Aquaculture supplies the production of animal protein in a profitable and sustainable way; however, it can generate changes at an ecological and environmental level. In this study, changes in water quality and sediments related to rainbow trout (Onchorhynchus mykiss) farmed in the RAMSAR - Guamuez Lake wetland, during high and low rainfall, were determined, comparing six zones with three replications and at three depths. Physicochemical and nutrient parameters in water and sediments were measured, performing analysis of variances and determining significant differences. The physicochemical parameters of the water presented less favourable values for the farming companies as opposed to control points, mainly in the upper part of the lake where there is a greater influence of anthropic activities. Aquaculture processes not only alter the quality of the water, but also, other anthropic activities; however, values were within acceptable ranges for aquaculture as well as for the ecology of the lake. Sediments act as a deposit of aquaculture residues, presenting symptoms in the physicochemical and nutrient parameters measured in the farming companies, mainly total phosphorus and total nitrogen, which presented acceptable ranges; however, their increase could cause eutrophication problems in the lake. The increase in rainfall contributes to pollution increase through tributaries and runoff that finally deposit contaminants in the lake; therefore, aquaculture is only one of the factors that can negatively affect a lentic aquatic system. | La acuicultura abastece la producción de proteína animal de forma rentable y sostenible, sin embargo, sus producciones generan cambios a nivel ecológico y ambiental. Para este estudio, se determinaron cambios en la calidad del agua y en los sedimentos relacionados al cultivo de trucha arcoíris (Onchorhynchus mykiss) en el humedal RAMSAR - Lago Guamuez, en pluviosidad alta y baja, y se compararon seis zonas con tres réplicas y tres profundidades. Se midieron parámetros fisicoquímicos y nutrientes en agua y sedimentos, realizando análisis de varianzas y determinando diferencias significativas. Los parámetros fisicoquímicos del agua presentaron valores menos favorables en las empresas de cultivo a diferencia de los diferentes puntos control, principalmente en la parte alta del lago donde existe mayor influencia de actividades antrópicas, lo que demostró que no solo los procesos acuícolas alteran la calidad del agua, sino también otras actividades antrópicas; no obstante, los valores se encuentran en rangos aceptables para la acuicultura y para la ecología del lago. Los sedimentos actúan como depósito de residuos acuícolas, y presentan alteración en los parámetros fisicoquímicos y nutrientes medidos en las empresas de cultivo, principalmente el fósforo total y el nitrógeno total, los cuales presentan rangos aceptables, sin embargo, su incremento podría causar problemas de eutrofización en el lago. El incremento de la pluviosidad contribuye al aporte de contaminación mediante afluentes y escorrentía que finalmente depositan contaminantes en el lago, por lo cual, la acuicultura solo es uno más de los factores que pueden afectar negativamente un sistema acuático léntico.

This research evaluated trajectories of agrarian change following liberalization and deregulation of the coffee commodity chain, assessing the transformation of agrarian class structures and livelihoods between 2000 and 2009 among landed coffee farmers from Agua Buena, Costa Rica. Simultaneous processes of differentiation, deagrarianization, and repeasantization are documented. Deagrarianization is identified as the result of either adaptive or maladaptive processes of livelihood diversification out of agriculture. Repeasantization is characterized by the widespread adoption of low external‐input agriculture driven by cultural norms of self‐sufficiency and labour flexibility within farm households. In order to ensure equitability and the continued viability of rural households in communities ravaged by commodity deregulation, aid and training need to be targeted towards resource‐poor households in two principal areas: first, to transition off‐farm livelihoods into stable and high return activities and, second, to provide the agroecological knowledge and resources for farming households to self‐provision and distantiate themselves from the market.

