<p><strong>Background.</strong><strong> </strong>Due to the negative impacts caused by the inadequate disposal of dairy cattle wastewater (DCW), alternatives are needed to reduce the environmental impact. <strong>Objective.</strong> The aim of this study was to evaluate the effects of applying DCW via fertigation on the physical and chemical characteristics of the soil and on the production of citronella essential oil (<em>Cymbopogon nardus</em> (L.) Rendle). <strong>Methodology.</strong><strong> </strong>Nitrogen (N) was adopted as a reference element and DCW equivalent amount to be applied so as to replace this element was calculated. Doses equivalent to 100%, 200%, 300% and 400% of the recommended N concentration were applied. After six months of cultivation, the availability of nutrients for the soil and its relationship to the production of essential oil were evaluated. <strong>Results</strong><strong>. </strong>The results showed that DCW supply for citronella cultivation was effective and, in most parameters, equivalent to the treatment with mineral fertilization. Besides, there was no significant difference between the treatments, regarding the quantity and quality of essential oil production. <strong>Implications</strong>: DCW does not increase the yield of essential oil, but it is an excellent alternative for the supply of nutrients in degraded soils.<strong> </strong><strong>Conclusions. </strong>Therefore, DCW use for fertigation of citronella cultivation is a valid alternative, helping to mitigate the impacts related to its disposal. However, new studies with a longer evaluation period and other types of soil are suggested.</p>

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The construction sector is increasingly seeking sustainable alternatives in its processes worldwide, with a particular focus on the production of eco-friendly materials. Additionally, the improper disposal of solid waste is rapidly increasing, particularly in the agro-industry, including the waste generated from beer processing such as malt bagasse. Therefore, the objective of this study was to incorporate malt bagasse residue into ceramic materials at varying proportions (0, 2.5, 5, 10, and 15%) as a partial substitute for clay, submitted to different sintering temperatures (750, 850, 950, and 1050 °C). The raw materials, namely ceramic mass and malt bagasse, were characterized based on their chemical properties (XRF, loss of fire, and elemental analysis), physical properties (grain size, Atterberg limits), and mineralogical properties (XRD) characteristics. The properties of the ceramics, both with and without the incorporation of waste, were evaluated using dilatometry, apparent density, apparent porosity, water absorption, linear shrinkage, and tensile strength. The compositions that exhibited the best sintering temperatures were subjected to microstructural characterization using optical microscopy and X-ray diffraction (XRD). Significant differences were observed in the properties of the ceramic material, particularly in terms of linear shrinkage and apparent porosity. It was concluded that as the amount of malt bagasse residue incorporated increased, the mechanical properties of the pieces decreased. The incorporation of 15% residue resulted in the lowest performance, primarily due to a greater loss of mass. However, it should be noted that the incorporation of up to 5% malt bagasse for all the studied temperatures can still be considered acceptable, as it meets the minimum recommended value of 1.5 MPa for masonry ceramic components. This incorporation of malt bagasse contributes to both the technological and environmental aspects of civil construction.

Resumo: Neste trabalho buscou-se avaliar a viabilidade da utilização do diagnóstico por meio de matriz estratégica como uma ferramenta que auxiliasse a identificar alternativas para o desenvolvimento local de uma atividade. O trabalho foi realizado em propriedades de agricultores familiares que comercializavam olerícolas em Oriximiná (Pará), sendo selecionados pelo método não-probabilístico de amostragem por julgamento. Os dados foram obtidos em campo por meio de entrevista, sendo montada matrizes SWOT que foram compiladas em uma matriz de análise estratégica apontando o potencial ofensivo e defensivo e a vulnerabilidade e debilidade dos empreendimentos perante a si mesmos e ao mercado. Pelo potencial ofensivo encontrado verificou-se que a atividade agrícola nestas propriedades é promissora, alcançando um valor em torno de 77% do potencial máximo, destacando-se a oferta de produtos diversificados e a adoção da tecnologia PAIS (Produção Agroecológica Integrada Sustentável). As debilidades no sistema que devem ser foco de estratégias são o investimento do poder público em assistência técnica para capacitar os produtores a utilizarem equipamentos e adotarem manejo adequado, seja para adaptação às dificuldades impostas pelo clima ou para agregar valor, bem como atender à legislação ambiental, permitindo maior retorno do investimento.

Hydroponics is a cultivation technique without soil. There are several modalities for the system and among them is the Nutrient Film Technique (NFT), which consists of using channels to circulate a nutrient solution intermittently. Due to the existence of risks of soil and water contamination in metropolitan areas, hydroponics is a potential alternative to conventional production. Therefore, the present work sought to verify the current study of knowledge of the NFT hydroponic system in the international literature and the performance of the countries on it. For this, a bibliographic survey was carried out from 2010 to 2019 on the international research bases Science Direct, Portal de Periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Scielo using the search terms “Hydroponics” and “Nutrient Film Technique Hydroponics”. An increase in the number of studies was observed in the last four years of the analyzed period, that is, from 2016 to 2019, thus representing an increase in interest in hydroponics, especially the NFT type. This increase may be related to the efficiency and ease of handling this model, gains in productivity and the potential that this technique has for reducing the carbon footprint. Thus, Nutrient Film Technique is of great value in urban agriculture, especially in Brazil – its greatest representative –, with the potential to grow a lot in the future, due to its numerous benefits.