11 pages | Peer reviewed

Carpeta 688, inéditos SEGEMAR | Fil: Doliner, Luis. Ministerio de Economía. Secretaría de Minería. Dirección Nacional de Geología y Minería; Argentina.

In determinations made with a porometer it was verified that the stomatal opening of coffee leaves increases in size immediately after the leaves are detached from the plant (fig. 1). This fact indicates that the method of rapid weighings of detached leaves is not suitable for studies on the transpiration of the coffee plant. The transpiration of coffee plants has been determined by the weighing potted plant method. Pots with a capacity for 51 liters were used. They were made of galvanized iron plate and had no drainage hole. When the moisture content of the soil approached the wilting point water was added to bring all the soil mass to fiel capacity. In order to avoid oxygen depletion the pots were not sealed. To decrease the direct evaporation at the soil surface a two-centimeter layer of rice hulls was used as mulch, and a celotex cover was placed on top of the pot. Three similar pots with the same type of protection, but without plants were used to measure the direct evaporation from the soil surface. The weight losses of these pots were subtracted from the weight losses of the pots with plants. Two to throe-year old plants of Coffea arabica var. bourbon were used. Three plants were employed each month and after this time their leaves were picked off, and the total leaf area was determined. The tests were carried out for a whole year. The transpiration rates were calculated in g/dm²/day. The total leaf area of an adult coffee plant was found to be 3,146 dm² (average of seven trees). Based on this average and on the transpiration rate of the experimental plants it was possible to calculate approximately the amount of water that an adult coffee plant would transpire under the same conditions. Since the plants submitted to the experiment did not suffer water shortage at any time, the present results show the approximate amount of water lost by the coffee plant under optimal soil-water conditions. The data are presented in table 1. The figure 1 shows the monthly amount of water lost by transpiration in a coffee* plantation compared with the monthly rainfall during a year. The environmental factors that influence plant transpiration vary much less between the same months of different years than between the different months of the same year. Hence the results obtained should not be far from the average; that would be obtained if the transpiration had been measured during a number of years. Comparing the water lost by transpiration of coffee trees with the average rainfall in'Campinas, State of São Paulo, Brazil, it is seen that from October to March rainfall exceeds water consumption. In April, June, and September the excess is small, and in May, July, and August the amount of water transpired exceeds the average rainfall (fig. 2). Since the rainfall distribution is variable, this figure may be different in a given year. The highest daily rate of transpiration encountered was 17.6 mg/dm²/m (over twelve; hours). Previous results obtained by the writers showed 18.2 mg/dm²/m to be the rate of transpiration in a very sunny and hot day. Nutman working in Africa (2) found a maximum daily rate of 20.67/dm²/m (over nine hours). These data are comparable and must represent approximately the maximum rate of transpiration of the coffee plant. The average daily transpiration encountered was 6.20 g/dm²/day and the total amount of water transpired by a coffee tree in one year was found to be 7,273 liters.

Sumario: Estudios sobre la evaporación. Pérdidas de agua libre y del agua en el suelo en relación con las carpidas. — Estudios sobre necesidades de aguas por las plantas. Curva de la absorción. Períodos de mayor consumo. — Dotaciones de agua. Cómo deben utilizarse los datos obtenidos por la experimentación sobre el campo. | Facultad de Ciencias Agrarias y Forestales

Este semestre pusimos a prueba los equipos diseñados para monitorear la calidad del agua, lo cual se hizo en el lago de la universidad. Los datos de la medición fueron recopilados y analizados. De igual manera, apoyamos las actividades de semilleros para colegio, participamos en actividades de Semilleros en Red (Cocreando soluciones), recibimos al personal visitante de la Universidad del Sur de Georgia (GSU) y realizamos una visita a GSU, como parte del proyecto 100K, donde los estudiantes participaron en actividades de investigación e intercambio académico. | 2024-1

