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Registro Completo |
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Biblioteca(s): |
Embrapa Pantanal. |
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Data corrente: |
09/09/1996 |
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Data da última atualização: |
09/09/1996 |
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Autoria: |
MILLER, R. H.; NICHOLAIDES, J. J.; SANCHEZ, P. A.; BANDY, D. E. |
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Afiliação: |
Department of Soil Science, North Carolina State University. |
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Título: |
Soil organic matter considerations in agricultural systems of the humid tropics. |
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Ano de publicação: |
1982 |
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Fonte/Imprenta: |
In: REGIONAL COLLOQUIUM ON SOIL ORGANIC MATTER STUDIES, 1982, Piracicaba. Proceedings. Piracicaba: [s.n.] 1982. p.105-110. |
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Idioma: |
Inglês |
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Conteúdo: |
The humid tropics encompasses those geographical areas with seven or more months annually with at least 1500 mm precipitation with no more than a four month period where potential evapotranspiration exceeds precipitation. This ecosystem is currently the focal point for considerable development and because of a widespread concern about the ecological consequences of deforestation. The dominant soils of the humid tropics of South America (Amazon basin) are highly weathered acid and infertile oxisols (45%) and ultisols (29%). Rather fertile, poorly drained alluvial soils (13%) are found along the flood plains of major rivers. Although most soils of the Amazon basin are on slopes less than 8%, some soils are on slopes which could present a severe erosion hazard if cropped to row crops without proper soil management. The dominant agriculture system in the humid tropics is primarily shifting cultivation associated with slash and burn clearing. With this system first crop yields are initially good because of the nutrients associated with the accumulated soil organic matter (litter and humus) as well as the ash from the burning operations. Crop yields decline about 70% after only two crops, and the fields are generally abandoned to forest regrowth for a 17-20 year fallow period. During this fallow period, the fertility is restored by the nutrient recycling and litter accumulation (range 3-15 tons/ha/year). This traditional form of shifting cultivations is functional and ecologically sound. Shifting cultivation does not substantially alter the soil organic matter levels reducing them to about 75% of that of the forest equilibrium level. The burning process itself has little effect on the soil organ ic matter but does volatilize most of the C, S and N of the vegetation.recently, however, increased population pressures in the humid tropics has shortened the forest fallow period and the soil fertility regeneration process. This form of shifting agriculture is less productive and results in increasing ecological damage and markedly increased rates of deforestation. The Tropical Soils Program of North Carolina State University has attempted to overcome these latter problems by developing soil management technologies for sustained agricultural production in the humid tropics. Sustained production on initially clared areas would markedly reduce the need for extensive deforestation currently associated with shifting cultivation systems. During the past decade research centered in Yurimaguas, Peru, and more redcently in manaus, Brazil, has shown that agriculture can be sustained with appropriate nutrient inputs and management strategies. This paper will examine these studies and discuss in detail those past, current or planned experiments dealing specially with organic matter management. Included will be data showing the changes in soil organic matter from forest conditions through sustained cultivation, experiments using existing crop residues and residue composts, the use of kudzu (Pueraria phaseoloides) as a short term fallow for soil fertility regeneration or as a green manure crop, possible use of certain tree species in sustained agroforestry system to maintain soil organic matter and recycle nutrients, the use of animal manures and agricultural residues for nutrient and organic matter enhancement, and the possible use of Azolla anabaena as a green manue crop and nitrogen source for rice culture on alluvial soils. MenosThe humid tropics encompasses those geographical areas with seven or more months annually with at least 1500 mm precipitation with no more than a four month period where potential evapotranspiration exceeds precipitation. This ecosystem is currently the focal point for considerable development and because of a widespread concern about the ecological consequences of deforestation. The dominant soils of the humid tropics of South America (Amazon basin) are highly weathered acid and infertile oxisols (45%) and ultisols (29%). Rather fertile, poorly drained alluvial soils (13%) are found along the flood plains of major rivers. Although most soils of the Amazon basin are on slopes less than 8%, some soils are on slopes which could present a severe erosion hazard if cropped to row crops without proper soil management. The dominant agriculture system in the humid tropics is primarily shifting cultivation associated with slash and burn clearing. With this system first crop yields are initially good because of the nutrients associated with the accumulated soil organic matter (litter and humus) as well as the ash from the burning operations. Crop yields decline about 70% after only two crops, and the fields are generally abandoned to forest regrowth for a 17-20 year fallow period. During this fallow period, the fertility is restored by the nutrient recycling and litter accumulation (range 3-15 tons/ha/year). This traditional form of shifting cultivations is functional and ecologically... Mostrar Tudo |
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Palavras-Chave: |
Agricultural system; Sistema de agricultura; Tropico umido. |
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Thesagro: |
Matéria Orgânica; Solo. |
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Thesaurus Nal: |
humid tropics; organic matter; soil. |
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Categoria do assunto: |
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Marc: |
LEADER 04229naa a2200253 a 4500
001 1789647
005 1996-09-09
008 1982 bl --- 0-- u #d
100 1 $aMILLER, R. H.
