Water scarcity in Brazil’s semi-arid region necessitates the agricultural reuse of aquaculture effluents, although emitter clogging remains a challenge. This study evaluated clogging mitigation in drip irrigation systems using liquid anti-clogging fertilizer. The experiment employed a split–split–plot scheme with three water treatments (supply water, aquaculture effluent, and effluent with liquid fertilizer) and three emitter types (ST, SL, and GA), assessing performance over 360 h. A water quality analysis at 0, 160, and 360 h complemented hydraulic evaluations of the average flow rate variation and Christiansen uniformity coefficient measured every 40 h. Energy-dispersive X-ray spectroscopy, X-ray diffractometry, and scanning electron microscopy were used to characterize biofouling. The results showed that the liquid fertilizer mitigated the clogging by biofouling in the three types of emitters, but only the ST emitter presented acceptable hydraulic performance rates. There are relationships between the anti-clogging effect of the liquid fertilizer, the structural characteristics of the emitters, and the flow velocity inside the labyrinths. The SL dripper applying only aquaculture effluent presented the highest clogging rate due to biofouling. Agricultural reuse is a strategy for the rational use of water resources that is of great relevance for arid and semi-arid regions and can insert aquaculture into the circular economy.

Nutrient export analysis is a reliable parameter to help sour passion fruit producers in the recommendation of fertilization and replacement nutrients to plants. Among the factors that can reduce export of nutrients to the fruits of sour passion fruit, the low-quality genetic material, inadequate supply of nutrients to the plants, and irrigation with saline water are the most limiting. The objective of this study was to evaluate the effects of the liquid cattle manure biofertilizer in the soil on the export of nutrients by the harvest of fruits of sour passion fruit cultivars irrigated with moderately saline water. The experiment was conducted in Nova Floresta, Paraíba, Brazil, in a randomized block design and in a 3 × 5 factorial scheme, with three replicates and three plants per plot, referring to three cultivars (‘Guinezinho’, ‘BRS SC1’, and ‘BRS GA1’) and five concentrations of biofertilizer (0, 10, 20, 30, and 40%), applied monthly in a constant volume of 5 L per plant with water of 1.2 dS m^-1. Liquid cattle manure biofertilizer should be applied at concentration of 40%, as it promotes an increase in the export of phosphorus, potassium, and copper to the fruits. ‘Guinezinho’ and ‘BRS GA1’ were the sour passion fruit cultivars that showed the highest export of nutrients by fruits. Nitrogen and copper were, respectively, the most and least exported elements to fruits of sour passion fruit, in the following order of export: [N > K > Ca > Mg > P] > [Fe > Zn > Mn > Cu].

The objective of this work was to determine the potential use of fish farming effluent associated with organic fertilization for the growth of ‘BRS 416’ cotton. The experiment was carried out in a greenhouse at the Center for Agrarian Sciences of the Federal Rural University of the Semi-Arid Region (UFERSA), Mossoró, RN, Brazil, in a randomized block design, with a 5 × 5 factorial scheme and four replicates. Treatments included mixtures of fish farming effluent and public-supply water (0, 25, 50, 75, and 100% effluent) and five concentrations of goat manure (0, 5, 10, 15, and 20% based on soil volume). Plant height, stem diameter, number of leaves, root length, leaf area, leaf dry mass, root dry mass, stem dry mass and total dry mass were evaluated. The use of substrate with 20% goat manure irrigated with dilution D4 (75% FFE and 25% PSW) favored the performance of the variables PH, SD, NL, RL, LA, LDM, RDM, SDM and TDM of ‘BRS 416’ cotton plants. Reuse of the fish farming effluent D5 (100% FFE), with electrical conductivity of 3.59 dS m-1, is an alternative that favors the growth and biomass production of ‘BRS 416’ cotton plants.

Os estudos de caracterização morfométrica colaboram para o planejamento e gerenciamento de microbacias hidrográficas, descriminando os parâmetros físicos e geográficos, de relevo e drenagem, buscando avaliar o comportamento hidrológico da bacia. O estudo objetiva caracterizar a morfometria da microbacia hidrográfica do Açude Canoas/CE. Para a delimitação automática da microbacia, empregou-se o Modelo Digital de Elevação (MDE), a partir do projeto TOPODATA, adquirido no Instituto de Pesquisas Espaciais (INPE), foi utilizado o SIG gratuito QGIS de linguagem aberta, empregando os plugins do GRASS e do SAGA, foram determinados os parâmetros vinculados ao relevo, drenagem, forma e classes de uso e ocupação de solo, conforme coleção 7 do projeto Mapbiomas. A microbacia possui uma área de 549,18 km², perímetro de 173,07 km. Segundo os índices morfométricos é considerada de 5ª ordem, com numerosa ramificação, e formato losangular, apresentando baixa tendência a enchentes, o relevo representante correspondeu de plano a suavemente ondulado. A utilização de ferramentas SIGs contribuem para estudos de caráter ambiental, possibilitando melhorias no gerenciamento dos recursos hídricos, tal qual o uso e ocupação da terra de maneira sustentável.