Diffuse agricultural pollution is a leading contributor to surface water degradation, particularly in regions undergoing rapid land use change and agricultural intensification. In many developing countries, conventional assessment approaches fall short of capturing the spatial complexity and cumulative nature of multiple environmental drivers that influence surface water vulnerability. This study addresses this gap by introducing the Integral Index of Vulnerability to Diffuse Contamination (IIVDC), a spatially explicit, multi-criteria framework that combines the Analytical Hierarchy Process (AHP) with Geographic Information Systems (GIS). The IIVDC integrates six key indicators—slope, soil erodibility, land use, runoff potential, hydrological connectivity, and observed water quality—weighted through expert elicitation and mapped at high spatial resolution. The methodology was applied to the Guachal River watershed in Valle del Cauca, Colombia, where agricultural pressures are pronounced. Results indicate that 33.0% of the watershed exhibits high vulnerability and 4.3% very high vulnerability, with critical zones aligned with steep slopes, limited vegetation cover, and strong hydrological connectivity to cultivated areas. By accounting for both biophysical attributes and pollutant transport pathways, the IIVDC offers a replicable tool for prioritizing land management interventions. Beyond its technical application, the IIVDC contributes to sustainability by enabling evidence-based decision-making for water resource protection and land use planning. It supports integrated, spatially targeted actions that can reduce long-term contamination risks, guide sustainable agricultural practices, and improve institutional capacity for watershed governance. The approach is particularly suited for contexts where data are limited but spatial planning is essential. Future refinement should consider dynamic water quality monitoring and validation across contrasting hydro-climatic regions to enhance transferability.

Water-quality monitoring in agricultural irrigation systems is challenging due to the dynamic and heterogeneous nature of mixed water sources, which complicates traditional and remote sensing-based assessment methods. Traditional water quality monitoring relies on water sampling and laboratory analysis, which can be time-consuming, labor-intensive, and spatially limited. In situ hyperspectral reflectance sensing (HRS) presents a promising alternative, offering high-resolution, non-invasive monitoring capabilities. However, applying HRS in mixed-water environments—where served-water effluent, precipitation, and natural river water converge—presents significant challenges due to variability in water composition and environmental conditions. While HRS has been widely explored in controlled or homogeneous water bodies, its application in highly dynamic agricultural mixed-water systems remains understudied. This study addresses this gap by evaluating the relationships between in situ hyperspectral data (450–900 nm) and key water-quality parameters—pH, turbidity, nitrates, and chlorophyll-a—across three campaigns in a Colombian tropical agricultural irrigation system. A Pearson’s correlation analysis revealed the strongest spectral associations for nitrates, with positive correlations at 500 nm (r ≈ 0.76) and 700 nm (r ≈ 0.85) and negative correlations in the near-infrared (850 nm, r ≈ −0.88). Conversely, the pH exhibited weak and diffuse correlations, with a maximum of r ≈ 0.51. Despite their optical activity, turbidity and chlorophyll-a showed unexpectedly weak correlations, likely due to the optical complexity of the mixed water matrix. Random Forest regression identified key spectral regions for each parameter, yet model performance was limited, with R² values ranging from 0.51 (pH) to −1.30 (chlorophyll-a), and RMSE values between 0.41 and 1.51, reflecting the challenges of predictive modeling in spatially and temporally heterogeneous wastewater systems. Despite these challenges, this study establishes a baseline for future hyperspectral applications in complex agricultural water monitoring and highlights critical spectral regions for further investigation. To improve the feasibility of HRS in mixed-water assessments, future research should focus on enhancing data-preprocessing techniques, integrating complementary sensing modalities, and refining predictive models to better account for environmental variability.

La susceptibilidad magnética (SM) es una propiedad que determina el grado de magnetización de un material de acuerdo con su composición, dado su potencial en el diagnóstico de suelos agrícolas. Con el objetivo de evaluar la aplicabilidad de este atributo en el análisis físico de suelos, se determinó su correlación con algunas propiedades físicas en suelos del Valle del Cauca. Se realizaron muestreos en dos lotes de caña de azúcar (Chondular y Santa Rosa), de 55 y 98 hectáreas, respectivamente. Los datos se analizaron por estadísticos descriptivos, así como por matriz de correlación espacial y Pearson entre SM y las propiedades físicas del suelo, a través de un software de sistemas de información geográfica. Se encontraron correlaciones espaciales altas entre SM y las propiedades analizadas, particularmente con arenas y arcillas (0,9 y -0,88, respectivamente, P<0,001) en el lote Chondular, aunque también se encontraron correlaciones superiores al 50% con capacidad de campo, conductividad térmica, densidad aparente y espacio poroso total. Por otra parte, las correlaciones de SM fueron más bajas en el lote Santa Rosa, siendo las más relevantes del orden de 0,59 y -0,65 (P<0,005) para arenas y arcillas en su orden. Estas diferencias de correlación se atribuyeron a alteraciones por labranza del suelo en el lote Santa Rosa. De acuerdo con lo anterior, la determinación de SM y su correlación espacial con algunas propiedades físicas de suelos agrícolas, es una técnica que podría simplificar su caracterización, particularmente la proporción de arenas y arcillas.

