Fil: Furque, Guillermo. Ministerio de Industria y Comercio. Dirección Nacional de Minería; Argentina. | Carpeta 143, inéditos SEGEMAR. Este informe fue aparentemente editado nueve años después de su elaboración, en la publicación Informe Técnico nro. 6. La misma puede accederse en: http://repositorio.segemar.gob.ar/handle/308849217/829

10 pages | [EN] After a brief criticism of the methods just now proposed to determine the chlorinity of sea waters, specially those of Mediterranean, the use of any sea water the chlorinity of which is known, as an auxiliary standard water to be used in Mohr-Knudsen’s method is proposed, giving also the special form of using Hydrographical Tables and to attain an economy of standard water from Copenhague. To determine the chlorinity of this auxiliary water use is made (at 17’5° C) of a sodium chloride solution, containing 32’7443 g. NaCl per liter (volume measured at 17’5° C), instead of the International standard sea water. It is also given some amendments in the practice of the valuations to malve its end point more apparent and exact | [ES] Precisándose conocer periódicamente en este Laboratorio de Biología Marina la salinidad y densidad de ls aguas de la región pesquera que es objeto de nuestras investigaciones, hemos tratado de hallar un método que nos permitiera determinarlas aplicando el de Mohr-Knudsen sin hacer uso de agual normal internaciona, de la cual carecemos. [...] Después de hacer una somera crítica de los métodos hasta la actualidad propuestos para determinar la clorinidad de las aguas marinas y en especial las del Mediterráneo, se propone el uso de un agua de mar cualquiera de clorinidad conocida como agua auxiliar patrón para ser utilizada en el método de Mohr-Knudsen, indicando el modo especial con que deben utilizarse las Tablas Hidrográficas, y conseguir un ahorro de agua normal de Copenhague. Para determinar la clorinidad de esta agua auxiliar se ha utilizado a i7°5 C. una disolución de CINa de 32'7443 g,/litro (volumen medido a I7°5 C.) en sustitución del agua normal internacional. Se indican algunas modificaciones en la práctica de las valoraciones para hacer más aparente y preciso el punto final | Peer reviewed

The present paper discusses the amount of water lost by the soil through the transpiration of coffee plants and shade trees in shaded coffee plantation. All methods and techniques employed in the study of transpiration of the shade tree Inga edulis Mart, were exactly the same as those described in a paper recently published (4). It was determined previously (3) that a shaded coffee plant receiving 55% of full sunlight transpired 80% as much as when in 100% full sunlight. The amount of water transpired by a coffee plant was calculated by taking 80% of the amount transpired in unshaded plantation (4). Comparing the water lost by transpiration of shaded coffee plants and shade trees with the average rainfall in Campinas, São Paulo, Brazil, it is seen that from April to September the amount of water transpired exceeds the average rainfall. This finding seems to agree with our previous conclusion (1, 2, 5) that water competition between shade trees and coffee plants is the factor that controls the success of growing coffee under shade in the State of São Paulo, Brazil. The highest daily rate of transpiration encountered, for Inga edvlis was 36.7 milligrams per square decimeter per minute. The average daily transpiration was found to be 9.90 grams per square decimeter per day. The total amount of water transpired by an Inga tree was calculated to be 71,140 liters per plant per year. Since the plants submited to the experiment did not suffer a water shortage at any time, the present results show the approximate amount of water lost by the Inga tree and shaded coffee plant under optimal soil-water conditions.

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.

Fil: Zöllner, W. Ministerio de Industria y Comercio. Dirección Nacional de Minería; Argentina. | Carpeta 394, inéditos SEGEMAR

Fil: Furque, Guillermo. Ministerio de Industria y Comercio. Dirección Nacional de Minería; Argentina. | Carpeta 133, inéditos SEGEMAR

Estudio realizado en el Laboratorio Oceanográfico del Instituto Español de Oceanografía en Vigo sobre los problemas que presenta la determinación de los nitratos en el agua de mar, reactivos utilizados para su determinación según Gómez Ibáñez, inconveniencias del método reactivo de la estricnina. Fundamentos para la utilización del método de la resorcina como reactivo. Descripción del método de la resorcina. Resultados de la experimentación con agua potable y con agua de mar. | No

5 pages | [EN] A comparative study is realized on the variation of the Cl concentration (g.Cl per liter) of a CINa solution wliich has, at equal temperatures, the same concentration as the international standard water. The obtained results indícate that the international standard water and the NaCl standard solution are equivalent at any temperature (10° 0.-30° O.). So, it is possible to utilize this standard solution instead of international standard sea water. A table in which there are the NaCl quantities to prepare a liter of sodium chloride standard solution. between those temperatures, is given with volume and vacuum weight corrections | [ES] Hemos indicado ya en otro trabajo (5) que a 17´5ºC es correcto emplear una disolución de CINa de igual Cl/l, que el del agua normal internacional, en la determinación de la clorinidad de las aguas de mar por el procedimiento de Mohr-Kundsen, ya que al tomar con la pipeta 15 c.c. de dicha disolución tomamos la misma cantidad de Cl que al tomar el mismo volumen de agua normal, a la misma temperatura. Como esta disolución equivale al agua normal, para el cálculo de las correcciones a efectuar con ayuda de las tablas Hidrográficas (2), se debe considerar que su clorinidad es de I9’370, la del agua normal.[...] | Peer reviewed