The value of manure - Manure as co-product in life cycle assessment

Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio

Estudos sobre a nutrição mineral do arroz: XIV. efeitos dos excessos de Al, Cl e Mn nas variedades IAC-25 e IAC-47

Rice plants were grown either in full strength nº 2 solution of HOAGLAND & ARNON (1950) or in the same with high levels of Al, Cl and Mn (25, 1750 and 25 ppm, respectively). Plants with excess of each element did not complete the reproductive phase of development. Symptoms of toxicity appeared in response to the high levels supplied in the substrate. Dry matter production was relatively more affected in the case of the variety IAC-47. On the other hand, both varieties were more sensitive to Mn toxicity than to Al excess. The leaves had the following levels of the elements under the respective treatments, respectively for the variety IAC-25 and for the variety IAC-47; Al-107 and 221 ppm; Cl-87,500 and 17,500 (lower and upper leaves), 44,125 and 16,250 (lower and upper leaves); Mn - 1,670 and 1,769. The Al content of the roots was 5,639 and 5,872 ppm. Al toxicity decreased P content in all plant parts.Plantas de arroz, variedades IAC-25 e IAC-47 foram cultivadas em solução nutritiva completa e com excesso de Al, Cl e Mn (25, 1750 e 25 ppm, respectivamente). As últimas não completaram o ciclo. Foram observados sintomas típicos de toxidez. A produção de matéria seca foi mais afetada pelos tratamentos na variedade IAC-47. Ambas as variedades mostraram-se mais sensíveis a toxidez de Mn que à de Al. Foram determinados os teores foliares de Al, Cl e Mn associados à toxidez correspondente

Studies on the mineral nutrition of the rice plant: XII. effects of the deficiencies of macronutrients on the varieties IAC-25 and IAC-47

Plantas de arroz, variedades IAC-25 e IAC-47, foram cultivadas em solução nutritiva completa e com deficiência de macronutrientes. Foram obtidos dados sobre a influência dos tratamentos na área foliar, produção de matéria seca e na composição mineral e observados os sintomas de carência. O estado nutricional das plantas deficientes em N foi também avaliado pela determinação da atividade da redútase de nitrato na folha.Rice plants, varieties IAC-25 and IAC-47 were grown in nutrient solution both in the presence and in the absence of macronutrients. Symptons of deficiency were observed in general agreement with description found in the literature. The deficiency of N affected most dry matter yield among the three major macronutrients. although the effect on grain production was greater when K was omitted. The following levels could be taken as indication of adequate nutrition when leaf samples are analysed at the boot stage (respectively) for var. IAC-25 and IAC-47): N - 4.18% and 3.54%; P - 0.36 and 0.27; K - 2.30 and 2.09; Ca - 1.22 and 1.00; Mg - 0.80 and 0.77; S - 0.24 and 0.18. Leaf nitrate reductase activity at the same physiological period correlated well both with N supply and dry matter production

Introducción de los temas transversales en el PEC y PCC : curso académico 1995-1996 : memoria

Proyecto educativo realizado en el Colegio Público Rufino Mansi de Alcaudete de la Jara de Toledo durante el curso académico de 1995-1996 por el Grupo de Trabajo integrado por 13 profesores del Centro. El objetivo de este documento es ofrecer un material de apoyo para facilitar el tratamiento de los temas transversales en las distintas áreas del currículo. El material elaborado se aplica tanto para la educación infantil como para los tres ciclos de la enseñanza primaria y en él se recogen los siguientes temas transversales: educación para la paz, educación moral y cívica, educación para la salud, educación sexual, educación para la igualdad de ambos sexos, educación del consumidor, educación mabiental y educación vial. Temas transversales que se aplican a las diferentes áreas temáticas de los distintos ciclos educativos, ya que el currículo incluye contenidos que lo propician. El trabajo ha dado como resultado una selección de elementos del currículo por ciclos y áreas que se relacionan con cada tema transversal. En la evaluación se evalúa la calidad de los materiales elaborados y la operatividad de las sesiones de trabajo.Castilla La ManchaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; Fax +34917748026; [email protected]