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• Bragantia 11 (4-6) • Jun 1951 • https://doi.org/10.1590/S0006-87051951000200002   copiar

A água do solo e o sombreamento dos cafezais na américa central

Autoria SCIMAGO INSTITUTIONS RANKINGS

Resumo

The coffee plant does not thrive well under shade in most of the coffee areas of the State of São Paulo, Brazil. It has been shown that water competition from the shade trees during the dry season is the factor responsible for the failure in growing coffee under shade in São Paulo. In all cases where the coffee plants were not thriving well under shade, the soil moisture after two to three months of drought was at the wilting point at the depths most utilised by the root systems of shade trees and coffee plants. In open plantations this was never observed. All commercial coffee plantations of Central America are shaded. Most of them are located in areas with a dry season as long as in São Paulo and some times even longer. A comparative study of the climatological factors, methods of cultivation and most common species of shade trees was made. No one of these factors explained the different behavior of the coffee plant under shade in Central America and in São Paulo. The available soil water was measured in many coffee plantations in Costa Rica and El Salvador after four months without apreeiable rainfall. In all cases it was' found that, the actual moisture percentage was considerably higher than the wilting point. The amount of available water held by soils in São Paulo and Central America does not seem to be significantly different, although this was not carefully determined. It is suggested that a comparative study of the moisture-tension curves of soils of São Paulo and Central America might explain the different behavior of the coffee plant with shade under these two different conditions. It is possible that, as a consequence of a much steeper moisture-tension curve, the plants in São Paulo soils transpire freely until the soil moisture reaches the wilting point. This would result in a rapid soil water consumption. If the Central American soils have a smoother moisture-tension curve, the Avater absorption and transpiration rate by plants may be slower and as a consequence the available water may last longer in the soil. The ratio of the moisture equivalent to the wilting point was found to be around 1.29 for the soils studied in the Meseta Central of Costa Rica, around 1.44 for those in El Salvador and 1.94 for the ashy soils in the vicinity of San Salvador volcano.

A água do solo e o sombreamento dos cafezais na américa central

Coaraci M. Franco(11) A execução do presente trabalho foi possível graças à colaboração do Instituto Interamericano de Ciências Agrícolas de Turrialba, Costa Rica; do Servicio Técnico Interamericario de Cooperación Agrícola (STICA), Costa Rica; do Centro Nacional de Agronomia e Federación Cafetalera Centro-America y Mexico em El Salvador. A todos os funcionários das instituições acima referidas, que, direta ou indiretamente, nos auxiliaram na elaboração deste trabalho, aqui deixamos consignados os nossos agradecimentos. Em virtude da dedicação que nos revelaram, deixando de lado seus afazeres, para que pudessem acompanhar-nos pessoalmente a inúmeros cafezais de onde retiramos amostras de solo, ajudando-nos ainda nesse mister com visível boa vontade, durante muitos dias, devemos também aqui expressar especiais agradecimentos às seguintes pessoas: Eng.° Agr.° Victor Manoel Perez, de Alajuela, Costa Rica; Sr. Tomaz Vilanova, de Santa Tecla, El Salvador; Eng.0 Agr.° Eduardo Montenegro, de Santa Tecla, El Salvador, e Sr. Raul Sahli, de Santa Ana, El Salvador.)

Engenheiro agrônomo, Secção ãe Fisiologia e Alimentação de Plantas, Instituto Agronômico de Campinas

SUMMARY

The coffee plant does not thrive well under shade in most of the coffee areas of the State of São Paulo, Brazil. It has been shown that water competition from the shade trees during the dry season is the factor responsible for the failure in growing coffee under shade in São Paulo. In all cases where the coffee plants were not thriving well under shade, the soil moisture after two to three months of drought was at the wilting point at the depths most utilised by the root systems of shade trees and coffee plants. In open plantations this was never observed.

All commercial coffee plantations of Central America are shaded. Most of them are located in areas with a dry season as long as in São Paulo and some times even longer. A comparative study of the climatological factors, methods of cultivation and most common species of shade trees was made. No one of these factors explained the different behavior of the coffee plant under shade in Central America and in São Paulo.

The available soil water was measured in many coffee plantations in Costa Rica and El Salvador after four months without apreeiable rainfall. In all cases it was' found that, the actual moisture percentage was considerably higher than the wilting point.

The amount of available water held by soils in São Paulo and Central America does not seem to be significantly different, although this was not carefully determined.

