BRIENZA JUNIOR, S.

DENICH, M.

VIELHAUER, K.

VLEK, P. L. G.

Repository Open Access to Scientific Information from Embrapa

Changing the slash-and-burn agriculture in Brazilian Eastern Amazoniaby enriching the fallow vegetationSilvio Brienza r-.', Konrad Vielhauer', Manfred Denich2 and Paul L.G. Vlek2IEMBRAPA Amazônia Oriental, Belém-PA, Brazil2Institute of Agriculture in the Tropics (IAT), University of Gõttingen, GermanyMost of the agriculture in the Eastern Amazon region of Brazil involves slash-and-burns withcropping for one to two years, followed by fallow periods among three to eight years. Duringthe fallow period a spontaneous secondary vegetation or "capoeira" grows up whichcontributes to the maintenance of the systerns productivity through biomass and nutrientaccumulation. In places of high demographic pressure the fallow periods are short and there isnot enough time to the soil recovers its fertility for the next cultivation cyc1e, resulting in adecrease of the agricultural productivity. To overcome this problem and in order to shorten thefallow period by improving the vegetation 's vitality and its biomass accumulation it wasevaluated the performance of fast growing leguminous tree planted associated with the annualcrops maize and cassava.I On an on-farm experiment in Igarapé-Açu (Northeast of Pará) the following leguminous treespecies were planted: Acacia angustissima, Acacia mangium, Clitoria racemosa, and Ingaedulis at densities of: 1 m x 1 m, 2 m x 1m and 2 m x 2 m. The experimental plot size was10m x 8 m and the treatments are arranged in randomized blocks with four replications.Planting the trees into the standing cassava crop resulted in a rapid development of the treesafter cassava harvest and accelerated biomass production. Cassava yield was not influencednegatively by the tree growth. Neither were the trees affected by the crop. Survival rates of thetrees were more than 90% for ali planted species. The shading by the cassava plant assuredgood establishment and controlled tree growth to a permitable extent as long as the crop werestill in the field. According to the A. mangium performance it is possible to estimate that after30 months the above-ground biomass it will be approximately equivalent to 4-5-year-old"capoeiras" .Mailing address: IEMBRAPA Amazônia Oriental - Cx. P. 48, 66095-100, Belérn-Para,Brazil; 2Institute of Agriculture in the Tropics - Grisebachstr. 6, D-37077, Gôttingen,Germany; e-mail: sbrienz@gwdg.de

Changing the slash-and-burn agriculture in brazilian eastern Amazonia by enriching the fallow vegetation.

RCAAP - Repositório Científico de Acesso Aberto de Portugal

http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/394558/1/A17.pdf

Changing the slash-and-burn agriculture in brazilian eastern Amazonia by enriching the fallow vegetation.

Abstract

Similar works

Full text

Available Versions

Repository Open Access to Scientific Information from Embrapa

RCAAP - Repositório Científico de Acesso Aberto de Portugal