O entendimento de que o modelo convencional de produção de alimentos é insustentável tem fortalecido e consolidado a agroecologia enquanto ciência e base para construção de novos modelos de agricultura, de forma a garantir a produção de alimentos saudáveis e a segurança alimentar e nutricional das populações. Neste contexto, esta pesquisa tem como objetivo analisar as práticas que se mostram adequadas a transição da agricultura convencional para modelos de agricultura baseados na Agroecologia no Projeto de Assentamento Jaraguá, em Água Boa, Mato Grosso, realizando também um recorte baseado em outras pesquisas nesta temática, de modo a compreender os reflexos destas na saúde e no meio ambiente. Como estratégia metodológica trata-se de uma pesquisa bibliográfica do tipo revisão de escopo. A busca ocorreu em duas bases de dados e uma biblioteca eletrônica, com o cruzamento dos descritores: Assentamento AND Agroecologia. Os critérios de inclusão foram: estudos em inglês, português e espanhol, com texto disponível na íntegra e publicados entre os anos de 2012-2022, que retratam as tecnologias agrícolas sustentáveis que se mostram adequadas ao modelo de transição da agricultura convencional para agroecologia. Não foram incluídos documentos que não respondessem ao objetivo deste estudo. Os dados foram organizados e descritos de forma narrativa e por meio de quadros. Como resultados, observou-se pela pesquisa a utilização de práticas sustentáveis em assentamentos, tais como: Cromatografia Circular de Pfeiffer, biomassa vegetal, policultivos, rotação e a consorciação de culturas, cultivos utilizando sementes crioulas, produção de compostagem, integração animal-vegetal através do uso de resíduos animais nos plantios, armazenamento de sementes, não desmatamento e queimadas, não uso de agrotóxicos, adubação verde, produção de mudas, diversificação de produção, participação de mulheres e circuito de comercialização, quintais produtivos e uso de biofertilizantes, e inovações de cuidados com uso de homeopatia e fitoterapia em animais. Conclui-se que as práticas utilizadas se mostram adequadas ao modelo de transição de sistemas de produção convencional para agroecológicos, com redução significativa dos impactos sobre o meio ambiente e saúde humana. | The understanding that the conventional model of food production is unsustainable has strengthened and consolidated agroecology as a science and basis for the construction of new models of agriculture, in order to guarantee the production of healthy foods and the food and nutritional security of the populations. populations. In this context, this research aims to analyze the appropriate practices for the transition from conventional agriculture to models of agriculture based on Agroecology in the Jaraguá Settlement Project, in Água Boa, Mato Grosso, also making a cut based on other research on this topic , in order to understand their effects on health and the environment. As a methodological strategy, this is a bibliographic research of the scope review type. The search took place in two databases and an electronic library, crossing the descriptors: Settlement AND Agroecology. Inclusion criteria were: studies in English, Portuguese and Spanish, with full text available and published between the years 2012-2022, that portray sustainable agricultural technologies suitable for the transition model from conventional agriculture to agroecology. Documents that did not respond to the purpose of this study were not included. Data were organized and described in a narrative form and through tables. As a result, the research observed the use of sustainable practices in the settlements, such as: Pfeiffer Circular Chromatography, plant biomass, polycultures, crop rotation and intercropping, cultivation with native seeds, compost production, animal-plant integration through the use of animal waste in plantations, seed storage, no deforestation and burning, no use of pesticides, green manure, seedling production, diversification of production, participation of women and the marketing circuit, productive backyards and use of biofertilizers, and innovations in the care with the use of homeopathy and phytotherapy in animals. It is concluded that the practices used are suitable for the model of transition from conventional to agroecological production systems, with a significant reduction in impacts on the environment and human health.

El balance de nutrientes puede ser un indicador apropiado para identificar posibles problemas ambientales relacionados a los recursos naturales agua y suelo. Se analizó el balance de nitrógeno, fósforo, potasio y calcio de la producción hortícola a campo de la provincia de Buenos Aires, Argentina. Se realizó un balance simplificado de nutrientes en 134 partidos de la provincia para 19 cultivos, agrupados en cuatro grupos. La mayor extracción de nutrientes correspondió a potasio, seguido de nitrógeno y, en menor medida a fósforo y calcio. El balance total de nutrientes dio positivo para nitrógeno, fósforo y calcio y negativo para potasio. Estos resultados señalan el potencial riesgo de contaminación de los acuíferos por exceso de nitrógeno y una disminución del “stock” de potasio en algunos suelos de la provincia. Resulta necesario profundizar estos análisis y emplearlos como instrumento para el desarrollo de políticas que tiendan al desarrollo de una agricultura sustentable. | The nutrients balance may be an useful indicator to identify potential environmental problems relating to natural resources as water and soil. The balance of nitrogen, phosphorus, potassium and calcium in field horticulture in the province of Buenos Aires, Argentina, were analyzed. A simplified nutrients balance in 134 districts in the province for 19 crops, grouped into four groups was made. The major extraction of nutrients accounted for potassium, followed by nitrogen and, to a lesser extent phosphorus, and calcium. The total nutrients balance was positive for nitrogen, phosphorus and calcium and negative for potassium. These findings suggest the potential risk of contamination of aquifers by excessive nitrogen and a decrease in the stock of potassium in some soils of the province. It is necessary to deepen these kind of analysis and use them as an instrument for develop sustainable agriculture policies. | Facultad de Ciencias Agrarias y Forestales

El paisaje de la Huerta y Laguna de Villena es un ejemplo de agroecosistemas mediterráneos semiáridos en el SurEste de España. Ha evolucionado en dos siglos de un escenario muy rico ecológicamente hablando a uno muy degradado. El hecho sorprendente es que los umbrales de irreversibilidad ecológica más relevantes se han superado bajo el marco de la puesta en práctica de las directivas ambientales de la Unión Europea. Se presenta este caso con el objetivo de incorporar nuevas perspectivas para mejorar las estrategias para poner en práctica los objetivos ambientales UE2020. | La Huerta y Laguna de Villena landscape is an example of semiarid mediterranean agricultural ecosystem in South Eastern Spain. It has evolved in two centuries from a very ecologically rich scenario to a very degraded one. The surprising fact is that the most relevant ecological irreversibility thresholds have been overpassed under EU environmental directives framework. This case is presented in order to incorporate new perspectives to the improve the implementation of EU 2020 environmental objectives.