It is suggested that a comparative study of the moisture-tension curves of soils of São Paulo and Central America might explain the different behavior of the coffee plant with shade under these two different conditions. It is possible that, as a consequence of a much steeper moisture-tension curve, the plants in São Paulo soils transpire freely until the soil moisture reaches the wilting point. This would result in a rapid soil water consumption. If the Central American soils have a smoother moisture-tension curve, the Avater absorption and transpiration rate by plants may be slower and as a consequence the available water may last longer in the soil.

The ratio of the moisture equivalent to the wilting point was found to be around 1.29 for the soils studied in the Meseta Central of Costa Rica, around 1.44 for those in El Salvador and 1.94 for the ashy soils in the vicinity of San Salvador volcano.

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LITERATURA CITADA

(

  • 1.  Briggs, L. J. e H. L. Shantz. A wax seal method for determining the lower limit of available soil moisture. Bot. Gaz. 51: 210-219. 1910.
  • 2.  Duncan, W. H. Wilting coefficient and waiting percentage of three forest soils of the Duke Forest. Soil Sci. 48: 413-420. 1939.
  • 3.  Franco, C. M. O problema do sombreamento dos cafezais em São Paulo. Bol. Sup. Serv. Café de S. Paulo 22: 708-717. 1947.
  • 4.  Franco, C. M. O problema do sombreamento dos cafezais em São Paulo. Ceres (Viçosa) 8: 37-51. 1948.
  • 5.  Franco, C. M. e H. Godoy. Chuvas e umidade relativa do ar em Campinas, de 1890 a 1945. Bragantia 6: 217-238. 1946.
  • 6.  Franco, C. M. e R. Inforzato. O sistema radicular do cafeeiro nos tipos de solo do Estado de São Paulo. Bragantia 6: 443-478. 1946.
  • 7.  Franco, C. M. e H. C. Mendes. Água inativa de alguns tipos de solos do Estado de São Paulo. Bragantia 7: 129-132. 1947.
  • 8.  Furr, J. R. e J. O. Reeve. The range of soil-moisture percentages through which plants undergo permanent wilting in some soils from semiarid irrigated areas. J. Agr. Res. 71: 149-170. 1945.
  • 9.  Kramer, P. J. Em Plant and soil water relationships. MeGraw Hill Book Co., 347 pág., l.Ş ed., 1949.
  • 10.  Lazo, A. C. Lecciones de Meteorologia Elemental. El Cafe de El Salvador 5: 216-328, 388-396. 1935.
  • 11.  Pittier, H. Capitulos Escogidos de la Geografia Fisica y Prehistorica de Costa Rica. Publ. do Museo Nacional de Costa Rica, Série Geográfica. 1 parte: 1-56. 1938.
  • 12.  Sapper, K. Em Climatology of Central America. Tradução do original alemão "Klimakunde von Mittel-amerika. Handbuch der Klimatologie, Berlin, 1932" pela U. S. Army Air Corps Weather Service. Editado por TJ. S. Weather Bureau.
  • 13.  Veihmeyer, F. J. e H. A. Hendrickson. The moisture equivalent as a measure of the field capacity of soils. Soil Sci. 32: 181-193. 1931.
  • 1
    ) A execução do presente trabalho foi possível graças à colaboração do Instituto Interamericano de Ciências Agrícolas de Turrialba, Costa Rica; do Servicio Técnico Interamericario de Cooperación Agrícola (STICA), Costa Rica; do Centro Nacional de Agronomia e Federación Cafetalera Centro-America y Mexico em El Salvador.
    A todos os funcionários das instituições acima referidas, que, direta ou indiretamente, nos auxiliaram na elaboração deste trabalho, aqui deixamos consignados os nossos agradecimentos.
    Em virtude da dedicação que nos revelaram, deixando de lado seus afazeres, para que pudessem acompanhar-nos pessoalmente a inúmeros cafezais de onde retiramos amostras de solo, ajudando-nos ainda nesse mister com visível boa vontade, durante muitos dias, devemos também aqui expressar especiais agradecimentos às seguintes pessoas: Eng.° Agr.° Victor Manoel Perez, de Alajuela, Costa Rica; Sr. Tomaz Vilanova, de Santa Tecla, El Salvador; Eng.
    0 Agr.° Eduardo Montenegro, de Santa Tecla, El Salvador, e Sr. Raul Sahli, de Santa Ana, El Salvador.

    • Datas de Publicação

    • Publicação nesta coleção
      26 Maio 2010
    • Data do Fascículo
      Jun 1951
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