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INSTITUTO DEMETEOROLOGIA

INSMET

INSTITUTO DE INVESTIGACIONESFUNDAMENTALES EN AGRICULTURA

TROPICAL

GEOGAAFIA, METEOROLOGIA Y AGRICUL11JAA TROPICAL. TROPICAL GEOGRAPHY, METEOROLOGY AND AGRICULTURE

PROGRAMA / RESUMENES. \

29 DE MARZO AL 2 DE ABRILMARCH 29 TO APRIL 2,1999

Palacio de Convenciones de La Habana / Havana International Conference Center

NINOVATlVE TECHNOLOGIES TOWARDSIMPROVING USE OF NATURAL RESOURCES BYSMALLHOLDERS IN / EASTERN AMAZONIA,BRAZll-l.

Vielhauer, K2, Sa, T. D. De A3; Kanashiro, M.3; Denich, M4 and Vlek, P. L. G.4

1 Activities of the project "Secondary format and fallow vegetation in theEastem Amazon region-function and managcment" a component of SHIFT(Studies on Hwnan Impact onForest and Ficodplains in the Tropics).

2 Institute of Agriculture in the Tropics (Lat), Gottingen, Gennany.3 Embrapa Amazônica Oriental, Belén, PA, Brazil.4. Center for Development Research (ZEF), University ofRonn, Germany.

As it ís common in the humid tropícs, most of the srnallholders enEastem Amazonia practicc salsh-and-burn agriculture, which ispresently undergoíng a productívíty crisís, as a result of decreasing soilfertility caused by intensífying cropping activities and shortening fallowperiods, due to dernographic pressure. Awore of the fact that anyattempt to change this scenario has to consider the fallow vegetation, aBrazilian-German cooperative project' started in 1991, focusing on itsfunction and its managernent possibilities, in the Bragantina region.Eastem Pará. Brazil, where agricultural settlement took place over acentury ago, as part of a systematic colonization processo During a firstphase, mainly biophysical and biogeochernical aspects of fallowvegetation and slash-and-burn practice were assessed by the project,providing relevant information about: floral functional diversity,reproductive strategies; water and nutrient balances; and soil enzymeactivity associated to sustainability. Based upon thesc findings, asecond phase is currently underway with pilot experiments onaltemative technologies developing, adapting and testing to reducewater and nutrient losses and to accumulate organic matter. Twomanagement techniques are involved: mulch based fire-free landpreparation (to reduce physical, chemical and biological soildegradation) and fallow vegetation enrichment with fast growinglegurninous trees (to shorten the fallow period and increase productivityover time).

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