsemi-intensiveareas,CPRwasthemostimportantsourceofTotalDigestibleNutrients(TDN)forcattle.Intheintensiveareaswithamajorityofcrossbredcattle,thefarmersreliedlessonCPRthanintheothertwoareas,butstillaboutonequarteroftheTDNrequirementsweremetbygrazingCPR.GrazingintheCPRprovidedthehighestproportionofNPinputsatfarmlevel;withoutgrazingonCPRallfourareaswouldhavehadhighlynegativesoilnutrientbalances.Intensificationoflivestockproductionthroughcrossbreedinghasnotresultedinmajorreductionsincattlenumbersperfarm,butitiscontributingtoreduceduseofCPRbyfarmers.IntensificationpartlyreplacesfarmnutrientflowsfromCPRwithnutrientinputsthroughincreaseduseofconcentrates,conservedfodder,andfertilizers.Moreawarenessofnutrientmanagementisrequiredamongfarmerscoupledwithmoreresearchonnutrientassessments.