Tropical agriculture requires sustainable irrigation solutions that balance water availability with quality and environmental protection. This review synthesizes current knowledge on riverbank filtration (RBF)—a nature-based technology for improving agricultural water quality—with objectives to elucidate design principles, water quality performance, and operational challenges specific to tropical contexts. Through systematic analysis of 128 peer-reviewed articles across topics including RBF hydrogeology, contaminant removal mechanisms, sediment transport, pathogen reduction, site selection criteria, and monitoring strategies, this work consolidates interdisciplinary evidence on RBF effectiveness for irrigation water supply. The Roldanillo–Unión–Toro (RUT) district in Valle del Cauca, Colombia, serves as a case study illustrating RBF application to sediment-rich, pathogen-prone rivers typical of tropical agricultural regions. While RBF is established for drinking water supply in temperate zones, its adaptation to tropical irrigation remains underexplored. This review identifies critical hydrogeological, environmental, and operational considerations for implementing RBF systems in tropical agricultural settings characterized by high water demand, seasonal variability, and challenging water quality conditions. Key findings are synthesized into a practitioner-oriented framework—covering site selection, design optimization, and adaptive management—intended to guide deployment of RBF for irrigation in tropical agricultural settings.

En este estudio se evaluó el efecto del agua tratada magnéticamente (ATM) en parámetros fisiológicos de ají Tabasco, rábano rojo y maíz amarillo. La mitad de las plantas de las tres especies se regaron con agua normal del acueducto, y la otra con agua tratada a través de un dispositivo magnético. Se midieron la fotosíntesis, la biomasa y el contenido mineral (este último solo en frutos de ají Tabasco). Todas las especies cultivadas con ATM aumentaron su tasa fotosintética y su conductancia estomática. Los parámetros de fluorescencia, como la fluorescencia variable (Fv /Fm) y la extinción no fotoquímica, permanecieron sin cambios en las especies evaluadas. En el ají Tabasco, el agua con tratamiento favoreció un mayor rendimiento, en parámetros como biomasa aérea, frutos por planta y área foliar, incrementándose también el contenido de nitrógeno y cationes divalentes en frutos. Además, hubo una relación parcialmente positiva entre el área foliar y el rendimiento de frutos por planta (r2=0,52 en el control y 0,30 con ATM). En contraste, en las plantas de maíz solo hubo un aumento en el peso y en los granos por mazorca, mientras que las de rábano mostraron una pérdida no significativa en la biomasa total. La mayor acumulación de biomasa observada en las plantas de ají Tabasco y maíz se atribuye a una mayor área foliar o a la asimilación de carbono. Debido a que la fluorescencia de la clorofila no se alteró, se propone que el ATM no provoca ningún cambio en el complejo de oxidación del agua del fotosistema II. Por otra parte, la falta de respuesta de algunas variables en las tres especies mostró que el ATM puede tener efectos interespecíficos. A pesar de lo anterior, esta tecnología puede ser una alternativa para mejorar el rendimiento de los cultivos, en particular en del ají Tabasco.

Magnetically treated water (MTW) has been used to promote biomass yield in different crops. Tabasco pepper is a high water-demanding crop often cultivated in areas with limited water supply. This study aims to evaluate the effect of MTW on the physiology and biomass yield of Tabasco pepper under water deficit. The experiment consisted of two groups of randomly distributed plants receiving normal water and MTW at two irrigation levels (100 % and 50 % of field capacity, FC) during the whole life cycle under mesh-house. Water was magnetically treated with a commercial irrigation device. Fruit biomass, photosynthesis, water potential, and leaf tissue status were measured. Fruit yield showed a non-significant increase in plants with MTW at both irrigation levels, although large- and medium-sized effects were detected regarding dry weight and fruits per plant (> 16 % increase). Concerning photosynthesis parameters, only quantum yield significantly increased, even though net assimilation and stomatal conductance exhibited a 17 % and 28 % increment, respectively. At 50 % FC, photosynthetic parameters and leaf water potential were severely impaired no matter the treatment used, but surprisingly, relative water content and electrolyte leakage in leaves were not significantly affected. Despite the minor physiological effects of MTW observed in this study, the size effect on fruit yield was noticeable at the end of the experiments. Hence, the application of MTW could help improve water use efficiency in Tabasco pepper in combination with reduced irrigation strategies.