A norma brasileira de potabilidade da água reconhece que há um grupo de substâncias, dentro do qual estão inclusos os agrotóxicos, que pode representar riscos à saúde da população. Este trabalho se propôs a verificar se os valores máximos permitidos para agrotóxicos na água potável asseguram a saúde de crianças e adolescentes. O estudo consistiu em uma pesquisa documental. Primeiramente, foi feita a caracterização dos ingredientes ativos de agrotóxicos mais vendidos no Brasil no período de 2010 a 2020. Para os ingredientes ativos mais vendidos sujeitos a monitoramento na água potável, foi verificada a classificação quanto a potencial carcinogenicidade e desregulação endócrina. Em seguida, foi apontado o fundamento jurídico que visa a garantir o direito à saúde para crianças e adolescentes. Por fim, os agrotóxicos da norma brasileira de potabilidade foram comparados com os constantes nas diretrizes da Organização Mundial de Saúde e nas normatizações dos Estados Unidos e da União Europeia. Constatou-se que 12 agrotóxicos que estiveram dentre os mais vendidos no período de 2010 a 2020 constam no padrão de potabilidade da água. Destes 12, 10 (83%) são classificados como desregulador endócrino conhecido ou como possível desregulador endócrino, e 8 (67%) como carcinogênico, provavelmente carcinogênico, ou possivelmente carcinogênico. Esclareceu-se que crianças e adolescentes são detentores de direitos. Entretanto, mostrou-se que, da forma como são calculados, os valores permitidos para agrotóxicos não têm a intenção de protegê-los. Esses valores consideram a massa corporal de um adulto. Logo, as quantidades permitidas de agrotóxicos na água potável são superiores àquelas que o Ministério da Saúde acredita que não acarretaria em risco à saúde de crianças e adolescentes. Ademais, percebeu-se que efeitos graves e irreversíveis à saúde, que podem afetar proporcionalmente muito mais as crianças, como desregulação endócrina, não são considerados no estabelecimento de tais valores. Estes efeitos não possuem limiar de toxicidade. Os resultados do estudo indicaram que é necessário adequar o padrão de potabilidade para agrotóxicos, e orientaram em relação a melhor prática a ser adotada, a saber: a utilização de valores de referência baseados em limites de quantificação de agrotóxicos em água. Estes valores devem ser usados para avaliar, principalmente, o plano de segurança da água e os processos de tratamento dessa água. | The Brazilian drinking water regulation recognizes a group of substances, including pesticides, which can represent a risk to people’s health. This documental research verifies if pesticides limits in drinking water protects children’s health. At first, this study characterized the most traded active ingredients for chemical pesticides between 2010 and 2020. Furthermore, it was verified the classification according to carcinogenicity and endocrine disruption for the soldest pesticides monitorized in drinking water. Subsequently, it presented legal basis that assures children’s right to health. Finally, pesticide’s limits established in the Brazilian drinking water regulation were compared with World Health Organization guidelines, and also with United States and the European Union standards. This comparison analyzed pesticides parameters and also the reasoning behind those values definition. The Brazilian drinking water regulation lists 12 of the soldest active ingredients between 2010 and 2020. Among those, 10 (83%) are classified as known or potential endocrine disruptors, and 8 (67%) are classified as carcinogenic, probably carcinogenic, or possibly carcinogenic. It was verified that although children have rights, maximum allowed values for pesticides in drinking water does not intend to protect them. Regarding to calculation methodology, Brazilian rules takes into consideration a 60kg adult. As a result, Ministry of Health sets limits for pesticides in drinking water that pose appreciable risks to children’s health. Moreover, it became clear that severe and irreversible effects on children's health, such as endocrine disrupting, are not considered in pesticide limits calculation. The results of this study indicate that it is necessary to update the Brazilian drinking water standard for pesticides and metabolites. It also guides towards the practice to be adopted, namely the utilization of reference values based on limits of quantification of pesticides in water. Such reference values must be used to evaluate the water safety plan and its treatment process.

Este trabajo examina las alternativas a la propuesta del Plan Hidrológico Nacional de transferir 1.050 hm cúbicos de agua desde el Valle del Ebro al Levante y Sureste, con un coste que probablemente sería superior al billón de pesetas (6.000 millones de euros). Los efectos sobre el sector agrario se analizan bajo dos escenarios de gestión de demanda: prohibición de la sobreexplotación de acuíferos y aumento de precios del agua para equilibrar la demanda y la oferta. El aumento de precios del agua tiene un impacto significativo sobre la renta neta de los agricultores, que deberían ser compensados por el aumento de precios. La reducción del uso del agua al subir los precios, evita las transferencias de agua externas a Levante y Sureste. La viabilidad del trasvase del Ebro que propone el Plan Hidrológico, se ha examinado simulando los efectos del precio del agua de trasvase sobre las comarcas de Levante y Sureste. (...)