245 $aSoil organic matter considerations in agricultural systems of the humid tropics.
260 $c1982
520 $aThe humid tropics encompasses those geographical areas with seven or more months annually with at least 1500 mm precipitation with no more than a four month period where potential evapotranspiration exceeds precipitation. This ecosystem is currently the focal point for considerable development and because of a widespread concern about the ecological consequences of deforestation. The dominant soils of the humid tropics of South America (Amazon basin) are highly weathered acid and infertile oxisols (45%) and ultisols (29%). Rather fertile, poorly drained alluvial soils (13%) are found along the flood plains of major rivers. Although most soils of the Amazon basin are on slopes less than 8%, some soils are on slopes which could present a severe erosion hazard if cropped to row crops without proper soil management. The dominant agriculture system in the humid tropics is primarily shifting cultivation associated with slash and burn clearing. With this system first crop yields are initially good because of the nutrients associated with the accumulated soil organic matter (litter and humus) as well as the ash from the burning operations. Crop yields decline about 70% after only two crops, and the fields are generally abandoned to forest regrowth for a 17-20 year fallow period. During this fallow period, the fertility is restored by the nutrient recycling and litter accumulation (range 3-15 tons/ha/year). This traditional form of shifting cultivations is functional and ecologically sound. Shifting cultivation does not substantially alter the soil organic matter levels reducing them to about 75% of that of the forest equilibrium level. The burning process itself has little effect on the soil organ ic matter but does volatilize most of the C, S and N of the vegetation.recently, however, increased population pressures in the humid tropics has shortened the forest fallow period and the soil fertility regeneration process. This form of shifting agriculture is less productive and results in increasing ecological damage and markedly increased rates of deforestation. The Tropical Soils Program of North Carolina State University has attempted to overcome these latter problems by developing soil management technologies for sustained agricultural production in the humid tropics. Sustained production on initially clared areas would markedly reduce the need for extensive deforestation currently associated with shifting cultivation systems. During the past decade research centered in Yurimaguas, Peru, and more redcently in manaus, Brazil, has shown that agriculture can be sustained with appropriate nutrient inputs and management strategies. This paper will examine these studies and discuss in detail those past, current or planned experiments dealing specially with organic matter management. Included will be data showing the changes in soil organic matter from forest conditions through sustained cultivation, experiments using existing crop residues and residue composts, the use of kudzu (Pueraria phaseoloides) as a short term fallow for soil fertility regeneration or as a green manure crop, possible use of certain tree species in sustained agroforestry system to maintain soil organic matter and recycle nutrients, the use of animal manures and agricultural residues for nutrient and organic matter enhancement, and the possible use of Azolla anabaena as a green manue crop and nitrogen source for rice culture on alluvial soils.
650 $ahumid tropics
650 $aorganic matter
650 $asoil
650 $aMatéria Orgânica
650 $aSolo
653 $aAgricultural system
653 $aSistema de agricultura
653 $aTropico umido
700 1 $aNICHOLAIDES, J. J.
700 1 $aSANCHEZ, P. A.
700 1 $aBANDY, D. E.
773 $tIn: REGIONAL COLLOQUIUM ON SOIL ORGANIC MATTER STUDIES, 1982, Piracicaba. Proceedings. Piracicaba: [s.n.] 1982. p.105-110.
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Embrapa Pantanal (CPAP) |
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| 1. |  | BEZERRA NETO, F. V.; REIS, N. A. dos; CORDEIRO, D. G.; BURLE, M. L.; LIMA, C. V. de; ARAÚJO, J. L. de; CORRÊA, V. de S. Coletas de sementes crioulas de feijão na região de Chapada Gaúcha-MG. In: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 8., 2015, Goiânia. O melhoramento de plantas, o futuro da agricultura e a soberania nacional: anais. Goiânia: UFG: SBMP, 2015. Resumo 65-4.| Tipo: Resumo em Anais de Congresso |
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