Time Domain Reflectometry (TDR) stands out among the techniques used for determining volumetric soil water content (θ) and monitoring bulk electrical conductivity (ECb). However, the accuracy of TDR in measuring solute concentrations strongly depends on the adequacy of the calibration procedure employed. Therefore, this study adjusted models to determine the bulk electrical conductivity (ECb) of the soil solution as a function of the TDR-measured bulk electrical conductivity (ECb). The study was carried out at Embrapa Cassava and Tropical Fruits, located in Cruz das Almas, Bahia, Brazil, using a PCTDR version 4.0® (Campbell Scientific) and two calibration methodologies. The Giese–Tiemann constant was determined through readings of different levels of electrical conductivity using potassium nitrate as the solute in: (i) soil samples with sandy loam and loam–sandy clay textures saturated with potassium nitrate solution, and (ii) pure and commercial potassium nitrate solutions. ECb measurements were obtained either using the TDR probe directly connected to the device or coupled via electromechanical multiplexers. To verify the accuracy and validate the constants obtained from linear regression, the following statistical indices were applied: R² (coefficient of determination), RMSE (root mean square error), d (Willmott’s index of agreement), and GSD (general standard deviation). The technique used to measure electrical conductivity did not directly affect the determination of the Giese–Tiemann constant. However, soil type, solute solution, and calibration methodology influenced the determination of this constant. Keywords: Geise and Tieman constant, salinity monitoring, time domain reflectometry.
Industrial activity has increased the presence of heavy metals in surface waters and effluents, posing an environmental and health threat due to their persistence, toxicity, and bioaccumulation potential. In this context, fish scales are a promising alternative as an adsorbent due to their composition, which is rich in proteins, collagen, calcium salts, hydroxyapatite, and chitosan—components that promote the retention of metal ions. This systematic review evaluated the effectiveness of fish scales in adsorbing heavy metals, with a particular focus on Pb, Cd, Cr, Zn, and Cu. To this end, studies published between 2015 and 2026 were analyzed, and 44 articles were selected based on inclusion criteria, following the PRISMA methodology. The results showed that the most commonly used species were black tilapia (Oreochromis niloticus), Mozambique tilapia (Oreochromis mossambicus), and Indian carp (Catla catla), which highlights their experimental relevance and availability as raw materials. Likewise, removal efficiency was influenced by variables such as pH, adsorbent dose, and contact time, reaching efficiency values between 80.37% and 100% under optimized conditions. It was also found that chemically modifying the scales—through acid treatments and the incorporation of hydroxyapatite or a combination with chitosan to improve porosity—increases the number of active sites and optimizes interaction with the metals. In conclusion, the evidence supports the use of fish scales as a low-cost, technically viable alternative—consistent with the circular economy—for the remediation of water contaminated with heavy metals. Keywords: adsorption, circular economy, heavy metals, scale-based treatment, water pollution.
This study analyzes the environmental indicators of the municipality of Cáceres, Mato Grosso, a territory that encompasses portions of three major Brazilian biomes: Amazon, Cerrado, and Pantanal. Due to its location at the convergence of these biomes, Cáceres represents an ecologically sensitive mosaic where land-use pressures interact with fragile transitional dynamics. The methodology combined a systematic literature review with geotechnological analysis based on data from the MapBiomas Project and Landsat images (1985–2022), integrated into the Pressure-State-Response model. The biome figures reported here refer to the fraction of each biome contained within the municipal boundary, not to the biomes in their entirety. Anthropic conversion was highest in the Amazon portion (57.8% of its area), followed by the Cerrado (33.8%) and the Pantanal (16.5%). Under a continuation of recent trends, the Amazon portion remains within the range that biome-scale studies associate with severe ecological degradation. The multivariate analysis identified cattle ranching, rather than crop expansion, as the driver whose annual dynamics most closely track native-vegetation loss. The institutional responses identified in this study encompass federal, state, and municipal legislation in environmental, economic, and social dimensions, including the Forest Code, Climate Change Policies, and specific measures for fisheries. However, gaps in implementation were revealed, particularly at the local scale. These results demand the development of integrated local environmental planning capable of articulating effective institutional responses to the ongoing environmental pressures. Keywords: biomes, deforestation, environmental indicators, environmental planning, land use.
Permanent Preservation Areas (PPAs) are essential for protecting sensitive ecosystems. However, their functions are increasingly compromised by human activities. Incorporating PPAs into environmental fragility assessments is strategic for identifying conflicts between land use and legally protected areas. Using Geographic Information Systems (GIS), this study proposes a methodology that integrates land use and land cover (LULC) data with PPA boundaries to generate an environmental fragility layer, using the municipality of Lorena, State of São Paulo, Brazil, as a case study. The method applies spatial overlay techniques and assigns different fragility levels to LULC classes according to their occurrence inside or outside water-related PPAs. The application of the methodology in Lorena showed that more than 60% of water-related PPAs are occupied by pastures and mixed-use mosaics, resulting in high-fragility areas diffusely distributed across the municipality. PPAs associated with urban areas, rocky outcrops, and non-vegetated areas concentrated very high fragility levels (0.2% of the territory) mainly in the central region. These patterns are driven by soil impermeabilization and consolidated land occupation. The integrated analysis enabled a more refined fragility classification than assessments based solely on LULC data. The proposed methodology effectively identified overlaps between anthropogenic land uses and legally protected areas, providing an environmental fragility diagnosis consistent with ecological and regulatory frameworks. It represents a robust and replicable tool for environmental management, supporting territorial planning, identification of priority areas for ecological restoration, and natural resource conservation in different regional contexts. Keywords: environmental planning, geographic information systems, land use and land cover.
The use of brackish water can cause severe effects and irreversible damage to the growth and physiological indices of agricultural crops. Thus, the agricultural environment emerges as an alternative to mitigate saline stress in tomato hybrids (Solanum lycopersicum L.). This study evaluated the gas exchange and growth of tomato hybrids irrigated with brackish water in different environments. The study was carried out in Aratuba, Ceará, Brazil. The experimental design was a randomized block design with split-split plots. The main plots consisted of two environments (protected environment and full sun); the subplots consisted of five levels of irrigation water electrical conductivity (ECw) (1.0, 1.7, 2.4, 3.1, and 3.8 dS m-1) and the sub-subplots consisted of two tomato hybrids (Itaipava and BS DI0014), with five replicates. Salt stress reduced CO2 assimilation rate and instantaneous carboxylation efficiency rates more intensely in the full sun environment, while the use of low electrical conductivity in the protected environment promoted greater stomatal conductance in tomato hybrids. The BS DI0014 hybrid was more tolerant to salt stress in terms of transpiration in the protected environment and in full sun than the Itaipava F1 hybrid. The Itaipava F1 and BS DI0014 hybrids grown in a protected environment had higher internal CO2 concentrations. Keywords: protected cultivation, salinity, Solanum lycopersicum L.
