Título:	Sustainability assessment of slash-and-burn and fire-free agriculture in Northeastern Pará, Brazil.
Autoria:	RODRIGUES, G. S. KITAMURA, P. C. SÁ, T. D. de A. VIELHAUER, K.
Afiliação:	GERALDO STACHETTI RODRIGUES, CNPMA PAULO CHOJI KITAMURA, CNPMA TATIANA DEANE DE ABREU SA, CPATU KONRAD VIELHAUER, University of Bonn.
Ano de publicação:	2003
Referência:	Separata de: BIENNIAL EMERGY CONFERENCE, 2., Gainesville. Theory and applications of the emergy methodology. Gainesville: University of Florida, 2004.
Páginas:	p. 95-107.
Conteúdo:	Slash and burn agriculture. largelv dependem 011 lhe duration of lhe fallow period 10 restore lhe productivitv of the land, is extensivelv practiced by small landholders in Pará State. Brazil. Due 10 a mounting demographic pressure, [allow periods have been shortened. and signs of agronomic and ecological [ailure such as decreasing crop vields and structural and compositional depletion of lhe secondary vegetation have been observed. ln order 10 circumvent these problems, fire-free agricultural management practices have been proposed. Among I se practices, lhe most importam are the (i) use of a bush-chopperfor mulching iinstead of burning] lhe biomass. iiIenrichment of the secondary vegetation with nitrogen-fixing. fast growing trees 10 improve nutrient recovery/fixation during the fallow period, and (iii) soilfertilization following mulching.for optima crop absorption of nutrients. A system overvie1\' ofthese management practices shows that mOS1~ lhe inpu s. ar, roduction correspond 10free coruributions from the environment. The release of nutrients contributed bv he slash-and-bum operarion represents a major input 10 vield. reaching almost one hal] of all nonrenewable contribution in this system. As this major input is replenished byfallow. with no requiremen SfTO ; e economy, the slash-and-burn system shows a larger emergv yield ratio. On lhe other hand. te input of fertilizer required in lhe fire-free management, added 10 lhe purchased labor and services needed for mulching, resul in a higher environmentalloading ratio, and a smaller emergv vield ra '0 or i is syste. ~ Hence. due TO dependency on purchased inputs. thefire-free management shows a smaller s stain i i ..index.In order o meliorate the adoption perspective of fi re-free agriculture, incentives could be paid ior soi! orga iic ma er buildup. as compensation to carbon sequestration under a policv scenario 0..' loba/ cli te c n e preven ion
Thesagro:	Agricultura Condição Ambiental Desenvolvimento Sustentável
Palavras-chave:	Pará
Tipo do material:	Artigo em anais e proceedings
Acesso:	openAccess
Aparece nas coleções:	Artigo em anais de congresso (CPATU)